WorldWideScience

Sample records for t-shaped isophorone derivatives

  1. Microbial transformations of isophorone by Alternaria alternata and Neurospora crassa.

    Science.gov (United States)

    Kiran, Ismail; Ozşen, Ozge; Celik, Turgay; Ilhan, Semra; Gürsu, Bükay Yenice; Demirci, Fatih

    2013-01-01

    Isophorone (3,5,5-trimethyl-2-cyclohexen-1-one), a monoterpene, and the structurally related 1,8-cineole and camphor, have demonstrated a protective effect against cancer, biological activity against a variety of microorganisms, and anti-oxidant properties. The derivatization of isophorone is, therefore, an important field of xenobiochemistry, pharmacology and toxicology. The aim of this study was to obtain derivatives of isophorone through microbial biotransformation and evaluate the biotransformation metabolites as potential antimicrobial agents. Incubation of isophorone with the fungi Alternaria alternata and Neurospora crassa afforded 4a-hydroxy- and 7-hydroxy-isophorone as transformation metabolites. The antimicrobial activities of isophorone and the metabolites were evaluated in vitro both by using agar dilution and microdilution methods. However, no significant antibacterial activity was observed when compared with those of standard substances.

  2. [Metabolic transformations of the trimethyl - 3,5,5, cyclohexene-2, one-1 (isophorone) (author's transl)].

    Science.gov (United States)

    Dutertre Catella, H; Phu Lich, N; Quoc Quan, D; Truhaut, R

    1978-07-01

    In the rabbit, isophorone alpha is partly eliminated, unchanged in the expired air and in the urine and, for another part, metabolized in the organism and excreted in the urine. The metabolites which have been characterized are : dimethyl-5,5, cyclohexen-1, one-3, carboxylic-1 acid, deriving from isophorone by methyloxidation, isophorol (trimethyl-3,5,5 cyclohexen-2, ol-1) formed by the reduction of the ketonic group into a secondary alcohol and eliminated as a glucuronide, dihydroisophorone (trimethyl-3,5,5, cyclohexanone) proceeding from the hydrogenation of the cyclohexen cycle and cis and trans trimethyl-3,5,5, cyclohexanols-1. These latter compounds, found in small quantities, are very likely issued from dihydroisophorone which is transformed in the organism into isophorone alpha and cis and trans trimethyl-3,5,5, cyclohexanols-1, according to a process of dismutation.

  3. Synthesis and characterization of isophorone diisocyanate based polyurethanes

    Science.gov (United States)

    Mirčeva, A.; Malavašič, T.; Osredkar, U.

    1990-03-01

    Polyurethane ionomers based on polycaprolactone glycol or polyoxytetramethylene glycol with isophorone diisocyanate and chain extenders 1,4-butanediol, 2,2'(dihydroxymethyl) propionic acid and in some cases water, were synthesized in solution. Stable aqueous dispersions from the ionomers were obtained when the concentration of ionic groups was at least 30 mmol per 100 g of polyurethane. Higher concentration of hard segments in the structure produced elastic and transparent films. Hard-soft segment interactions in a series of model compounds were estimated by Fourier transform infrared spectroscopy. Thermal properties of the films were determined by differential scanning calorimetry and by FTIR as well.

  4. Feasibility of using T-shaped feedback in teraohmmeters

    Science.gov (United States)

    Yermoshin, N. I.; Yakimov, E. V.

    2018-01-01

    The paper investigates the feasibility of using T-shaped feedback in teraohmmeters. Theoretical and experimental dependences of the output voltage of the T-shaped feedback converter on the measured resistance and circuit parameters are obtained. The use of T-shaped feedback is found to decrease the reference resistance rating from 10 GOhm to 100 Ohm that indicates 100-fold reduction (with an error of less than 1%).

  5. multiband millimeter wave t-shaped antenna with optimized patch

    African Journals Online (AJOL)

    Adamu Halilu

    This paper proposed a simple T-shaped patch antenna for millimeter waveband frequency operation. Millimeter wave is a frequency ranges between 30GHz to 300GHz in an electromagnetic spectrum. The proposed antenna consists of T- shape radiating patch mounted on rectangular substrate (FR4-4) and microstrip line ...

  6. T-Shaped Emitter Metal Structures for HBTs

    Science.gov (United States)

    Fung, King Man; Samoska, Lorene; Velebir, James; Muller, Richard; Echternach, Pierre; Siegel, Peter; Smith, Peter; Martin, Suzanne; Malik, Roger; Rodwell, Mark; hide

    2006-01-01

    Metal emitter structures in a class of developmental InP-based high-speed heterojunction bipolar transistors (HBTs) have been redesigned to have T-shaped cross sections. T-cross-section metal features have been widely used in Schottky diodes and high-electron-mobility transistors, but not in HBTs. As explained, the purpose served by the present T cross-sectional shapes is to increase fabrication yields beyond those achievable with the prior cross-sectional shapes.

