Human development Essay

Life starts at conception. Immediately fertilization takes place changes and events occur that will determine the kind of person to be born. This research tries to find out the effect of early life on the later life of an individual. And if early life affects the later life of the individual, then do children who grow up in violent communities have a tendency to exhibit violent behaviors as adults? The research will apply the cross-sectional design. People who differ in age are studied at the same time. A comparison of age related changes and the social behavior is done. A hypothesis is put forward and a cross-sectional experiment is done to test it. One advantage of this design is that one can collect data from different ages of children over a short period of time. Stages of human development After fertilization takes place, the zygote is formed. The zygote undergoes cell division some hours after it is formed. It takes one week to reach the uterus. In the uterus there occurs implantation. The zygote makes connection to the blood vessels. This process takes about one week(Brian & Scott, 2005). After the zygote completely implant into the uterus, it becomes the embryo. This stage occurs between the 3rd week and the 9th week. During this stage the human body structure start to develop. The internal organs also start developing. The embryo consist of three layers: the ectoderm, the outer layer; the endoderm, the middle layer and the endoderm, inner layer. The ectoderm develops into the skin and hair; the mesoderm develops into bones , cartilages and the cardiovascular system ; the third layer develops into the internal organs . The heart start beating after four weeks. By 8 most body organs can be seen in although not well developed. Brian and Scott, 2005 ). The embryo rest in the amniotic sac which contains amniotic fluid. This fluid protects it. The embryo is connected to the mother via the placenta and the umbilical cord. The development of the embryo follows two principles: the cephalocaudal i. e it develops from head towards the legs and the proximodistal – the parts near the centre of the body develops first e. g the arm develops before the hands (Lichtenberg & Norton,1970). The third stage is the Fetus stage. This stars from the ninth week. At this stage, most body organs start to work. There is remarkable increase weight. During this period, the body systems like the respiratory system develop. The fetus can move and play in the uterus. It can hear the heart mother’s hear beat and the mother speak. It can detect flavor. The fetus’s senses are developed. The sensory influence can have a lifetime effect on the fetus. A research done by deCasper and Spence( cited in Lorraine ) shows that the last few months of prenatal developments can shape the life of the newborn infant. It can have either positive or negative effect on the infant. For instance extreme stress in the mother can have several effects: First, the stress tigress the production of hormones which reduces the level of oxygen consumption of the fetus. Second, stress may affect eating habits of the mother thus affecting the fetus in turn. Third, it may cause the mother not to take onto account resting, exercising and may influence her to drink. All these have negative effect on the fetus (Joseph , & Sandraw,1994). The mother’s age. The mother’s age seems to have an effect on the newborn baby. For instance teenage mothers mothers are likely to have problems during pregnancy and during birth. This is because they may not have the resources and skills to give them a good prenatal care. Again children born by teenage mothers may have problems. However a study ( Leavitt, 1993) revealed that it is the environmental and economic background that affect the child and not necessarily the age of the mother. Also the prenatal care given to the mother determines the behavior of the child. Nevertheless, older women, over 35 years experience more problems during pregnancy than younger women. They also record higher rates of miscarriage and Down ’s syndrome (Cited in Nelson). In general, for a healthy pregnancy and healthy baby, the age of the mother should be between 20 to 35 years. Teratogens. : Drugs, deseases and environmental harzards. Teratotegen is anything that affect a pregnancy. Some teratogens are: Drugs: Many drugs consumed by pregnant women pose great danger to the fetus and the mother. This was discovered after a drug called thalidomide caused women to bear children with malformed body organs. Thalidomide was being used by pregnant women to assist them sleep Other examples of teratogens are alcohol, cocaine, caffeine, nicotine and cigarettes. Joseph & Sandraw, 1994). Diseases: Some diseases do not have any serious effect on the pregnant women. However most viral and bacterial diseases have effect on the pregnancy. The most serious ones are AIDS, gonorrhea, syphilis and genital herpes. These may cause low immune system and various disorders in the unborn (Lichtenberg & Norton, 1970). Environmental hazards: The wastes from the industries contain chemicals. These chemicals may be absorbed into the mother’s body in small quantities through breathing and drinks. These cause great damage to the fetus since they are teratogens. Environmental teratogens are more serious because the mother may not be aware that she is taking it. Thus she may not have control over it. (Joseph &Sandraw, 1994). However some teratogens may be avoided especially those found in food as food additives. Freud(1954) suggested that life starts at birth. Most psychoanalysts of his time believed so. They believed that the brain developed at infancy. Winnicot(cited in Freud) did a research which found that the experience of the unborn is very important the infant. It could have emotional implications that could affect the person even as an adult. Winnicott observed children and saw that there very many differences. He noted that problems caused during labor could traumatize the baby who develops a lot of distress. He conclusively said that the experience gained in the womb remain in memory for a