Internal Curing Concrete Essay Example for Free

Internal Curing Concrete Essay Early-age cracking, autogenous shrinkage and self-desiccation are almost inevitable problems for concrete, especially for mass high performance concrete, for the permeability of which is too low for external curing water to get in and fully hydrate the cement paste inside. The better hydration of the cement paste, the less and smaller cracks the concrete have, and the better durability and reliability the concrete structures do. In order to solve this problem, scientists have consider an unconventional methods to cure the concrete from the inside out so a better hydration can be achieved. As early as 1957, Paul Klieger[1] have mentioned how helpful the saturated lightweight aggregates would be to supply internal curing water and improve the long-term strength in his report. Nowadays, this method as internal curing has been fully developed and widely used to get low-cracking high-performance concrete with better hydration by replacing part of natural fine aggregates with saturated lightweight aggregates. The goal is clear and simple, but the ways to achieve the same purpose is various and have different advantages and disadvantages. In this report, several techniques and materials with different properties that could be used in internal curing, such as expanded shale clay or slate(ESCS)[2] and Superabsorbent polymers(SAP)[3], would be introduced and comment. Internal curing has a good performance especially in fields like mass concrete, or high performance concrete with low permeability. The properties why internal curing is a practical consideration for these instance s would be discussed in this report. 1 Introduction 1.1 Background Concrete has many good properties as modern building material. It has high compression strength, fire proof, and cheap to produce. Since the using of concrete has a long history, the techniques of concrete structure construction may be fully developed. However, there still are some problems that almost inevitable for concrete, such as self-desiccation, autogenous shrinkage and chemical shrinkage. All of these issues may lead to cracking of concrete, and the chloride may penetrate through the cracks easily and cause corrosion of the reinforcement. As we all know, most of the failures of concrete structures are due to the corrosion of the reinforcement. Hence, concrete with less cracks or later to have cracks may contribute to a longer service life of a concrete structure. What’s more, most of these unwanted cracks develop at the early-age of concrete placing. That’s why proper curing, which limits the early shrinkage and lowers the chance of early-age cracking, is so important to ensure the concrete develop the required properties and durability to reach their designed service life. Conventional curing uses methods to provide additional water to keep high relative humidity on the concrete surface, such as ponding and misting, or uses curing compounds, plastic membrane and evaporation retarder to slow evaporation. No matter water adding or moisture loss avoiding work mostly on the upper part of concrete, since the permeability of concrete is limited, the deeper inside concrete, the harder for water to penetrate. On the other hand, self-desiccation (the reduction of the internal relative humidity in the concrete due to hydration reaction) will lead to autogenous shrinkage (concrete volume change occurring without moisture transfer to the environment) even without external moisture loss. Concrete shrinkage over time , will induce cracking that can reduce the service life expectation of concrete structure severely. In short, even proper conventional external concrete curing cannot provide perfect environment for concrete to develop its durability efficiently. Since 1980’s, the production of high-performance concrete(HPC) became more common, and to achieve their much higher strength and durability properties, lower water cement ratio and lower permeability is required. The self-desiccation and autogenous shrinkage problem became even more severe a situation for HPC than for normal portland cement, because external curing water would be more difficult to penetrate deeply into the low permeable concrete to supply the loss water due to hydration and evaporation. When shrinkage happens, cracking is almost inevitable. Concerning a long time situation, internal relative humidity has a strong relationship with free autogenous shrinkage. 1.2 Internal curing Is there any solution that can settle down this problem? Or is there a way that can cure concrete more efficiently so can limit the cracks? The answer is yes. Since curing concrete from outside in has its limit, deeper part inside the concrete cannot be cured properly, how about cure concrete from inside out? As early as 1957, Paul Klieger [1] have mentioned how helpful the saturated lightweight aggregates would be to supply internal curing water and improve the long-term strength in his report. In 1991, Philleo [2] suggested incorporating saturated lightweight fine aggregate into the concrete mixture to provide an internal source of water to replace that consumed by chemical shrinkage during hydration of the paste. Nowadays, this method that use water-containing materials , replacing with normal aggregates to cure concrete, has been well developed and been named as internal curing. Such water-containing material could be saturated lightweight fine aggregates, sup erabsorbent polymers, or saturated wood fibers. Internal curing has been defined by the American Concrete Institute (ACI) as â€Å"supplying water throughout a fleshly placed cementitious mixture using reservoirs, via pre-wetted lightweight aggregates, that readily release water as needed for hydration or to replace moisture lost through evaporation or self-desiccation† 2 Benefits of internal curing Internal curing distributes the extra curing water throughout the 3-D concrete microstructure so that it is more readily available to maintain saturation of the cement paste during hydration, avoiding self-desiccation in the paste and reducing autogenous shrinkage. Along with this process, the main benefits bring about by internal curing may be concluded as below: 2.1 Reducing cracks due to shrinkage Concrete is susceptible to plastic shrinkage cracking at early age, especially when the evaporation rate is high. Right after placing, the concrete paste is still in a fluid state. The aggregates and cement particles tend to settle down due to gravity, while internal water is likely to bleed out onto the surface. Such layer of water will keep the evaporation of the concrete surface in a relatively constant rate. But this situation won’t last for a long time after the cement particles contact each other and start to develop strength. The rate of settlement will highly reduce along with much less water bleeding. During this period, highly tensile stress occur inside the concrete due to surface tension of drying out internal water. Because at this time, concrete is under a plastic state but having develop enough strength to resist this tensile stress, cracks will occur. For internal curing concrete, the pre-wetted aggregates will provide water to replenish the evaporation from the surface of concrete. It makes the pores within the hydrating cement pastes fluid filled and thus helps to reduce the tensile stress. Shrinkage will be much less sever and cracks will less likely to happen. Besides limiting the happening of cracking, internal curing also contributes to delaying the age of cracking. As the volume of pre-wetted aggregates increases, the age of cracking is delayed, until an asymptote appears to be reached when sufficient pre-wetted aggregates has been added according to the research done by Schlitter et al (2010).