122 research outputs found
The Ultimate Mission to Israel: discorso pubblico e sicurezza dei militari israeliani
No full textThis article reports the participation in an eight-day military tour in Israel organized by an Israelian association in 2007. The aim is to describe the construction of the Israelian military's public discourse with regard to the history and security of the State of Israel. The author visited places of importance (museums, military bases and courts, ministries and kibbutzim), observed institutional ceremonies, and listened to the discourse of witnesses (Mossad agents, Shin Bet commanders, members of the armed forces, judges, war heroes and kibbutzniks). In particular, the politico-military construction of conflict, self-narration by various kinds of witnesses, and denial of the Palestinian enemy were examined
A Context-specific Design of an Electrosurgical Unit and Monopolar Handheld to Enhance Global Access to Surgical Care: a Design Approach Based On Contextual Factors
No full textTo comply with the large global need for surgery, surgical equipment that fits the challenging environment in low-and middle-income countries (LMICs) should be designed. The aim of this study is to present a context-specific design of an electrosurgical unit (ESU) and a monopolar handheld to improve global access to surgery. This paper presents both a detailed description of electrosurgery in clinical practice in LMICs and the design of an ESU generator and monopolar handheld for this specific setting. Extensive fieldwork (by means of surveys, interviews, observations, and collection of maintenance records) was done by authors RO, KO, and LH. Feedback from users working in Kenya on the first demonstrator designs was obtained, after which the designs were adapted into conceptual prototypes. These were further evaluated by surveying respondents who attended the annual meeting of the College of Surgeons of East, Central, and Southern Africa (COSECSA) in Kigali, Rwanda in December 2018. Conceptual prototypes were developed for (a) an affordable ESU that is compact and battery powered and (b) a robust reusable monopolar handheld that can be cleaned in the autoclave and by chemicals (e.g., glutaraldehyde solution). The conceptual prototypes were positively received by the 51 respondents of the survey. The findings from the field work and the feedback from users during the design phase have led to a clear understanding of the specific needs and potential solutions. The presented conceptual prototypes need to be further developed into functional prototypes, which could be implemented in Kenya and other settings for further evaluation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Medical Instruments & Bio-Inspired TechnologyDesign for Sustainabilit
LARGE NONRESONANT 3RD-ORDER HYPERPOLARIZABILITIES OF ORGANIC CHARGE-TRANSFER COMPLEXES
No full textLarge nonresonant third-order hyperpolarizabilities, gamma-1111, for solutions of three organic charge-transfer complexes in tetrahydrofuran have been measured. The values obtained for nonresonant gamma-1111 are 5.8 X 10(-32) esu for Perylene/tetracyanoethylene, 1.2 X 10(-32) esu for Pyrene/tetracyanoethylene, and 7.2 X 10(-33) esu for Naphthanthracene/tetracyanoethylene. The corresponding values of the third-order susceptibility chi-1111(3) for the solid state are estimated to be 1.0 X 10(-9) esu, 2.3 X 10(-10) esu, and 1.3 X 10(-10) esu, respectively.Physics, AppliedSCI(E)0ARTICLE4381-3835
Design of an electrosurgical unit for low- and middle-income countries
No full textWith the provision of essential surgical care millions of lives can be saved and this realization has reached the international agenda. There are however many obstacles that make it hard to provide safe, qualitative, affordable and accessible surgical care to the more than 4.8 billion people for whom this is currently out of reach. One of the obstacles is the lack of medical equipment that is suitable for use in the harsh environment found at the district hospitals. Problems that could be expected at the district hospital are the shortage of consumables, the lack of spare parts, the lack of a steady electricity network, financing problems and a shortage of qualified surgeons and technicians. The goal of this project is to: design a user-friendly, robust and easy to maintain electrosurgical unit that can safely be used by surgeons and clinical officers at the district hospitals in low- and middle-income countries The electrosurgical unit (ESU) is a device that can be used during many surgical procedures and it would be a welcome addition to the operating rooms (ORs) in these district hospitals. The ESU is however accompanied with its own set of problems. A problem with electrosurgery is that the underlying principles of electrosurgery are not widely known, even though it is a very common surgical technique. In addition to the lack of knowledge, there is the problem that the existing devices are very complex due to the lack of standardization in user-interface, the brand specific names for power and waveform outputs and the wide range of available instruments. To aid personnel in low- and middle- income countries (LMIC) that have limited training possibilities, the focus has been on reducing the complexity of the ESU by only providing the necessary functions on the interface. The minimum set of requirements necessary for an ESU to be safe and effective is unknown. However, data from surgeries performed at Reinier de Graaf Gasthuis (RdGG) and Leiden University Medical Center (LUMC) made it possible to get some insight in how the power settings and modes are used during surgery. It showed that surgeons are free to use the instrument, mode and power setting they prefer. No rules or strict guidelines exist on its use. At LUMC different settings were used for similar surgeries performed at