Hebrew Bible Essay Example | Topics and Well Written Essays - 1000 words

Hebrew Bible - Essay Example According to the research findings, it can, therefore, be said that the chapters 5 to 12 of the Hebrew Bible are mainly concerned with the record of miraculous happenings that result because of the pharaoh time and again not keeping his promise to Moses to grant them the freedom to pray to Jehovah in the wilderness. It is his pride and unbelief that leads to the occurrence of the ten plagues that visit the Egyptians one after the other and culminate in the death of the firstborn among the Egyptians but still the pharaoh is unrepentant and according to Jehovah is destined to the destruction of his people and himself. His wise men and sorcerers enact the miracles that are performed by Moses but even they are fully convinced that they are not dealing with some odd magician, but instead some supernatural power at work on behalf of Moses. They are convinced that the power or force that backs Moses is beyond them, and they stand no chance but the pharaoh’s heart and mind by the know ledge of the Lord God are hardened against the truth and the righteous. Faith, especially in the Hebraic and the Islamic tradition, is pure and simple blind belief in Jehovah and Allah, so either you possess it or you do not there are no two opinions about it. But for the sake of the unbeliever Jehovah manifests himself through the miracles to open up the eyes of the unbeliever but all to no avail as far as the pharaoh is concerned. The Twelfth chapter is concerned about the feast of Passover and how to avoid the wrath of Jehovah. Historical Background: It has been a topic of heated debate that the account of Bible is historically accurate. This is the traditional view. The opposing view is that the text is not historically correct, not because Bible is a holy book but exactly for that fact because Bible is a religious testament, concerned more with leading the men to good and righteousness and abstain from evil. The historical background is that for four hundred and thirty years th e Israelites were oppressed and kept in utter bondage. The miraculous events that take place, though cannot be verified what can be easily sifted through the annals of another historical record that have been recovered, discovered and unearthed by the researchers. A very important testament, that verifies the miraculous happenings recorded in the Hebrew Bible, of an age and time, specifically of Exodus is (revealed word of Allah), that is the Holy Quran. The story narrated in the Hebrew Bible and the Holy Quran agrees most of the important instances. The whole Surah Al-Baqarah (this title literary translated into English as â€Å"The Cow†), the longest chapter of the â€Å"Holy Quran†, accurately records the history and the travails of â€Å"Bani-Israel† (the Israelites) including the events mentioned in Exodus. It is mentioned on many occasions in the Holy Quran that the Israelites are the most beloved people of Lord God or more accurately Allah. According to à ¢â‚¬Å"Historiography and Self-definition: Josephus, Luke-Acts and Apologetic Historiography†, an authoritative book on the Exodus considers and proves it as â€Å"general history† as opposed to a monograph or antiquarian history.

The film's place either within its genre (s) or as a type of art Essay

The film's place either within its genre (s) or as a type of art cinema - Essay Example Highlighting the reasons why it is considered the biggest success of all time and how it contributed to the growth of Indian Cinema. To fulfill this rigorous task, the analysis is segregated in to sections; it will be initiated by an introduction of the Indian cinema, followed by an analysis on the movie. A discussion will be presented, on the kind of fashion; the movie forwarded which eventually transformed the Hindi Film Industry. The transnational perspective along with the will be presented in the methodology. The Indian Cinema The Indian Film industry or 'Bollywood' is often surmised as the temples of modern India. They lure the public with their magical colors, hues and light, gods and goddesses are admired, followed and even worshipped. Writer, Vijay Mishra goes on to elaborate that the movie madness among Indians is similar to a devotee visiting a shrine and religiously following his idol. According to a research, 800 films are released each year more than 11 million people v isit cinema halls every day; these are also exported to more than 100 countries worldwide (Mishra, 2002). 1931 was an important year in the history of the visual world in India when the first sound film 'Alam Ara' was released. The Indian Cinema grew by leaps and bounds during these eight decades. Initiated with black and white movies until 60’s, followed by Eastman Colors during the 70s and graduating to the unbelievable virtual world of 3d today (Nihalani G. et al, 2003). The movies are generally 3 hours long and a typical bollywood movie is packed with a complete doze of entertainment, a hero who is an ideal son, and a boyfriend who possesses multitalented genes, he is the knight in shinning armor, he dances, he sings, he knocks down the villain, takes revenge and concludes the movie in a happy ending (Grant, 2011). The Various Genres The Indian audiences today have accepted all genres of movies, including some based on very dark and serious subjects known as ‘experi mented movies’. The term is however, referred to a movie which belongs to a completely unique genre and is not considered under the category of the most popular genres like romantic, romantic comedy, family drama, or action movie (Carty, 2006). This trend of experimenting is not new, in fact there is an Indian movie from the 70’s which brought a storm of transformations and offered a spectacular experience to the audience, breaking the moulds of the popular 'family drama or romantic' genre which dominated the industry for many decades ( Chopra, 2000). The movie was 'Sholay' and it brought along a revolution within the Indian Film Industry, its success is recorded in golden words. Movie World Pre-'Sholay' Until 1960, the film industry was under the domination of production companies, artists and technicians were employees and worked under contracts. In the late 60's gradually, artists took the freelancing method which resulted in a huge 'star system' which was centered on distributors. The studio system ended as the artists chose to work beyond any contractual obligations, as freelancers they started demanding the remuneration proportionate to the success of their recent movie. The superstardom was being associated with many male

Polymer formulation