[3] 2.2 Long-term strength gaining Cement particles inside concrete finish most of hydration in the first 28 days, but the cement particles have not been completely hydrated after 28 days. Some unhydrated cement remain in the concrete and takes time to continue hydration. That’s the reason why as time goes by, the strength of concrete will increase even after a long period of time. For lower water cement ratio concrete, the required time to be fully hydration is longer. As to very low water cement ratio concrete, it may even be impossible for it to be fully hydrated. The hydration will stop when there is no longer capillary water available. In conventional curing, the capillary water inside the concrete will soon run out after early hydration, and the external water is not easy to penetrate into the concrete to hydrate the unhydrated cement particles. By using internal curing method, after most of the capillary water been used, the internal relative humidity drops, and the pre-wet ted aggregates will provide water for cement to keep hydrating steadily for a longer time. As for the using of light-weight aggregates to provide internal curing, the reduction strength due to the light-weight aggregates can be compensate by this long-term strength gaining. 2.3 Reduction of permeability The principal contribution of internal curing results in the reduction of permeability due to a significant extension in the time of curing. It was shown that extending the time of curing increased the volume of cementitious products formed which caused the capillaries to become segmented and discontinuous.Reducing permeability leads to less penetration of aggressive agents that accelerate corrosion of embedded reinforcement. This decrease in permeability results from internal curing could obviously enhance the durability of concrete structures. 2.4 Working well with SCM Environment problem have been paid more and more attention by people today. In order to lower carbon footprint for using concrete, replacing cement with supplementary cementitious materials (SCMs i.e., silica fume, fly ash, metokaolin, calcined shales, clays and slates) is suggested as a way to use substantially less clinker. SCMs (except for silica fume) take longer time to hydrate, therefore requiring water to be present for a longer time. While more than one research has shown both internal curing and SCMs improve long term durability performance. Luckily, recent work has shown that internal curing works particularly well with SCMs. Internal curing enables the SCMs in these mixtures to react for a longer time, since the higher water content needed to support the reaction of the SCMs can be maintained. 2.5 Improving behavior of the contact zone Contact Zone refers to two distinctly different phenomena: (1) the mechanical adhesion of the cementitious matrix to the surface of the aggregate; (2) the variation of physical and chemical characteristics of the transition layer of the cementitious matrix close to the aggregate particle (ASTM STP 169 D [2006] Chapter # 46 Holm Ries). In the contact zone, the C-S-H is not evenly distributed in the outer product, and porosity is greater at aggregate surface within 15-50 µm. What’s more, the obvious elastic difference between aggregate and the surrounding cementitious matrix make the transfer of stress from bulk cement paste to stiffer aggregate causes ‘softening’(microcracking) in interfacial transition zone. High incidence of interfacial cracking or aggregate debonding will have a serious effect on durability if these cracks fill with water and subsequently freeze. All of these factors make the contact zone a weaker location in the concrete. By using internal curing, more internal water can be provide around the aggregates and lead to a better hydration at the interfacial transition zone, which decrease the porosity and increase the strength. The lower permeability also contributes to the difficulty for the chloride to penetrate. What’s more, the lower modulus of the light weight aggregate and the improved transition zone around the light weight aggregate particles due to their generally vesicular surface, helped reduce stress concentrations between the paste and the aggregate and those reductions subsequently reduced the amount of early-age cracking in the concrete. 3 Material and methods for internal curing As long as the principle is the same, different ways can be applied to achieve internal curing. Besides of light weight aggregates, the properties of other techniques and materials will be presented in this chapter. And their advantages and disadvantages will be commented. 3.1 Bentonite clay Bentonite is an absorbent aluminium phyllosilicate. It has a high specific surface, most of which more than 100 m2/g, and this property enables them to adsorb several molecular layers of water between their platelet structures [10]. The absorbed water is held by secondary chemical bonds and the bentonite may swell up to 14 times as its original volume as a result of the water absorption. If the relative humidity in the surroundings is lowered, this water is reversibly released. Potentially, bentonite or other layered clay minerals may be used as a water reservoir for internal water curing. However, there still one important problem remain to be solved for the application of bentonite. In high ionic media, such as in cementitious materials, these clays agglomerate and form a compact structure instead of spreading out evenly [11]. And whether inducing same charge into bentonite as water reducer do to make the bentonite particles repel from each other could solve this problem remain to be investigated. Figure 3.2 Superabsorbent polymers A superabsorbent polymer, SAP, is a polymeric material which is able to absorb a significant amount of liquid from the surroundings and to retain the liquid within its structure without dissolving [12], SAPs are principally used for absorbing water and aqueous solutions. With the present polymer types the theoretical maximum water absorption is approx. 5000 times their own weight. However, the absorbency of commercially produced SAPs is around 50 g/g in dilute salt solutions such as urine, and in high ionic solutions such as cement paste pore fluid the absorbency may be below 20 g/g [13]. The absorption of water in the SAP is based on secondary chemical bonds, and the water is so loosely held that all of it essentially can be considered bulk water. Most SAPs are cross-linked polyelectrolytes. Because of their ionic nature and interconnected structure, they absorb large quantities of water and other aqueous solutions without dissolving. SAPs have found a wi despread use as a high-tech material e.g. for contact lenses, breast implants, fire fighting, drug delivery, in baby diapers and as soil conditioners. Today’s world production exceeds 500,000 tons per year of which about 85% is used for baby diapers [14]. Figure 5.1: Superabsorbent polymers are swellable substances which can absorb many times their own weight of liquids by forming a gel. The absorbed liquid is not released even under moderate pressure [12]. The picture shows a dry, collapsed and a swollen suspension polymerized SAP particle. A description of the use of SAP for internal water curing can be found in the literature [2,13,15]. Compared with lightweight aggregate SAP has some peculiarities. SAP can be used as a dry concrete admixture since