Design Of A New Liquid Liquid Hydrocyclone Geometry Engineering Essay

Design Of A New Liquid Liquid Hydrocyclone Geometry Engineering Essay Abstract A Liquid to Liquid hydrocyclone is a static machine that use centrifugal force and apply it on the liquid mixture which will make the separation of heavy and between the mixture components (light and heavy components) of this liquid. A Liquid to Liquid hydrocyclone will normally consist of the three parts Cylindrical section Conical base The angle The key difference between the centrifuges and Liquid to Liquid Hydrocyclones that the Hydrocyclones are passive separators where it capable to apply the modest amounts of centrifugal force, but the centrifuges are called dynamic separators which are generally able to concern more centrifugal force than The Hydrocyclones. Another difference between hydroclones and centrifuges devices is the cost where the Centrifuges are expensive machines because its often need sophisticated control but the Hydrocyclones doesnt contain moving parts and it usually doesnt contain controls systems and because of this it at all so they are lesser cost devices There are any types of a hydrocyclone where it could be used to separate solids from liquids or to separate liquids of unlike density. This project aims to Make and generate new design for liquid/liquid hydrocyclone to use it in the process of separation of light dispersed phases to overcome all disadvantageous of the old designs of similar systems the features and benefits of this design are to include a compact design with high efficiency with construction materials that provide superior corrosion and erosion resistance for longer design life. CHAPTER 1: INTRODUCTION Introduction A Liquid to Liquid hydrocyclone is a static machine that use centrifugal force and apply it on the liquid mixture which will make the separation of heavy and between the mixture components (light and heavy components) of this liquid. A Liquid to Liquid hydrocyclone will normally consist of the below three parts (see figure 1) Cylindrical section Conical base The angle DSeriesCyclone3 2 Figure : Diagrams of a Hydrocyclones The key difference between the centrifuges and Liquid to Liquid Hydrocyclones that the Hydrocyclones are passive separators where it capable to apply the modest amounts of centrifugal force, but the centrifuges are called dynamic separators which are usually able to concern more centrifugal force than The Hydrocyclones. Another difference between hydroclones and centrifuges devices is the cost where the Centrifuges are expensive machines because its often need sophisticated control but the Hydrocyclones doesnt contain moving parts and it usually doesnt contain controls systems and because of this it at all so they are lesser cost devices There are any types of a hydrocyclone where it could be used to separate solids from liquids or to separate liquids mixture of unlike density. The hydrocyclone is used in various applications in many industries, from degritting sewage sludge to removing oil droplets from produced water. The governing principles are difficult to quantify because of the complexity of the fluid dynamics with multiple phases in highly swirling flows. The majority of applications are in the processing of mineral ores however, and experience has helped develop a basis for predicting the hydrocyclone classification performance in these duties. The factors that affect performance, both process and hydrocyclone design, will be covered in this paper. The focus will be on providing information that an engineer who is designing a hydrocylone system will find useful. A cutaway of a hydrocyclone is shown in Figure 2. The slurry enters the area of the hydrocyclone called the inlet head from the inlet feed pipe. The slurry is introduced next to the wall of the cylindrical inlet, which induces a swirling action. Figure : Hydrocyclone Cutaway  [1]   This action helps develop the inertial forces that enable the classification of particles within the hydrocyclone. The slurry is further accelerated in the conical sections of the separator. The swirling action produces a low-pressure vortex in the center of the hydrocyclone where the finer, lower-mass particles migrate. The relatively light particles are removed with the overflow stream by an upward swirling flow through the vortex finder. The heavier particles are removed with an underflow stream by a downward swirling flow through the apex region of the hydrocyclone classifier. Figure : Hydrocyclone, Tangential Velocity Distribution  [2]   Figure : Hydrocyclone, Tangential Velocity Distribution  [3]   Figure : Hydrocyclone, Tangential Velocity Distribution  [4]   Figures 3 and 4 shows the mean axial and tangential components of the velocity at different cross-sections in the upper portion of a 250-mm diameter hydrocyclone (Petty et al., 2002). These single-phase numerical calculations were developed using the Reynolds averaged Navier-Stokes (RANS) equation, and standard transport equations for the Reynolds stress (RSM model) and the turbulence dissipation. The simulation imposes a backpressure on the overflow and underflow streams to avoid the air core. The Reynolds number based on the effective diameter of the feed entry and the volumetric flow rate of the feed stream is about 200,000. Figure 5 shows the pressure distribution predicted by the simulation. The results, which are qualitatively similar to experiments by Kelsall (1952) and to multi-phase flow calculations reported by Devulapalli and Rajamani (1994), predict a Rankine vortex flow with a maximum tangential velocity near the radius of the vortex finder (see Figure 4). This feature distinguishes hydrocyclone flows from other swirling flows encountered in centrifugal separators. As illustrated by Figure 5, the swirling action of the flow field causes a lower pressure to develop in the core of the hydrocyclone. It is noteworthy that the Computational Fluid Dynamics (CFD) simulation captures the important qualitative flow features of a hydrocyclone classifier. Applications of Liquid to Liquid Hydrocyclone: In pulp and paper mills. In the sector of water treatment industry. In petroleum industry sector to separate oil from water or water from oil. In Food industries. In chemicals industries. Basic Parameters for Standard Cyclone The definition of a standard cyclone is that cyclone which has the proper geometrical relationship between the cyclone diameter, inlet area, vortex finder, apex orifice, and sufficient length providing retention time to properly classify particles. As with the involutes type design, the graphs and mathematical relationships shown for proper selection and sizing of cyclones apply to the standard cyclone geometry. The main parameter is the cyclone diameter. This is the inside diameter of the cylindrical feed chamber. The next parameter is the area of the inlet nozzle at the point of entry into the feed chamber. This is normally a rectangular orifice, with the larger dimension parallel to the cyclone axis. The basic area of the inlet nozzle approximates 0.05 times the cyclone diameter squared. The next important parameter is the vortex finder. 