lifetime. In the womb, traumatized fetus even develops defensive mechanisms to face the expected trouble. Later research therapists conducted research and were able to conclude that early trauma created a lot of fear for the rest of the life of the infant. The feelings of anxiety, seeing being devoured by ogres, falling into a bottomless bit are as a result of early trauma. An example is given of an infant who was mistakenly exposed to cold in a very cold night (Lorraine). This child always dreamt lying in the refrigerator and this continued even after 30 years. This shows that early trauma caused the infant to expect disaster at any time. However the discovery of the effect of perinatal trauma on the life of an individual helped therapists to treat patients with problems related to early trauma (Freud, 1954). Recent research by perinatal psychologists, neurobiologists, experimental psychologists has shown great connection of fetal trauma to problems experienced later in life. Initially biologists used to think that the fetus had incomplete myelination of neurons and therefore it could not have memories. Research shows that the thinly myelinated nerves of fetus can transmit waves but at a lower rate. Joseph et al.. Thus the experience gained in the womb may make one to be aware of violence, disaster lack faith. With this in mind, parents have started to consider the unborn as part of the member of the family. A father who played a game with a baby and the mother found that the next baby easily learnt the game. These parents tried to avid any experiences that may cause fetal distress (Lichtenberg & Norton,1970). Fourteen independent studies have shown the relationship between antenatal maternal anxiety and emotional distress in the child. Prenatal stages are likely to be affected by antenatal stress. These reports have suggested that maternal distress affect the fetus as evidenced by increased fetal heart rate (FHR). This is done by use of ultrasound and monitoring FHR over long periods of time. Both the experimental and distress –induced study design have been employed to achieve this. For a normal case, at about the 15th week of the pregnancy fetal movements exhibit a certain pattern. As developments progress the fetal movements become dependent on specific heart rate pattern. These patterns finally develop into sleep-wake patterns which characterize stable temporal origination near term. There is a relationship between body movements and FHR accelerations. Fetal behavior is organized in rest – activity or sleep- wake cycle (Lichtenberg & Norton, 970). Effect war and social violence Family violence and trauma caused by war are passed through generations. Adults who were exposed to abuse and violence are more likely to show violence to their own offspring. They have difficulty forgetting their past and live normally. War and violence are everywhere in our societies. Many ethnic clashes continue for years and our children are being exposed to their effects. The children are being thought that disputes are being solved by use of violence. This violence is passed from generation to generation. Research and behavioral science has began to confront the problems of children exposed to violence. (Heidi, 2002). Over the last few decades, there has been an increase in the prevalence of domestic violence. Domestic violence has severe effect on families and society in general. Domestic violence can be in the form physical abuse, psychological abuse and sexual abuse. Exposure to violence creates traumatic stress. Traumatic stress can be either short term or long-term. Terr ( cited in Brian & Scott, 20005) describes short term trauma as â€Å"Type I† e. g a single event of rape or beating. He described repeated or prolonged trauma as â€Å"Type II†. Type II has more serious effects than type I. Individual exposed to this kind of trauma may develop Post Traumatic Stress disorder (PTSD). PTSD makes one to show routine withdrawal and oversensitivity. Many children from domestic violence homes show levels of (PTSD) (Leavitt, 1993). If untreated, the children exhibit violent behaviors, delinquency and other social and psychological problems. Since young child do have the ability to express themselves verbally, the emotional problems developed are behavioral such as lack of sleep, feeding problems, inability to concentrate, withdrawn and physical complaints. The pre-adolescents child may in addition to the above problems show loss of interest in peers, poor self concept violence,, defiant behavior and temper out bursts. Adolescents are likely to fail academically and start abusing drugs. Youth who exhibit violent behaviors can be traced to families experiencing domestic violence. An estimated 20% 30% of dating teenagers abuse or are being abused by their partners mentally, sexually, emotionally or physically. Between 30% and 50 % of adult relationships show the same cycle of violence (Leavitt, 1993) Nelson ( 2000), points out that community violence also has an impact on children who were victimized or who witnessed member of community or family members being victimized get affected. The effect of violence spread to even those children who are not directly affected by violence. Violence tampers with activities of the child which might make the child a better person. Impact of violence on the child depends on the level of development of the child. Early exposure to violence is more detrimental than later exposure( p. 266) In 1995 FBI report it reported that 27% of all violent crime involved domestic violence. All forms of violence affect the child’s mind. One study was done to show the connection between the brain and someone’s violence. Psychologists observed brain imaging data for a great number of people with violent behaviors. The research focused on specific brain regions. One was the orbital frontal cortex and the amyglada. The results showed that most of the cases, there was absence of normal activity in the orbital and anterior regions. While the shoed normal activity. The two regions will not counteract and this may explain some people are hyper aroused ( Lorraine).

