67 research outputs found
Itai-Itai disease and the countermeasures against cadmium pollution by the Kamioka mine
No full textThe Itai-Itai disease case is one of four major pollution-related lawsuits occurring in Japan after World War H. This paper, which is based on investigations of the pollution source, the Kamioka mine, considers (1) the history of the disturbances to the environment caused by the Kamioka mine; (2) the Itai-Itai disease suit; (3) the pollution nprevention measures and methods of the Kamioka mine and refinery; (4) the reduction of cadmium pollution in the Jinzu River; and (5) the actual application of the "polluter pays principle". The authors conclude that the court decision and the agreements between the victims and Mitsui Mining made it possible to control and reduce the damage caused by cadmium pollution and four additional, contributory factors
AN EXAMINATION OF ETHICAL ISSUES CONFRONTING OPERATIONS OF SELECTED HYBRID MEDIA ORGANISATIONS IN THE DIGITAL AGE IN NAMIBIA
No full textThis qualitative study examined ethical issues confronting operations of selected hybrid
media organisations in the digital age in Namibia. It specifically used the cases of Namibia
Media Holdings and The Namibia, which are the biggest hybrid media organisations in
Namibia in terms of readership and circulation thus far. The overall research question was:
what contextual factors have shaped ethical dilemmas experienced by full-time journalists
and news editors working for the Namibia Media Holdings (NMH) and The Namibian? It
located itself with the interpretivism philosophical underpinning, in which a case study
research design was used to as it provides room for observing multiple actors within specific
contextual parameters. A total of sixteen (16) full-time employed journalists and five (5) news
editors were selected using purposive sampling technique. Qualitative data were collected
through the administration of focus group discussions and interviews. Thematic analysis was
used to analyse data, in which emerging themes were categorised, labelled and interpreted
in response to each research question. Key findings indicate that a number of contextual
factors responsible for shaping ethical dilemmas encountered by professional journalists
working for selected hybrid media organisations in the digital age in Namibia. These include:
the ever-changing technological landscape; the immediacy of internet; media sustainability;
the integration of social media platforms in the news work; the absence of specific ethical
framework for hybrid media organisations; conflicts of interest; and the notion of public
interest. It came out clear that traditional media ethics such as accuracy, truthfulness and
impartiality are still relevant to inform operations of hybrid newsrooms and are also
cornerstones without, which there is no professional journalism. In order to inform the
operations of hybrid media organisations in the digital age in Namibia, the following media
accountability ethical frameworks and policies were cited: revision of the Code of Ethics for
the Namibian Print, Broadcast and Online Media; strengthening of digital fact-checking
mechanisms; and additional journalistic training
The kids are running away. From the history of Jewish refugee children during World War II
No full text"Jeseni 1940, Recha Freier, tvorac zamisli Omladinske Alije a i organizatorka spasavanja jevrejske djece iz Njemačke mi je povjerila misiju brige za tu djecu, dok ne uspiju da odu u Palestinu. Bio sam s tom djecom gotovo pet godina i vodio ih preko tri granice, brinuo se za njih koliko se moglo brinuti u tim godinama 1941-1945. Sve te slike strahota koje su se mogle desiti, i koje su se oko nas i dešavale, sve to još živi u nama" reči su Josefa Itai-Indiga, autora ovog teksta."In the fall of 1940, Recha Freier, the creator of the idea of Youth Alia and the organizer of the rescue of Jewish children from Germany, entrusted me with the mission of caring for these children until they were able to go to Palestine. I was with these children for almost five years and led them across three borders, caring for them as much as could be cared for in those years 1941-1945. All these images of the horrors that could have happened, and which have been happening around us, are still living in us" are the words of Josef Itai-Indig, author of this text
Steering self-organisation through confinement
No full textSelf-organisation is the spontaneous emergence of spatio-temporal structures and patterns from the interaction of smaller individual units. Examples are found across many scales in very different systems and scientific disciplines, from physics, materials science and robotics to biology, geophysics and astronomy. Recent research has highlighted how self-organisation can be both mediated and controlled by confinement. Confinement is an action over a system that limits its units’ translational and rotational degrees of freedom, thus also influencing the system's phase space probability density; it can function as either a catalyst or inhibitor of self-organisation. Confinement can then become a means to actively steer the emergence or suppression of collective phenomena in space and time. Here, to provide a common framework and perspective for future research, we examine the role of confinement in the self-organisation of soft-matter systems and identify overarching scientific challenges that need to be addressed to harness its full scientific and technological potential in soft matter and related fields. By drawing analogies with other disciplines, this framework will accelerate a common deeper understanding of self-organisation and trigger the development of innovative strategies to steer it using confinement, with impact on, e.g., the design of smarter materials, tissue engineering for biomedicine and in guiding active matter.</p