3.jpg Figure : Hydrocyclone Cutaway  [5]   The primary function of the vortex finder is to control both the separation and the flow leaving the cyclone. Also, the vortex finder is sufficiently extended below the feed entrance to prevent short circuiting of material directly into the overflow. The size of the vortex finder equals 0.35 times the cyclone diameter. The cylindrical section is the next basic part of the cyclone and is located between the feed chamber and the conical section. It is the same diameter as the feed chamber and its function is to lengthen the cyclone and increase the retention time. For the basic cyclone, its length should be 100% of the cyclone diameter. The next section is the conical section, typically referred to as the cone section. The included angle of the cone section is normally between 100 and 200 and, similar to the cylinder section, provides retention time. Figure : Involuted Feed vs. Tangential Feed  [6]   The termination of the cone section is the apex orifice and the critical dimension is the inside diameter at the discharge point. The size of this orifice is determined by the application involved and must be large enough to permit the solids that have been classified to underflow to exit the cyclone without plugging. The normal minimum orifice size would be 10% of the cyclone diameter and can be as large as 35%. Below the apex is normally a splash skirt to help contain the underflow slurry. Construction of the Liquid to Liquid Hydrocyclone: A typical Liquid to Liquid hydrocyclone made of a conically shaped vessel this vessel open at its apex or underflow this is fixed to a cylindrical section which has feed inlet at the tangent. The top of the cylindrical section is congested with a plate which exceed through the axial mounted pipe of overflow and the pipe is lengthen into the body of the hydrocyclone by small removable section known as the vortex finder the function of this vortex finder to prevent the short-circuiting feeding directly into the overflow. The bottom of the vortex finder is protruding below the feed chamber. The feed chamber and the cones are lined inside with the rubber or synthetic linings due to the abrasive nature of most metallurgical slurries. The lined material is made from hard rubber such as neoprene or urethane and the apex is fixed with a concentric hardwearing synthetic rubber (See Figure 8). Figure : Construction of the Hydrocyclone Working Principle of Liquid to Liquid Hydrocyclone: The Liquid to Liquid hydrocyclone generally is a closed vessel that designed to make conversion for the incoming velocity of the liquid into rotary motion. This is achieved by direct inflow tangentially near to the top of a vertical cylinder where this will spins the entire contents of the cylinder and creating centrifugal force in the liquid so that the Heavy Liquid will go Outward toward the cylinder wall, where they farm and a spiral down the wall to a port in the bottom of the ship and in the light of Liquid will move toward the axis of the hydrocyclone (see figure 9) where they will move toward the outlet which is exist at the top of the vessel. 1 Figure : Working principle of the Liquid to Liquid Hydrocyclone CHAPTER 2: SIZING AND SELECTION OF HYDROCYCLONES Performance In determining the proper size and number of cyclones required for a given application, two main objectives must be considered. The first is the classification or separation that is required, and the second is the volume of feed slurry to be handled. Before determining whether these objectives can be achieved, it is necessary to establish a base condition as follows: 1. Feed liquid water at 20O C. 2. Feed solids spherical particles of 2.65 sp gr. 3. Feed concentration less than 1% solids by volume 4. Pressure drop 69 kPa (10psi). 5. Cyclone geometry standard cyclone as described above Classification Historically, classification has been defined as the particle size of which 1% to 3% reports to the cyclone overflow with coarser particles reporting to the cyclone underflow. Recent investigations have defined classification as the particle size of which 50% reports to the overflow and 50% to the underflow, or the so-called D50C point. Figure 10 shows the typical relationship between particle diameter and the percent recovered to underflow. The portion of the curve near the 50% recovery level is quite steep and lends itself readily to determining an accurate particle diameter. Examination of the recovery curve near the 97% to 99% recovery level shows that the curve is nearly horizontal and a small differential could change the micron diameter considerably. Figure 11 also shows that the actual recovery curve does not decrease below a certain level. This indicates that a certain amount of material is always recovered to the underflow and bypasses classification. If a comparison is made between the minimum recovery levels of solids to the liquid that is recovered, they are found to be equal. Therefore it is assumed that a percent of all size fractions reports directly to the underflow as bypassed solids in equal proportion to the liquid split. Then each size fraction of the actual recovery curve is adjusted by an amount equal to the liquid recovery to produce the corrected recovery curve shown in Figure 10. As the D50C point changes from one application to another, the recovery curves shift, along the horizontal axis. Figure : Particle Diameter VS. Particle Recovery  [7]   In order to determine a single graph which represents the corrected recovery curve, the particle size of each size fraction is divided by the D50C value and a reduced recovery curve can be plotted, as shown in Figure 11. Investigations have shown that this curve remains constant over a wide range of cyclone diameters and operating conditions when applied to a slurry containing solids of a single specific gravity and a typical or normal size distribution such as those encountered in most grinding circuits. Equation 1 gives a mathematical relationship which can be used to calculate the reduced recovery. This recovery, along with the bypassed solids, is used to predict the complete size distribution for the underflow product. Where Rr = Recovery to underflow on corrected basis. X = Particle diameter /D50C particle diameter. Figure : Reduce Recovery  [8]   In designing comminution circuits the objective is to produce an overflow from the cyclone which has a certain size distribution, normally defined as a given percent passing a specified micron size. An empirical relationship shown in Table 1 is used to relate the overflow size distribution to the D50C required producing the specified separation. The relationship of this table is for typical or average grinding size distributions and may vary slightly Depending upon the grinding characteristics of the ore itself. The separation a cyclone can achieve can be approximated using Equation 2. The D50C (base) for a given diameter cyclone is multiplied times a series of correction factors designated by C1, C2, and C3. Table : Relationship of D50C to Overflow Size Distribution Required Overflow Size Distribution (percent Passing) of