it takes up water during the mixing process. Furthermore, the use of SAP permits free design of the pore shape and the pore size distribution of the hardening concrete, however, the pores introduced by the SAP in the concrete may preferably be selected in the range 50-300  µm. 3.3 Crushed Returned Concrete Aggregates Recycled aggregate consists of stone particles with mortar from the original concrete attached to them. The volume fraction of this mortar may amount to 20 to 60%, and results in a significantly higher water absorption of recycled concrete aggregates compared to conventional aggregates [8]. The relatively high water absorption of recycled aggregate, however, may be difficult to utilize for internal water curing. The cement paste fraction of recycled aggregate will, typically, have a fine and tight pore structure which cannot supply water to the coarse pore structure of a hydrating cement paste at early ages. For this reason, recycled aggregate may be less useful than normal aggregate for internal water curing. However, some experiments have shown promising results for recycled aggregate. By blending the crushed returned concrete aggregates with an appropriate lightweight aggregate sand, a substantial reduction in autogenous shrinkage will be a chieved, with minimal reduction in long term compressive strength. The mortars based on light weight aggregate sand substitutions alone provided the highest compressive strengths and the greatest reductions in autogenous shrinkage. But, blending the crushed returned concrete aggregates with the light weight aggregate sand may provide the optimum mixture in terms of material costs and sustainable development.[ICwCCA] 3.4 Artificial LWA Expanded Shale, Clay and Slate Lightweight Aggregate The Earth has been producing LWA from volcanoes since the beginning of time. This natural material, however, is inconsistent and very little is suitable for making concrete. ESCS is specially made for concrete and has been manufactured from surface†mined raw shale, clay or slate for nearly 100 years. (ESCS raw materials typically do not have any other conventional purpose in the construction industry because they are too soft.) The raw materials for ESCS production are placed into a rotary kiln at approx. 1200 °C until it turns into a strong consistent material which is called expanded shale, clay or lightweight aggregate or just ESCS for short. ESCS is a uniform, high quality, ceramic aggregate that’s about 1/2 the weight of natural aggregates. Pores are created in ESCS during the manufacturing process as gases escape due to the application of heat. The newly created pores are ideally suited to accommodate the absorption of water, much like a sponge. ESCS’s greatest contribution is its ability to desorb water. Unlike a sponge, it does not have to be squeezed for the water to be released. This characteristic naturally permits water to egress or be desorbed from the pores of pre-wetted ESCS when the cement demands more water during the hydration process. The physical ability of the pores to manage water movement is the key to internal curing. However, the manufacturing heating process of ESCS is relatively expensive. Moreover, compared with other lightweight aggregate, ESCS has a relatively fine and less continuous pore system, a large part of the pores are closed. Some of the pore water is held down to at least RH=70%. Consequently only a part of the water held in ESCS will be useful for internal curing [6]. 3.5 Natural LWA – Perlite and Pumice Perlite is a naturally occurring silicious, glassy rock which contains 2-6% combined water. When quickly heated to above 900 °C, the crude rock expands 4-20 times its original volume as the combined water vaporizes and creates countless tiny bubbles. This results in a bulk density in the range 30-400 kg/m3, and a water absorption of 200-600%. Perlite has found multiple uses such as for filtration, as an abrasive and within horticulture to provide aeration and moisture retention. However, perlite is primarily used within the construction area for example as concrete aggregate and as a cavity-filling insulation. Disintegration of perlite particles has been observed during mixing due to their high porosity and consequently low strength [18]. This may have adverse effects on the concrete. Fully saturated, the water content of perlite may be 4.5 kg/kg [18]. Pumice is a porous volcanic rock which resembles a sponge, see Figure 5.2. The porous s tructure is formed by dissolved gases which are precipitated during the cooling as the lava hurtles through the air. All types of magma may form pumice. The connectivity of the pore structure may range from completely closed to completely open. A representative value for the absorption of pumice is 0.27 kg/kg [18].

Project cost management

Project cost management Introduction The successful design, development and implementation of projects are very complex and at times daunting tasks for many project managers. The sum of growth in competition and globalization, institutionalization of innovation-based economics, rapid development of technologies, the uses of outer resources, increase in the significance of customers focus and the shortening of products and services cycles means that projects cost management has become a multifaceted issue for majority of businesses today. In essence, this has resulted in the need for the adoption and focus on project based on cost management of business activities. Indeed a lot of researchers emphasis the need for a multi-project environmental management of projects that pays cognizance to the key ingredients that will ensure for the success in projects. This paper will synthesis, analyze and dissect the key attributes that are seen to be inherently important for ensuring effective project cost management. Towards this, an insightful and succinct discussion of the following key factors for successful projects shall be done; appropriate senior management levels commitment to the project, adequate project funding, project requirements analysis and specifications, stakeholders involvement, risks management and presence of a contingent plan. While several dimensions could be pursued under each element only few will be highlighted Ensuring for effective project cost management Phillips (1) illustrates that From IT to construction, most projects have to purchase materials: routers and cables, shingles and cement, and so on; we must always buy some things to complete the project work. Without even underlining the scope or schedule of a given IT project, funds must be availed and properly managed and appropriated to achieve the goals of the project. In the cost management of IT projects, there are three major estimates cost techniques that project managers should make use to effectively manage their projects. These include the Ballpark estimate, the budget estimate and the definitive estimate. According to Barkley (68) Ballpark estimate is also known as the rough order of magnitude (ROM)which is based on high-level objectives, provides a birds-eye view of the project deliverables, and has lots of wiggle room in that most ROM estimates are dependent on the industry and have a range of variances from -25% all the way to +75%. The budget estimate that is also known as the top down estimate is more accurate than the Ballpark estimate and is always formulated at the beginning of the projects life. It includes a number of conditions just like the Ballpark estimate in that it takes into consideration a range of variances and assumptions that are characteristics of any projects