A Trade-Off Analysis Between Random Noise Attenuation and Muscle State Preservation: A Simulation Study on Stretch Reflex Responses
No full textThe surface electromyographic (sEMG) signals that originate from skeletal muscle electrical activity, are used clinically and experimentally to determine muscular behaviour, e.g. amplitude, area under the curve and onset of activity. Surface EMG signals are inevitably contaminated by noise and artefacts from the site between the skin and electrodes, non-target muscles and recording hardware. After recording, signal processing methods like filtering, are used in an attempt to determine the underlying active state of the muscle, portrayed by the motoneuron pool firing. As EMG is in fact a deformed representation of the actual muscle activity, processing is used to extract a more veracious description of the active muscle states. This study investigated the effects of random noise - which in practice resembles transducer noise -, and filtering on the simulation accuracy of short and long latency muscle stretch responses, extracted from simulated EMG signals. To obtain the deviation from the noiseless signals, a fiber potential model was developed to simulate the EMG surface potentials that used an existing motoneuron pool firing model by Schuurmans et al. 2009. The resulting EMGs were the muscle responses to stretch perturbations at different velocities and amplitudes combinations (1.5, 2, 3, 5 rad/s and 0.06, 0.10, 0.14 rad). Consecutively, the EMG signals were contaminated with different noise intensities (SNR: -1, 2, 5, 7, 9 dB) and then filtered with a \nth{3} order Butterworth low-pass filter, with cut-off frequencies between [1-200Hz]. Finally, the short- and long latency stretch responses areas were calculated and compared between the filtered noiseless and filtered noisy EMG signals, by calculating the difference between the values as a fraction of the value from the noiseless simulated signal. It was found that a signal-to-noise ratio of at least 5 dB with a 85Hz cut-off low-pass filter was necessary to keep the error below 10\% maintaining M1 and M2 characteristics. It was also seen that M1 was more affected than M2 under the same amount of contamination, suggesting different spectral frequency contents between the stretch responses, and different underlying neuronal firing behaviour. The described signal-to-noise ratio thresholds and proposed cut-off frequencies resulting in acceptable signal error, can be used as a reference on accuracy of latency response simulations. The error courses provide information about the way error and signal are attenuated or preserved. Besides, the differences in error course comparing the two latency responses provides an insight into the difference in behaviour between the underlying reflex mechanisms. Apart from the findings the combination of adapted and developed model can be used in future research where noise-free surface potentials are required, and can be further developed to produce veracious EMG signals
The Effects of a Vitamin D-deficient Diet on Chronic Cadmium Exposure in Rats
No full textItai-itai disease (IID) of humans is one of the most severe forms of chronic Cadmium (Cd) intoxication occurring mainly in post-menopausal women and is characterized by osteoporosis with osteomalacia, renal tubular disorder, and renal anemia. Some researchers insist the major cause of IID is not Cd but malnutrition, especially hypovitaminosis D. We administrated a low concentration of Cd chloride intravenously to OX female rats that were fed a vitamin D deficient diet or a normal diet for 50 weeks. The vitamin D deficient diet decreased serum concentration of vitamin D, but did not affect the metabolism of the kidney or bone. Cd treatment alone induced a decrease in serum concentration of vitamin D as well as renal dysfunction, renal anemia and abnormal bone metabolism. Osteoporosis with osteomalacia, tubular nephropathy, fibrous osteodystrophy and bone marrow hyperplasia occurred following Cd treatment. In rats treated with Cd and administered a vitamin D deficient diet, the toxic effects of Cd on kidney, bone and hematopoiesis were enhanced in comparison to rats treated with the Cd and a normal diet. The present experiment demonstrated that hypovitaminosis D did not evoke morphologic features of IID in humans but did enhance the Cd-induced toxicity in the rat model of this disease
Impact of morphology and confinement effects on the properties of aligned nanofiber architectures