  7. A T-shape linear piezoelectric motor with single foot.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Yang, Xiaohui; Liu, Junkao

    2015-02-01

    A new T-shape piezoelectric motor using the hybrid of two orthogonal longitudinal vibrations is proposed in this work. Six pieces of PZT ceramic plates are bonded on the upside and downside surfaces of a T-shape duralumin alloy base respectively to form the proposed motor. Elliptical movement can be generated on the driving tip by applying sine and cosine voltages to the PZT elements. The horizontal displacement of the driving tip will push the runner while the vertical displacement can overcome the preload. Finite element method is used to accomplish the design and analysis process. The resonance frequencies of the two vibration modes are tuned to be close by modal analysis, while the motion trajectory of the driving tip is observed by transient analysis. After the fabrication of a prototype, the vibration characteristics and mechanical output ability are measured. The no-load speed and the maximum output thrust force of the proposed motor are tested to be 718 mm/s and 3.5 N under an exciting frequency of 53.1 kHz. The proposed T-shape piezoelectric motor exhibits merits of simple structure, easy to realize miniaturization, easy to be fabricated, and high power-to-weight ratio. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Resonance Transport of Graphene Nanoribbon T-Shaped Junctions

    International Nuclear Information System (INIS)

    Xiao-Lan, Kong; Yong-Jian, Xiong

    2010-01-01

    We investigate the transport properties of T-shaped junctions composed of armchair graphene nanoribbons of different widths. Three types of junction geometries are considered. The junction conductance strongly depends on the atomic features of the junction geometry. When the shoulders of the junction have zigzag type edges, sharp conductance resonances usually appear in the low energy region around the Dirac point, and a conductance gap emerges. When the shoulders of the junction have armchair type edges, the conductance resonance behavior is weakened significantly, and the metal-metal-metal junction structures show semimetallic behaviors. The contact resistance also changes notably due to the various interface geometries of the junction

  9. The T-Shape dilemma in industrial engineering and management curriculum

    Directory of Open Access Journals (Sweden)

    Sigal Koral Kordova

    2014-10-01

    Full Text Available Purpose: This paper deals with the undergraduate “Industrial Engineering and Management” curriculum. The research’s purpose was to examine the in-depth coverage of teaching/learning in the combined field of industrial engineering and management, as opposed to the extent of widthwise multidisciplinary teaching/learning in this field (T-Shape dilemma. According to this purpose, the following research question was derived: With respect to widthwise multidisciplinary teaching and the depth extent of teaching in industrial engineering and management, what is the desired situation as opposed to the actual situation? Design/methodology/approach: In order to examine the T-shape dilemma, 16 in-depth interviews were conducted with senior-level managers in industry, and with leading academics in the fields of industrial engineering and management. The interviewees were asked questions regarding the planning and design of the curriculum in these fields. An analysis of the interviews was carried out by dividing the interviews into categories, and presenting the categories with the highest frequency occurring in all of the interviews. Findings and Originality/value: One of the most significant results was the great variability between the answers of senior-level managers in industry and those of the academics. While individuals in the business field (senior-level managers place great importance on focusing studies on the management-business aspect, and acquiring multidisciplinary knowledge, academics emphasized the great importance of understanding the theories and rationale behind the learned material, acquiring a strong theoretical basis, and studying the basic principles, whose implementation is then expressed in a wide diversity of applications. Research limitations/implications: Owing to time limitations, the research only included 16 in-depth interviews. In order to enlarge the external validity of this research more interviews should be executed

  10. Transient four-wave mixing in T-shaped GaAs quantum wires

    DEFF Research Database (Denmark)

    Langbein, Wolfgang Werner; Gislason, Hannes; Hvam, Jørn Märcher

    1999-01-01

    The binding energy of excitons and biexcitons and the exciton dephasing in T-shaped GaAs quantum wires is investigated by transient four-wave mixing. The T-shaped structure is fabricated by cleaved-edge overgrowth, and its geometry is engineered to optimize the one-dimensional confinement...

  11. An analytical model of a curved beam with a T shaped cross section

    Science.gov (United States)

    Hull, Andrew J.; Perez, Daniel; Cox, Donald L.