Polymer formulation CHAPTER 1 INTRODUCTION Pigments are additives in a polymer formulation which provide countless possibilities to designers who want to differentiate their product. Legislation and uprising environmental awareness has led to the gradual phasing out of heavy metal inorganic pigments and increased usage of organic pigments. Despite their good heat stability, light fastness, tinctorial strength and low cost, certain organic pigments are widely known to cause significant warpage in polyethylene mouldings (even at pigment concentrations as low as 0.1% wt).[1,2] This phenomenon is especially common in large thin-walled mouldings such as lids, bottle crates and trays.[3] It is generally accepted that the warpage phenomenon is caused by the nucleating effect these organic pigments have on polyethylene. They act as nucleating agents, increasing crystallisation rate and altering the morphology of mouldings. Morphological changes cause higher internal stress which leads to distortion.[2] Adding on to the problem, different organic pigments nucleate polyethylene to different degrees, making it impossible to produce mouldings with identical dimensions using identical processing conditions when a variety of pigments are used.[4] Numerous attempts have already been made, with usually moderate success, to solve organic pigment induced warpage. They range from adjusting process parameters, mould design changes, pre-treatment of pigments, to incorporation of additional additives. A review of literature in this research area showed that although some studies have been conducted to investigate the incorporation of nucleating agents to override nucleating effects of organic pigments on polypropylene, limited information of this sort exists for polyethylene. The specific mechanism behind nucleating agents overriding nucleation by organic pigments is also still unclear. Therefore, it is the aim of this research to study the influence of nucleating agents, based on potassium stearate and carboxylic acid salts, on the crystallisation and warpage behaviour of high density polyethylene containing copper phthalocyanine green pigment. Differential Scanning Calorimetry (DSC) and Optical Microscopy (OM) will be employed to follow the crystallisation behaviour of the formulations and correlations between rate of crystallisation and shrinkage behaviour will also be made. CHAPTER 2 LITERATURE REVIEW 2.1. Nucleation and Crystallisation of Semi-Crystalline Polymers 2.1.1. Crystallisation Mechanisms Crystallisation involves the formation of an ordered structure from a disordered phase, such as melt or dilute solution.[5] The crystallization process of polymers is thermodynamically driven. It is governed by change in Gibbs free energy, ΔG.[6] ΔG = ΔH TΔS (2-1) Where ΔH is change in enthalpy, T is absolute temperature and ΔS is change in entropy. When ΔG is negative, crystallisation is thermodynamically favourable. This occurs when loss of enthalpy upon crystallization exceeds the loss of entropy multiplied by absolute temperature. It can therefore be derived that as the absolute temperature of the system falls, the driving force of crystallisation will increase.[7] For a polymer to crystallise, it must conform to the following requirements:[8] Molecular structure must be regular enough to allow crystalline ordering Crystallisation temperature must be below melting point but not close to glass transition temperature Nucleation must occur before crystallisation Crystallisation rate should be sufficiently high A hundred percent crystallinity is not possible in polymers due to factors such as chain entanglements, viscous drag and branching. Thus they are termed ‘semi-crystalline. All semi-crystalline polymers exhibit a unique equilibrium melting temperature above which crystallites melt and below which a molten polymer starts to crystallise. The crystallisation of semi-crystalline polymers is a two-step process consisting crystal nucleation and crystal growth.[6] 2.1.2. Primary Nucleation Primary nucleation can be defined as the formation of short-range ordered polymer aggregations in melt which act as a focal centre around which crystallization can occur.[9] There are three mechanisms of primary nucleation, namely, homogeneous nucleation, heterogeneous nucleation and orientation induced nucleation.[10] 2.1.2.1. Homogeneous Nucleation Homogeneous nucleation involves the spontaneous creation of nucleus in a semi-crystalline polymer melt when it is cooled below its equilibrium melting temperature.[7] This process is termed as sporadic as nuclei are formed in timely succession.[11] Creation of nuclei occurs when statistical variation within a polymer melt results in the formation of ordered assemblies of chain segments larger than a critical size[7]; usually between 2-10nm.[11] Below this critical size, the nuclei are unstable and may be destroyed.[11] Generally, super-cooling to between 50-100Â °C below equilibrium melting temperature is minimally required to achieve true homogeneous nucleation.[12] The super-cooling is attributed to the energy barrier homogeneous nuclei are required to overcome to reach stability.[7]. When molecular segments pack next to each other to form an embryo, there is a change in free energy, ΔG, caused by two opposing mechanisms. The creation of new crystal surface increases free energy (ΔS is negative) while the reduction in volume of the system decreases free energy (Δ(U+pV) ≈ ΔH is negative). The two opposing mechanisms lead to a size-dependent free energy curve which defines critical nucleus size.[13] A small embryo has high surface to volume ratio and so ΔG is positive; in other words, crystal growth is not thermodynamically favourable.[13,14] However as nuclei grow, the surface to volume ratio decreases up to a point where volume change outweighs the creation of new surface and change in free energy decrease; crystal growth becomes increasingly probable. This point is defined as critical nuclei size and above this point, the energy barrier is overcome.[13,14] Eventually when ΔG becomes negative, nuclei are thermodynamically stable, pavi ng the way for further growth into lamellae or spherulites.[14] The minimum number of unit cells required to form a stable nuclei decrease when temperature decrease, due to a reduction in energy barrier. In other words, the rate of homogeneous nucleation increases when temperature of the polymer decreases.[7] 2.1.2.2. Heterogeneous Nucleation In practice, one usually observes heterogeneous nucleation and not homogeneous nucleation.[15] Heterogeneous nucleation involves the formation of nuclei on the surface of foreign bodies present in the molten phase of a semi-crystalline polymer. The foreign bodies can take the form of adventitious impurities such as dust particles or catalyst remnants, nucleating agents added on purpose or crystals of the same material already present in the molten phase (self-seeding).[7,8] The presence of foreign bodies greatly reduces the energy barrier for the formation of stable nuclei. This reason for this is, polymer molecules which solidify against pre-existing surfaces of foreign bodies create less new liquid/solid interface than the same volume of polymer molecules forming a homogeneous nucleus.[6] In turn, critical size of nuclei is smaller in heterogeneous nucleation as compared to homogenous nucleation so that heterogeneous nucleation always occurs at lower supercooling.[16] Foreign bodies with crystallographic spacings matching the semi-crystalline polymer are especially effective heterogeneous nucleating agents. Favorable nucleation sites include crystal grain boundaries, cracks, discontinuities and cavities.[7] 2.1.2.3. Orientation-Induced Nucleation Orientation-induced nucleation is caused by some degree of molecular alignment in the molten phase of a semi-crystalline polymer. Molecular alignment reduces the entropy difference between the molten and crystalline state of the polymer. This kind of nucleation is important in various processes such as fibre melt-spinning, film-forming and injection moulding. In these processes, polymer melt is sheared before and during crystallisation.