estimation. The definitive estimate or bottom up estimate is the real opposite of the budget estimate (Haughey, 29). In effective cost management of an IT project, it is imperative that all the estimate methods are used to mitigate the effects of overhead costs on the project. Baldwin, Rose-Anderssen, Ridgway, Allen, Lopez, Strathern, and Varga (1), clearly demonstrates that The definitive estimate requires a work breakdown structure (WBS) and a WBS is not a list of activities, it is a detailed description of deliverables-oriented decomposition of the project scope. The attention to the creation of goods and services and technologies has significantly increased over the last few years that have prompted and preconditioned the need for better and more efficient projects cost management. This call for paying cognizance to the following key factors; Senior management support The success of projects will to a large extent rely on the interests, support and commitment of the senior management. This is in order to ensure that everybody in the project team and indeed the whole employees are focused and committed. Most projects in organization are sometimes conceived, funded and developed without appropriate senior management involvement or approval. Armstrong (25) has for example noted that some projects go forward without the management clearly conceptualizing what the project entails. A distinction between mere approval and commitment should be clearly discerned so that the projects run smoothly. According to Dennis (87) and Blair (13), most projects fail when the senior management lacks a clear understanding and a paucity of the projects perceived benefits, risks and difficulties. This is fundamental because the management plays a central role in costs appropriations and budget allocations for project activities. This means that while the projects approva l may actually have been acquired, in the euphoria of getting the projects approved; some of the risks may be ignored or glossed over. Efficient project cost management especially in the field of IT should however ensure that projects approvals are not based on hype and unrealistic calculations but on a framework that encapsulates a realistic assessment of the projects benefits, risks and costs. Adequate financing or funding for the project This forms the fundamental groundwork for the achievement any IT related projects objectives and goals. Most IT projects being initiated will require some substantial funding and resources deployment because they are always characterized by abnormally huge overhead costs. However, Kerzner (11) and Loosemore, Raftery and Reilly (161), have noted that ample project funding is not in itself a panacea to projects success. It has been advanced that inadequate project funding will most invariably result on delivery of less than promised. The realization of projects success has been positively correlated with efficient resources management and budget controls. According to Armstrong (32) effective resources management as well as its impact on the compatibility between the costs management and project value accumulation has been empirically proved in literature. Researchers show that in order to avoid the gap between the organizational strategies and the limited resources, it is purposive that available resources are reviewed and aligned to the budget in a seamless manner. This means that a lot needs to be arranged before and also during projects executions. A clear delineation of all the resources that are essential to the successful running of the project and a formulation of a budget that captures all the needs and requirements is therefore important. Armstrong (33), succinctly state that A project funding should be seen as a continuing and flexible process in that while a reasonable estimate of project expense must be made to obtain initial approval, this figure should not be considered as the final project cost. This point is further buttressed by Meyer (172) in illustrating that As the true scope of an IT project is revealed, the project manager can more accurately identify project expenses and recalculate the costs at several checkpoints in the project life cycle so that the new figures are communicated to senior management. Requirements analysis Requirements analysis should be carried out in order to develop the architectural design or frameworks of the specific IT project for the initiation and inception of the project. This calls for a thorough discussion between the clients and/or the stakeholders in order that all the salient issues are brought to the fore and the project is set off on a sound footing. According to Armstrong (27), client consultation at all the stages of an IT project development should always be done in order to avoid situations where repeated references to the project requirements are the case or projects are discontinued entirely. Requirements analysis should be detailed and the analysis or the project manager should visit, communicate and discuss the project requirements with the clients on a conclusive and comprehensive manner. A clear delineation of what will be delivered or not within projects scope should ideally be done. Project managers will attest to the fact that taking a thorough requirement analysis ahs the benefit of arriving at an accurate estimate on a project. This will reduce the effects of time wasted in search of more funds and convincing clients and other stake holders to increase funding after its initiation. In addition to the above, it comes with the added advantage of taking due care of crash programs and thus protects the projects from the effects external factors (Meyer, 171). Development of a comprehensive project plan and its cost components Basically, there are three main benefits to be realized through the development of a clear, comprehensive and elaborate project plan. One such benefit is that through adequate planning, the planners are able to present a clear and well documented or properly focused understanding of project. Secondly, adequate planning ensures that all issues are raised to help avoid instances of overlooking some issues that may later prove problematic. Finally, adequate planning reinforces and helps build confidence in the success of the project. Jiang and Gary (20) elucidates that project planning should never be viewed as a waste of time. This point has been buttressed by Armstrong (29) who has advanced that a very strong correlation between the lengths of time allocated to the project planning and the ultimate projects success abides. Stakeholders involvement The attainment of all the stakeholders involvement has been cited as an important ingredient in the success of IT projects in organizations. This means that every stakeholder in the organization is seen too own the project. This ensures that there are no complains about the project contents and performance when it is completed. This becomes more poignant when it is noted that projects warrants large investment of resources such as time, efforts and money. The involvement of the employees, internal customers and other important stakeholders should therefore be paid utmost cognize (Raz, Erez, 48). Frequent project status reporting should accompany the progress of the project and this should be done on as a regular interval in as far as is soundly possible. As early as the projects life, frequent reporting should help spot and identify adverse issues, as well as how these can be overcome. Jiang and Gary (31) have noted that it is not important that regular updates are provided but the accuracy of such