RdGG, so the assumption can be made that the preference for certain power settings is hospital specific. To simplify the interface it was chosen to introduce pre-set power settings. In the new design only four different power settings can be selected that do not show its corresponding value in Watt, but an intensity level. The interface also provides the option to connect a monopolar instrument, a dispersive electrode, a bipolar instrument, a foot pedal and a choice between two coagulation modes. A questionnaire was used to determine if the users would trust the new interface design, if they perceive it as safe and to find out whether the interface has been simplified too much. Two surgeons, one resident and 13 OR assistants have filled out the questionnaire. It could be concluded that staff from RdGG had trouble trusting the new design due to the inability to set precise values. Whether this is because of the limited power settings or because they do not like to see a device they are used to change was not clear. More research is needed to identify the functions that are truly indispensable on the ESU and which ones could be eliminated in order to reduce the complexity of the ESU. To get meaningful feedback from the intended users it would be best to speak to them directly and on scene. During this project it was decided to focus on only one component of the ESU. To make the ESU more suitable for use in LMIC there should be done more research for each component separately. It should also be noted that the differences in resources and such between LMIC are enormous. If the challenges in designing an appropriate ESU have been overcome, there are still problems to expect. To be successful local support and training is needed.BioMedical Engineering, MIMSBioMechanical EngineeringMechanical, Maritime and Materials Engineerin
NONRESONANT 3RD-ORDER OPTICAL NONLINEARITY OF ALL-CARBON MOLECULES C-60
No full textThe nonresonant third-order hyperpolarizability of all-carbon molecules C60 is measured by nanosecond degenerate four-wave-mixing experiment in C60 toluene solution. The value of gamma(1111) measured is 1.6 X 10(-31) esu, which corresponds to an estimated value of the third-order nonlinear optical susceptibility chi(1111E)(3) = 3.3 X 10(-9) esu for the solid compound.Physics, AppliedSCI(E)90NOTE63025-30267
Ultrafast third-order nonlinear optical properties of graphene in aqueous solution and polyvinyl alcohol film
No full textThe ultrafast third-order nonlinear optical properties of graphene in both suspension and film status are studied using femtosecond time resolved optical Kerr gate technique at 800 nm. The third-order nonlinear optical susceptibility is 4.2 x 10(-14) esu for solution of 0.010 mg/ml. The corresponding second-order hyperpolarizability is 3.4 x 10(-32) esu per carbon atom in graphene, which is the largest among the carbon family. The graphene embed in the polymer matrix of polyvinyl alcohol film (OD = 0.43) exhibits strong ultrafast nonlinear optical response of 3.3 x 10(-12) esu and shows its potential application in non-linear optics. (C) 2011 Elsevier B.V. All rights reserved.Chemistry, PhysicalPhysics, Atomic, Molecular & ChemicalSCI(E)EI0ARTICLE104-10652
Critical Design Requirements for an Electrosurgical Unit used in Low-Middle Income Countries
No full textIntroduction: Over five billion people in mainly low and middle income countries (LMICs) do not have access to safe surgery. This is due to a lack of available and functional medical equipment, where up to 70% of the existing equipment is broken. Some reasons for this shortage in medical equipment are a lack of funding, maintenance, training, educated procurement and infrastructure. To improve access to affordable quality equipment in LMICs, the design of a low cost and high quality Electrosurgical unit (ESU) is suggested. An ESU is an essential operating tool to assist surgeons on various operations. To start the design process, critical design requirements are laid out in this paper based on the properties and thermal performance of three existing devices.Theoretical Background: Electrosurgery is used in various operations to cut and coagulate tissue through high frequency current. By changing the power intensity and waveform of the current, tissue can be heated to different levels. The coagulation of tissue occurs between 60-100°C, while vaporization occurs >100°C. Hazards in electrosurgery include current leakage and the detachment of the return electrode, which can cause burns to the user, staff or patient. Methods: The design requirements were obtained by conducting experiments and comparing three ESUs. Two of the ESUs are regarded as high-end devices, while the third, due to a low price and a simplified design, can be seen as a low-end device. Through a Property Test and a Thermal Camera Test, cut and coagulation modes were tested for each electrosurgical device at different powers and loads. For the Property Test the power, waveforms, crest factor, current and voltage at activation were measured and analysed. To understand the effects of the measured properties, a thermal camera was used to measure the heat map on tofu samples (simulating human tissue) that were exposed to currents from each of the three ESUs.Results: The actual power was measured to be lower than the set power at rated loads for all three ESUs. The wave-shape of all three devices differed considerably, producing a different thermal output on the tofu samples. All devices dropped their power with an increase in load. One ESU exceeded the 100 mA current leakage limit set by standards. In the Thermal Camera Test, high end devices produced temperature values more similar to those expected from literature. Discussion: The most important design requirements to consider include an efficient waveform design and a steady power control. With a small, light weight, and repairable hardware using sterilisable accessories, the ESU would become more transportable, robust, and independent from the manufacturer; therefore also more suitable for a LMICs. A split return electrode and low leakage are important design criteria to prevent any injury to patients and users. Improvements to the study include a wider pool of different ESUs for a better market analysis, using a camera with a higher temperature measurement than 177°C and larger tofu samples for a better thermal analyses
