The Design of Molecular Magnets

The Design of Molecular Magnets Ashlea Hughes 1. Polyoxometalates Polyoxometalates (POMs) are clusters consisting of linked metal oxide polyhedral. They are commonly anionic, although some cationic species have been reported.1 Due to this charge, counter ions are often associated with POMs. The metal ions which form the POMs often belong to group 5 or group 6 in the periodic table and possess a high oxidation state causing an electron configuration of either d0 or d1. The nuclearity of POMs differs widely from single monomeric species to high nuclearity (i.e. over 100 metal ions) species. The three major transition metals that form POMs are: vanadium, molybdenum and tungsten. 1.1 Structures The building blocks of polyoxometalates often correspond to tetrahedral, tetragonal pyramids, and octahedra, sharing corners and edges which results in a variety of caged, ribboned, wheel or basket like structures e.g. [P6Mo18O73]11-.2 It is this variety in potential structures of POMs that causes a number of complex molecular spin arrays to be available. Figure 1: Five Baker-Figgis isomers adapted from Zhou et al. 3 The keggin structure, named after J. J. Keggin who determined its structure, is a very common structure found in POMs.4 It consists of a central tetrahedrally coordinated atom, caged by 12 octahedrally coordinated atoms. Five rotational isomers, known as Baker-Figgis isomers, of the keggin structure exist, and are shown in Figure 1, as do defect structures known as lacunary structures.3 Due to the conformation of these structures they have high stability and so aid in the exchange coupling between other keggin molecules. The POMs comprising of the transition metal, tungsten, all favour this structure and larger tungsten POMs can be considered to be made up of keggin subunits. The Dawson structure and Anderson structure are similar structures that have also been reported many times within literature. The wheel structure is yet again another commonly found structure and is desired for POM formation. The cavity/cavities the wheel contains are accessible and allow the coordination of other clusters, and form chains in a step by step growth, forming very large POMs. 1.2 Traditional synthesis POM based clusters are traditionally made via a one-pot synthesis. The aggregation and condensation of the reagents is controlled via experimental variables.5 These variables can include: concentration, pH, temperature, ligand effects, counter ions and various other experimental variables. The synthesis usually begins with the acidification of the metal salt, sequentially followed by condensation of the molecules forming a variety of architectural structures. 1.3 Uses Polyoxometalates possess a wide variety of properties. Their diversity means that they are used for many applications. They are used as catalysts in a range of organic reactions. The acidity and solubility of POMs make them ideal candidates to use as homogeneous catalysts, as well as their redox abilities. They have many uses in biological systems, in particular the POM ferritin, which is the protein responsible for iron storage and is a cofactor in the photosynthesis process within plants. This property in particular has inspired research into many energy and photosensitive related devices using POMs. In addition there is also research being done into medicinal applications as potential uses in antiretroviral drugs for diseases such as AIDS. 6 Aside from all these applications, and many others, certain POMs also bear magnetic properties that I shall discuss herein.5 2. Magnetism Magnetic properties arise from the spin and orbital angular momentum of unpaired electrons. Paramagnetism is a property of compounds which contain unpaired electrons. These compounds have a relative permeability greater than one and consequently attract magnetic fields. When a field is applied the spins of electrons start to align parallel to each other. The magnetisation of paramagnetic materials is directly proportional to the magnetic field that is applied; this, however, does vary with temperature. This relationship between temperature and magnetization is described by Curies Law: Where M is the resulting magnetisation, B is the applied magnetic field, T is the temperature and C is the Curie constant which is specific for each individual material. Figure 2: Hysteresis Curve 7 Hysteresis is a property of paramagnetic materials. If a magnetic material is magnetised in regard to a direction and the material does not relax back to zero magnetisation then the material is exhibiting hysteresis. If an alternating field is applied a hysteresis loop is formed as shown in Figure 2. Bulk magnets exhibit hysteresis, as do some polyoxometalates.8 This provides many advances into information storage as exhibiting hysteresis means the material has magnetic bistability, meaning the material can present two stable phases and can change between the two with response to an external stimulus, a vital property for memory elements. 