reporting be the case so as to ensure that the status of the projects progress are accurate, realistic and timely. Risk assessment in an IT project It is important that a detailed risks assessment is carried in an IT project so as to ensure for the success of a project. Essentially, risks assessment may fall into two categories, i.e. the more usual and obvious risks and the risks that may be generated from the functions and requirements of a particular problem (Raz, Erez, 53). A businesslike approach to project management requires carefully considering and addressing these risks with internal customers and senior management as part of the projects approval process and if the risk analysis leads to a decision not to move forward, it is much better for everyone involved that the decision is made sooner, rather than later (Raz, Erez, 55). Armstrong (34) has advised that it is prudent to consider the possibility of some failures in the projects that would call for the development of contingent plans to overcome difficult situations should they arise and a project may have to incorporate items that were overlooked, or changes in the business needs associated with the project. This may result in delay of some projects that were dependent on this project or indeed some other business activities. Successfully and efficient project cost management will therefore entail the development of contingent plans to mitigate against such occurrences. In the course of an IT project development, a lot of issues and difficulties may arise. Thus, while some problems may have been anticipated, some occurrences, the need to clear to meet deadlines among others may create insurmountable pressures and tensions. These must be mitigated through the adoption of sound cost management approaches that ensures that issues and matters arising are addressed and mitigated. In some instances, continued top management support must be continually sought so that commitment to the project remains true, and un-anticipated funding requirements are met or delays in operations are understood. In obtaining senior management support, project managers must be willing to present an accurate picture of the potential difficulties inherent in the project in that insofar as is practical, senior management must be given a realistic assessment of the potential for difficulty and be willing to stay the course if things go wrong (Dennis, 95). Conclusion Effective project cost management is a multifaceted issue especially in an IT related project and difficulties abide in the identification and management of all potential difficulties and the ramifications that are associated with the successful development, budget appropriation and implementation of projects. This will depend to some extent on the size of the project where it is seen that the larger the size, the greater the probability of unseen contingencies. In large IT projects for example, the task can prove overwhelming and massive to coordinate. Organizations attempting to find and resolve all IT project difficulties and potential difficulties may not find the issues presented here as all inclusive as there are a lot more issues that must be paid cognizance for the efficient project cost management. However, while the draft does not strive for perfection, it can nonetheless be adjudged that paying attention to the issues raised, a project manager will be better prepared and k nowledgeable enough that undoubtedly greatly enhances the likelihood of a successful project and cost management strategies. WORKS CITED Armstrong, Mark. 2007. Simplified Risk Assessment. Engineering management journal.10, 1: 19-24. Baldwin, James, S., Rose-Anderssen, Chris., Ridgway, Keith., Allen, Peter, M., Lopez, Alvaro.,Strathern, Mark and Varga, Liz. (2006). Management Decision-Making: Risk Reduction Through Simulation. Website: http://www.palgrave-journals.com/rm/journal/v8/n4/pdf/8250020a.pdf Barkley, Bruce. 2004. Project risk management. McGraw-Hill Professional. Blair, Gerald, M. 2007. Planning a Project. http://www.see.ed.ac.uk/~gerard/Management/art8.html?http://www.ee.ed.ac.uk/~gerard/Management/art8.html Dennis, Lock. . 2007. Project management. 9th edition. London: Cooper Lybrand Haughey, Duncan. 2000. Planning a Project using a Work Breakdown Structure Logic Network. Website: http://www.projectsmart.co.uk/planning-a-project-using-a-work-breakdown-structure-and-logic-network.html Jiang, James, J. and Gary, Klein. Software project risks and development focus. Project management journal, 32, 1: 4-9. 2001. Kerzner, Harold. Project management: A Systems approach to planning, scheduling, and controlling. 9th edition. New York: John Willey Sons. 2006. Loosemore, Mark, Raftery, Justin and Reilly, Chris. Risk management in projects. Taylor Francis. 2006. Meyer, Brad, C. Project Costs and Crashing. 2002. Retrieved on February 22, 2010 from Website: http://www.cbpa.drake.edu/bmeyer/webm120/PPT_Crashing.pdf Phillips, Joseph. Project Cost Management. 2010. Retrieved March 15th, 2010 from Website: http://www.projectsmart.co.uk/project-cost-management.html Raz, Tzvi and Erez, Michael. Benchmarking the use of project risks management tools. Proceedings of the project management Institute Annual Seminars and Symposium.1999.

Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia Intravascular papillary endothelial hyperplasia, regarding a case INTRODUCTION Intravascular papillary endothelial hyperplasia (IPEH) was first described as a malignant lesion by Pierre Masson in 1923(1), warning his histological similarity to angiosarcoma. Later, Henschen(2) described an intravascular endothelial proliferation that he interpreted like a reagent process due to inflammation and stasis vascular. We present a case of a patient diagnosed with intravascular papillary endothelial hyperplasia in renal vein. CASE REPORT 61 years old male referred to our department with symptoms compatible with right renal colic. He has previous history of hypertension, obstructive sleep apnea syndrome and benign prostatic hyperplasia with alpha-blocker therapy. The patient relates intense pain in the right flank, sometimes radiating to ipsilateral inguinal region. On physical examination revealed pain with percussion in the right flank. Blood and urine analysis, abdominal radiography and ultrasound are requested, all of them normal. Due to the persistence of symptoms, CT scan with contrast was requested (Fig. 1), in which a solid mass of 3.5 x 3 x 4 cm, lobulated and with heterogeneous necrotic center located at the right renal hilum infiltrates renal vein is seen . This mass is adjacent to lower portion of adrenal gland, kidney, and posterior portion of the duodenum, not clearly identifying dependency. To try to understand the dependence of this mass MRI is requested (Fig. 2), which describes hypointense on T1 and hyperintense on T2 tumor, with probable adrenal gland dependence. Suspecting adrenal injury, hormonal and metabolic study is carried on in blood and urine of 24 hours, all was normal. Scintigraphy was also performed with MIBG finding no enhancing lesions. Given previous findings, and the likelihood of adrenal malignancy (nonfunctional), surgery is decided. By a subcostal laparotomy, a tumor about 4 cm, firmly adhered to the renal hilum is observed. Right radical nephrectomy is performed due to impossibility the tumor excision alone. Postoperative course without incidences and the patient was discharged on the fourth day. Microscopic examination of the surgical specimen revealed kidney and adrenal gland unaltered. Near of the renal hilum and, at least partially, contained within a dilated vein, thrombosis and endothelial reactive area proliferation (capillary and papillary), compatible with papillary endothelial hyperplasia intravascular (Fig 3). Currently the patient is reviewed every six months, with analytical tests and CT normal. DISCUSSION Enzinger and Clearkin(3) suggested several morphological features that served in the differential diagnosis between IPEH and angiosarcoma, including intraluminal location of the lesion, absence of necrotic tissue and presence of thrombotic material, and proposed the intravascular papillary endothelial hyperplasia term. The etiology of IPEH is still unknown. Trauma has been proposed as the main etiological factor, but the traumatic history is exceptional. Several authors agree with the view of Clearkin and Salyer who believe it is due to an alteration in the thrombosis process, consisting of an unusual and peculiar way of organizing thrombus.