Specified Micron Size Multiplies (To be Multiplied Times Micron Size) 98.8 0.54 95.0 0.3 90.0 0.91 80.0 1.25 70.0 1.67 60.0 2.08 50.0 2.78 Example: Produce an overflow of 80% passing 149 microns (100 meshes). Multiplier from Table 1 at 80% passing = 1.25. Micron size for application = 149 microns (100 mesh). D50C required = 1.25149 = 186 microns for application. This D50C (base) is the micron size that a standard cyclone can achieve operating under the base conditions and is given in Figure 12 or calculated from Equation 3. For example, a 25.4 cm (10 in.) diameter cyclone has a base D50C point of 24 microns. Figure : Cyclone Diameter V.s D50 (For Typical Cyclones)  [9]   Where D = Cyclone diameter in cm. The first correction (C1) is for the influence of the concentration of solids contained in the feed slurry. The graphical representation of this correction is shown in Figure 13 and can be calculated using Equation 4. Figure 13 indicates that the level of percent solids is extremely important in determining the proper separation, as the higher the concentration the coarser the separation. It should be pointed out that this correction is a relative measure of slurry viscosity and is affected by such things as the size of particles present as well as particle shape. For example, a feed that contains a large amount of clay would tend to shift this curve to the left and result in a coarser separation, whereas the absence of fines would shift the curve to the right and result in a finer separation. Many other variables such as liquid viscosity also affect this correction. Where C1 = Correction for the influence of cyclone feed concentration. V = Percent solids by volume of cyclone feed. Figure : Correction for Feed Concentration  [10]   The second correction is for the influence of pressure drop across the cyclone as measured by taking the difference between the supply or feed pressure and with overflow pressure. Pressure drop is a measure of the energy being utilized in the cyclone to achieve the separation. It is recommended that pressure drops, whenever possible, be designed in the 40 to 70 kPa (5 to 10 psi) range to minimize energy requirements as well as reduce wear rates. This is especially true for coarse separations usually associated with primary or secondary grinding circuits. The correction for pressure drop is shown in Figure 14 and can be calculated from Equation 5. As indicated, a higher pressure drop would result in a finer separation and lower pressure drop in a coarser separation. Where C2 = Correction for influence of pressure drop. à ¢Ã‹â€ Ã¢â‚¬  P = Pressure drop in kPa. Figure : Correction for Pressure Drop  [11]   The next correction is for the effect that specific gravity of the solids and liquid have on the separation. Since the cyclone does not actually achieve a size separation but rather a mass separation, the specific gravity of the particle is extremely important in determining the separation. It is especially meaningful in applications where the mineral has a higher specific gravity than the gangue material which allows better liberation of mineral particles at a coarser overall separation size. It has been found that Stokes law can be applied to determine particle diameters which would produce the same terminal settling velocity for a particle of known specific gravity in a liquid of known specific gravity as compared to a particle of 2.65 specific gravity in water. This relationship is shown in Figure 15 and can be calculated using Equation 6. Where C3 = Correction for influence of specific gravity GS = Specific gravity of solids GL = Specific gravity of liquid (normally 1.0) Figure : Correction for Solids Specific Gravity (in water)  [12]   The cyclone diameter, along with the three corrections of percent solids, pressure drop, and specific gravity, are the main variables necessary for preliminary sizing and selection of cyclones. Other variables, such as the vortex finder and inlet size, also have an effect on separation. For example, a larger vortex finder size would tend to coarsen the separation, whereas a smaller size would tend to achieve a finer separation. Due to this fact, most cyclones have a replaceable vortex finder with different sizes available. Vortex finder diameters vary from a minimum of about 25% of the cyclone diameter to a maximum of about 45%. The inlet area also shows the same effect as the vortex finder, but not as pronounced. The apex size also has an effect on separation but the effect is minor unless the apex is too small and becomes a physical constraint, forcing material into the overflow. Cyclone retention time is also a minor factor influencing cyclone performance. Within limits, increased retention time would help achieve a finer separation; whereas reduced retention time would coarsen the separation. The retention time of the cyclone can be altered by either changing the length of the cylindrical section or by changing the cone angle. There are numerous other variables which also have an effect of separation; however, these variables are relatively minor and may be neglected for the preliminary sizing and selection of cyclones. Flow Rate The second main objective which must be considered is to provide adequate cyclone capacity for the application. The volume of feed slurry that a given cyclone can handle is related to the pressure drop across the cyclone. The relationship between flow rate and pressure drop for several different sizes of standard cyclones is shown in Figure 16. As shown, the flow rate increases as the pressure drop increases. In order to utilize this graph, the pressure drop used for calculating the separation is used to determine the flow rate for the cyclone diameter which was also used for determining the separation. The flow rate is then divided into the total flow for a specific application to determine the number of units necessary. Since the flow rate given in Figure 16 is for water rather than slurry, it should be mentioned that slurry normally increases the capacity of a cyclone over that shown for water; however, for preliminary estimates this factor can be neglected. This will result in th e number of cyclones calculated being slightly higher than those actually needed. Approximately 20% to 25% standby cyclones are recommended for operational as well as maintenance flexibility. The vortex finder size and inlet area of a cyclone also have an effect on the volumetric flow rate that a given cyclone can handle. Larger vortex finders or inlet areas would increase the capacity, whereas smaller vortex finders or inlet areas would decrease the capacity. The shaded area in Figure 17 corresponding to each standard cyclone gives the approximate range of capacity for each cyclone. Figure : Pressure Drop V.s Volumetric Flow rate  [13]   Shown that an underflow density of 50% to 53% solids by volume is typical for primary grinding circuits, whereas an underflow density of 40% to 45% solids by volume is normal for regrind circuits. Therefore, an underflow density can be assumed which establishes the total flow rate that must report through each cyclone apex. Figure 17 shows the approximate flow rate