    2018-03-01

    This paper derives a comprehensive analytical dynamic model of a closed circular beam that has a T shaped cross section. The new model includes in-plane and out-of-plane vibrations derived using continuous media expressions which produces results that have a valid frequency range above those available from traditional lumped parameter models. The web is modeled using two-dimensional elasticity equations for in-plane motion and the classical flexural plate equation for out-of-plane motion. The flange is modeled using two sets of Donnell shell equations: one for the left side of the flange and one for the right side of the flange. The governing differential equations are solved with unknown wave propagation coefficients multiplied by spatial domain and time domain functions which are inserted into equilibrium and continuity equations at the intersection of the web and flange and into boundary conditions at the edges of the system resulting in 24 algebraic equations. These equations are solved to yield the wave propagation coefficients and this produces a solution to the displacement field in all three dimensions. An example problem is formulated and compared to results from finite element analysis.

  12. Excitons, Biexcitons and Dephasing in GaAs T-shaped quantum wires

    DEFF Research Database (Denmark)

    Langbein, Wolfgang; Gislason, Hannes; Hvam, Jørn Märcher

    2000-01-01

    The binding energy of excitons and biexcitons and the exciton dephasing in T-shaped GaAs quantum wires is investigated by transient four-wave mixing. The T-shaped structure is fabricated by cleaved-edge overgrowth and its geometry is engineered to optimize the one-dimensional confinement...... structures due to the different confinement of electron and hole in the T-shaped wire. A dispersion of the homogeneous linewidth within the inhomogeneous broadening due to phonon-assisted relaxation is observed. An exciton acoustic-phonon scattering coefficient of 6.1 +-0.5 ìeV/K is found, which is larger...

  13. Fully reconfigurable terahertz devices enabled by T-shaped graphene two-parallel-sheet

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Han, E-mail: hanren@my.unt.edu [Electrical Engineering Department, University of North Texas, 3940 N. Elm St., Denton, TX 76207 (United States); Ding, Jun, E-mail: stevendingjun@gmail.com [Electrical and Computer Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Arigong, Bayaner; Zhou, Mi [Electrical Engineering Department, University of North Texas, 3940 N. Elm St., Denton, TX 76207 (United States); Lin, Yuankun [Electrical Engineering Department, University of North Texas, 3940 N. Elm St., Denton, TX 76207 (United States); Physics Department, University of North Texas, Denton, TX 76203 (United States); Zhang, Hualiang, E-mail: hualiang_zhang@uml.edu [Electrical and Computer Engineering Department, University of Massachusetts Lowell, Lowell, MA 01854 (United States)

    2017-01-30

    In this letter, we investigate fully reconfigurable terahertz (THz) devices enabled by a T-shaped graphene two-parallel-sheet (GTPS). The proposed T-shaped GTPS is constructed by two series-connected GTPS sections and one shunt-connected open-ended GTPS section. By applying electrical gating to the T-shaped GTPS, both electrical length and characteristic impedance of the terahertz waveguide (i.e. T-shaped GTPS) can be fully tuned. To demonstrate the tuning feature of the T-shaped GTPS, a variety of tunable THz devices are designed based on it, including reconfigurable tunable THz transmission lines and a tunable THz coupler. The simulation results verify the large tuning range and multifunction of proposed devices. - Highlights: • Tunable terahertz devices are achieved by a T-shaped graphene two-parallel-sheet. • Electrical length and characteristic impedance of the THz waveguide can be tuned. • Waveguide can be tuned by the bias voltage on the top and bottom graphene sheets. • The simulation results verify the large tuning range and multifunction.

  14. Regulation of flow through a T-Shaped open cavity by temperature dependent P, PI, and PID controllers

    International Nuclear Information System (INIS)

    Saha, Sourav; Mojumder, Satyajit; Saha, Sumon

    2016-01-01

    P (proportional), PI (proportional-integral), and PID (proportional-integral-derivative) controllers are popular means of controlling industrial processes. Due to superior response, accuracy, and stable performance, PID controllers are mostly used in control systems. This paper presents a mathematical model and subsequent response analysis regarding regulation of flow in mixed convection through a T-shaped open cavity by temperature dependent controllers. The T-shaped cavity has cold top and hot bottom walls, while air is flowing through the inlet at surrounding temperature. The inflow is regulated by a controlled gate which operates according to the signal received from the controller. Values of proportional gain (k p ), integral gain (k i ), and derivative gain (k d ) are varied to obtain the desired system response and to ensure a stable system with fastest response. At first, only P controller is used and eventually PI and finally PID control scheme is applied for controller tuning. Tuning of different controllers (P, PI, and PID) are carried out systematically based on the reference temperature which is continuously monitored at a certain location inside the cavity. It is found that PID controller performs better than P or PI controller.

