780 resultados para EXPLOSION


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NONEL tube finds vast applications in civil and military because of its safe and confined explosion technique. Spectroscopic and chemical analysis of a NONEL tube with an uniform mixture of HMX and Al is reported here. Peak temperature obtained at the open end of the NONEL tube due to the detonation of the explosive has been calculated using Planck’s radiation law. The products of the chemical reaction taking place due to the ignition of HMX + Al are characterized using FTIR spectroscopy.

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This paper presents a cautious argument for re-thinking both the nature and the centrality of the one-to-one teacher/student relationship in contemporary pedagogy. A case is made that learning in and for our times requires us to broaden our understanding of pedagogical relations beyond the singularity of the teacher/student binary and to promote the connected teacher as better placed to lead learning for these times. The argument proceeds in three parts: first, a characterization of our times as defined increasingly by the digital knowledge explosion of Big Data; second, a re-thinking of the nature of pedagogical relationships in the context of Big Data; and third, an account of the ways in which leaders can support their teachers to become more effective in leading learning by being more closely connected to their professional colleagues.

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The explosive sensitivity of methylammonium perchlorates has been investigated by differential thermal analysis, thermogravimetric analysis, mass spectrometry and explosion delay experiments. The decomposition temperature of these compounds increases in the order CH3NH3ClO4>(CH3)2NH2ClO4>(CH3)3NHClO4. The activation energy shows the reverse order, indicating thereby that the stability increases with increasing substitution. Mass spectrometric investigation, however, suggests an increasing reactivity with increasing substitution. A possible explanation for such behaviour is proposed. It appears that explosion delay is correlated with thermal decomposition and impact sensitivity.

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The dissertation consists of four essays and a comprehensive introduction that discusses the topics, methods, and most prominent theories of philosophical moral psychology. I distinguish three main questions: What are the essential features of moral thinking? What are the psychological conditions of moral responsibility? And finally, what are the consequences of empirical facts about human nature to normative ethics? Each of the three last articles focuses on one of these issues. The first essay and part of the introduction are dedicated to methodological questions, in particular the relationship between empirical (social) psychology and philosophy. I reject recent attempts to understand the nature of morality on the basis of empirical research. One characteristic feature of moral thinking is its practical clout: if we regard an action as morally wrong, we either refrain from doing it even against our desires and interests, or else feel shame or guilt. Moral views seem to have a conceptual connection to motivation and emotions – roughly speaking, we can’t conceive of someone genuinely disapproving an action, but nonetheless doing it without any inner motivational conflict or regret. This conceptual thesis in moral psychology is called (judgment) internalism. It implies, among other things, that psychopaths cannot make moral judgments to the extent that they are incapable of corresponding motivation and emotion, even if they might say largely the words we would expect. Is internalism true? Recently, there has been an explosion of interest in so-called experimental philosophy, which is a methodological view according to which claims about conceptual truths that appeal to our intuitions should be tested by way of surveys presented to ordinary language users. One experimental result is that the majority of people are willing to grant that psychopaths make moral judgments, which challenges internalism. In the first article, ‘The Rise and Fall of Experimental Philosophy’, I argue that these results pose no real threat to internalism, since experimental philosophy is based on a too simple conception of the relationship between language use and concepts. Only the reactions of competent users in pragmatically neutral and otherwise conducive circumstances yield evidence about conceptual truths, and such robust intuitions remain inaccessible to surveys for reasons of principle. The epistemology of folk concepts must still be based on Socratic dialogue and critical reflection, whose character and authority I discuss at the end of the paper. The internal connection between moral judgment and motivation led many metaethicists in the past century to believe along Humean lines that judgment itself consists in a pro-attitude rather than a belief. This expressivist view, as it is called these days, has far-reaching consequences in metaethics. In the second essay I argue that perhaps the most sophisticated form of contemporary expressivism, Allan Gibbard’s norm-expressivism, according to which moral judgments are decisions or contingency plans, is implausible from the perspective of the theory of action. In certain circumstances it is possible to think that something is morally required of one without deciding to do so. Morality is not a matter of the will. Instead, I sketch on the basis of Robert Brandom’s inferentialist semantics a weak form of judgment internalism, according to which the content of moral judgment is determined by a commitment to a particular kind of practical reasoning. The last two essays in the dissertation emphasize the role of mutual recognition in the development and maintenance of responsible and autonomous moral agency. I defend a compatibilist view of autonomy, according to which agents who are unable to recognize right and wrong or act accordingly are not responsible for their actions – it is not fair to praise or blame them, since they lacked the relevant capacity to do otherwise. Conversely, autonomy demands an ability to recognize reasons and act on them. But as a long tradition in German moral philosophy whose best-known contemporary representative is Axel Honneth has it, both being aware of reasons and acting on them requires also the right sort of higher-order attitudes toward the self. Without self-respect and self-confidence we remain at the mercy of external pressures, even if we have the necessary normative competence. These attitudes toward the self, in turn, are formed through mutual recognition – we value ourselves when those who we value value us. Thus, standing in the right sort of relations of recognition is indirectly necessary for autonomy and moral responsibility. Recognition and valuing are concretely manifest in actions and institutions, whose practices make possible participation on an equal footing. Seeing this opens the way for a kind of normative social criticism that is grounded in the value of freedom and automomy, but is not limited to defending negative rights. It thus offers a new way to bridge the gap between liberalism and communitarianism.