for a given diameter apex orifice. Figure : Apex Capacity Diameter VS. Flow rate  [14]   Operational and Design Considerations One of the most important considerations is to insure that cyclones are installed properly. A detailed list of Dos and Donts is given in a later chapter. Feed Piping and Distribution A most important consideration for a given cyclone system is proper delivery of the slurry to the cyclone or cyclones. It has been found that a pipe size which produces a line velocity of 200 to 300cm/sec (7 to 10 ft/sec) is high enough to prevent particles from settling, even in horizontal sections, but low enough to minimize wear. Normally for a single cyclone installation the inlet pipe size of the manufacturers recommendation produces a velocity in this area. If the slurry is to be distributed to a number of cyclones operating in parallel, extreme care should be given to the design of the distribution system, and a radial type of manifold is recommended. This is a system where the cyclones are fed from a central circular chamber. When properly designed the central chamber becomes a mixing area and the line velocity should be lowered to approximately 60 to 90 cm/sec (2 to 3 ft/sec). This will help insure that each cyclone is fed with the same slurry concentration as well as the sa me particle size distribution and also will reduce wear rates. Using the radial manifold also makes it easier to install standby cyclones. Should an inline type manifold be utilized, the cyclones do not receive good distribution. It is typical that the high mass particles or coarser particles tend to pass the first cyclones and report to the final cyclone. This results in the last cyclone receiving a higher feed concentration of coarser particles, which accelerates the wear of the last cyclone as well as produces a coarser separation due to the higher feed density. Also, the last cyclone, once shut off, becomes difficult to restart because the solids will tend to pack into the feed pipe. For applications where the separation is not critical or one in which the feed concentration is extremely low, an inline manifold is acceptable and is much less expensive than the radial type. Pressure Drop Calculation As mentioned earlier, the pressure drop across a cyclone is measured by taking the difference between the feed pressure and the overflow pressure. If the overflow is discharged at near atmospheric pressure as recommended, the feed pressure is the same as the pressure drop. Cyclone selection provides the pressure drop required, and for pump calculations this must be converted to meters of slurry which can then be added to the static and friction heads to determine the total dynamic head for the pump. Equation 7 is used for conversion of pressure drop to meters of slurry. Where M = Meters, slurry. à ¢Ã‹â€ Ã¢â‚¬  P = Pressure drop, kPa. G = Sp gr of slurry. As stated, it is recommended that both the overflow and underflow products be discharged at atmospheric pressure. Should the overflow be discharged against a positive head, some of the fluid which normally reports to the overflow is forced to report to the underflow. This does not have a major effect on classification but does increase the amount of bypass solids and reduces underflow density. Should the overflow be discharged at a point lower than the feed entrance, a possible siphon can be established which would cause a breakdown in classification and could bring larger particles into the overflow. A large siphon effect could actually dislodge a worn liner which in turn would plug the overflow piping. Siphons can be prevented by installing a vent pipe on the overflow piping of each cyclone. The underflow should also be discharged at or near atmospheric pressure. Should the underflow be discharged at a negative pressure, the effect would be similar to a positive pressure at the cyc lone overflow. If the underflow is discharged against a positive pressure, the amount of flow is reduced and a larger apex must be selected in order to insure that the SUMP/PUMP Design Another chapter covers the selection and sizing of slurry pumps and should be consulted for more detailed information concerning sump/pump design. Specifically regarding cyclone applications, the feed slurry being delivered to a cyclone should be as steady as possible with regard to both volumetric flow rate and slurry density. Unsteady feed conditions such as severe pump surging or extreme variations in slurry density are very detrimental to good cyclone performance. In general, a sump/pump system for a cyclone application should have a sump with as much depth as possible and a minimum cross-sectional area consistent with the pump manufacturers recommended retention time. A sump of this design will normally eliminate pump surging by allowing small variations in sump level well above the minimum pump suction level. The small cross-sectional area will reduce the buildup of solids in the bottom of the sump and help prevent large sections of the settled solids to slough into the pump su ction and plug either the cyclone feed line or the cyclone apex. Therefore, a tall sump with a small crosssectional area provides much smoother operation. Apex Discharge Pattern An Important part of cyclone operation is being able to observe the type of pattern that the cyclone apex is producing. An apex operating at atmospheric pressure should produce a cone shaped discharge with an angle of 20O to 30O and a hollow center. If the cyclone consistently produces a high angle cone spray, the apex orifice should be reduced in size to maximize the slurry density being discharged. On the other hand, should the cone spray be void of the hollow center and resemble a rope, then the apex is too small and oversize material may be reporting to the cyclone overflow. In this case, a larger apex orifice should be installed. CHAPTER 3: DESIGN VARIABLES, HYDROCYCLONE GEOMETRY Hydrocyclone Inlet Design Hydrocyclones designed prior to 1950 featured outer wall tangential feed entry and 12-15 mm thick rubber liners. This design was not adequate for fine separations or for abrasive slurry applications. Most hydrocyclone manufacturers have redesigned their inlets to include some form of involutes, ramped or scrolled feed style and all of these provide a measured advantage in hydrocyclone performance compared to earlier tangential designs. Figure 18 illustrates the various types of hydrocyclone feed entries. The inlet opening or cross-sectional area of the orifice feeding into the cylindrical section of the inlet has an effect on capacity as well as D50, and most hydrocyclone models have several options to increase or decrease this area based on the desired flow rates and cutpoint. In general, the larger inlet area, the higher the hydrocyclone capacity and the larger predicted D50. Cylinder Section Typically hydrocyclones have a cylinder section length equal to the hydrocyclone diameter. This can be a separate section or integral to the inlet head. Figure 19 illustrates a hydrocyclone without a cylinder section plus hydrocyclones with a single and double cylinder. While the longer cylinder section provided greater residence time and thus more capacity, it also reduces the tangential velocity. The added cylinder length results in minimal improvement in hydrocyclone separation and will increase hydrocyclone capacity at the same pressure by 8-10%. Larger 660-840mm diameter hydrocyclones typically have shorter cylinder sections. Figure : Hydrocyclone Inlet Styles  [15]   Figure : Hydrocyclone Cylinder Length  [16]   Cone Section Figure 20 illustrates the different hydrocyclone cone angles that are used in different applications. The 20-degree cones ha