No full textThesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 151-168).The intrinsic and scale-dependent properties of nanofibers (NFs), nanowires, and nanotubes have made them the focus of many application-specific nanostructured materials studies. However, various NF morphology and proximity effects can lead to > 1000x reductions in the performance of NF-based material architectures, such as bulk materials and structures comprised of scalable aligned NF arrays. The physical and chemical origins of these effects, along with the concomitant structure property mechanisms of materials comprised of aligned NFs, are not currently known and cannot be properly integrated into existing theories. This originates, in part, from an incomplete understanding of the morphology of real NF systems, particularly in three-dimensions. Through experiments, theory, and multi-scale simulation, this dissertation presents a framework capable of modeling the stochastic 3D morphology of a relevant NF system, carbon nanotubes (CNTs), assembled into aligned CNT (A-CNT) arrays. New descriptions of the multi-wall A-CNT morphology demonstrate that the CNT tortuosity, quantified via sinusoidal amplitude-wavelength waviness ratio (w), decreases significantly from w ~/~ 0:2 to 0:1 as the CNT volume fraction (Vf) is increased from Vf ~ 1 to 20%. Using these new relations, a 3D stochastic morphology description is presented, and used to quantify the mechanical behavior of A-CNT arrays, A-CNT polymer matrix nanocomposites (A-PNCs), and A-CNT carbon matrix nanocomposites (A-CMNCs) via a mechanics analysis that was previously applied to carbon nanocoils. Focusing on deformations in the A-CNT axial reinforcement direction, torsion and shear deformation mechanisms, which are governed by the low ( 90% in the experimental A-CNT w regime, and are inferred to be the physical mechanisms responsible for the previously observed ~ 100x increase in the ACNT effective indentation modulus as Vf is increased from ~ 1 to 20%. In the case of A-PNCs, the polymer matrix effectively eliminates the torsion compliance contribution, so that the observed ~ 2x enhancement in the effective axial elastic modulus of A-PNCs as Vf is increased from ~ 1 to 20% is explained. The geometry of the graphitic crystallites that comprise the pyrolytic carbon (PyC) matrix of A-CMNCs is found to not evolve significantly at pyrolysis temperatures of 1000 to 1400°C, and crystallite size estimates from Raman spectroscopy reveal that the Tuinstra-Koenig correlation disagrees with the sizes measured by x-ray diffraction, suggesting a new amorphization transition crystallite size of 6 nm instead of 2-3 nm. In the case of A-CMNCs, CNT reinforcement is shown to lower the energy barrier (inferred through the pyrolysis temperature) for meso-scale self-organization of the graphitic crystallites of the PyC matrix, while having no effect on the PyC matrix on the atomic scale. Mechanical property analysis and modeling indicates that the aerospace materials selection criterion of the A-CMNCs can be enhanced to >8 GPa x (g/cm3)-2 at Vf >20% (experimentally we observe a value of ~ 5 GPa x (g/cm3)-2 at Vf ~ 10%). A-CMNCs introduced in this work have the potential to outperform state-of-the-art superhard materials, such as diamond (~/~ 7:8 GPa x (g/cm3)-2) and cubic boron nitride (~/~ 5:2 GPa x (g/cm3)-2). Using the structure-property prediction tools developed in this thesis, precise tailoring and prediction of application-specific performance of aligned NF based architectures is enabled, and specific new understanding of A-CNT systems is established. Future paths of study that enable the design and manufacture of several classes of next-generation materials are recommended.by Itai Y. Stein.Ph. D
2D model of water
No full textBoston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.2999-01-0
Memory box, an interactive teaching application for young students with Attention Deficit Hyperactivity Disorder
No full textThis thesis presents an outline and fundamental design for the development of an interactive teaching application for young students with Attention Deficit Hyperactivity Disorder or (ADHD). The project proposes a visual teaching aid used by sixth to ninth grade middle school students with Attention Deficit Hyperactivity Disorders. The author argues that the combination of various modern instructional methods, focusing on user experience and interactivity, can improve the learning experience for students with ADHD. He also argues that students can achieve higher marks and improve their overall educational experiences by adding visual and interactive elements to the written educational material. The major areas of research include: user experience, innovations in interactive technologies, and assistive teaching, with a goal of improving the way students learn by using present technologies. The information gathered from various resources on the topic will also be used to outline and structure the final product. In addition, the final product will include a written outline of the interactive teaching application and a physical functional interface. In conclusion to the research, the author further states a need for the proposed visual, interactive teaching application in traditional classrooms
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