  15. Regulation of flow through a T-Shaped open cavity by temperature dependent P, PI, and PID controllers

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Sourav, E-mail: ssaha09@me.buet.ac.bd; Mojumder, Satyajit, E-mail: satyajit@me.buet.ac.bd; Saha, Sumon, E-mail: sumonsaha@me.buet.ac.bd [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh)

    2016-07-12

    P (proportional), PI (proportional-integral), and PID (proportional-integral-derivative) controllers are popular means of controlling industrial processes. Due to superior response, accuracy, and stable performance, PID controllers are mostly used in control systems. This paper presents a mathematical model and subsequent response analysis regarding regulation of flow in mixed convection through a T-shaped open cavity by temperature dependent controllers. The T-shaped cavity has cold top and hot bottom walls, while air is flowing through the inlet at surrounding temperature. The inflow is regulated by a controlled gate which operates according to the signal received from the controller. Values of proportional gain (k{sub p}), integral gain (k{sub i}), and derivative gain (k{sub d}) are varied to obtain the desired system response and to ensure a stable system with fastest response. At first, only P controller is used and eventually PI and finally PID control scheme is applied for controller tuning. Tuning of different controllers (P, PI, and PID) are carried out systematically based on the reference temperature which is continuously monitored at a certain location inside the cavity. It is found that PID controller performs better than P or PI controller.

  16. Regulation of flow through a T-Shaped open cavity by temperature dependent P, PI, and PID controllers

    Science.gov (United States)

    Saha, Sourav; Mojumder, Satyajit; Saha, Sumon

    2016-07-01

    P (proportional), PI (proportional-integral), and PID (proportional-integral-derivative) controllers are popular means of controlling industrial processes. Due to superior response, accuracy, and stable performance, PID controllers are mostly used in control systems. This paper presents a mathematical model and subsequent response analysis regarding regulation of flow in mixed convection through a T-shaped open cavity by temperature dependent controllers. The T-shaped cavity has cold top and hot bottom walls, while air is flowing through the inlet at surrounding temperature. The inflow is regulated by a controlled gate which operates according to the signal received from the controller. Values of proportional gain (kp), integral gain (ki), and derivative gain (kd) are varied to obtain the desired system response and to ensure a stable system with fastest response. At first, only P controller is used and eventually PI and finally PID control scheme is applied for controller tuning. Tuning of different controllers (P, PI, and PID) are carried out systematically based on the reference temperature which is continuously monitored at a certain location inside the cavity. It is found that PID controller performs better than P or PI controller.

  17. T-shaped competency profile for water professionals of the future

    NARCIS (Netherlands)

    Uhlenbrook, S.; De Jong, E.

    2012-01-01

    Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model

  18. Site-Selective Modification of Cellulose Nanocrystals with Isophorone Diisocyanate and Formation of Polyurethane-CNC Composites.

    Science.gov (United States)

    Girouard, Natalie M; Xu, Shanhong; Schueneman, Gregory T; Shofner, Meisha L; Meredith, J Carson

    2016-01-20

    The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and isocyanate functionality. The chemical functionality of the modified CNCs was verified with ATR-FTIR analysis and elemental analysis. The selectivity for the secondary isocyanate group using dibutyl tin dilaurate (DBTDL) as the reaction catalyst was confirmed with (13)C NMR. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs. Polyurethane composites based on IPDI and a trifunctional polyether alcohol were synthesized using unmodified (um-CNC) and modified CNCs (m-CNC). The degree of nanoparticle dispersion was qualitatively assessed with polarized optical microscopy. It was found that the modification step facilitated superior nanoparticle dispersion compared to the um-CNCs, which resulted in increases in the tensile strength and work of fracture of over 200% compared to the neat matrix without degradation of elongation at break.

  19. [Three-dimensional Finite Element Analysis to T-shaped Fracture of Pelvis in Sitting Position].

    Science.gov (United States)

    Fan, Yanping; Lei, Jianyin; Liu, Haibo; Li, Zhiqiang; Cai, Xianhua; Chen, Weiyi

    2015-10-01

    We developed a three-dimensional finite element model of the pelvis. According to Letournel methods, we established a pelvis model of T-shaped fracture with its three different fixation systems, i. e. double column reconstruction plates, anterior column plate combined with posterior column screws and anterior column plate combined with quadrilateral area screws. It was found that the pelvic model was effective and could be used to simulate the mechanical behavior of the pelvis. Three fixation systems had great therapeutic effect on the T-shaped fracture. All fixation systems could increase the stiffness of the model, decrease the stress concentration level and decrease the displacement difference along the fracture line. The quadrilateral area screws, which were drilled into cortical bone, could generate beneficial effect on the T-type fracture. Therefore, the third fixation system mentioned above (i. e. the anterior column plate combined with quadrilateral area screws) has the best biomechanical stability to the T-type fracture.