[8,17] 2.1.3. Crystal Growth 2.1.3.1. Primary Crystallisation Primary crystallisation occurs when melt of a semi-crystalline polymer is cooled below its equilibrium melting temperature. It involves molecular segments depositing onto the growing face of crystallites or nuclei. The resultant crystal growth occurs along the a and b axes, relative to the polymers unit cell. These additions of molecular segments can occur through two mechanisms: tight fold adjacent re-entry or independent deposition (illustrated in Figure 2.3).[6] Tight fold adjacent re-entry requires that chain stems be laid down continuously from a single polymer molecule in a series of hairpin bends until its length is exhausted. This single molecule is thought to be ‘reeled in from surrounding molten material.[7] This mechanism requires that molecular motions along the polymer molecules contour length to be several times faster than the rate of crystal growth. On the other hand, the independent deposition mechanism only requires localized motion of molecular segments. Molecular segments only need to re-organise sufficiently to align with molecular segments at the crystallite face.[6] tight fold adjacent re-entry independent deposition[6] 2.1.3.2. Secondary Crystallisation After a semi-crystalline polymer is cooled to room temperature, crystallisation is still thermodynamically favourable but restricted by the low mobility of molecular segments in its amorphous regions. Over an extended period of time, which can span from hours to weeks, re-arrangement of molecular segments within amorphous regions can lead to further crystal growth. This process is defined as secondary crystallisation. Secondary crystallisation can take two forms; either thickening of pre-existing crystallites by re-organisation of amorphous chain segments adjacent to crystallite surface or creation of new crystallites by re-organisation of amorphous chain segments in interstitial regions between pre-existing crystallites. [6] 2.1.4. Rate of Crystallisation The crystallisation of semi-crystalline polymers is a two-step process and therefore overall crystallisation rate is governed by both nucleation rate and crystal growth rate. Both factors are highly temperature dependent, as illustrated in Figure 2.4. When temperature is just below equilibrium melting point, there exists a meta-stable region where rate of nucleation is low as nuclei that are formed dissolve easily due to high thermal motions.[8] As super-cooling increases, thermodynamic conditions become more favourable and rate of nucleation increases and reaches a maximum near the glass transition temperature. On the other hand, kinetic conditions are less favourable as super-cooling causes viscosity to increase. This results in a shift in maximum rate of crystal growth to higher temperatures where viscosity decrease is balanced by formation of nuclei.[8,18] Overall crystallisation rate at a given temperature is usually expressed as the inverse of time needed for half of the crystals to grow in the polymer (1/ t1/2).[8] When crystallisation occurs under isothermal conditions, its progress can be expressed by the Avrami equation:[8] Xc(t) = 1 exp (-K.tn) (2-2) Where Xc(t) is the fraction of material transformed at time t, n is the Avrami exponent and K is the Avrami rate constant. Equation (2-2) may also be written as:[19] ln ( -ln |1-Xc(t)| ) = n ln (t) + ln K (2-3) So that n and K may be obtained by plotting ln ( -ln |1-Xc(t)| ) against ln (t); n is the slope while ln K is the y-intercept.[19] The value of the Avrami exponent, n, is dependent on mechanism of nucleation and geometry of crystal growth. Theoretical values of n corresponding to different nucleation modes and crystal growth shape are tabulated in Table 2.1.[19] Crystal Growth Shape Nucleation Mode Avrami Exponent (n) Rod Heterogeneous 1 Homogeneous 2 Disc Heterogeneous 2 Homogeneous 3 Sphere Heterogeneous 3 Homogeneous 4 Table 2.1: Relation between n and nucleation mode / crystal growth shape[19] When crystallisation occurs under constant-cooling-rate conditions, its progress can be expressed by the Ozawa equation:[8] Xc(t) = 1 exp (-Ä ¸(t) / Ï•m) (2-4) Where Ä ¸(t) is the Ozawa rate constant, Ï• is the constant cooling rate (- ÃŽ ´T/ÃŽ ´t) and m is the Ozawa exponent. Equation (2-4) may also be written as: ln ( -ln |1-Xc(t)| ) = m ln (t) + ln Ä ¸(t) (2-5) So that m and Ä ¸(t) may be obtained by plotting ln ( -ln |1-Xc(t)| ) against ln (t); m is the slope while ln Ä ¸(t) is the y-intercept. Qiu et al. combined the Avrami and Ozawa equations to make a connection between the Avrami and Ozawa exponents:[20] log Ï• = log F(T) a log t (2-6) Where a = n/m and the kinetic function F(T) = (Ä ¸(t) / K)1/m. At a given degree of crystallinity, a plot of log Ï• against log t will yield a and log F(T) as the slope and y-intercept respectively.[20] 2.2. High Density Polyethylene (HDPE) 2.2.1. Chemical Structure, Crystallisation Rate and Morphology High density polyethylene, HDPE, is a semi-crystalline polymer made up of repeat units (C2H4)n and has a general form as illustrated in Figure 2.5. It consists mainly of unbranched molecules with very few defects to disrupt its linearity or hinder crystalline packing. As such, HDPE has a high rate of crystallisation, degree of crystallinity and density (0.94-0.97 g/cm3).[7] Being a semi-crystalline polymer, HDPE exhibits a three-phase morphology consisting of submicroscopic crystals surrounded by a non-crystalline phase comprising a partially ordered layer adjacent to the crystals and disordered material in the intervening spaces. This is illustrated in Figure 2.6.[7] The unit cell of HDPE, defined as the smallest arrangement of its chain segments that can repeat in three dimensions to form a crystalline matrix, is orthorhombic; a cuboid with each of its axes having different lengths while the angles of adjoining faces are all 90Â °. Each unit cell is made up of two ethylene repeat units; a complete unit from one chain segment and parts of four others from surrounding chain segments.[7] Bank and Krim[21] reported that the a, b and c axes of a polyethylene unit cell are of dimensions 7.417, 4.945 and 2.547Ã… respectively. This is illustrated in Figure 2.7. orthogonal view, view along c-axis[7] HDPE unit cells pack together in a three dimensional array to form small crystals known as crystallites. Most commonly, crystallites of HDPE take the form of ‘lamellae; crystallites with a and b dimensions that are much greater than their c dimensions. Lamellae thicknesses are usually between 50 to 200Ã… while lateral dimensions can range from a few hundred angstroms to several millimetres. Figure 2.8 illustrates a HDPE lamella.[7] Various models have been proposed to explain the arrangement of molecular chains in lamellae. They include adjacent re-entry with tight folds, switchboard, loose loops and a model with combined features (illustrated in Figure 2.9). As molecular length of HDPE is known to be many times greater than lamellae thickness, all models indicate some form of chain folding. However, they differ in their specific nature of folding.