Uae ; Cultural Differences

List of Abbreviations GDPGross Domestic Product MASMasculinity PDIPower Distance Index UAEUnited Arab Emirates UAIUncertainty Avoidance Index UKUnited Kingdom Table Of Contents I. – List of Abreviations II. – Introduction2 III. – The United Arab Emirates2 III. 1 – History2 III. 2 – Economy4 IV. – Important values for a successful business in the UAE5 V. – Culture7 V. 1 – Cultural differences at the national level7 V. 2 – Cultural differences at the organizational level10 VI. – Kuhne + Nagel12VII. – List of References14 II. – Introduction In the current business environment, in times of globalization, financial crisis and terror, there is a growing consciousness about difficulties that can occur when different cultures collide. These difficulties especially need to be regarded when wanting to expand a business internationally or wanting to enter a foreign market. In this paper the United Arab Emirates is analyzed with focus on critical information for operating a business there.This paper will take into account the history, the cultural aspects as well as differences, the business development and opportunities based on an example of the German logistics company Kuhne & Nagel, which is doing business in the UAE since the 70`s. III. – The United Arab Emirates III. 1 – History The Palm islands, The World, the Burj al Arab and the Burj Dubai and other superlatives come to our mind when thinking about the United Arab Emirates, but they only represent the timeframe since the 1990’s. The UAE was founded in 1971.To really understand the UAE and its culture it is important to take a look at the history and the developments before the foundation and the oil. About 1500 years ago the people in the Arabic region were living in tribes, their lives were dictated by the harsh natural conditions and pearl fishing was the prevalent dedication[1]. The community was very import ant within the tribes and a deep social family structure was established. [2] At that time the Islamic Belief was introduced to the gulf region and is therefore deeply rooted in the history and its culture. 3] As trade and piracy rose in the 18th and 19th century the area became known as the Pirate Coast until the British navy launched several attacks on the pirate strongholds to secure the trade. [4] This lead to the signing of 3 truce treaties in total, including the final treaty in 1892, which made them become the â€Å"Trucial States† and preventing them from entering into relationships with any other country but the United Kingdom (UK) as well as disposing territory to anyone besides the UK, in return for coastal protection and support in case attack of land[5].The first discovery of oil in 1958[6] in Abu Dhabi, which led to many more, was very fortunate as the region, which relied heavily on pearl fishing, saw the pearl market collapse between the First and Second World War. [7] The discovery of oil and the hence evolving wealth had a strong influence on the further development of the area. When the British first announced their intention of withdrawing from the Arabian Gulf by the end of 1971, Sheikh Zayed bin Sultan Al Nahyan of Abu Dhabi immediately wanted to establish closer relationships between the Arabic states. 8] He and Sheikh Rashid of Dubai, became the initiators towards an union of Arabic Emirates, including the Trucial States, Bahrain and Qatar. [9] Since no agreement could be reached between the nine and Qatar and Bahrain became independent, the rulers of Abu Dhabi and Dubai, Sheikh Zayed and Sheikh Rashid, decided to form a union between their emirates and later on present its constitution to the other 5 emirates with the offer to join. [10] One day after the Britsh-Trucial Sheikdoms Treaty expired, the United Arab Emirates were founded on December 2nd, 1971.Four emirates joined immediately and Ra’s al-Kaihmah followed on Feb uary 10th, 1972. [11] Since its foundation the UAE has experienced an incredible growth and has managed to go from one of the least developed countries, to achieving an income level comparable to that of the industrialized nations in less than 30 years. [12] The oil revenues of course have contributed in a major way to the modern development and prosperity, but also political stability as well as the leadership by Sheikh Zayed were very influential. 13] The sheikh, who was born around 1918 and raised under poor circumstances, wanted his people to benefit from the country’s resources, while making sure that the people are aware of their roots and that the country’s history and culture are kept. [14] Through his efforts the Arabian culture has been preserved and passed on to the following generation.He was very popular not only within the nation but also in Europe and the US due to his pro-western mentality. 15] His open-mindness also had a big effect on the UAE and enab led it to become one of the most liberal and pluralistic countries in the Gulf region, with its now massively multicultural population. [16] When he died in 2004 his oldest son HH Sheikh Khalifa bin Zayed al Nahyan became the ruler of Abu Dhabi and president of the UAE. [17] III. 2 – Economy Since the oil was discovered the oil sector was the main contributor to the GDP of the UAE. [18] However the country has steadily tried to reduce its dependability of oil and to diversify its economy. 19] The oil revenues were at first reinvested in to healthcare, education and the national infrastructure to raise the standard of living and pave the way for a sustainable economic development. [20] In 1985 the first free zone of the UAE was opened. In the Jebel Ali Free Zone no taxes had to be paid and foreign companies could establish subsidiaries without a domestic partner. [21] The concept of the free zone became very popular in the region and was the first step towards being an attract ive location for subsidiaries of companies that want to open up the Middle Eastern market.Today more than 850 companies have registered in the Jebel Ali Free Zone and almost 6,000 companies from over 110 countries conduct business there. [22] All in all more than 10,000 companies are registered in one of the 15 free trade zones in the UAE. [23] Due to the geographical location of the UAE in the Middle East and between the markets in the east, whose importance to the western companies has been steadily rising, and Western Europe the United Arab Emirates has become the hub for the complete Middle East, India, Afirca and the Commonwealth of Independent States. 