2.1 Magnetic POMs POMs commonly contain transition metal centres, some of which are paramagnetic with respect to their spin states. The paramagnetic transition metal centres therefore correspond to the d1 electron configuration mentioned above, e.g. polyoxovanadates (IV). When the paramagnetic metal ions are brought together they interact and can give rise to a wide variety of magnetic properties. The magnetic interaction between the ions is defined by the Heisenburg Hamiltonian. These POMs which possess magnetic properties are known as single molecule magnets. Polyoxovanadates are the most common magnetic POM. [VIV15As6O42(H2O)]6- is a relatively large oxovanadium (IV) POM whose magnetic properties have been widely investigated.7 2.2 Quantum or classical behaviour? POMs are relatively large, organically bridged, molecular magnets, and are thought to potentially be the bridge between the quantum properties of the smallest atoms and the classical properties possessed by larger magnets that we know in our day-to-day lives. Events in classical physics are either allowed or forbidden in contrast to the events in quantum physics which all have a various probability of occurring. It has been thought that the mesoscopic size of the POMs would cause the classical properties seen in bulk magnets to also be observed in these intermediate sized magnets. Some magnetic POMs are thought to behave quasi-classically as they can exhibit both quantum as well as classical magnetic properties.8 This 15 vanadium centred POM was however, found not to behave in a classical way. Though, it has been reported that the quantum/classical behaviour is not just based on the size of the magnet, but also the individual spins of the metal ions. If the individual ions within the POM have a small spin (S= 1/2) then quantum models approximate properties of the material the best, however when reaching relatively high spins similar results to the quantum models are shown by using classical models. This has been confirmed in smaller clusters which contain larger spins.7 It is interesting that smaller clusters with higher spins possess more classical magnetic properties, opposed to larger clusters which possess small spin ions. Electron paramagnetic resonance (EPR) is a technique used to study materials with unpaired electrons, i.e. paramagnets. Line widths present in EPR spectra can dictate whether a material is expressing quantum or classical behaviour. 9 2.3 Spin frustration Figure 3. Spin fustrastion within [VIV15As6O42(H2O)]6- 7 To achieve a large spin ground state is a difficult challenge for scientists. However, spin frustration effects can lead to isolated systems that contain this property. The layered structure of [VIV15As6O42(H2O)]6- comprising of three layers, with the central layer only having three interacting centres, then the spin cannot be resolved by Hund’s rule and is said to be frustrated, as shown in Figure 3. Much research has been done into the use of large POMs as magnets, however with current technology allowing the miniaturisation of most devices, the question posed is who can make the smallest POM in which both quantum and classical effects coexist? For this to be answered the synthesis of POMs needs to be carefully controlled and fine-tuned. 2.4 Mixed valence clusters The magnetic properties of mixed valence clusters are often more difficult to interpret due to their electrons which are delocalised over the structure as opposed to the simpler localised valence species, described above. The mixed valence cluster [Mn12O12(O2CCH3)16(H2O)4].2CH3COOH.4H2O, comprising of Mn4IV and Mn8III has been found to exhibit both quantum and classical properties. It has been established that this cluster behaves like a small bulk magnet when subjected to low temperatures. 2.5 Single molecule magnets Single molecule magnets (SMMs) are usually based on first row transition metals. They require a high spin ground state along with a negative uniaxial anisotropy. A relatively high blocking temperature (the temperature at which relaxation of magnetisation is slow) is also desirable.9 Flexibility in the structure of SMMs provides difficulties in the regulation of intermolecular exchange coupling, however, due to their rigid conformation, POMs have an environment which is ideal for magnetic structures. To produce SMMs the intermolecular magnetic interactions between molecules must be negligible. 