  20. Effect of Local Junction Losses in the Optimization of T-shaped Flow Channels

    Science.gov (United States)

    Kosaraju, Srinivas

    2015-11-01

    T-shaped channels are extensively used in flow distribution applications such as irrigation, chemical dispersion, gas pipelines and space heating and cooling. The geometry of T-shaped channels can be optimized to reduce the overall pressure drop in stem and branch sections. Results of such optimizations are in the form of geometric parameters such as the length and diameter ratios of the stem and branch sections. The traditional approach of this optimization accounts for the pressure drop across the stem and branch sections, however, ignores the pressure drop in the T-junction. In this paper, we conduct geometry optimization while including the effect of local junction losses in laminar flows. From the results, we are able to identify a non-dimensional parameter that can be used to predict the optimal geometric configurations. This parameter can also be used to identify the conditions in which the local junction losses can be ignored during the optimization.

  1. Biomechanical Analysis of the Fixation System for T-Shaped Acetabular Fracture

    Directory of Open Access Journals (Sweden)

    Yanping Fan

    2015-01-01

    Full Text Available This study aims to evaluate the biomechanical mechanism of fixation systems in the most frequent T-shaped acetabular fracture using finite element method. The treatment of acetabular fractures was based on extensive clinical experience. Three commonly accepted rigid fixation methods (double column reconstruction plates (P × 2, anterior column plate combined with posterior column screws (P + PS, and anterior column plate combined with quadrilateral area screws (P + QS were chosen for evaluation. On the basis of the finite element model, the biomechanics of these fixation systems were assessed through effective stiffness levels, stress distributions, force transfers, and displacements along the fracture lines. All three fixation systems can be used to obtain effective functional outcomes. The third fixation system (P + QS was the optimal method for T-shaped acetabular fracture. This fixation system may reduce many of the risks and limitations associated with other fixation systems.

  2. Control of single-photon routing in a T-shaped waveguide by another atom

    Science.gov (United States)

    Huang, Jin-Song; Wang, Jing-Wen; Wang, Yan; Li, Yan-Ling; Huang, You-Wen

    2018-04-01

    Quantum routers with a high routing rate of much more than 0.5 are of great importance for quantum networks. We provide a scheme to perform bidirectional high routing-rate transfer in a T-shaped coupled-resonator waveguide (CRW), which extends a recent unidirectional scheme proposed by Lu et al. (Opt Express 23:22955, 2015). By locating an extra two-level atom in the infinite CRW channel of the T-shaped CRW with a three-level system, an effective potential is generated. Our numerical results show that high routing capability from the infinite CRW channel to the semi-infinite channel can be achieved, and routing capability from the semi-infinite CRW channel to the infinite channel can also be significantly enhanced, with the help of the effective potential. Therefore, the proposed double-atom configuration could be utilized as a bidirectional quantum routing controller to implement high transfer rate routing of single photons.

  3. Fano interferences in the transport properties of triple quantum dot T-shaped systems

    International Nuclear Information System (INIS)

    Tifrea, I; Crisan, M; Grosu, I

    2009-01-01

    We consider the transport and the noise characteristic in the case of a triple quantum dots T-shaped system where two of the dots form a two-level system and the other works in a detector-like setup. Our theoretical results are obtained using the equation of motion method for the case of zero on-site Coulomb interaction in the detector dot. The transport trough the T-shaped system can be controlled by varying the coupling between the two-level system dots or the coupling between the detector dot and the exterior electrodes. The Fano dips in the system's conductance can be observe both for strong (fast detector) and weak coupling (slow detector) between the detector dot and the external electrodes. Due to stronger electronic correlations the noise in the case of a slow detector are much higher. This setup may be of interest for the practical realization of qubit states in quantum dots systems.

  4. T-shaped competency profile for water professionals of the future

    Directory of Open Access Journals (Sweden)

    S. Uhlenbrook

    2012-10-01

    Full Text Available Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field (i.e. hydrology; vertical leg of the T, and other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc. and functional, personal and values competencies and meta-competencies (all summarized in the horizontal bar of the T. It is based on the holistic model of professional competencies by Cheetham and Chivers (1996 and related studies (Oskam, 2009. The T-shape profile should apply to all levels of higher education (1st degree till doctorate level in hydrology and related fields. For the effectiveness of hydrologists as professionals, a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (lifelong learning, and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  5. A three-dimensional model for T-shaped acoustic resonators with sound absorption materials.