Odyseus vs. Superman essays

Odyseus vs. Superman essays Odysseus and Superman are some what a like. They have been around for a long time. They both have strength and skills, both of them are smart and strong. In some ways they are very much different in mind and body. Odysseus took a trip around the world and superman tried to save the world. In my opinion superman is stronger than Odysseus and but Odysseus is smarter than superman. Odysseus was the son of Laertes and was the ruler of the island kingdom of Ithaca. He was one of the most prominent Greek leaders in the Trojan War, and was the hero of Homer's Odyssey. He was known for his cleverness and cunning, and for his eloquence as a speaker. Odysseus was a good king; everyone believed that he could do anything. He was known for the things he did. Odysseus was one of the original suitors of Helen of Troy. When Menelaus succeeded in winning Helen's hand in marriage, it was Odysseus who advised him to get the other suitors to swear to defend his marriage rights. However, when Menelaus called on the suitors to help him bring Helen back from Troy, Odysseus was reluctant to make good on his oath. He pretended to have gone mad, plowing his fields and sowing salt instead of grain. Palamedes placed Odysseus' infant son in front of the plow, and Odysseus revealed his sanity when he turned aside to avoid injuring the child. Odysseus had many children. He loved his wife Penelope. Odysseus was sent on a voyage around the world it took him ten years to get back. He went through a lot, many people thought he wasnt going to make it back. They told Penelope to remarry but she loved Odysseus to much to do that. Suitors were all around the castle trying to marry her, when found Odysseus out he snuck in the castle and killed all of them. Now superman was the super hero that saved the world by killing bad villains and stuff. Superman was the man of steel couldnt nobody defeat him. He had many powe ...

Should Abortions be Illegal Essay Example | Topics and Well Written Essays - 1750 words

Should Abortions be Illegal - Essay Example As such, abortion should be illegal given that it does not provide a long term solution to the recurrent problem of unwanted pregnancies especially among the teenagers. Abortion should not be treated as an option but concerted efforts should be made to address the root cause of this problem in every society. Against this background, this argumentative essay is going to argue in favour of the topic which suggests that abortion should be illegal. However, the second part will look at the topic from the other angle where some advocates argue that abortion should be legalised. A synthesis will be drawn at the end of the paper to summarise the main points discussed and defend the argument in favour of the topic. Tribe (1992, p. 3) posits to the effect that â€Å"no right is more basic than the right to live and the untimely death of a young child is among life’s most awful tragedies.† To cause such a death to an innocent soul is a great wrong which deserves to be treated wit h the contempt. The right to life is an inalienable right that is conferred to every person upon birth. However, in some instances, unborn babies are denied this right before even seeing the earth as a result of aborted pregnancies. Basically, abortion can be described as the process of terminating or ending unwanted pregnancies (Wharton, 1989). ... cle/12504-teen-pregnancy-rates-usa/>, The Center for Disease control says â€Å"that the United States has the highest teen pregnancy rate in the industrialized world whereby one-third of girls get pregnant before the age of 20.† It also states that Teenpregnancy.org, a site which is managed by the National Campaign to Prevent Teen and Unplanned Pregnancy has revealed that about 750  000 teen pregnancies are reported annually where eight out of ten of these are not planned. The trend is similar in many countries and abortion should not be treated as a viable option given that teenagers for instance indulge in sexual activities without properly weighing the consequences hence they should not have any legal right to terminate life unless otherwise it is beyond their control. There are many reasons why unplanned pregnancies occur and carelessness is one of them (Gutman, 1987). Some teenagers have misguided perceptions that they want to believe that having sex at an early age ca n prove their manhood or woman hood which is not correct. As a result, unplanned pregnancies are reported and this cannot be the problem of the unborn fetus in the womb given that it is life already developing which must not be ended unceremoniously. It is the responsibility of the mother in particular to ensure that they take preventive measures against unwanted pregnancies. For instance, the use of contraceptives such as pill as well as condoms is another viable way of preventing unwanted pregnancies. Instead of preferring abortion as the last resort, both men and women need to take responsibility for contraception since this is the best alternative to abortion. Abortion is therefore considered as murder hence cannot be condoned. No society likes abortion and the main task is to enable the women to

Prescription, Nonprescription, and Herbal Medication Research Paper