( 3,6 ) IPEH can occur at any age, more frequently in female. Most of the cases are localized to skin vessels, in head and neck, where they appear as small hard mass of bluish red coloration to the skin. Although there have also been less frequent locations as jejunum, central nervous system, liver, and lungs (4,5). Three forms have been described: Primary, on dilated vascular lakes; secondary or mixed, with preexisting vascular lesion as hemangioma , arteriovenous malformations or pyogenic granuloma; and the third and less frequent, extravascular, resulting in a hematoma (7). The finding of IPEH in the renal vein is rare, there are very few cases reflected in the literature. The symptoms are variable, ranging from an incidental finding, asymptomatic, to colic pain and hematuria. In imaging, with the CT scan with contrast we can find a solid lesion with heterogeneous contrast enhancement, and in MRI a lesion hypointense on T1 and hyperintense on T2 , which does not exclude malignancy(8, 9). In a case reported(10), preoperative diagnosis was performed with excision of the lesion and kidney preservation. But in most cases, it was impossible to rule out malignancy, and the radical surgery is usual, either for technic impossibility by proximity to the renal vessels, or the suspicion of malignancy. No metastases or malignant degeneration has been reported. Preoperative diagnosis of IPEH is difficult as there are no characteristic symptoms or an imaging test that allows adequate differential diagnosis. There are several neoplastic and non-neoplastic lesions that can be found in the renal hilum. Among them: renal carcinoma, angiomyolipoma , schwannoma , myelolipoma , hemangiopericytoma , lymphoma, cysts, Castleman disease or lipomas. Therefore, this condition, although rare, must fall within the diagnostic possibilities, especially if their dependency or proximity to vessels is detected. CONFLICT OF INTEREST The authors declare no conflict of interest REFERENCES Masson P. Hemangioendothelioma vegetant intra-vasculaire. Bull Soc Anat Paris 1923;93:517–23. Henschen F. L ´endovasculite proliferante thrombopoietique dans la lesion vasculaire locale. Ann anat Pathol 1932;9:113-21. Clearkin KP, Enzinger FM. Intravascular papillary endotelial hiperplasia. ARch Pathol Lab MEd 1976;10:441-4. Johraku A, Miyanaga N, Sekido N, et al. A case of Intravascular Papillary Endothelial Hyperplasia Arising from Renal sinus.Jpn J clin Oncol 1997; 27(6) 433-36. Pelosi G, Sonzogni A, VIale G. Intravascular Papillary Endothelial Hyperplasia of the renal vein. Int J Surg Pathol 19(4) 518-20 Salyer WR, Salyer DC. Intravascular angiomatosis: development and distinction from agniosarcoma. Cancer. 1975; 36: 995-1001 Hashimoto H, Daimaru Y, Enjoji M. Intravascular papillary endothelial hyperplasia. A clinicopathological study of 91 cases. AM J Dermatopathol. 1983; 5:539-46 Kuo T, Sayers CP, Rosai J. Masson ´s `Vegetant intravascular hemangioendothelioma ´: a lesion often mistaken for angiosarcoma. Cancer 1976; 38: 1227-36. Van den bogaert S, Boel K, Van Poppel H, et al. Masson ´s tumour of the kidney. Cancer Imaging. 2002; 2: 116-9. Akhtar M, Aslam MAL-Mana H, et al. Intravascular Papillary endothelial Hyperpasia of Renal Vein. Arch Pathol Lab med. 2005;129: 516-520 LEGENDS TO FIGURES Fig.1CT: heterogeneous mass with necrotic core located in the right renal hilum. Fig. 2 T1-weighted MR image: hypointense mass on the right renal hilum. Fig. 3 Histological specimen. Close to the renal vascular pole and partially including a dilated vein, an intravascular thrombus and a reactive endothelial proliferation zone (capillary and papillaroid) are observed. Fig. 4 Greater magnification of the previous image, which can be seen proliferation of papillary structures that tend to anastomose that are lined by a row of endothelial cells, centered on an axis of collagen and fibrin. No images of necrosis, atypia or mitosis (not characteristic of malignancy) were observed.

White-Collar Crime in South Africa Essay -- financial crimes, corruptio

It would be nearly impossible to find a South African who has not been affected by crime in one way or another. â€Å"White-collar crime,† a term first used by Edwin Sutherland in 1939, describes crime that is non-violent, but for the purpose of personal financial gain. This type of crime, including fraud and corruption, is becoming a greater problem in South Africa every year, and it is negatively affecting the country as a whole. Although they are not violent, fraud and corruption cause as much harm as any other types of crime, and a great effort must be made soon to stop them. All over the world, financial crimes are wreaking havoc. People have been scamming others, taking bribes, and doing other greedy things forever. It’s human nature, but in today’s society, it’s unacceptable. In just one fiscal year (2012/2013), the South African government’s Financial Intelligence Centre (FIC) recovered over 1.1 billion rand from the illicit economy. This money came from the proceeds of fraud, money laundering, tax evasion, corruption, and other financial crimes. One billion rand may seem like a lot, and its recovery is a great achievement, but that is only a fraction of what was lost. No one knows how much wasn’t recovered, but it’s safe to guess that it’s in the billions It is not easy to detect fraud, and criminals have been getting away with it for decades. With the birth of the internet, it has become even easier to scam people, communicate with other criminals all over the world, and hide your profits. It wasn’t until 2008 that South Africa created their Financial Intelligence Centre to help combat white-collar crimes. Most financial crime in South Africa is international, so the FIC collaborates with global organizations like the Fin... ...rime. â€Å"Corruption Watch. Defining the real meaning of corruption.† Sunday Times, The (Johannesburg, South Africa), February 3, 2013. Accessed March 2, 2014. http://infoweb.newsbank.com.libdb.belmont-hill.org:2048/iw-search/we/InfoWeb?p_product=AWNB&p_theme=aggregated5&p_action=doc&p_docid=14440CF59A86A640&p_docnum=1&p_queryname=6. â€Å"Countries.† Financial Action Task Force. Accessed February 27, 2014. http://www.fatf-gafi.org/countries/. â€Å"Jordan, South Africa and Tunisia join the movement.† Transparency International. Last modified December 18, 2013. Accessed March 1, 2014. http://www.transparency.org/news/feature/jordan_south_africa_and_tunisia_join_the_movement. â€Å"South Africa Country Profile.† Business Anti-Corruption Portal. Accessed March 1, 2014. http://www.business-anti-corruption.com/country-profiles/sub-saharan-africa/south-africa/general-information.aspx.