2.6 POMs as ligands Although POMs themselves can have magnetic properties, due to their variety of shapes if they possess defects, as in the lacunary structure, and the cavities the wheel structure often has, they can also be used as multidentate ligands.10 They can bind to paramagnetic coordination clusters, causing encapsulation of small clusters of magnetic ions.11 By doing this the POM ligand effectively dilutes the smaller, encapsulated molecule and therefore reduces the dipolar interactions that are undesirable for SMMs. The magnetic molecule encapsulated could possess both antiferromagnetic and ferromagnetic properties; however, which property is expressed could potentially be determined by the POM surrounding it. The wheel structure, due to the nature of its shape also possesses a cavity, which could also be used to bind smaller clusters, increasing the distance between the magnetic molecules and in doing so reducing the interactions between them. 12 3. Designing POMs The design of molecular clusters with magnetic properties, or as ligands for small clusters, that possess magnetic properties is challenging. The traditional one-pot synthesis controlled by numerous variables does not give the desired purity of species or the fine tuning abilities required to design SMMs. The degree of functionality required for these systems relies upon directed assembly of the building blocks into disciplined architectures.13 3.1 Solvothermal and ionothermal synthesis Solvothermal synthesis reduces the limitations of the experimental variable of temperature used in the regular synthesis. Water and common organic solvents used in the regular synthesis limit the temperature the system can reach; however, autoclaves used in the solvothermal process reduce this limitation and create the opportunity for higher temperatures and pressures of the reaction mixture. Reproducibility of these reactions is very difficult as it requires tight control of experimental conditions. Ionothermal synthesis adapts this solvothermal synthesis by using an ionic liquid as a solvent. These ionic liquids influence the assembly of the POMs by functioning as templates and can potentially create selective architectures.14 3.2 Linking clusters Lacunary structures have been used as precursor molecules with other metal ions as linkers to produce high nuclearity POMs.11,15 This is often known as the ‘building block strategy’.{16} It opens up opportunities to expand the POM size beyond what has currently been synthesised. However, difficulties have been found due to the architecture of the potential building blocks rearranging and reorganizing due to not being stable enough in solution. Due to the stability of tungsten POMs this methodology is widely used within tungsten chemistry; however, these limitations cause problems for other complexes such as molybdenum. Stabilising the initial building blocks is currently a task being researched widely by several research groups.11,16 3.3 Counter ion effect As previously mentioned, POMs are charged species, generally anionic, and so must possess a counter ion. Anionic POMs possess cationic counter ions and vice versa. The properties of the counter ion i.e. size, charge etc, can affect the reactivity of the POM. The larger the counter ions, the more stable the POM is against aggregation. Amines are a common example of bulky counter ions which provide this stability. Organic amines have also been found to be capable of directing the self-assembly of small building blocks, enabling the creation of the desired structure.17 3.4 Top down A novel â€Å"top down† synthesis has been reported.18 Opposed to all previously mention syntheses this is a truly unique and novel idea. It suggests the idea of a pH controlled decomposition of a very large POM into smaller fragments. The large POM; [P4W52O178]24- , has confirmed this approach to be successful with the controlled fragmentation of [P3W39O134]19-, the scheme is shown in Figure 4.5 Not only could this technique potentially enable the formation of new architectures, but it could also help to identify the building blocks that made the POM in the first place, revealing new insights into the mechanism of formation. 