Prescription, Nonprescription, and Herbal Medication - Research Paper Example As the essay declares the aging process is defined by numerous impairments of several regulatory processes that play a critical role in cells and organs. In addition, other physiological changes are evident in advanced age, and have the capacity to affect the absorption, distribution, metabolism, and excretion of drugs. The geriatric population exhibits cardiac dysfunctions. The relaxation and contraction of heart muscles change remarkably a one ages. Blood flow becomes slower, a factor that may affect drug distribution. In addition, aging brings about the reduction of renal mass. Fewer nephrons define the reduction of renal mass. According to the research findings there is a notable delay in the kidney functions, a factor that affects the elimination of drugs. The gastrointestinal system is also affected by aging because elderly people have lower rates of hydrochloric acid and pepsin. Research has highlighted that aging may contribute to potential changes in the enzyme secreting cells or hormonal glands a factor that minimizes the efficiency of the gastrointestinal system. In the small intestines, absorption of some substances reduces with age, while in the colon, the transit time may prove to be slower. Other digestive enzymes such as lipase and trypsin usually decrease as one age. The liver is a critical organ in the metabolism of drugs. With advancing age comes a remarkable reduction in the liver blood flow. In other cases, the liver structure may change over time while enzymes may cease to function effectively.

Corparate finance Essay Example | Topics and Well Written Essays - 2500 words - 1

Corparate finance - Essay Example In the case of Hoad limited the capital investment is the resources needed to acquire new and replace old production equipment. Organizations should come up with efficient capital investment plans for how the budget should be allocated and how the financing will be acquired. An organization can obtain funds through two approaches namely equity and debt. Equity investments refer to a situation where the company offers ownership to investors or uses retained earnings to finance projects (Dow, 2009: p.91). In the case of Hoad limited, the retained earnings and issuing of more stock won’t be adequate to fund their intended capital expenditure. The other option that is viable to Hoad limited is the use of debts. Debt financing involves acquiring investors who receive a promise of future payments without acquiring ownership of the organization (Dow, 2009: p.91). Deciding on the best funding approach is relevant for Hoad Limited given that investment is a crucial component for organizations. Though markets may be the preferred mode of financing in developed countries for organizations, establishing an alternative finance option is critical in regions with underdeveloped stock exchange (Allen, Carletti, Qian, & Valenzuela, 2012: 4). In regions with under-developed stock exchange, a well-established system is crucial in exploiting the gains from trade. These opportunities ought to be matched with relevant funding based on the standard and non-standard sources and also domestic and international sectors. Before Hoad limited decides on the best approach to adopt in acquiring debts to finance the capital expenditure, the organization has to evaluate its capital structure and determine the best way forward. The business has to decide whether to use more equity or more debt in its capital structure (Dow, 2009: p.95). The company can increase its expected returns when the return from a capital investment is greater than the cost of

The Crucible within the play Essay Example for Free

The Crucible within the play Essay What is The Crucible within the play, and how does it bring about change or reveal the individuals true character? A crucible is a cup-shaped piece of laboratory equipment used to raise metals to very high temperatures, and extract impurities. Therefore, I think that the court is the crucible within the play. The Crucible is a play written by Arthur Miller based on the events which actually happened in 1692, which led to the Salem witch trials, a series of hearings before the court, which prosecuted over 150, on the grounds that they were practicing witchcraft. These events occurred in Massachusetts, between February 1692 and May 1693. He likened the events in his play to the situation with the House Un-American Activities Committee. Miller wrote the play to warn people to plead for freedom. Later, Miller himself was called upon to appear before the McCarthy Committee and was questioned about his activities with the American communist party. Arthur Miller was an American playwright, who lived from October 1915 till February 2005. He was an important figure in American literature for over 60 years, and wrote many plays, including very famous plays, such as The Crucible, A View from the Bridge, All My Sons, and Death of a Salesman, which are still studied and performed all over the world. He was born to Jewish-American parents in Manhattan, in New York. His father owned a womans clothes manufacturing business, which failed in the Wall Street Crash of 1929. After the business failed, his family moved to Brooklyn. Because of the effects of the Wall Street Crash on his family, Miller had little money for college after graduating in Abraham Lincoln High School. In order to gain a place at the University of Michigan, Miller had to work in a number of low status jobs to pay for his tuition. In order to fully understand The Crucible, we must first understand some of the plays background and history. The term Witch-hunt was first used to describe the searching out and persecution of a religious minority, or a political group with ideas different to the majority of the population. After World War Two, US relations with the Soviet Union deteriorated, and there followed a period known as the cold war. A large amount of people feared Russia, and believed that they intended to take over the world. This is what started the fear of Communism in the US. We must also understand what the Puritan societies in Salem were like. Salem was originally founded by Pilgrim Fathers, who had left their own countries in order to practice their religion in peace. The Puritans had very strict moral codes, and this is probably what caused the girls to rebel, and experiment in the forest.