24] This development is especially explicit in Dubai, which has evolved with over 140 scheduled fairs into one of the top locations for international trade shows and multilateral negotiations. [25]Due to the booming construction industry and tourism after 20 years of budget deficit there has been a balance surplus since 2005. [26 ] The GDP in 2007 grew by 7,5% to 192,6 billion US$. 27] The United Arab Emirates now has one of the most diversified economies in the gulf region and managed to lower its dependence on the oil industry to a GDP-contribution below one third, as sectors like manufacturing, wholesale and retail trade, tourism, construction and real estate increased their share. [28] IV. – Important values for a successful business in the UAE To successfully operate a business in the UAE it is mandatory that certain basic values of the Arabian culture are known and respected. [29] One has to aware of his own culture and depart from the wrong and right thinking of rong or right and better or worse when it comes to cultures, as cultures are just different without any judgement. [30]First of all one needs to be aware that time is seen in a totally different way in the Arab world and is not considered to be an issue. Business meetings and negotiations take longer, people are not as punctual and dead lines are often not met. [31] Since personal relations are of highest importance for a successful business it is crucial, when first entering into business relations with people from the United Arab Emirates, to establish a trustworthy and respectful relation, much like a friendship. 32] The first face-to-face meetings are commonly time absorbing and used to become acquainted with the prospective counterpart. [33] Impatience or anger because of the often lengthy process should not be expressed as it would be conceived as rude and disrespectful possibly leading frustration of the business relations. [34] Business meetings generally take longer in the Arab world as at the beginning time is usually spent on inquiries on the well-being of the family members. [35] A strong effect on the business practices has the religious faith.The working hours are for example interrupted for praying[36] and during the holy month of Ramadan overall business slows down in the Arabian area. [37] In norma l business practice the religion also comes into play, inasmuch as some decisions are left to â€Å"fate†. [38] Therefore negotiations might end with the term â€Å"Insh'allah† – â€Å"if God wills†, which underlines the strong belief that the course of events cannot be controlled by the individual meaning that the decision will be made by god and not by them. [39] One of the highest values in the Arabian culture is the belonging to groups, especially the family. 40] Family matters are of higher significance than business[41] and interruptions of e. g. business meetings due to family and personal matters are no exception and should not be misinterpreted as rude.[42] Since age also plays a significant role in the Arabian culture, greater respect must always be shown to the more elderly person, by e. g. greeting the most senior person in a meeting first. [43] Often age and status has a greater influence on the career of an Arab than the actual personal achi evements. 44] The interaction with women is not always straightforward and therefore the behavior of the Arabs in the situation should be adopted in terms of how to greet a woman for example. [45] When negotiating and also in normal interactions with Arabian counterparts the concept of saving face needs to always be kept in mind.Criticism should not be expressed publicly and one should avoid to put anyone in a uncomfortable situation, since it could result in loosing face which seriously harms the person’s and his family’s reputation. 46] Dignity and respect are key elements in Arabian culture and saving face, through the use of compromise, patience and self-control is a means by which these values are maintained. [47] Since confrontation and conflicts are to be avoided in the Arabian culture business communication is done differently. Arabia has been identified by Edward T. Hall as a high context region where one has to read between the lines in contrast to Germany wi th a low context country where explicit words have specific meanings[48].A yes for example may mean a perhaps as the Arabs often communicate indirectly through body language or other forms of non-verbal communication like eye-contact or facial cues rather than communicating directly through words. [49] As, one should be aware of the so called â€Å"High Context Communication†[50] and try to carefully observe his counterpart during a conversation and always pay attention to the way the complete message is conveyed. [51] Management in the UAE is mostly done through centralized decision making and tall hierarchies. 52] Employees in the UAE expect to receive clear instructions and orders from their superiors, rather than having the freedom and the responsibility to manage their own work. [53] Due authority being an element of the Arabian culture, the orders are normally obeyed and only rarely questioned. [54] V. – Culture V. 1 – Cultural differences at the national level The biggest difference between the German culture and the culture in the United Arab Emirates obviously is the religion. Religion in Germany exists and is practiced, but not in an extent comparable to the United Arab Emirates.The culture in the UAE can be defined as the Arabian Culture as it is mostly the same in all Arab nations with some local differences and is mainly influenced by their history and even more their religion. [55] Arabs living in the United Arab Emirates are almost all Muslims and believe that the Islam is not only a religion but a way of living. [56] Their God Allah controls their entire life and even the law called Sharia is partly build on the Holy Koran. Praying five times a day as well as drinking no alcoholic drinks, eating no pork and fasting during the holy month of Ramadan is usual Islamic behavior. 57] Where as in the UAE religion dictates to a large extent the life of the people, in Germany to the contrary, religion is practiced as well, but itâ⠂¬â„¢s done in a considerably more relaxed way. [58] The most popular religion in Germany is Christianity, but Islam, Judaism and Buddhism are among other practiced as well. [59] Even though a majority of the Germans consider themselves as Christian, it has only minor effects on their lives. [60]. The way people eat, dress or behave is rather set by themselves and their parental education than by their religion.The Christian calendar defines the national holidays like Christmas and Easter and the day of rest being Sunday. The festivities of Christmas and Easter are celebrated in most of the Christian families, but on the normal every day life religion has almost no effect, compared to the United Arab Emirates. [61] The calendar in the UAE is also influenced by the religion, as the Muslim New Year is around February and March and Ramadan in October. [62] Even the weeks are separated differently, since Friday is the day of rest and either Thursday or Saturday is given off respectively to form the weekend. 