Small proteins: untapped area of potential biological importance
No full textPolypeptides containing ≤ 100 amino acid residues are generally considered to be small proteins. Many studies have shown that some small proteins are involved in important biological processes, including cell signaling, metabolism and growth. Small protein generally has a simple domain and has an advantage to be used as model system to overcome folding speed limits in protein folding simulation and drug design. But small proteins were once thought to be trivial molecules in biological processes compared to large proteins. Because of the constraints of experimental methods and bioinformatics analysis, many genome projects have used a length threshold of 100 amino acid residues to minimize erroneous predictions and small proteins are relatively under-represented in earlier studies. The general protein discovery methods have potential problems to predict and validate small proteins, and very few effective tools and algorithms were developed specially for small proteins identification. In this review, we mainly consider the diverse strategies applied to small proteins prediction and discuss the challenge for differentiate small protein coding genes from artifacts. We also summarize current large-scale discovery of small proteins in species at the genome level. In addition, we present an overview of small proteins with regard to biological significance, structural application and evolution characterization in an effort to gain insight into the significance of small proteins
Second harmonic generation in Langmuir-Blodgett films of an asymmetrically substituted metallophthalocyanine
No full textThe formation of Langmuir-Blodgett (LB) films of an asymmetrically substituted metallophthalocyanine, copper nitro-tri-tert-butyl-phthalocyanine, is reported. From the second-harmonic generation (SHG) measurement, macroscopic second-order susceptibility, molecular hyperpolarizability and tilt angle for the molecules on a substrate were determined to be 1.63 X 10(-5) esu, 2.11 X 10(-27) esu and 26.1 degrees, respectively. The SHG behaviour both in Z-type deposition and in alternating deposition LB films were investigated. A nearly quadratic relation between SH intensity and layer numbers was observed up to seven layers.Materials Science, MultidisciplinaryMaterials Science, Coatings & FilmsPhysics, AppliedPhysics, Condensed MatterSCI(E)17ARTICLE1-2282-28528
Формування педагогічної майстерності фахівців початкової освіти у процесі магістерської підготовки
No full textThe article raised the issue features forming constituents’ pedagogical skills of primary school teachers of the New Ukrainian School; the basic requirements, criteria and indicators of formation levels are defined; the existing gaps in working with future specialists at the present stage are highlighted.The author reveals the essence of the concept of “pedagogical skill” of the teacher, while listing its various functions and constituents, on which other scientists have paid special attention. The article emphasizes that pedagogical skill is an important condition for the professional activity of the teacher, an integral part of his professionalism and pedagogical culture. Without her, no teacher can efficiently and effectively educate, educate and develop students, and to achieve the goals put forward by her and her pupils.The author defines the main normative documents on education, which emphasize the need to revise approaches to professional training in education. A special place is given to the Concept of the New Ukrainian School, which attaches great importance to the formation of not only a student of the new millennium, but also a teacher and the very first institution. Thus, according to the conceptual provisions, the last teacher must be creative personality, ready for change, with high intelligence and morally stable, creative. This suggests the urgency of the problem of raising and developing the level of pedagogical mastery of the teacher, which should begin in the process of studying at a higher school.In the article special attention is paid to the realities of the present, the existing level of formation of the pedagogical skill of future specialists. The author conducts an experimental study, including masters to the forms and types of work, observing, questioning, and so on. Thus, the author highlights the gaps and omissions in the formation of pedagogical skills, defines the main reasons for this, outlines ways to overcome them and the main techniques and methods for improving the efficiency of the development process of masters’ pedagogical skills.The given comparative analysis allows to define the basic constituents of pedagogical skill of future teachers which have already formed during the studies in high school. However, the author notes that this issue is particularly relevant and requires further study in order to provide the educational sector with a high professional level.У статті порушено проблему особливостей формування складових компонентів педагогічної майстерності майбутніх учителів початкових класів Нової Української Школи; визначено основні вимоги, критерії та показники рівнів сформованості; виокремлено наявні прогалини у роботі з майбутніми фахівцями на сучасному етапі
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