Self-healing Materials and Shape Memory Polymers

Self-healing Materials and Shape Memory Polymers Topic Area: self-healing materials, shape memory polymers and flame retardant polymers Emerging Polymer materials       Md Hossion Shovon Introduction: The ability of a nation to harness nature as well as its ability to cope up with the challenges posed by it is determined by its complete knowledge of materials and its ability to develop and produce them for various applications. Advanced Materials are at the heart of many technological developments that touch our lives. Electronic materials for communication and information technology, optical fibers, laser fibers sensors for the intelligent environment, energy materials for renewable energy and environment, light alloys for better transportation, materials for strategic applications and more. Advanced materials have a wider role to play in the upcoming future years because of its multiple uses and can be of a greater help for whole humanity. Emerging technologies are those technical innovations which represent progressive developments within a field for competitive advantage. List of currently emerging technologies, which contains some of the most prominent ongoing developments, a dvances, and Materials Science and Nanotechnology Innovations are Graphene, Fullerene, Conductive Polymers, Metamaterials, Nanomaterials: carbon nanotubes, Superalloy, Lithium-ion batteries, etc. Over the last decade, smart polymeric materials have been used in biochemical sciences in many ways. Since the term, smart polymeric materials encompasses a wide spectrum of different compounds with unique potential for biological applications, Self-healing Polymers: Self-healing polymers are a new class of smart materials that have the capability to repair themselves when they are damaged without the need for detection or repair by manual intervention of any kind. Increasing demand for petroleum feedstocks used to produce polymer and the need for polymeric materials with improved performance in challenging applications continue to drive the need for materials with extended lifetimes. One way to extend the lifetime of a material is to mitigate the mechanism leading to failure. In brittle polymers, failure occurs through crack formation and propagation (1,2) and the ability to repair these cracks when they are still very small will prevent further propagation thus extending the lifetime of the material. Emerging self-healing technologies designed to give polymeric materials the capability to arrest crack propagation at an early stage thereby preventing catastrophic failures will go a long way in helping to increase the scope of applications of the se materials. With the need for autonomic repair of materials without external intervention thus evident, more recent research has focused on developing fully self-healing systems. One approach to the design of such systems employs the compartmentalization of a reactive healing agent, which is then incorporated into a composite material. Thus, when a crack propagates through the material, it causes the release of the healing agent from the compartment in which it is stored into the crack plane where it solidifies and repairs the material. The first basic application of this approach consisted of an epoxy matrix with suspended glass capillaries filled with either cyanoacrylate or a two-part epoxy resin. When a crack propagated through the cured epoxy matrix, the glass capillaries were fractured and the cyanoacrylate monomer or the two-part epoxy generally referred to as healing agents, were released into the crack plane where they reacted and polymerized. A significant recovery of the mechanical properties of the samples after they were allowed to heal suggests that the cracked material was effectively repaired by the polymerized healing agent. Since the healing requires only crack propagation as the trigger for the healing mechanism, it represents a truly autonomic or self-healing material. While a successful demonstration of self-healing, the labor-intensive process of manually filling capillaries and distributing them evenly throughout the matrix make this approach unsuitable for scale-up. Shape-memory Polymers: Shape-memory polymers are an emerging class of active polymers that have the dual-shape capability. They can change their shape in a predefined way from shape A to shape B when exposed to an appropriate stimulus. While shape B is given by the initial processing step, shape A is determined by applying a process called programming. The shape-memory research was initially founded on the thermally induced dual-shape effect. This concept has been extended to other stimuli by either indirect thermal actuation or direct actuation by addressing stimuli-sensitive groups on the molecular level. Finally, polymers are introduced that can be multifunctional. Besides their dual-shape capability, these active materials are