[7] d) composite model[7] In HDPE, the most common large scale-structures composed of crystalline and non-crystalline regions are known as ‘spherulites. A spherulite consists of lamellae growing outward radially from a common nucleation site. As this growth advance into amorphous molten polymer, local inhomogeneities in concentrations of crystallisable segments will be encountered. This causes the folded chain fibrils to inevitable twist and branch. As illustrated in Figure 2.10a, a spherulite will resemble a sheaf in its early stage of development. Fanning out of the growing lamellae will subsequently produce a spherical structure but true spherical symmetry is never achieved due to impingement of neighbouring spherulites. This growth of spherulites also involves the segregation of non-crystalline materials into regions between lamellar ribbons. Thus the overall structure of a spherulite consists of twisted and branched lamellae with polymer chains mostly perpendicular to their long axis and amorphous regions (illustrated in Figure 2.10b).[22] 2.3. Organic Pigments 2.3.1. Copper Phthalocyanine Pigments: Copper Phthalocyanine Green Copper phthalocyanines are a class of organic pigments which dominate the sectors of blue and green coloration of polymers. This dominance can be attributed to desirable properties such as high tinctorial strength, bright hues, excellent light and weather fastness excellent heat stability and good chemical resistance.[23] In addition, in spite of its structural complexity, this class of pigments is inexpensive as they are manufactured in high yield from low cost starting materials.[24] The parent compound of copper phthalocyanine pigments is extremely easy to prepare; a phthalic acid derivative is condensed with a source of nitrogen such as urea and a copper salt such as cuprous chloride in the presence of a metal catalyst such as vanadium or molybdenum. This is usually done in organic solvents, at elevated temperatures (approximately 200Â °C) and sometimes under increased pressure. The resultant crude copper phthalocyanine (yields of over 90%) is purified commercially by one of several processes; salt attrition, solvent-free salt attrition, acid pasting and acid swelling.[3,25] Figure 2.11 illustrates the chemical structure of the copper phthalocyanine parent compound. It consists of a tetrabenzoporphyrazine nucleus containing a central copper atom. The planar molecule is in the form of a quadratic shape with length and thickness of 1.3nm and 0.34nm respectively.[27] This parent copper phthalocyanine compound, which is characterised by unsubstituted benzene rings, is used as blue pigment. Copper phthalocyanine blue is polymorphous and exists in five crystal forms. Out of the five, the two of commercial importance are the alpha and beta forms while the other three are distorted ÃŽ ± forms.[27] Different crystal forms bring about a variation in the blue shade. Alpha crystals exhibit a bright-red-shade blue while beta crystals exhibit a green-shade blue.[26] C.I. pigment green 7, b) C.I. pigment green 36 (3y), C.I. pigment green 36 (6y)[28] Copper phthalocyanine green, the pigment of interest in this project, is produced from the copper phthalocyanine blue by replacing the hydrogens on the four benzene rings with halogens. Unlike its blue counterpart, where variation of shade is achieved by modification of crystal form, variation in the green shade is controlled by degree of chlorination or bromination. Copper phthalocyanine green only has one known crystal form.[26] The two types of copper phthalocyanine green pigments are colour index (C.I.) pigment green 7 and colour index (C.I.) pigment green 36. C.I. pigment green 7 is a blue-shade green made by introducing thirteen to fifteen chlorine atoms to replace hydrogens in the benzene ring of the copper phthalocyanine blue molecule (illustrated in Figure 2.12(a)). C.I. pigment green 36 is a yellow-shade green made by gradual replacement of chlorine atoms in C.I. pigment green 7 with bromine atoms. The most brominated C.I. pigment green 36, known as 3y, has an extreme yello w shade (illustrated in Figure 2.12(c)) while the least brominated C.I. pigment green 36, 6y, has a much more bluish shade (illustrated in Figure 2.12(b)).[28] The outstanding tinctorial and fastness properties of both copper phthalocyanine green pigments allow their application under the harshest conditions. They can be used effectively in masstone tints and shades down to the very palest depth. Both green pigments can be processed at temperatures in excess of 260Â °C with little colour change. They have even better chemical and colour stability than copper phthalocyanine blues. On comparison, C.I. pigment green 7 is preferred over C.I. pigment green 36. The latter is weaker and more opaque and accounts for less than 5% of copper phthalocyanine greens used in the polymer industry.[3] 2.3.2. Effect of Copper Phthalocyanine Green and Other Organic Pigments on Properties and Crystallisation Behaviour of Moulded Polyolefins Although the combination of spectacular performance and low cost make copper phthalocyanine green ideal pigments, its use is not without challenges. It is widely known that copper phthalocyanine green and a few other pigments can cause unacceptable levels of shrinkage and warpage in moulded parts of polyolefins.[2,29] The problem persists even at pigment concentrations as low as 0.1% wt.[2] Shrinkage can be described as reduction in moulded part dimensions in reference to mould cavity dimensions.[30] Warpage is a measure of out-of-plane distortion and commonly arises from the relaxation of unbalanced residual stress in a moulded part or unbalanced shrinkage in flow and transverse direction.[30] The early work of Turturro et al.[2] demonstrated that this shrinkage and warpage phenomenon is only limited to organic pigments. It was reported that no distortion occurred in HDPE mouldings containing inorganic pigments such as BBS red (cadmium selenide), 21 M yellow (blend of PbCrO4, PbSO4 and PbMoO4) and 500 L yellow (complex of Ni and Ti). Findings from later studies by Bugnon et al.[31] and Suzuki Mizuguchi[29] are in good agreement. Suzuki Mizuguchi[29] reported similar observations when they incorporated inorganic pigments, TiO2, Fe2O3 and Cd Y into HDPE and PP. Using scanning electron microscopy, Bugnon et al.[31] were able to show that when inorganic pigments such as CdS or CrTiO4 are incorporated into HDPE, there is no interaction between pigment surface and polymer. The polymer essentially builds a cavity around the pigment. On the other hand, an organic pigment of diketo-pyrrolo-pyrrole chemistry was found to blend into the HDPE matrix. This led them to propose that in organic pigments do not induce shrinkage and warpage as their chemical constitutions and polar hydrophilic surfaces have no interactions with polymers and do not influence their crystallisation behaviour. It is generally agreed that the shrinkage and warpage of polyolefins induced by copper phthalocyanine green and other organic pigments is associated with the nucleating effect these compounds have on the polymers.[2,29,31] These compounds provide a foreign surface that reduces the free energy of formation of a new polymer nucleus.