4. Conclusion Polyoxometalates are a very versatile class of compounds. Their potential has been subdued in the past due to a lack of understanding and the traditional one-pot synthesis. With the discovery of the importance of POMs in their various applications, and in particular as molecular magnets, there have been many developments within the past decade with regard to their careful and controlled synthesis. However, the mechanism of formation of POMs is still not fully understood. The controlled design of the structure and function of POMs is still being investigated and there is little doubt it will lead to the engineered functionality required for many capabilities POMs are already showing to have. The debate between quantum and classical mechanics has been going on for centuries. Quantum properties describe those with discrete levels, whereas classical properties have a continuous scale. The idea that POMs can be used as a â€Å"stepping stone† between the quantum and classical magnetic behaviour has started to unite both the theories and has started collaborative research between both physicists and chemists. This breakthrough enables the development and use of POMs in quantum computing and miniaturisation of devices, paving the way for new and exciting technologies. 5. Reference List G. Johansson, Acta Chem. Scand., 1960, 14, 771-773. W. G. Klemperer, T. A. Marquart, and O. M. Yaghi, Angew. Chem. Int. Ed., 1992, 31, 49-51. B. Zhou, B. L. Sherriff, F. Taulelle, and G. Wu, Can. Mineral., 2003, 41, 891-903. J. F. Keggin, Proc. R. Soc. London, Ser. A, 1934, 144, 75-100. H. N. Miras, J. Yan, D. L. Long, and L. Cronin, Chem. Soc. Rev., 2012, 41, 7403-7430. W. Rozenbaum, D. Dormont, B. Spire, E. Vilmer, M. Gentilini, C. Griscelli, L. Montagnier, F. Barre-Sinoussi, and J. C. Chermann, Lancet, 1985, 1, 450-451. M. T. Pope, A. Muller, and Editors., Polyoxometalates: From Platonic Solids to Anti-Retroviral Activity. Kluwer, 1994, 411. D. Gatteschi, A. Caneschi, L. Pardi, and R. Sessoli, Science, 1994, 265, 1054-1058. E. C. Yang, C. Kirman, J. Lawrence, L. N. Zakharov, A. L. Rheingold, S. Hill, and D. N. Hendrickson, Inorg. Chem., 2005, 44, 3827-3836. J. Liu, J. Guo, B. Zhao, G. Xu, and M. Li, Transition Met. Chem., 1993, 18, 205-208. H. Abbas, A. L. Pickering, D. L. Long, P. Kogerler, and L. Cronin, Chem. Eur. J., 2005, 11, 1071-1078. J. Lehmann, A. Gaita-Arino, E. Coronado, and D. Loss, Nat. Nanotechnol., 2007, 2, 312-317. A. Muller, F. Peters, M. T. Pope, and D. Gatteschi, Chem. Rev., 1998, 98, 239-271. A. S. Pakhomova and S. V. Krivovichev, Inorg. Chem. Commun., 2010, 13, 1463-1465. D. L. Long, H. Abbas, P. Kogerler, and L. Cronin, J. Am. Chem. Soc., 2004, 126, 13880-13881. J. M. Cameron, J. Gao, L. Vilà ¡-Nadal, D. L. Long, and L. Cronin, Chem. Commun., 2014, 50, 2155-2157. Y. Jun, L. De-Liang, N. M. Haralampos, and L. Cronin, Inorg. Chem., 2010, 49, 1819-1825. C. P. Pradeep, D. L. Long, C. Streb, and L. Cronin, J. Am. Chem. Soc., 2008, 130, 14946-14947.

The Image of Nursing

The Image of Nursing Dawn Davis Texas A&M University-Texarkana The Image of Nursing Following is a discussion of the image of nursing and professional identity. Factors contributing to nursing image and the effects of nursing image are included. The Image of Nursing What is the professional identity, or the image of nursing? How does the public view this hardworking profession? Do they understand what a nurse does? Do they understand the thought processes involved in caring for patients. Do they understand the knowledge involved in critical thinking?Do they have any idea that we formulate plans of care and that we put together nursing diagnosis with treatment plans, nursing interventions, expected outcomes? Do they understand that we are their advocates? Do they understand that all care is channeled through nursing and that we are their main defense for patient safety? Are we professionals in the eyes of the public, and in our own eyes? For my own research on this paper, I randomly q uizzed ten people that I met in public, not people that knew me personally. I asked them what they thought of nurses, and asked them to give me some adjectives to describe nurses in general.Some of the positive responses that I received were; kind, caring, cool, they help the doctors, they take care of patients, outstanding, knew what they were doing, they saved my life, and excellent. I also received some negatives. One person told me that they knew one nurse that was totally uncaring, unprofessional, and mean. Another individual told me that many years ago her son, who passed away, was HIV positive and she felt that the nurses neglected him because of his diagnosis. I was appalled at the negative answers, and somewhat disappointed with the positives.While the positives that I received were all fantastic traits, not one person mentioned traits such as educated or professional. My very limited random research was completely in line with the findings in our text book, Professional Is sues in Nursing. So, it would seem that, in general, the public doesn’t completely understand the wide scope of nursing. They understand some of the basic functions of nursing. The few random