Gender Bias In Language :: essays research papers fc

Language is a very powerful element. It is the most common method of communication. Yet it is often misunderstood an misinterpreted, for language is a very complicated mechanism with a great deal of nuance. There are times when in conversation with another individual, that we must take into account the person's linguistic genealogy. There are people who use language that would be considered prejudicial or biased in use. But the question that is raised is in regard to language usage: is the language the cause of the bias or is it reflective of the preexisting bias that the user holds? There are those who believe that the language that we use in day-to-day conversation is biased in and of itself. They feel that the term mailman, for example, is one that excludes women mail carriers. Then there are those who feel that language is a reflection of the prejudices that people have within themselves. That is to say that the words that people choose to use in conversation denote the bias that they harbor within their own existence. There are words in the English language that are existing or have existed (some of them have changed with the new wave of "political correctness" coming about) that have inherently been sexually biased against women. For example, the person who investigates reported complaints (as from consumers or students), reports findings, and helps to achieve equitable settlements is ombudsman (Merriam Webster Dictionary) (Ombudsperson here at Indiana State University). This is an example of the gender bias that exists in the English language. The language is arranged so that men are identified with glorified and exalted positions, and women are identified with more service-oriented positions in which they are being dominated and instructed by men. So the language used to convey this type of male supremacy is generally reflecting the honored position of the male and the subservience of the female. Even in relationships, the male in the home is often referred to as the "man of the house," even if it is a 4-year-old-child. It is highly insulting to say that a 4-year-old male, based solely on his gender, is more qualified and capable of conducting the business and affairs of the home than his possibly well-educated, highly intellectual mother. There is a definite disparity in that situation. In American culture, a woman is valued for the attractiveness of her body, while a man is valued for his physical strength and his accomplishments (50).

Reflections for Creativity Essay

1. What reflections will you need to make before you can start brainstorming ideas? We will need to reflect on each team members personal skills. Evaluate the team’s needs and what the team wants to acheive. 2. Why is it important to acknowledge and learn about the backgrounds and skills of the team members within your group? Its important to know the skills of the people in the group to know what their strong points are and to delegate them to task to efficiently work together. 3. as team leader, give 5 examples of ground rules you would establish, after consulting with the other members of your team. 1) All team members should respect each other’s ideas. 2) Hold each person accountable and responsible. 3) Communication and information sharing procedures 4) Encourage creativity and the development of effective relationships between members of the team. 5) Accept that each member comes from diverse backgrounds, must treat each other with fairness and honesty. 4. Name 5 characteristics you believe you need to possess in order to be an effective team leader? 1) Must be fair and honest 2) Knowledge of how to encourage team members to produce effective results. 3) Provide resources, time and support for the team to form and develop. 4) Teach winning strategies and tactics for the team 5) run interference and remove barriers in order to let employees do their jobs. 5) It is important to utilize external stimuli, to effectively generate new ideas and solutions. Name 5 sources of external stimuli that you could access? 1) Legislation 2) Research data 3) Customer, supplier, shareholder and other stakeholder feedback 4) Best practice information  5) Political and socio-economic information that will impact on operations 6) Describe 3 methods of encouraging your team members to share their knowledge and experience. 1) Celebration of successful innovation 2) Employee recognition, such as employee of the month program 3) Rewards, could be monetary incentive 7) Why is debriefing an integral activity that should be exercised regularly? It is necessary to debrief regularly to ensure that team members are confident of their own abilities and those of other team members. This allows them to reflect individually and as a team on what they have achieved and what is needed to be improved. 8) Your team is generating ideas that you believe have been over used by other fundraising volunteers. List three constructive ways that you can push your team to generate more innovative ideas? 1) We can hold a drawing, and the person with the most innovative idea wins a large prize. 2) Suggest to the team to use external stimuli or other resources to come up with more innovative ideas. 3) Suggest to the team to network and attend seminars to build on more innovative ideas.

Eu Law Synopsised Judgment of Marshall Essay

The case of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 arose in the United Kingdom. It concerned a Miss Marshall who had been employed as a Senior Dietician with the Southampton and South West Hampshire Area Health Authority (Teaching) from the 23rd of May 1974 until her dismissal on the 31st of March 1980, that is to say four weeks after she reached the age of 62. Since 1975 the Southampton and South West Hampshire Area Health Authority (Teaching) had a written policy of that in general, its female employees should retire at 60 while its male employees should retire at 65. The policy stated that â€Å"the normal retirement age will be the age at which social security pensions become payable†. The policy was an implied term of Miss Marshall’s employment contract. Miss Marshall’s employers waived this general policy in the case of Miss Marshall. If her employers had not done this, then s he would have been dismissed on the 4th of February 1978 (upon reaching the age of 60) but was in fact employed until the 31st of March 1980 (four weeks after she reached the age of 62), therefore her employer waived they’re general retirement policy in respect of Miss Marshall for two years. The applicable pension legislation in the United Kingdom at the time of the dismissal stated that men were eligible to receive a state pension at the age of 65 and that women were to receive state pensions from the age of 60 (Section 27 (1) of the Social Security Act 1975). However this legislation does not impose any obligation to retire at the age at which the state pension becomes payable and when a person continues in employment after the date when their state pension becomes payable, the payment of the pension is deferred. According to the order of reference, the sole reason for the dismissal of Miss Marshall was the fact that she was a woman who had passed the retirement age applied by her employer to women. In view of the fact that she suffered financial loss consisting of the difference between her earnings as an employee of her employer and her pension and also since she lost the satisfaction she got from her work, Miss Marshall instituted proceedings against her employer in the Industrial Tribunal. She contended that â€Å"her dismissal at the date and for the reason indicated by her employer which was that she was a woman who had passed the retirement age applied by her employer to women constituted discriminatory treatment by her employer on the grounds of sex and ,accordingly, unlawful discrimination contrary to the Sex Discrimination Act and Community law†. Her claim was dismissed by the industrial tribunal as it was based on the â€Å"infringement of the Sex Discrimination Act 1975, since section 6(4) of that Act permits discrimination on the grounds of sex where it arises out of ‘provision in relation to retirement’ ; the Industrial Tribunal took the view that the employers general policy constituted such provision† but her other claim that the principle of equality of treatment laid down by directive 76/207 had been infringed was upheld by the industrial tribunal. Miss Marshall