biofunctional or biodegradable. Potential applications for such materials as active medical devices are highlighted. Shape-memory polymers are dual-shape materials belonging to the group of actively moving polymers. They can actively change from a shape A to a shape B. Shape A is a temporary shape that is obtained by mechanical deformation and subsequent fixation of that deformation. This process also determines the change of shape shift, resulting in shape B, which is the permanent shape. In shape-memory polymers reported so far, heat or light has been used as the stimulus. Using irradiation with infrared light, application of electric fields, alternating magnetic fields, or immersion in water, indirect actuation of the shape memory effect has also been realized. The shape-memory effect only relies on the molecular architecture and does not require a specific chemical structure in the repeating units. Therefore, intrinsic material properties, e.g. mechanical properties, can be adjusted to the need of specific applications by variation of molecular parameters, such as the type of monomer or the comonomer ratio. An example of a cross-linked polymer network synthesized by polyaddition of monofunctional monomers with low molecular weight or oligomeric cross-linkers has been realized in polyurethanes by the addition of trimethyl owl to the reaction mixture. The reaction of tetra-functional silanes, working as net points, with oligomeric silanes, which work as spacers and to which two distinct benzoate-based mesogenic groups have been attached, results in a formation of a main-chain smectic-C elastomer38. In contrast to other liquid-crystalline elastomers, which display a shape-changing behavior and have been compared to shape-memory polymers recently, these elastomers have shape-memory properties. The cross-linking process during synthesis defines the permanent shape. The shape-memory effect is triggered by the thermal transition of the liquid-crystalline domains. In the programming process, the polymer network is heated to the isotropic state of the liquid crystalline domains, stretched or twisted, and then cooled below the clearing transition temperature of the smectic-C mesogens. Upon reheating over this clearing transition, the permanent shape can be recovered. In contrast to shape-changing liquid crystalline elastomer systems, thes e polymers display shape-memory behavior because the liquid crystalline moieties work as a switch. In shape-changing liquid-crystalline elastomers, the molecular movement of the single liquid crystals is converted into a macroscopic movement Another class of thermoplastic shape memory polymers with Trans = Tg are polyesters. In copolyesters based on poly(Ɇº-caprolactone) and poly (butylene terephthalate), the poly (butylene terephthalate) segments act as physical cross-linkers25. The shape-memory capability can also be added to a polymer using a polymer-analogous reaction. A polymer-analogous reaction is the application of a standard organic reaction (like the reduction of a ketone to an alcohol) to a polymer having several of these reactive groups. An example is the polymer-analogous reduction of a polyketone with NaBH4/THF, which results in a poly(ketone-co-alcohol). The polyketones are synthesized by late transition metal catalyzed polymerization of propene, hex-1-ene, or a mixture of propane and hex-1-ene with CO. The Tg of this polymer is directly related to the degree of reduction, which can be adjusted by the amount of NaBH4/THF. The most promising shape-memory material is a partly reduced poly (ethylene -co-propane-co-carbon oxide), which displayed a phase-separated morphology with hard microcrystalline ethylene/CO-rich segments within a softer amorphous polyketone ethylene-propene/CO-rich matrix. The crystalline domains of this material work as physical cross-linkers. This results in an elastic behavior above Tg because the glass transition temperature (Trans = Tg) is related to the switching phase. Partial reduction of the material allows control of Tg, which can be adjusted from below room temperature to 75 °C. Flame-retardant Polymers: Fire-safe polymers are polymers that are resistant to degradation at high temperatures. There is need for fire-resistant polymers in the construction of small, enclosed spaces such as skyscrapers, boats, and airplane cabins. In these tight spaces, ability to escape in the event of a fire is compromised, increasing fire risk. In fact, some studies report that about 20% of victims of airplane crashes are killed not by the crash itself but by ensuing fires. Fire-safe polymers also find application as adhesives in aerospace materials, insulation for electronics and in military materials such as canvas tenting. Some fire-safe polymers naturally exhibit an intrinsic resistance to decomposition, while others are synthesized by incorporating fire-resistant additives and fillers. Current research in developing fire-safe