individuals that I spoke with based their perceptions mainly on personal past experiences with nurses. Nursing Image What is Nursing Image?This is a concept that needs more clarification and study to increase nurse’s awareness of factors that affect public perception. â€Å"Understanding the moral values in today’s nursing practice will help nurses to work together with a common comprehension of their aims. This should also allow greater appreciation of the practice of nursing highlighting the equal importance of both fundamental basic nursing care and the advanced clinical roles† (Horton, Tschudin, & Forget, 2007) Nursing image also affects the decision to enter nursing as a profession, to remain in nursing, and to encourage others to become a nurse.A broad definiti on is â€Å"Nursing Image is a multidimensional, all-inclusive, paradoxical, dynamic, and complex concept. † (Rezaei-Adaryani, Salsali, & Mohammadi, 2012) To further define: * All-inclusive and paradoxical refers to both stereotypical and professional image. * Dynamic includes the changing view of nursing as a profession. * Complex, because many factors influence the formation of the image. Factors affecting Nursing Image Many factors combine to influence the image of nursing as a profession.Some of The factors include media, poor communication and visibility, clothing style, the nurses’ behaviors, gender issues, and professional organizations. (Rezaei-Adaryani, Salsali, & Mohammadi, 2012) * Media- Historically media has not painted a very professional image of nursing, although, recently this has improved to portray a more capable, independent, strong, intelligent individual. * Poor communication and invisibility- Nursing is an invisible profession and this is a major threat to nursing’s social status and perceived value.It is believed that since nursing is mostly female, that there is poor communication with media and reporters. Nurses also somewhat reluctant to share knowledge, experience, expertise, competence, and intelligence to change portrayal in the media. (Rezaei-Adaryani, Salsali, & Mohammadi, 2012) * Clothing style- Appearance is the first thing a person notices. A professional uniform that also defines them from other disciplines increases professionalism. * Nurses’ behaviors- Some believe that the nurse is not identified as professional individual, we refer to the physician as Dr. ___, and the nurse is known by the first name. Different levels of nursing education do the same job; this may devalue nursing as an intellectual profession. Nurses with negative image of nursing may also project that to others. â€Å"Self-image shapes behavior and performance in the workplace and affects how we think and act. † (Fletc her, 2007) * Gender issues- Generally nursing is viewed as a female dominated profession. Men are normally viewed as having positions of power. Women are thought of as caring, more emotional and less aggressive than men.This gender stereotype tends to limit the number of males recruited and retained in nursing. (Rezaei-Adaryani, Salsali, & Mohammadi, 2012) * Professional organizations-Globally, there are 14 million nurses. Nurses are the largest group of health professionals in the world. Unfortunately, there is limited unity. Involvement in professional organizations, and standing together on issues is important in changing nursing image and increasing professional identity. (Rezaei-Adaryani, Salsali, & Mohammadi, 2012) Effects of Nursing Image on NursingOne very important effect of public misunderstanding of the profession of nursing and the knowledge and skill required is a limited number of potential candidates for the future of nursing. Thirty years ago a significant number of young people would have chosen to be a nurse when they grow up, less than 5% of students responded so in a 2004 study. (Huston, Professional Issues in Nursing, 2010) Another important factor is that inaccurate nursing stereotypes may have a negative effect on the self-esteem f nursing as a whole. Both of these factors combined lead to increase in nursing shortage, short-staffing, heavy workload, job dissatisfaction, and burn-out. This can lead to current nurses leaving the profession. In general, nurses’ image of nursing tends to be better than that of the public. This is related to the fact that nurses are educated about the profession. I also asked several Registered Nurses to give adjectives to describe nursing.I received responses such as; educated, professional, critical thinkers, overworked, advocates, compassionate, unappreciated, caring, researchers, knowledgeable, multitasker, empathetic, thorough, supportive, educators, and leaders. Many changes need to be made to c hange the image