63] The Islam also has influence on the way Emiratis have to dress. Women have to wear the traditional abaya, which is a garment that covers their whole body with exception of the feet, hands and face. They might even have to cover up totally, depending on how strictly the husband practices his religion. [64] Men are required to wear a white cotton thobe at with a guthra covering the head. [65]Leaving aside the religious influence on the people in the UAE, Arabs are very conservative as it is. Emotions and feelings towards each other are not openly expressed in public, as they generally try not to attract any attention. 66] This behavior and urge for privacy can also be found in the way the houses are built, as a lot of space between buildings and thick walls are preferred and used to clearly keep the family inside and leave the rest out. [67] The family in the interior is of highest importance to the Arabs and stands over everything. Family members are very lo yal and close to each other, which has originated from the past. [68] Traditionally the father is the head and leader who provides the family with what is needed for living. [69] Although nowadays the situation s slowly changing and women gain e. g. opportunities in regards of education and are not as underprivileged anymore, the role of the woman still predominantly includes taking care of the children and the house as well as being the center for love and emotional support. [70] Additionally women are still treated differently by the law.[71] German family members also live closely together and parents are very caring for their children, but at the same time statistically every third German marriage fails and commonly children have to grow up in different homes. 72] Generally men and women are more equal in Germany in terms of the law as well as in terms of family. The man is not the predetermined head of the family, as the power is more or less equally divided between the father and the mother. [73] The role of the father as the sole provider is slowly diminishing as more and more women work and have careers even though men yet have to get used to the concept of staying at home to take care and raise the children. [74] Similarities in the development towards equality can be seen in both countries, although Germany seems to be a little bit further than the UAE.Like the family, the community is also of high importance to the Arabs. Relatives, friends and neighbors always support each other in every life situation, while one cares for each other and the community. They are usually very patient and open to compromises, as conflicts or embarrassment are avoided. [75] Criticism is not openly expresses because they do not want anyone to feel inconvenient or harm their dignity, because it could lead to someone loosing his face. [76] To â€Å"keep face† is very important and if someone lost face there would be a strong impact on the family’s reputation . 77] Guests are also always taken care of very generously, since the Arabs are known for their hospitality.[78] Such a strong community cannot be found in Germany, where the people are more independent and concerned of their own good. [79] Germans behave very differently and are a lot more individualistic. People are primarily concerned about themselves and secondly about others. [80] There is no concept of â€Å"keeping face† and therefore conflicts are common, issues are openly addressed and discussed. Germans can be emotional and loud publicly unlike the people living in the Arab world. 81] Their openness for new things is also more distinct and attracting and standing in the middle of attention is not regarded as improper behavior in contrast to the conservative Arabs. [82] Another big difference is the outwards appearance of the people in Germany to the people in the UAE since there is neither a predefined kind of clothing nor any limit to the individualism due to the c onstantly changing fashion trends and styles. [83] V. 2 – Cultural differences at the organizational level To show the differences between the two cultures of Germany and the UAE at the organizational level Hofstede’s analysis is a good instrument to apply.The Dutch professor and influential author Gerard Hendrik Hofstede performed from 1968 to 1972 a survey among 116,000 IBM employees about their preferences in management style and working conditions. [84] Through his study he demonstrated that the behaviour of societies and organizations are affected by national and regional cultural groupings. Out of the results Hofstede identified the four dimensions called Power Distance, Uncertainty Avoidance, Individualism/Collectivism and Masculinity/Femininity among which the different groups can be differentiated. 85] The first dimension Power Distance is defined as the extent to which less powerful members of institutions and organizations accept unequal distribution of powe r. [86] In the Arab world, which includes the UAE, a high Power Distance Index of 80 points has been recorded, meaning that people tend to follow orders without hesitation and organizations have a rather steep hierarchy. It can also be said that there are a lot of laws, rules and regulations that have to be followed to reduce the amount of uncertainty.87] The Power Distance Index in Germany is considerably lower than in Arabia with 35 points. Hence Germans have fewer superiors and their orders are more likely to be question than it would be the case in Arabia. Subsequently unequal distribution of power is not unconditionally accepted, the organizational structures are much flatter and decentralized decision making is common applied. [88] The Uncertainty Avoidance Index describes the level of discomfort people feel in insecure situations and the beliefs and means like organizations and institutions that were developed to reduce the uncertainty. 89] In this dimension the UAE and Germa ny are almost at the same level. [90] Both countries have adopted and implemented strict rules, laws, policies, and regulations to avoid those uncertain situations. A high need for security, structured activities and a strong belief in the knowledge of experts mutually applies as well. [91] The way of conducting business though differs, since the Arabian way is affected by their religious belief. They believe their time is controlled by Allah and that they have no influence it.Long talks with lots of coffee and tea are very common in a business meeting and should not be refused, whereas Germans certainly belief that they control their time themselves and are usually on tight schedules and have fixed dates which they administrate. [92] Germans are even famous for creating appointment schedules and seemingly never missing them too. The third dimension is the Collectivism and Individualism (IDV) respectively. This dimension displays whether people rather take care of themselves or othe r people around. [93] The Arabs have a very low IDV score of 38 points compared to the world average of 64 points.This makes the UAE a collectivistic country, where a strong relationship to the member group is very important. That is e. g. the family offering life-long protection and loyalty, which is prior to all other rules. [94] This translated into business as most jobs and promotions are obtained due to age and family status. In Germany to the contrary the IDV score of 67 is relatively high and above the world average, meaning that it is an individualistic country. People rather take care of themselves in stead of others and e. g. job promotions are based on one’s own efforts and market value rather than the family background. 