polymers is focused on modifying various properties of the polymers such as ease of ignition, rate of heat release, and the evolution of smoke and toxic gases. Standard methods for testing polymer flammability vary among countries; in the United States common fire tests include the UL 94 small-flame test, the ASTM E 84 Steiner Tunnel, and the ASTM E 622 National Institute of Standards and Technology (NIST) smoke chamber. Research on developing fire-safe polymers with more desirable properties is concentrated at the University of Massachusetts Amherst and at the Federal Aviation Administration where a long-term research program on developing fire-safe polymers was begun in 1995. The Center for UMass/Industry Research on Polymers (CUMIRP) was established in 1980 in Amherst, MA as a concentrated cluster of scientists from both academia and industry for the purpose of polymer science and engineering research. Controlling the flammability of different materials has been a subject of interest since 450 B.C. when Egyptians attempted to reduce the flammability of wood by soaking it in potassium aluminum sulfate (alum). Research on fire-retardant polymers was bolstered by the need for new types of synthetic polymers in World War II. The combination of a halogenated paraffin and antimony oxide was found to be successful as a fire retardant for canvas tenting. Synthesis of polymers, such as polyesters, with fire retardant monomers were also developed around this time.. Additives are divided into two basic types depending on the interaction of the additive and polymer. Reactive flame retardants are compounds that are chemically built into the polymer. They usually contain heteroatoms. Additive flame retardants, on the other hand, are compounds that are not covalently bound to the polymer; the flame retardant and the polymer are just physically mixed together. Only a few elements are being widely used in this field: aluminum, phosphorus, nitrogen, antimony, chlorine, bromine, and in specific applications magnesium, zinc and carbon. One prominent advantage of the flame retardants (FRs) derived from these elements is that they are relatively easy to manufacture. The most important flame retardants systems used act either in the gas phase where they remove the high energy radicals H and OH from the flame or in the solid phase, where they shield the polymer by forming a charred layer and thus protect the polymer from being attacked by oxygen and heat. Fl ame retardants based on bromine or chlorine, as well as a number of phosphorus compounds act chemically in the gas phase and are very efficient. Others only act in the condensed phase such as metal hydroxides (aluminum trihydrate, or ATH, magnesium hydroxide, or MDH, and boehmite), metal oxides and salts (zinc borate and zinc oxide, zinc hydroxystannate), as well as expandable graphite and some nanocomposites (see below). Phosphorus and nitrogen compounds are also effective in the condensed phase, and as they also may act in the gas phase, they are quite efficient flame retardants. Overviews of the main flame retardants families, their mode of action and applications are given in. Besides providing satisfactory mechanical properties and renewability, natural fibers are easier to obtain and much cheaper than man-made materials. Moreover, they are more environmentally friendly. Recent research focuses on application of different types of fire retardants during the manufacturing proces s as well as applications of fire retardants (especially intumescent coatings) at the finishing stage. A good example for a very efficient phosphorus-based flame retardant system acting in the gas and condensed phases is aluminum diethyl phosphonate in conjunction with synergists such as melamine polyphosphate (MPP) and others. These phosphonates are mainly used to flame retard polyamides (PA) and polybutylene terephthalate (PBT) for flame retarded applications in electrical engineering/electronics (EE). These are well illustrated by the investigations on glass fiber reinforced polyamide 66 flames retarded with red phosphorus (PA 66-GF/Pr), which demonstrate these charming characteristics Figure 1 shows the thermal and thermo-oxidative decomposition of PA 66-GF/Pr in comparison to PA 66-GF, as well as the performance in cone calorimeter experiments. For both materials, decomposition is characterized by at least three different processes, which strongly overlap for PA 66-GF and are clearly separated for PA 66-GF/Pr. Some decomposition processes are shifted to lower temperatures so that the decomposition region is broadened. There is only a small increase in thermal stability for the final decomposition step. Thermal decomposition changes from a one-step decomposition to a two-step decomposition characteristic. In fire tests, PA 66-GF/Pr is an effective charging material, achieving a clear reduction in THE and HRR in the cone calorimeter, as well as the highest