[27] Vonk[32] was one of the first few individuals who pointed out that organic pigments can act as nucleating agents for polyethylene. The nucleating effect of organic pigments on polyolefins has since been the focus of intensive studies over the years. The key literature identified from this research area is that produced by Koh[33] for Clariant (Singapore) Pte Ltd. Koh[33] studied the influence of C.I. pigment green 7 and C.I. pigment green 36 on the crystallisation and properties of HDPE. It was reported that the high level of differential shrinkage in HDPE mouldings incorporated with copper phthalocyanine greens was accompanied by increased crystallisat ion rate, increased peak / onset crystallisation temperature and reduced spherulite size. These findings clearly indicate that copper phthalocyanine green can act as a nucleating agent for HDPE. It was also reported that increasing pigment concentration will cause an increase in crystallisation rate and level of differential shrinkage. Kohs[33] findings are in line with those from similar studies carried out by Turturro et al.[2], Suzuki Mizuguchi[29] and Silberman et al.[34] Turturro et al.[2] observed a similar nucleating effect of copper phthalocyanine green on HDPE with the aid of depolarisation and dilatometry techniques. In addition, they found that the Avrami exponent value of HDPE decreases with increasing concentration of copper phthalocyanine green; which indicates a shift in morphology, away from the spherulitic one characteristic of pure polyethylene. They proposed that the strong nucleating effect of copper phthalocyanine green causes only the development of fibrils in HDPE, which subsequently do not organise into spherulites. Interestingly, they also found that pigments do not affect the absolute level of crystallinity in HDPE; implying that these compounds affect only the kinetics and not the thermodynamics of the crystallisation process.[2] Suzuki Mizuguchi[29] and Silberman et al.[34] showed that , apart from HDPE, copper phthalocyanine green can also act as a nucleating agent for PP. Moreover, Silberman et al.[34] found that the addition of copper phthalocyanine green into PP would increase its lamellar size and decrease the activation energy (Uact) of its crystallisation process. The explanation they put forward for these observations was based on the specific chemical structure of the pigment. The symmetry of nitrogen in the copper phthalocyanine green molecule, with an absence of complex structures was thought to promote the dynamic adsorption of PP molecules on the pigment surface and the subsequent crystallisation process. This will lead to the formation of a perfect crystal structure of large lamellar size. Together, the works from all three authors demonstrated that, besides copper phthalocyanine green, organic pigments of anthraquinone, perylene, quinacridone, copper phthalocyanine blue and condense azo chemistries can also act as nucleating agents for polyolefins.[ 2,29,34] At this point, with the aid of various papers, it is established that shrinkage and warpage of polyolefins induced by copper phthalocyanine green and other organic pigments are associated with these pigments serving as nucleating agents for the polymer. However the specific mechanism correlating nucleating effect and shrinkage or warpage has yet to be discussed. Both Turturro et al.[2] and Suzuki Mizuguchi[29] proposed the same explanation for this phenomenon. In a moulding process such as injection moulding, the quench rate is not the same at different parts of the polymer. Polymer melt in contact with mould walls crystallise and ‘freeze very quickly, which results in crystals of low perfection with polymer chains oriented in the direction of flow. This layer of imperfect crystals in turn impedes heat exchange between polymer melt in the core regions and the mould walls. As a result, polymer melt in the core regions cool slowly and give rise to regular crystals. As the surfac e ‘freezes very quickly, contraction in the core regions due to crystallisation will produce stress in the ‘frozen outer layer and cause distortion. In addition, relaxation of oriented regions after removal of polymer from the mould will also cause internal stress and lead to distortion. The presence of a strong nucleating agent such as copper phthalocyanine green will limit the time available for oriented chains to recover during cooling and also increase the thickness of the skin layer. Both factors will lead to more pronounced distortion.[2,29] Apart from altering the shrinkage and warpage behaviour of polyolefins, the nucleating effect of copper phthalocyanine green and other organic pigments is thought to also have a marked influence on the mechanical properties of polyolefins. An investigation of how certain organic pigments affect the mechanical properties of HDPE was undertaken by Lodeiro et al.[1] They found that tested pigments, copper phthalocyanine blue and irgalite yellow do affect the principal mechanical properties of HDPE. In particular, it was observed that the presence of small amounts of phthalocyanine blue in HDPE is sufficient to cause an increase in ductility, reduction in Youngs modulus (up to 10%), reduction in yield stress and increase in failure strain. They attributed these consequences to smaller and more numerous spherulites induced by the pigment; smaller spherulites in larger numbers, each surrounded by amorphous material, results in a polymer that will deform more readily and have lower yield st ress and higher failure strain. 2.4. Nucleating Agents 2.4.1. Heterogeneous Nucleation of Polyethylene: Nucleating Agents Based on Potassium Stearate and Carboxylic Acid Salts Nucleating agents have traditionally been added to semi-crystalline polymers to enhance processing and end product characteristics. The incorporation of these compounds results in shorter cycle time as they increase the crystallization rate of semi-crystalline polymers, ensuring faster solidification from the melt upon cooling. Their addition also results in the formation of smaller spherulites in semi-crystalline polymers. This change in spherulite size improves mechanical properties (such as tensile strength, hardness and modulus) and optical properties (such as haze and transparency).[8,35] Polyethylene, and in particular high density polyethylene, has an extremely fast rate of crystallization, which makes it very hard to nucleate.[8,35] This is probably the reason why little has been published on its nucleating agents. That being said, a handful of nucleating agents have been identified to date. Together, the works of Solti et al. and Ge et al. showed that benzoic acid, talc and Na2CO3 can effectively nucleate polyethylene.[8] Besides the use of particulate or low molecular weight nucleating agents, polyethylene can also be nucleated by epitaxial crystallization on another polymer substrate. Loos et al. was able to demonstrate the melt crystallisation of LLDPE on oriented HDPE.[8] Potassium stearate is another nucleating agent tha

The Inescapable Life Cycle of Dubliners :: Essays Papers