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In this paper, we consider a more realistic model of a spherical blast wave of moderate strength. An arbitrary number of terms for the series solution in each of the regions behind the main shock - the expansion region, the nearly uniform region outside the main expansion and the region between the contact surface and the main shock, have been generated and matched across the boundaries. We then study the convergence of the solution by using Pade approximation. It constitutes a genuine analytic solution for a moderately strong explosion, which, however, does not involve a secondary shock. The pressure distribution behind the shock however shows some significant changes in the location of the tail of the rarefaction and the interface, in comparison to the planar problem. The theory developed for the spherical blasts is also extended to cylindrical blasts. The results are compared with the numerical solution.

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The prognosis of patients with glioblastoma, the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation and chemotherapy.Genetic heterogeneity of glioblastoma warrants extensive studies in order to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. Serum biomarkers have the potential to revolutionize the process of cancer diagnosis, grading, prognostication and treatment response monitoring. Besides having the advantage that serum can be obtained through a less invasive procedure, it contains molecules at an extraordinary dynamic range of ten orders of magnitude in terms of their concentrations. While the conventional methods, such as 2DE, have been in use for many years, the ability to identify the proteins through mass spectrometry techniques such as MALDI-TOF led to an explosion of interest in proteomics. Relatively new high-throughput proteomics methods such as SELDI-TOF and protein microarrays are expected to hasten the process of serum biomarker discovery. This review will highlight the recent advances in the proteomics platform in discovering serum biomarkers and the current status of glioma serum markers. We aim to provide the principles and potential of the latest proteomic approaches and their applications in the biomarker discovery process. Besides providing a comprehensive list of available serum biomarkers of glioma, we will also propose how these markers will revolutionize the clinical management of glioma patients.

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The current explosion of DNA sequence information has generated increasing evidence for the claim that noncoding repetitive DNA sequences present within and around different genes could play an important role in genetic control processes, although the precise role and mechanism by which these sequences function are poorly understood. Several of the simple repetitive sequences which occur in a large number of loci throughout the human and other eukaryotic genomes satisfy the sequence criteria for forming non-B DNA structures in vitro. We have summarized some of the features of three different types of simple repeats that highlight the importance of repetitive DNA in the control of gene expression and chromatin organization. (i) (TG/CA)n repeats are widespread and conserved in many loci. These sequences are associated with nucleosomes of varying linker length and may play a role in chromatin organization. These Z-potential sequences can help absorb superhelical stress during transcription and aid in recombination. (ii) Human telomeric repeat (TTAGGG)n adopts a novel quadruplex structure and exhibits unusual chromatin organization. This unusual structural motif could explain chromosome pairing and stability. (iii) Intragenic amplification of (CTG)n/(CAG)n trinucleotide repeat, which is now known to be associated with several genetic disorders, could down-regulate gene expression in vivo. The overall implications of these findings vis-à-vis repetitive sequences in the genome are summarized.

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Social work in health care has been established for more than 100 years and is one of the largest areas of practice for social workers. Over time, demographic changes and growth in the aging population, increased longevity rates, an explosion in rates of chronic illness together with rapidly increasing cost of health care have created serious challenges for acute hospitals and health social workers. This article reviews the Australian health care system and policies with particular emphasis on the public hospital system. It then examines current hospital social work roles, including the continued role in discharge planning and expanding responsibility for emerging client problems, such as patient complexity, legal, and carer issues. The article concludes with a discussion of evolving issues and challenges facing health social work to ensure that social work remain relevant within this practice context.

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The propagation of a shock wave of finite strength due to an explosion into inhomogeneous nongravitating and self-gravitating systems has been considered, using similarity principles, supposing that the density varies as an inverse power of distance from the centre of explosion. A large number of systems, characterised by different density exponents and different adiabatic coefficients of the gas have been considered for different shock strengths. The numerical integration from the shock inward has been continued to the surface of singularity where density tends to infinity and which acts like a piston in the self-gravitating case and to the surface where the velocity gradient tends to infinity in the nongravitating case. The effect of variation of shock strength, density exponent and adiabatic coefficient on the location of these singularities and on the distribution of flow parameters behind the shock has been studied. The initial energy of the system and the manner of release of the explosion energy influence strongly the flow behind the shock. The results have been graphically depicted.

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We have found an exact similarity solution of the point explosion problem in the case when the total energy of the shock wave that is produced is not constant but decreases with time and when the loss due to radiation escape is significant. We have compared the results of our exact solution with those of exact numerical solutions of Elliot and Wang and have explained the cause why our solution differs from theirs in certain aspects.