self-extinction classifi cation V-0 in the UL 94, whereas in the case of PA 66-GF all of the polymeric material is consumed so that only the glass fibers remain. Thermo-oxidative decomposition of PA 66 was concluded to occur in cone calorimeter experiments before ignition when a black skin is built up, and during afterglow after flame-out, when a further decrease in mass occurs accompanied by CO production. During the forced-flaming between ignition and flame-out, a stable flame rules out a major influence of oxygen on the decomposition during pyrolysis. The mass loss after flaming combustion and the burning time are used to estimate an average effective pyrolysis temperature. This temperature was estimated by the necessary equivalent isothermal thermos gravimetry with the same mass loss in the burning time. This is a very rough estimation, of course, since the sample in the cone calorimeter, which is characterized by a temperature profile developing over time, is described by a constant temperature independent of place and time. However, since the specimens investigated were rather thin (2.8 mm) and contained inert filler, and because the fire residue was rather homogenous, the values summarized in Table 3 reasonably estimate the effect. The pyrolysis temperature for PA 66-GF is controlled by the decomposition temperature of the polymer and remains more or less constant for all irradiations used. The calculated temperature is higher than-but still close to-the temperature characteristic for the maximum mass loss rate in thermos grav imetry, and the temperature increases slightly with increasing irradiation. The PA 66 is consumed nearly completely by the pyrolysis zone running through the sample. The approximated pyrolysis temperature of PA 66-GF/Pr is characterized by the decomposition temperature of the first decomposition step and thus crucially lower than the temperatures concluded for PA 66-GF. Summary: The development and characterization of self-healing synthetic polymeric materials have been inspired by biological systems in which damage triggers an autonomic healing response. This is an emerging and fascinating area of research that could significantly extend the working life and safety of the polymeric components for a broad range of applications The past decade has witnessed remarkable advances in stimuli-responsive shape memory polymers (SMPs) with potential applications in biomedical devices, aerospace, textiles, civil engineering, bionics engineering, energy, electronic engineering, and household products. Shape memory polymer composites (SMPCs) have further enhanced and broadened the applications of shape memory polymers. In addition to reinforcement, SMPCs can enable or enhance thermal stimuli-active effects, novel shape memory effect, and new functions. Many thermal stimuli-responsive effects have been achieved such as electroactive effect, magnetic-active effect, water- active effect, and photoactive effect. The typical examples of novel shape memory effects are multiple shape memory effect, spatially controlled shape memory effect, and two-way shape memory effects. In addition, new functions of SMPCs have been observed and systemically studied such as stimuli-memory effect and self-healing. Flame retardancy of polymeric materials is conducted to provide fire protection to flammable consumer goods, as well as to mitigate fire growth in a wide range of fires. Incorporating flame-resistant additives into polymers became a common and relatively cheap way to reduce the flammability of polymers, while synthesizing intrinsically fire-resistant polymers has remained a more expensive alternative, although the properties of these polymers are usually more efficient at deterring combustion References: Fame, Fire and Materials http://onlinelibrary.wiley.com A review of stimuli-responsive shape memory polymer composites http://www.sciencedirect.com Emerging Areas of Materials Science and Nanotechnology http://materialsscience.conferenceseries.com Schartel, Bernhard Phosphorus-based Flame Retardancy Mechanisms-Old Hat or a Starting Point for Future Development Braun, U.; Balabanovich, A.I.; Schartel, B.; Knoll, U.; Artner, J.; Ciesielski, M.; Dà ¶ring, M.; Perez, R.; Sandler, J.K.W.; et al. Influence of the Oxidation State of Phosphorus on the Decomposition and Fire Behaviour of Flame-Retarded Epoxy Resin Composites. Polymer 2006, 47, 8495-8508 Perez, R.; Sandler, J.K.W.; et al. Influence of the Oxidation State of Phosphorus on the Decomposition and Fire Behaviour of Flame-Retarded Epoxy Resin Composites. Polymer 2006, 47, 8495-8508 Zhang, H. Fire-Safe Polymers and Polymer Composites, Federal Aviation Administration technical report; U.S. Department of Transportation: Washington, D.C., 2004. Kumar, D.; Gupta, A. D.; Khullar, M. Heat-resistant thermosetting polymers based on a novel tetrakisaminophenoxycyclotriphosphazene. J. Polym. Sci. Part A: Polym. Chem. 1993, 31 (11), 2739-2745.