The Inescapable Life Cycle of Dubliners The book Dubliners was published in 1914, by James Joyce. He wanted to give the audience a vivid and solid background of the inescapable cycle the Irish Society was going through. In the stories Counterparts, Encounter and the Dead we can see the theme of laciness, entertainment, work, and frustrated goals that lead to alcoholism. In "Counterparts" Joyce introduces us the story of a man named Farrington, which works at a clerking office, copying legal documents and correspondence by hand. Farrington lives an awful and frustrating life were alcoholism seems to help him escape the sad reality that he is living. Then in an "Encounter" we can see the reality of two kids, Mahoney and Leo. They represent what a kid life is. It is a live were responsibility is not a primary value and their inexperience leads them to crazy choices in search of adventures. Finally, we have "the Death" one of the most complex stories in the book Dubliners. In "The Dead" we see all the characteristics of th e stories come together at the party in Missis Morkan house. The principal character in this story is Gabriel and Gretta. Through him we can get a small picture of Dublin's society. It is the story of a man that feels powerless when his wife thinks of an old love. In this story we see many of the themes discuses through the readings, especially autonomy and sense of duty. As reading these different stories we will have to analyze them in depth. In Dubliners we can see that "alcohol" is a frequent tool used to run away reality. But all the characters in this stories can seem to escape an undesirable destiny. It is one of the saddest time in Ireland were the people is trying to recuperate from the great depression caused by the Great Famine at that time. In the first story "Counterparts" we see how Farrigtons life is being affected by the Great Depression Ireland was going though. He had a tedious work were he didn't gain many money to make a dissent life. Since the beginning of the story we can see that Farrington hates his work. He dosent do his work on time and leaves everything to last minute. The boss is constantly remembering and telling Farrington what to do. The Inescapable Life Cycle of Dubliners :: Essays Papers The Inescapable Life Cycle of Dubliners The book Dubliners was published in 1914, by James Joyce. He wanted to give the audience a vivid and solid background of the inescapable cycle the Irish Society was going through. In the stories Counterparts, Encounter and the Dead we can see the theme of laciness, entertainment, work, and frustrated goals that lead to alcoholism. In "Counterparts" Joyce introduces us the story of a man named Farrington, which works at a clerking office, copying legal documents and correspondence by hand. Farrington lives an awful and frustrating life were alcoholism seems to help him escape the sad reality that he is living. Then in an "Encounter" we can see the reality of two kids, Mahoney and Leo. They represent what a kid life is. It is a live were responsibility is not a primary value and their inexperience leads them to crazy choices in search of adventures. Finally, we have "the Death" one of the most complex stories in the book Dubliners. In "The Dead" we see all the characteristics of th e stories come together at the party in Missis Morkan house. The principal character in this story is Gabriel and Gretta. Through him we can get a small picture of Dublin's society. It is the story of a man that feels powerless when his wife thinks of an old love. In this story we see many of the themes discuses through the readings, especially autonomy and sense of duty. As reading these different stories we will have to analyze them in depth. In Dubliners we can see that "alcohol" is a frequent tool used to run away reality. But all the characters in this stories can seem to escape an undesirable destiny. It is one of the saddest time in Ireland were the people is trying to recuperate from the great depression caused by the Great Famine at that time. In the first story "Counterparts" we see how Farrigtons life is being affected by the Great Depression Ireland was going though. He had a tedious work were he didn't gain many money to make a dissent life. Since the beginning of the story we can see that Farrington hates his work. He dosent do his work on time and leaves everything to last minute. The boss is constantly remembering and telling Farrington what to do.

Nodody Won Essay

Abstract When the Arthur Andersen LLP/Enron scandal surfaced in 2001, there was much confusion as to whom committed what crime and how many employees were actually involved. After the facts and criminal charges were final, the sequence of events makes sense; the union of two companies, the rise of the participating executives, and finally the end of the money ride. The leaders of both companies used dishonesty to make an abundant amount of money and gain power status (Thomas 2002). Christopher Bergland said it best when he wrote, â€Å"Karma is a boomerang and the long-term shame and anxiety of cheating will ultimately negate the short-term gains of victory,† . This definitely held true for the employees who were disgraced at the conclusion of the legal proceedings; they may have had more money than they needed, but they ultimately lost in the end. The Beginning The joining between Arthur Andersen LLP and Enron was a marriage too good to be true . The relationship started in 1986 when Enron hired the accounting firm Arthur Andersen LLP to perform â€Å"creative accounting,† allowing the energy company to appear more powerful on paper than it really was . Enron Corporation started investing massive amounts of money in â€Å"Special Purpose Entities† to generate huge amounts of revenues. Special Purpose Entities are creative ways for companies to more efficiently raise debt, but they also make it tougher for investors to decipher a company’s actual debt exposure . Company Backgrounds Both companies were built on determination, dedication, and hard work. The founder, Arthur Andersen, who was orphaned at the age of 16, worked as a mailboy during the day and attended school at night. By the age of 23, he became the youngest CPA in Illinois. A mere five years later he started his own accounting firm . The same mind set Andersen possessed in his teen years carried over to his adult life. He realized the key to his business succeeding was by â€Å"†¦promoting integrity and sound audits†¦Ã¢â‚¬  . Enron was founded on the same characteristics plus a few others: pride, arrogance, and greed. Kenneth Lay wanted to have the largest money making company he could and succeeded by pushing for deregulation of the power industry. In 1985, Mr. Lay took advantage of the government’s decision to let gas prices fluctuate/float with the currents of the market. By doing this, Enron grew from 10 billion to 65 billion in assets in 16 years . Lay had visions of what he wanted Enron to be and then sold them to his staff. Hitting it Big In order for a new idea to be successful, a leader with self-assurance and confidence must be present. Mr. Lay found these qualities present in Jeffrey Skilling and hired him as a Chief Executive Officer. Skilling believed in the survival of the fittest. He had an opinion that money is the only incentive that motivated people and he created a competitive, ruthless, and cutthroat workplace. Skilling implemented the Performance Review Committee. Performance Review Committee, or PRC, is an employee evaluation system which graded workers from 1-5, 5 being the lowest and resulting in dismissal from the company. The Enron staff knew it better as â€Å"rank and yank† . One employee who was a trader was quoted saying, â€Å"†¦if I can get a $5 million bonus for stepping on someone’s toes, I’ll stomp on their throat†¦Ã¢â‚¬  . Both companies worked hard to build a reputation. Andersen expected all of his staff to be honest and always to put the client’s needs in front of their own agenda unless it involved falsifying documentations. Early in the company’s beginning, Mr. Andersen was faced with a moral decision concerning fabricating records for a client. Andersen, with his integrity intact, refused . The firm continued with the â€Å"think straight