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Ultrathin films at fluid interfaces are important not only from a fundamental point of view as 2D complex fluids but have also become increasingly relevant in the development of novel functional materials. There has been an explosion in the synthesis work in this area over the last decade, giving rise to many exotic nanostructures at fluid interfaces. However, the factors controlling particle nucleation, growth and self-assembly at interfaces are poorly understood on a quantitative level. We will outline some of the recent attempts in this direction. Some of the selected investigations examining the macroscopic mechanical properties of molecular and particulate films at fluid interfaces will be reviewed. We conclude with a discussion of the electronic properties of these films that have potential technological and biological applications.

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The hazards associated with major accident hazard (MAN) industries are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst as it has the potential to cause extensive fatalities. Qualitative and quantitative hazard analyses are essential for the identification and quantification of these hazards related to chemical industries. Fault tree analysis (FTA) is an established technique in hazard identification. This technique has the advantage of being both qualitative and quantitative, if the probabilities and frequencies of the basic events are known. This paper outlines the estimation of the probability of release of chlorine from storage and filling facility of chlor-alkali industry using FTA. An attempt has also been made to arrive at the probability of chlorine release using expert elicitation and proven fuzzy logic technique for Indian conditions. Sensitivity analysis has been done to evaluate the percentage contribution of each basic event that could lead to chlorine release. Two-dimensional fuzzy fault tree analysis (TDFFTA) has been proposed for balancing the hesitation factor involved in expert elicitation. (C) 2010 Elsevier B.V. All rights reserved.

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Tinnitus is a frequent consequence of noise trauma. Usually, however, the main focus regarding the consequences of noise trauma is placed on hearing loss, instead of tinnitus. The objectives of the present study were to assess various aspects of noise-related tinnitus in Finland, such as to determine the main causes of conscript acute acoustic traumas (AAT) in the military, assess tinnitus prevalence after noise trauma, characterize long-term AAT-related tinnitus prevalence and characteristics, assess occupational tinnitus, and evaluate the efficacy of hearing protection regulations in preventing hearing loss and tinnitus. The study comprised several independent noise-exposed groups: conscripts performing their military duty, former conscripts who suffered an AAT over a decade earlier, bomb explosion victims, and retired army personnel. Tinnitus questionnaires were used to assess tinnitus prevalence and characteristics. For occupational tinnitus, occupational noise-induced hearing loss (NIHL) reports to the Finnish Institute of Occupational Health were reviewed. Tinnitus is a common result of AAT, blast exposure and long-term noise exposure. Despite hearing protection regulations, up to hundreds of AATs occur annually among conscripts in the Finnish Defence Forces (FDF). The most common cause is an accidental shot, accounting for approximately half of the cases. Conscript AATs are mainly due to accidental shots, while the ear is unprotected. Only seldom is an AAT due to negligence. The most common causative weapon of conscript AATs is the assault rifle, accounting for 81% of conscript AATs. After AAT, the majority of tinnitus cases resolve during military service and become asymptomatic. However, in one-fifth of the cases, tinnitus persists, causing problems such as sleeping and concentration difficulties in many. In Finland, occupational tinnitus often remains unreported in conjunction with NIHL reports. In a survey of occupational NIHL cases, tinnitus was mentioned in only four per cent. However, a subsequent inquiry revealed that almost 90% in fact had tinnitus, indicating that most cases remained undetected and unreported. The best way to prevent noise-related tinnitus is prevention of noise trauma. In the military, hearing protection guidelines have been revised several times over the years. These regulations have been effective in reducing hearing loss of professional soldiers. There has also been a reduction in cases with tinnitus, but the decrease was not significant. However, with improved hearing protection regulations, a significant reduction in the risk of more serious, disturbing tinnitus was observed.

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The thermal and explosive characteristics of ring-substituted arylammonium perchlorates have been studied by differential thermal analysis, explosion delay, and impact-sensitivity measurements. The decomposition and dissociation temperatures, as well as activiation energy for explosion, increase with increasing basicity of the corresponding arylamine. These parameters, when plotted against σ, the Hammett substituent constant, show a linear relationship in the case of meta- and para-substituted derivatives. The results indicate that a proton transfer from arylammonium ion to perchlorate ion is involved in the decompostion and also in the explosion process of these arylammonium perchlorates.

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Fiber bragg grating (FBG) sensors have been widely used for number of sensing applications like temperature, pressure, acousto-ultrasonic, static and dynamic strain, refractive index change measurements and so on. Present work demonstrates the use of FBG sensors in in-situ measurement of vacuum process with simultaneous leak detection capability. Experiments were conducted in a bell jar vacuum chamber facilitated with conventional Pirani gauge for vacuum measurement. Three different experiments have been conducted to validate the performance of FBG sensor in monitoring vacuum creating process and air bleeding. The preliminary results of FBG sensors in vacuum monitoring have been compared with that of commercial Pirani gauge sensor. This novel technique offers a simple alternative to conventional method for real time monitoring of evacuation process. Proposed FBG based vacuum sensor has potential applications in vacuum systems involving hazardous environment such as chemical and gas plants, automobile industries, aeronautical establishments and leak monitoring in process industries, where the electrical or MEMS based sensors are prone to explosion and corrosion.