    Science.gov (United States)

    Yu, Ganghua; Cheng, Li; Li, Deyu

    2011-05-01

    Recent development in noise control using T-shaped acoustic resonators calls for the development of more reliable and accurate models to predict their acoustic characteristics, which is unfortunately lacking in the literature. This paper attempts to establish such a model based on three-dimensional theory for T-shaped acoustic resonators containing sound absorption materials. The model is validated by experiments using various configurations. Predictions on fundamental and high-order resonance frequencies are compared with those obtained from the one-dimensional model and finite element analyses, and the effects of the physical and geometric parameters of the absorption materials on the resonance frequencies and Q-factor are also investigated numerically and experimentally. Limitations and applicability of existing one-dimensional models are assessed. The proposed general three-dimensional model proved to be able to provide an accurate and reliable prediction on the resonance frequencies for T-shaped acoustic resonators with or without absorption materials. This can eventually meet the requirement for resonator array design in terms of accuracy.

  6. Research on a Linear Piezoelectric Actuator Using T-Shape Transducer to Realize High Mechanical Output

    Directory of Open Access Journals (Sweden)

    Sijia Shao

    2016-04-01

    Full Text Available A modified large thrust ultrasonic linear motor using a T-shape configuration composed of two orthogonal sandwich-type transducers has been proposed in this paper. It is an improved version of a previous T-shape motor. The vertical transducer is used to generate the normal force between the driving foot and slider, while the other push-pull–type horizontal transducer is applied to generate driving force to push the working platform. By superimposing the two longitudinal vibrations, the proposed motor generates an elliptical movement on the driving foot. In order to improve the vibration characteristics and amplify the driving vibration amplitude, the shape of the driving foot and horn have been redesigned and optimized. The finite element method (FEM is used to adjust the structural parameters to degenerate the two working mode frequencies. The prototype has been fabricated and its mechanical output ability has been measured. The output characteristics of the modified motor, compared with the previous T-shape motor, achieve a relatively high level. The typical no-load speed and maximum output thrust of the prototype are 0.83 m/s and 56 N under an exciting voltage of 150 Vrms.

  7. T-shaped competency profile for water professionals of the future

    Science.gov (United States)

    Uhlenbrook, S.; de Jong, E.

    2012-03-01

    Global environmental changes expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field, (i.e. hydrology; vertical leg of the T) other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc.) and functional, personal and values competencies and meta-competencies (horizontal bar of the T). It is based on the holistic model of professional competencies by Cheetham and Chivers (1996) and related studies (Oskam, 2009). The T-shape profile should apply to all levels of higher education (1st degree till doctorate level) in hydrology and related fields. For the effectiveness of hydrologists as professionals a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (life long learning), and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  8. T-shaped competency profile for water professionals of the future

    Science.gov (United States)

    Uhlenbrook, S.; de Jong, E.

    2012-10-01

    Global environmental changes introduce new challenges and expose future university graduates in hydrology and related fields to problems of unprecedented complexity and magnitude. The T-shape model is proposed as a generic competency profile guiding the design of university curricula. This model differentiates between cognitive competencies in a certain field (i.e. hydrology; vertical leg of the T), and other cognitive/knowledge competencies in neighboring fields (e.g. hydraulics, aquatic ecology, land use management etc.) and functional, personal and values competencies and meta-competencies (all summarized in the horizontal bar of the T). It is based on the holistic model of professional competencies by Cheetham and Chivers (1996) and related studies (Oskam, 2009). The T-shape profile should apply to all levels of higher education (1st degree till doctorate level) in hydrology and related fields. For the effectiveness of hydrologists as professionals, a variable mix of competencies is required and further discussed. Key aspects are an open attitude for learning, continuous professional development (lifelong learning), and integrative and team working skills. Furthermore, a stimulating learning environment that promotes active learning is essential. As examples that substantiate the proposed T-shape model, the post-graduate education programmes of UNESCO-IHE and the main outcomes from a university curriculum workshop to promote education for sustainable development are introduced.

  9. Enantioselection on Heterogeneous Noble Metal Catalyst: Proline-Induced Asymmetry in the Hydrogenation of Isophorone on Pd Catalyst.