appealed this case to the Employment Appeals Tribunal and they upheld the decision of the Industrial Tribunal as regards that the claim was based on the infringement of the Sex Discrimination Act 1975, since section 6(4) of that Act permits discrimination on the grounds of sex where it arises out of ‘provision in relation to retirement but in relation to the second question, the Employment Tribunal set aside the question of whether the dismissal violated the principle of equality of treatment laid down by Directive 76/207, because although it did violate directive 76/207, the Employment Appeals Tribunal said that an individual could not rely on an infringement of a directive before a United Kingdom Court or Tribunal. Miss Marshall appealed the decision of the Employment Appeal Tribunal to the Court of Appeal of England and Wales. The Court of Appeal stated that Southampton and South West Hampshire Area Health Authority (Teaching) was â€Å"constituted under section 8(1)A(b) of the National Health Service Act 1977 and was therefore an â€Å"emanation of the State†Ã¢â‚¬ . The Court of Appeal of England and Wales referred two questions to the Court of Justice for a preliminary ruling, for an interpretation of European Union law. These questions were; 1. Whether the dismissal of Miss Marshall after she was sixty and on the grounds that she was a woman who had passed the retirement age applied by the Southampton and South West Hampshire Area Health Authority (Teaching) to women was discrimination which was prohibited by the Equal Treatment Directive 76/207. 2. If the answer to question one is yes, can the Directive 76/207 be relied upon in this case in national courts or tribunals in spite of the fact that there may be inconsistencies between the Directive and section 6 (4) of the Sex Discrimination Act 1975. The appellant (Miss Marshall) and the European Commission considered that the first question must be answered in the positive. The appellant argued that the said age limit falls within the term â€Å"working conditions† within the meaning of articles 1 (1) and 5 (1) of Directive 76/207. Furthermore the appellant argues that the discrimination on the grounds of sex is one of the main reasons for having fundamental human rights and therefore the general principles of EU community law, and the exceptions to these principles must be interpreted strictly, moreover the exception provided for in Article 7(1) of Directive 79/7 is not relevant. The respondent (Southampton and South West Hampshire Area Health Authority (Teaching)) maintains as regards the first question, that the laying down of different ages at which you can compulsory terminate a contract just reflects the minimum ages stated by the State Social Security Scheme in the U.K. The respondent also considers that the state pension does not fall under directive 76/207 but is an aspect of social security and therefore falls under the directive 79/7 in which member-states can impose different ages to entitlement. The Court of Justice decided on the first question that the directive it fell under was Directive 76/207 as the question it was referred concerns the fixing of an age limit as to when to terminate employment following a general policy of dismissal. The question therefore relates to the conditions and rules governing dismissal. The court further stated that Article 5 (1) of Directive 76/207 provided that men and women are entitled to equal treatment in working conditions which includes conditions governing dismissal meaning that men and women are guaranteed the same working conditions without discrimination on grounds of sex. Following a policy of compulsory dismissing workers even if they get a retirement pension still falls under the term â€Å"dismissal†. The Court summed up the answer to the first question in saying that article 5 (1) of Directive 76/207 must be interpreted in meaning that having a policy whereby you dismiss a person for the reasons being that she is a women who has reached the age of qualifying for a state pension, when the age is different for men as it is to women, constitutes discrimination on the grounds of sex, contrary to Directive 76/207. The Court of Justice realised that since the answer to the first question was yes, then it is necessary to consider whether the appellant can rely on Directive 76/207 specifically Article 5 (1) of that directive in national courts and tribunals (Direct Effect). The appellant stated in their argument that â€Å"directives are capable of conferring rights on individuals which may be relied upon directly before the courts of the member-States; national courts are obliged by virtue of the binding nature of a directive, in conjunction with Article 5 of the EEC Treaty, to give effect to the provisions of directives where possible, in particular when construing or applying relevant provisions of national law†. The appellant also stated that articles 2 (1) and 5 (1) of Directive 76/207 was sufficiently clear to let the courts apply them, a view which the commission shared with the appellant. The respondent stated in its argument that the directive should not have direct effect as directives can never impose obligations on individuals and that it can only confer obligations on a member state in its capacity as a public authority and not as an employer and finally it would be improper to put persons employed by the state in a better position than those employed by a private employer. The respondent also stated that the articles in Directive 76/207 were not clear and unconditional enough to give rise to direct effect. In answering the second question, the Court of Justice stated that it does not matter whether the state is an employer or a public authority when an individual is relying on a directive against a member state in legal proceedings. This is necessary to prevent the state taking advantage of its own failure to comply with community law. The Court of Justice stated that the articles in the Directive 76/207 are sufficiently precise and clear in that they prohibit â€Å"any discrimination on grounds of sex with regard to working conditions, including the conditions governing dismissal, in a general manner†. Where a state fails to implement a directive by the end of the time period given, and if the provisions of the directive are unconditional and sufficiently precise, the Court of Justice ruled that the directive may be relied upon against the state, because otherwise it would not be compatible with Article 189’s binding nature on directives. The Court of Justice answered the second question in saying that Article 5 in Directive 76/207 which â€Å"Prohibits any discrimination on grounds of sex with regard to working conditions, including the conditions governing dismissal may be relied upon as against a state authority acting in capacity as an employer†. The Advocates General’s opinion concurred with the judgement of this case. The legal significance of this case is that an individual may only rely on a directive in a national court when suing a public body but the term public body has been given a wide interpretation by the European Court of Justice. Although Direct Effect was founded originally in the Case 26/62,Van Gend en loos [1963] ECR 1, in the Marshall case we have just looked at, the vertical nature of the directive meant that Marshall could take advantage of it, although an employee in the private sector would not have been able to. This would seem to give public sector employees an unfair advantage over their private sector counterparts, but this glitch in EU law was fixed by the subsequent Case 14/83 Von Colson & Kamann v Land Nordrhein-Westfalen which established the doctrine of Indirect Effect which is a mechanism of effectively using indirect means, to give a directive horizontal effect for all employees. Bibliography Cases 1. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 ——————————————– [ 1 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 3, line 11. [ 2 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 11, line 37. [ 3 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 11, line 36. [ 4 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 11, line 51. [ 5 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 15, line 37 [ 6 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 17, line 2. [ 7 ]. Judgement of Marshall v Southampton and South West Hampshire Area Health Authority (Teaching) (Marshall (No.1)) [1986] 1 C.M.L.R. 688 page 17, line 19.