and talk straight† tradition after the death of Andersen and through the transition of promoted employee Leonard Spacek .With Spacek at the controls, the company continued to thrive while remaining committed to the regimented management style of the founder . Offices were opened throughout the United States, then ultimately around the world. At this point, the firm started consulting as well as offering audits. Under Spacek’s supervision, Arthur Andersen LLP became one the most prominent accounting firms labeling them as one of the â€Å"Big Five† . The company grew so immensely that Spacek had to turn down clients. Enron had the same growth spurt as Andersen. In a few short years, the company became the seventh largest corporation. It was touted as being led by the best and the brightest . Ken Lay, Cliff Baxter, Jeff Skilling, and Lou Pi were men who thought they were unstoppable. These ruthless leaders took huge risks in order to make money. They were failing miserably, but Ken Lay reported otherwise to the public. He said in news conferences that Enron was thriving and prospering because of his staff’s willingness to take risks. With the growing of both firms, it was evident that structural changes were needed. Structural Changes at Andersen The client load for Andersen was becoming too much for just one company. It was evident that balancing the commitment to auditing while adding a consulting practice was so much of a struggle that Arthur Andersen LLP decided to create another division within the company. In the mid-1980’s, the majority of Andersen’s revenues were being generated from the consulting fees, but were still being dispersed with the accounting side . This caused a strain between the two parties. The consultants felt since they were contributing more to the company their salaries should be increased. The only solution was to change the current organizational structure and create two divisions. Andersen Consulting along with Arthur Andersen LLP became subunits of Andersen Worldwide Organization . Spacek, like his predecessor, was a leader who liked to be seen by his staff, was well informed of business dealings, and continued to encourage honesty. Being decentralized allowed the decision-making to be made by the divisions, branches, departments, or subsidiaries . Both parts of Andersen Worldwide Organization could operate however they chose and make their own decisions, including which clients they took on. Ultimately, it was the accounting division that took on Enron. How the Two Companies Fit Enron officials knew that Andersen had made some questionable decisions in the past and were coming off of a quiet lawsuit that involved some â€Å"creative accounting† . Andersen fit the profile that Skilling knew he needed in order for his visions to work. With Andersen being divided up into two divisions, Spacek could not control what was happening in both sides of the firm. Lay, on the other hand, knew exactly what his executives were doing . Enron hired the accounting firm to make the energy company to appear more powerful on paper than it really was . Enron Corporation started investing massive amounts of money in â€Å"Special Purpose Entities† to generate huge amounts of revenues. Special Purpose Entities are creative ways for companies to more efficiently raise debt, but they also make it tougher for investors to decipher a company’s actual debt exposure . They were also using mark-to-market to book potential future profits regardless of actual money. Profits were whatever Enron said they were based on hypothetical future value or HFV. Mike Muckleroy, a former Enron executive, warned Mr. Lay of the risks associated with betting on the oil market, but Lay did not change any policies or procedures. In fact, he approved of the current behaviors. Lay sent out a memo to his executives saying to keep up the good work. As long as money was being made, he chose to ignore the dishonesty. The money ride came to a sudden halt in 2001. For approximately sixteen years, Arthur Andersen LLP would audit Enron’s financial statements. Not only would the accounting firm provide external audit services, but also handle the internal auditing processes as well. As Enron’s revenues dramatically increased year after year, the paperwork and audit information had to match accordingly. Enron needed Arthur Andersen’s employees to make the visual parallel happen and compensated them millions of dollars for their services. At one time, Arthur Andersen LLP had approximately one hundred people assigned distinctively to Enron. There had become such a significant amount of work that accounting offices were designated for the accounting employees and staff was transferred to Enron’s headquarters in Houston. Eventually, the responsibility of Enron’s Chicago and London locations were added to their caseloads making Enron one of Arthur Andersen LLP’s largest clients worldwide . Pump-n-Dump Top leaders in both firms were making an obscene amount of money. An anonymous tip was given to authorities about former President of Enron, Louis Borget. It was said he had taken over three million dollars of corporate funds and put it into his own account, and that was just the beginning. Enron reported a loss in the third quarter earnings at the same time as a reduction of stockholder equity. Former CEO Jeff Skiing, current CEO Kenneth Lay, and other executives started to sell large amounts of Enron stock as prices dropped from $90 to less than a dollar; this practice was called â€Å"pump-n-dump† . This scheme allowed top executives to push the stock prices up then cash in their multimillion dollar options. Lou Pi was the leader for Enron Energy Services at the time and after he sold his stock using this method, he made profited $250 million . Selling of this much stock gained attention of the U.S. Securities and Exchange Commission which led to an investigation. It was apparent that a divorce, a trial, and probably prison time was in the near future for Arthur Andersen LLP and Enron leaders who were involved. No matter what the outcome of the trial was going to be, the once impeccable Arthur Andersen and powerhouse Enron were doomed companies because the damage had already been done. Crumbling Companies Andersen’s company, once led by an honest, visible leader who was filled with integrity by making ethical choices was now being led by greedy, selfish executives who saw dollar signs instead of morals. Andersen’s reputation was ruined and finding clients was going to be next to impossible because of the publicity the scandal received. David Duncan who was responsible for the Enron audit, was fired by Arthur Andersen LLP for mass destruction of Enron documents and Enron relieved Arthur Andersen LLP of all accounting and auditing duties . Even though Arthur Andersen pled not guilty to the charges brought against them, the final decision of the courts was Arthur Andersen LLP was found guilty of obstruction of justice and received five years probation, had to pay a $500,000 fine, lost their license in the state of Texas, and ceased their auditing services. Resulting in a devastating loss of clientele and over 7,000 workers had to find new jobs . More people were affected by Enron’s outcome than that of Arthur Andersen’s. After the investigation, Enron filed bankruptcy, over 20,000 people lost jobs, many officials served a prison sentence, and shareholders lost tens of billions