    Science.gov (United States)

    Rodríguez-García, Laura; Hungerbühler, Konrad; Baiker, Alfons; Meemken, Fabian

    2015-09-23

    In the (S)-proline-mediated asymmetric hydrogenation of isophorone (IP) on supported Pd catalyst, excellent enantioselectivity is achieved, with an enantiomeric excess of up to 99%. The role of the heterogeneous catalyst has been the subject of a controversial debate, and the current mechanistic understanding cannot explain the observed enantioselectivity of this catalytic system. The lack of in situ information about the role of the heterogeneous catalyst has prompted us to investigate the surface processes occurring at the methanol-Pd catalyst interface using attenuated total reflection infrared spectroscopy. Time-resolved monitoring of the homogeneous solution and of the catalytic solid-liquid interface coupled with catalytic data provides crucial information on the catalytically relevant enantiodifferentiating processes. While the condensation of IP and the corresponding chiral product 3,3,5-trimethylcyclohexanone with the chiral amine is connected to the enantiodifferentiation, it was found that the crucial enantioselectivity-controlling steps take place on the metal surface, and the reaction has to be classified as heterogeneous asymmetric hydrogenation. The presented spectroscopic and catalytic results provide strong evidence for the existence of two competing enantioselective processes leading to opposing enantioselection. Depending on surface coverage of the Pd catalyst, the reaction is controlled either by kinetic resolution ((S)-pathway) or by chiral catalysis ((R)-pathway). Steering the hydrogenation on the (R)-reaction pathway requires sufficient concentration of IP-(S)-proline condensate, as this chiral reactive intermediate becomes the most abundant surface species, inhibiting the competing kinetic resolution. The unraveled (R)-reaction pathway emphasizes an intriguing strategy for inducing chirality in heterogeneous asymmetric catalysis.

  10. Density effect on the mixing efficiency and flow modes in T-shaped micromixers

    Directory of Open Access Journals (Sweden)

    Lobasov Alexander

    2017-01-01

    Full Text Available Flow patterns and mixing of liquids with different densities in T-shaped micromixers are numerically investigated at Reynolds number range from 1 to 250. The density ratio of the mixing media varies from 1 to 2; its effect on the flow structure and the mixing is studied. The dependences of the mixing efficiency and the pressure difference in this mixer on the density ratio and the Reynolds number are obtained. It is shown that the density ratio has a considerable effect on the flow structure, especially before the transition from the symmetric to the asymmetric flow pattern.

  11. T-shaped Pectoralis Major Musculocutaneous Flap for Reconstruction of an Extensive Circumferential Pharyngeal Defect

    Directory of Open Access Journals (Sweden)

    Shimpei Miyamoto, MD

    2014-04-01

    Full Text Available Summary: In the era of free-flap transfer, the pectoralis major musculocutaneous flap still plays a unique role in head and neck reconstruction. We report on a patient with a recurrent hypopharyngeal carcinoma after total pharyngolaryngectomy and adjuvant chemoradiotherapy in whom defects included a circumferential defect of the oropharynx and the entire tongue. The defects were successfully reconstructed with a T-shaped pectoralis major musculocutaneous flap whose skin island included multiple intercostal perforators from the internal mammary vessels. This flap design is effective for reconstructing circumferential pharyngeal defects in vessel-depleted neck.

  12. Thermal mixing of two miscible fluids in a T-shaped microchannel.

    Science.gov (United States)

    Xu, Bin; Wong, Teck Neng; Nguyen, Nam-Trung; Che, Zhizhao; Chai, John Chee Kiong

    2010-10-01

    In this paper, thermal mixing characteristics of two miscible fluids in a T-shaped microchannel are investigated theoretically, experimentally, and numerically. Thermal mixing processes in a T-shaped microchannel are divided into two zones, consisting of a T-junction and a mixing channel. An analytical two-dimensional model was first built to describe the heat transfer processes in the mixing channel. In the experiments, de-ionized water was employed as the working fluid. Laser induced fluorescence method was used to measure the fluid temperature field in the microchannel. Different combinations of flow rate ratios were studied to investigate the thermal mixing characteristics in the microchannel. At the T-junction, thermal diffusion is found to be dominant in this area due to the striation in the temperature contours. In the mixing channel, heat transfer processes are found to be controlled by thermal diffusion and convection. Measured temperature profiles at the T-junction and mixing channel are compared with analytical model and numerical simulation, respectively.