of nursing in public view. Nurses must be heard in the media. Nurses must speak positively about their profession. The public needs to be educated about the profession of nursing. Nurses should act, perform, and dress like professionals. Nurses should actively encourage bright individuals to join the profession.Current nurses should positively socialize nursing students, and new nurses, acting as optimistic and confident mentors, sharing their expertise. Nurses should join and be active in professional organizations, to increase unity, and be active in the political processes. Imagine the strength and respect nursing would command if half of the nurses joined. In summary, the image of nursing needs to be changed for the better. Change starts with the profession itself. Every nurse should take accountability to make these positive changes through action, involvement, education, and behavior.Bibliography Fletcher, K. (2007). Image: changing how women nurses think about themselves. The Author, 207-215. Horton, K. , Tschudin, V. , & Forget, A. (2007). The Value of Nursing: A Literature Review. Sage Publication. Huston, C. J. (2010). Professional Issues in Nursing (second ed. ). (H. Surrena, Ed. ) Philadelphia, PA, USA: Wolters Kluwer Health/Lippincott Williams & Wilkins. Rezaei-Adaryani, M. , Salsali, M. , & Mohammadi, E. (2012, December). Nursing Image: An Evolutionary Concept Analysis. Contemporary Nurse, 81-89.

An Overview of Early Childhood Education

Early Childhood Education is a term that refers to educational programs and strategies geared toward children from birth to the age of eight. This time period is widely considered the most vulnerable and crucial stage of a persons life. Early childhood education often focuses on guiding children to learn through play. The term commonly  refers to preschool or infant/child care programs. Early Childhood Education Philosophies Learning through play is a common teaching philosophy for young children. Jean Piaget developed the PILES theme to meet the physical, intellectual, language, emotional and social needs of children. Piagets constructivist theory emphasizes hands-on educational experiences, giving children the chance to explore and manipulate objects. Children in preschool learn both academic and social-based lessons. They prepare for school by learning letters, numbers, and how to write. They also learn sharing, cooperation, taking turns, and operating within a structured environment. Scaffolding in Early Childhood Education The  scaffolding method of teaching  is to offer more structure and support when a child is learning a new concept. The child may be taught something new by employing things they already know how to do. As in a scaffold that supports a building project, these supports can then be removed as the child learns the skill. This method is meant to build confidence while learning. Early Childhood Education Careers Careers in early childhood and education include: Preschool Teacher: These teachers work with children ages three to five who are not yet in kindergarten. The educational requirements vary by state. Some require only a high school diploma and a certification, while others require a four-year degree.Kindergarten Teacher: This position may be with a public or private school and may require a degree and certification, depending on the state.Teacher for First, Second, and Third Grades: These elementary school positions are considered to be part of early childhood education. They teach a full range basic academic subjects to a class rather than specializing. A bachelors degree is required and a certification may be needed, depending on the state.Teacher Assistant or Paraeducator: The assistant works in the classroom under the direction of the lead teacher. Often they work with one or more students at a time. This position often does not require a degree.Childcare Worker: Nannies, babysitters, and workers at childcare centers usually perf orm basic duties such as feeding and bathing in addition to play and activities that may be mentally stimulating. An associates degree in early childhood development or a credential may result in a higher salary.Childcare Center Administrator: The director of a childcare facility may be required by a state to have a bachelors degree in Early Childhood Education or a certification in Child Development. This position trains and supervises the staff as well as performing the administrative duties of the facility.Special Education Teacher: This position often requires additional certification beyond that for a teacher. The special education teacher would work with children who have special needs, including mental, physical, and emotional challenges.