95] In the last dimension the Masculinity Index (MAS) shows the people’s preference for â€Å"masculine† values like competitiveness, authority and materialism.[96] The MAS of 53 in the Arab World is slightly above the average of 50,2 , but still 13 points lower than in Germany, which means that Arabians prefer both â€Å"masculine† and â€Å"feminine† values. [97] They like authority and materialism, while valuing quality of life and relationships at the same time. Germans are mostly â€Å"masculine† in this respect and value especially competition, power and high salaries. 98] Considering the results of Hofstede’s analysis it can be said that religion and tradition have a great influence on the way business is done in the UAE and that there is a fast differences to the Germany, which can not be neglected when doing business. VI. – Kuhne + Nagel Kuhne + Nagel is a German logistics company, which was founded in 1890 in Bremen by August Kuehne and Friedrich Nagel.[99] Since then it has evolved from a traditional international freight forwarder to a globally leading transportation and logistics provider offering integrated supply chain solutions. 100] The company today has 850 off ices in  over 100 countries with more than 54,000 employees. [101] Their concept of helping to turn the customer’s logistic challenges into a competitive advantage through superior service and integrated end-to-end supply chain management solutions has been successful and still is. [102] Kuhne + Nagel has entered the market of the United Arab Emirates in 1977[103], when an office was established in Dubai. [104] For internationally operating logistic companies a global network of representations is very important in order to guarantee a smooth transit of goods.That way in case of any problems the local office can cope with it and is familiar with standards and processes at that location. Like in most Arab countries, a subsidiary can only be established with a domestic sponsor or partner. [105] Therefore the office in Dubai was not owned by majority by Kuhne + Nagel and there was not a lot of business actually taking place in the UAE, but an increasing number of goods passed through, thus the office was at first mainly used for project support. [106] Kuhne + Nagel also moved their office to the Jebel Ali Free Zone and could thus conduct their business independently.With the increasing business activities in the UAE, the branch office in Dubai gained in importance as well. In 2008 there were 120 employees in three Dubai offices, which makes Kuhne + Nagel the 7th biggest German employer in Dubai. [107] Since the company had already established many offices in other countries they are experienced in dealing with different cultures and mentalities. They have always been aware of the cultural differences between e. g. Germany and the United Arab Emirates and paid attention and adjusted to them.As Germans though they enjoyed good reputation and made only positive experiences in making business with the Arabian people as long as they were treated respectfully. [108] With the hotel industry booming, Kuhne + Nagel introduced in 2001 an innovative product contain ing a tailor-made logistics solutions associated with the construction and furnishing of hotel and tourist facilities. Apart from warehousing, the service portfolio further includes the entire management of suppliers and transport. [109] In 2005 this service was even deepened as firstly introduced to the hotels in the UAE by Kuhne +Nagel, which includes supplying amenities to hotels on a regular basis. [110] Kuehne + Nagel is responsible for the entire supply chain, including order management and procurement. Due to its great acceptance the global availability of this service followed in 2006. [111] The general trend towards becoming the â€Å"hub† of the Middle East, makes the location Dubai logistically even more important. [112] The success of Kuhne + Nagel in the UAE is also displayed through the plans of the company to expand its logistic infrastructure as part of the Dubai Logistics City adding about 52,000 m2 to its existing facilities in the Jebel Ali Free Zone. 113]T his new logistic centre will allow the company to optimally provide all the markets in the Middle East and meet the increasing storage requirements of many companies due to the relocating of their stock to the Middle East rather than supplying the area from Europe or Asia in order to reduce their costs and delivery time. [114] VII.

Rhenium Facts (Re or Atomic Number 75)

Rhenium is a heavy, silvery-white transition metal. It has element symbol Re and atomic number 75. The elements properties were predicted by Mendeleev when he designed his periodic table. Here is a collection of rhenium element facts. Rhenium  Basic Facts Symbol: Re Atomic Number: 75 Atomic Weight: 186.207 Electron Configuration: [Xe] 4f14 5d5 6s2 Element Classification: Transition Metal Discovery: Walter Noddack, Ida Tacke, Otto Berg 1925 (Germany) Name Origin: Latin: Rhenus, the Rhine River. Uses: Rhenium is used to make high-temperature superalloys that are used in jet engines (70% of rhenium production). The element is also used to prepare platinum-rhenium catalysts used to make high-octane unleaded gasoline. The radioactive isotopes rhenium-188 and rhenium-186 are used to treat liver cancer and may be applicable to pancreatic cancer. Biological Role: Rhenium serves no known biological role. Because the elements and its compounds are used in small amounts, they have not been widely studied for toxicity. Two compounds studied in rats (rhenium trichloride and potassium perrhenate) displayed very low toxicity, comparable to that of table salt (sodium chloride). Rhenium  Physical Data Density (g/cc): 21.02 Melting Point (K): 3453 Boiling Point (K): 5900 Appearance: dense, silvery-white metal Atomic Radius (pm): 137 Atomic Volume (cc/mol): 8.85 Covalent Radius (pm): 128 Ionic Radius: 53 (7e) 72 (4e) Specific Heat (20 °C J/g mol): 0.138 Fusion Heat (kJ/mol): 34 Evaporation Heat (kJ/mol): 704 Debye Temperature (K): 416.00 Pauling Negativity Number: 1.9 First Ionizing Energy (kJ/mol): 759.1 Oxidation States: 5, 4, 3, 2, -1 Lattice Structure: hexagonal Lattice Constant (Ã…): 2.760 Lattice C/A Ratio: 1.615 Sources Emsley, John (2011).  Natures building blocks: An A-Z Guide to the Elements. Oxford University Press. ISBN 978-0-19-960563-7.Greenwood, Norman N.; Earnshaw, Alan (1997).  Chemistry of the Elements  (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.Hammond, C. R. (2004). The Elements, in  Handbook of Chemistry and Physics  (81st ed.). CRC press. ISBN 978-0-8493-0485-9.Scerri, Eric (2013). A Tale of Seven Elements. Oxford University Press. ISBN 978-0-19-539131-2.Weast, Robert (1984).  CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.