of dollars . As officials dug deeper into the scam, recovered documents and many of the testimonies revealed many banks were guilty as well. Bank employees detailed how the banks engineered fake transactions to keep billions of dollars of debt off Enron’s balance sheet and create the illusion of increasing earnings and operating cash flow . As a result, stricter accounting laws regarding audits were later passed by the SEC . Conclusion In this situation, having a leader who exhibits good judgment, morals, ethical conduct, and integrity can strengthen an alliance within a work place. When Arthur Andersen and Leonard Spacek were the supervisors, Arthur Andersen LLP was a major company with a flawless reputation that was completely shattered by a few employees who did not exemplify such characteristics as the former leaders. Arthur Andersen LLP split into two separate divisions, which I think was the correct move because the company was growing and the current staff could not handle the clientele load. In order for the split to work, though, both units needed supervisors like what the company was founded on; managers who could be trusted and held accountable. If I was a partner in Andersen and realized what was being committed, I would have tried to put an end to it. Maybe if someone had the gumption to stand up for what was right, many jobs could have been saved and investor’s money would not have been lost. Enron, on the other hand, was dishonest from the beginning and it was only a matter of time before the leaders were caught of wrong doings. Enron, in my opinion, was being led by the inspiring leaders with excellent leadership skills and work ethics; they just did not have the morals to go with it. Mr. Borget was the first to get caught; Ken Lay was aware of Borget’s actions, but ignored it because he was not incriminated or even suspected yet, but as history reveals, his time was coming . Finally several years later, Lay and his associates received their forthcoming. In the 2001 trial, Ken Lay was charged with 11 criminal acts. Jeff Skilling was sentenced to prison and to this day still claims he did nothing wrong, Cliff Baxter committed suicide before he was to appear in court, and Lou Pi lost 6 million in an insurance policy from the corporation, but never saw any jail time . Had Andersen Worldwide Organization declined on Enron’s business proposal, the accounting firm may have continued to grow and possibly dominate the number’s world. From my point of view, this scandal was a lose-lose situation to everybody involved, from entry level positions all the way up to Chief Executive Officers. Enron became a major power-house in sixteen years and only took 24 days to collapse and go bankrupt . A devastating ending to both firms; several criminal charges were filed against numerous employees, hearings were held, and the companies which were built on ambition and drive were destroyed and are no longer are in existence. In this case, nobody won. References Answers. (2012). Retrieved from Advantages and disadvantages of centralization and decentralization?: http://wiki.answers.com/Q/Advantages_and_disadvantages_of_centralization_and_decentralization BBC. (2003). The Enron Affair. Retrieved from BBC News: http://news.bbc.co.uk/1/hi/in_depth/business/2002/enron/ Bergland, C. (2012). Cheater’s Never Win. Psychology Today. Brickley, J., Smith, C. & Zimmerman, J. (2009). Managerial Economis and Organizational Architecture (5th Ed.). Boston, MA: McGraw-Hill Irwin. Byrne, T. (2002). Special- Purpose Entities Are Often A Clever Way to Raise Debt Levels. Retrieved from nyu.edu: http://pages.stern.nyu.edu/~adamodar/New_Home_Page/articles/specpurpentity.htm Findlaw. (2003). Indictment (US v. Arthur Andersen, LLP). Retrieved from News: http://news.findlaw.com/hdocs/docs/enron/usandersen030702ind.html FundingUniverse. (2005). Anderson History. Retrieved from FundingUniverse: http://www.fundinguniverse.com/company-histories/andersen-history/ Geller, R. (2002). Background of the Banks’ Role in the Enron Debacle. Retrieved from The Enron Fraud: http://www.enronfraud.com/ Gibney, A. (Director). (2004). Enron-Smartest Guys in the Room [Motion Picture]. Houston Chronicle. (2002, April 19). Hot Topic Anderson. Houston Chronicle. Investopedia. (2011). The Enron Collapse: A Look back. Retrieved from Investopedia: http://www.investopedia.com/financial-edge/1211/The-Enron-Collapse-A-Look-Back.aspx#axzz23riaPOrn NewsHour. (2002). Enron: After the Collapse. Retrieved from PBS: http://www.pbs.org/newshour/bb/business/enron/player6.html Thomas, W. (2002). The Rise and Fall of Enron. Retrieved from Journal of Accountancy: http://www.journalofaccountancy.com/Issues/2002/Apr/TheRiseAndFallOfEnron.htm Wikipedia. (2012). Arthur Anderson. Retrieved from Wikipedia: http://en.wikipedia.org/wiki/Arthur_Andersen

Critical Incident Essay

It was a cold friday afternoon as I sat at the bus stop waiting to get home. I had just got out of an intense Friday lecture from the Northampton local Mosque. The Imam was furious and obviously disgusted at the behavior of our generation. â€Å"How do we live with ourselves† Imam Aseem Ibrahim had said. â€Å"Most of us have enough to feed ourselves and our family, even buy the latest gadgets just because we can but do we feed the poor? Do we clothed them?† He said in anger as he chocked on the words. The lecture kept on playing in my head as I waited for the bus. It made me realize, we could do some good with the money we spend on some unnecessary things especially the ones we buy for ourselves to please others. Earlier, I had planned on buying the new Manchester United away jersey, but with what the Imam said, I don’t think I need it anymore. I could use at least half the money to do good for others. Just as I drift on my thoughts, I noticed a fish and chips cart which reminded me of the breakfast and lunch I had missed. I had been staying up late studying that I forgot about a couple of meals. â€Å"Don’t starve yourself in the course of feeding others.† The Imam had said while giving his lectures. I starved myself but it wasn’t because I was trying to feed anybody, I was just trying to catch up on loss time. I got up and got myself some fish and chips then sat back at the bus stop seats. As soon as I had the first swallow, I realized I could help poor people by feeding them delicious food with a reasonable amount of money. The food was relatively cheap. I smiled and continued to enjoy. Halfway through my meal, I saw a little Indian boy with an elderly woman walking towards my direction. The boy smiled at me so I smiled and offered him my food. The little boy smiled again and shook his head. â€Å"Are you sure?’ He shook his head and stopped walking. â€Å"Alright then.† I went on with my meal. A few minutes later, the bus arrived and just as I motioned to get on it, the elderly woman furiously said some words to me in Hindu. I shrugged and got on the bus. When I arrived home, I found my roommate Taneem watching a Hindu movie. I noticed something weird as I watched a little with him. â€Å"Why is the subtitle saying yes while the woman keeps shaking her head?’ I asked. â€Å"Because shaking your head is to Indians as nodding your head is to us. She’s saying yes.† Taneem explained. Even though it was minutes after I had left the boy and the woman, I felt so embarrassed at what I did to the boy. My intentions were good, but it looked otherwise.