The European Overseas Empires - Overview

Europe is a relatively small continent, especially compared to Asia or Africa, but during the last five hundred years, European countries have controlled a huge part of the world, including almost all of Africa and the Americas. The nature of this control varied, from the benign to the genocidal, and the reasons also differed, from country to country, from era to era, from simple greed to ideologies of racial and moral superiority such as The White Mans Burden. They are almost gone now, swept away in a political and moral awakening over the last century, but the after-effects spark a different news story almost every week. A Desire to Find New Trade Routes Inspired Exploration There are two approaches to the study of the European Empires. The first is straightforward history: what happened, who did it, why they did it, and what effect this had, a narrative and analysis of politics, economics, culture, and society. The overseas empires began to form in the fifteenth century. Developments in shipbuilding and navigation, which allowed sailors to travel across the open seas with much greater success, coupled with advances in maths, astronomy, cartography, and printing, all of which allowed better knowledge to be more widely spread, gave Europe the potential to extend over the world. Pressure on land from the encroaching Ottoman Empire and a desire to find new trade routes through to the well-known Asian markets—the old routes being dominated by Ottomans and Venetians—gave Europe the push—that and the human desire to explore. Some sailors tried going around the bottom of Africa and up past India, others tried going across the Atlantic. Indeed, the vast majority of sailors who made western voyages of discovery were actually after alternative routes to Asia—the new American continent in between was something of a surprise. Colonialism and Imperialism If the first approach is the sort you will encounter mainly in history textbooks, the second is something youll encounter on the television and in the newspapers: the study of colonialism, imperialism, and the debate over the effects of empire. As with most isms, there is still an argument over exactly what we mean by the terms. Do we mean them to describe what the European nations did? Do we mean them to describe a political idea, which we will compare to Europes actions? Are we using them as retroactive terms, or did people at the time recognize them and act accordingly? This is just scratching the surface of the debate over imperialism, a term thrown around regularly by modern political blogs and commentators. Running alongside this is the judgmental analysis of the European Empires. The last decade has seen the established view—that the Empires were undemocratic, racist and thus bad—challenged by a new group of analysts who argue that the Empires actually did a lot of good. The democratic success of America, albeit achieved without much help from England, is frequently mentioned, as are the ethnic conflicts in African nations created by Europeans drawing straight lines on maps. Three Phases of Expansion There are three general phases in the history of Europes colonial expansion, all including wars of ownership between the Europeans and indigenous people, as well as between the Europeans themselves. The first age, which began in the fifteenth century and carried on into the nineteenth, is characterized by the conquest, settlement, and loss of America, the south of which was almost entirely divided between Spain and Portugal, and the north of which was dominated by France and England. However, England won wars against the French and Dutch before losing to their old colonists, who formed the United States; England retained only Canada. In the south, similar conflicts occurred, with the European nations being almost thrown out by the 1820s. During the same  period,  European nations also gained influence in Africa, India, Asia, and Australasia (England  colonized  the whole of Australia), especially the many islands and landmasses along the trading routes. This influence only increased during the nineteenth and early twentieth century, when  Britain, in particular, conquered India. However, this second phase is  characterized by the New Imperialism, a renewed interest and desire for overseas land felt by many European nations which prompted The Scramble for Africa, a race by many European countries to carve up the entirety of Africa between themselves. By 1914, only Liberia and  Abysinnia  remained independent. In 1914, the First World War began, a conflict partly motivated by imperial ambition. The consequent changes  in  Europe and the world eroded many beliefs in Imperialism, a trend enhanced by the Second World War. After 1914, the history of the European Empires—a third phase—is one of gradual  decolonization  and independence, with the vast majority of empires ceasing to exist. Given that European colonialism/imperialism affected the whole world, it is common to discuss some of the other rapidly expanding nations of the period as a comparison, in  particular, the United States and their ideology of manifest destiny. Two older empires are sometimes considered: the Asian part of Russia and the Ottoman Empire. The Early Imperial Nations England, France, Portugal, Spain, Denmark, and the Netherlands. The Later Imperial Nations England, France, Portugal, Spain, Denmark, Belgium, Germany, Italy, and the Netherlands.