  13. Study of droplet flow in a T-shape microchannel with bottom wall fluctuation

    Science.gov (United States)

    Pang, Yan; Wang, Xiang; Liu, Zhaomiao

    2018-03-01

    Droplet generation in a T-shape microchannel, with a main channel width of 50 μm , side channel width of 25 μm, and height of 50 μm, is simulated to study the effects of the forced fluctuation of the bottom wall. The periodic fluctuations of the bottom wall are applied on the near junction part of the main channel in the T-shape microchannel. Effects of bottom wall's shape, fluctuation periods, and amplitudes on the droplet generation are covered in the research of this protocol. In the simulation, the average size is affected a little by the fluctuations, but significantly by the fixed shape of the deformed bottom wall, while the droplet size range is expanded by the fluctuations under most of the conditions. Droplet sizes are distributed in a periodic pattern with small amplitude along the relative time when the fluctuation is forced on the bottom wall near the T-junction, while the droplet emerging frequency is not varied by the fluctuation. The droplet velocity is varied by the bottom wall motion, especially under the shorter period and the larger amplitude. When the fluctuation period is similar to the droplet emerging period, the droplet size is as stable as the non-fluctuation case after a development stage at the beginning of flow, while the droplet velocity is varied by the moving wall with the scope up to 80% of the average velocity under the conditions of this investigation.

  14. Fano effect and Andreev bound states in T-shape double quantum dots

    International Nuclear Information System (INIS)

    Calle, A.M.; Pacheco, M.; Orellana, P.A.

    2013-01-01

    In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling

  15. Confocal micro-PIV measurement of droplet formation in a T-shaped micro-junction

    International Nuclear Information System (INIS)

    Oishi, M; Kinoshita, H; Fujii, T; Oshima, M

    2009-01-01

    This paper aims to investigate a mechanism of microdroplet formation using 'multicolor confocal micro particle image velocimetry (PIV)' technique. The present system can measure dynamical behavior of multiphase flow separately and simultaneously. It also enables to identify the interactions between two immiscible fluids. We have applied this system to measure the water droplet formation at a micro T-shaped junction. We have also succeeded in dispersing fluorescent tracer particles into both phases. The interaction between the internal flow of to-be-dispersed water phase and of continuous oil phase is measured as a liquid-liquid multiphase flow. As a result of PIV measurement and interface scanning, the relationship between flow structure of each phase and interface shape is clarified. It indicates that the gap between the tip of to-be-dispersed phase and capillary wall, and interface area play an important role in the flow structure and shear stress on the interface.

  16. The Utility of a Three-Dimensional Approach with T-Shaped Osteotomy in Osseous Genioplasty

    Directory of Open Access Journals (Sweden)

    Jung Jae Jegal

    2013-07-01

    Full Text Available BackgroundFacial beauty depends on the form, proportion, and position of various units of the face. In terms of the frontal view and facial profile, the chin is the most prominent aesthetic element of the lower third of the face. Many methods have been implemented to obtain good proportions of the lower face. In this study, we applied the T-shaped genioplasty method to correcting chin deformities.MethodsAll of the procedures in 9 cases were performed under general anesthesia. For genioplasty, a horizontal cutting line and 1 or 2 vertical cutting lines were drawn 5 mm below the mental foramen. Osteotomed bone segments of the chin were used for horizontal widening using bone grafts or for horizontal shortening. Likewise, they were used as bone grafts for vertical lengthening or vertical shortening. The bone segments were approximated in the midline and held in place using miniplates.ResultsThe postoperative appearance of the 9 cases showed that the lower third of the face had been naturally changed. At the same time, vertical lengthening or shortening, and horizontal widening or shortening could be implemented during the operation. Satisfactory results were obtained based on reviews of the patients' preoperative and postoperative photographs. The patients were also satisfied with the outcomes.ConclusionsUsing T-shaped genioplasty, we efficiently adjusted the shape and position of the chin to obtain good proportions of the lower face and change its contour to obtain an aesthetically appealing oval face in accordance with East Asians' aesthetic preferences.

  17. Impact of T-shaped skill and top management support on innovation speed; the moderating role of technology uncertainty

    Directory of Open Access Journals (Sweden)

    Shabnam Hamdi

    2016-12-01

    Full Text Available This study examines the moderating role of technology uncertainty on the relationship between team contextual factors of top management support and T-shaped skills with innovation speed. For the purpose of this study, the data were collected from 227 new products from 147 biotechnology firms in Malaysia. The overall results confirmed the moderating effect of technology uncertainty on the relationship between T-shaped skills, as well as top management support with innovation speed. The results further confirmed that under the high technology uncertainty, this effect is higher in comparison to the low and medium uncertainty. This indicates that the effect of top management support and T-shaped skills on innovation speed improves when technology uncertainty increases. On the practical side, the report equips biotech firms with valuable insights to develop effective strategies.

  18. Investigation of high frequency external perturbation effects on flow in a T-shape microchannel by μLIF technique

    Science.gov (United States)

    Kravtsova, A. Yu; Meshalkin, Yu E.; Bilsky, A. V.

    2017-11-01

    Investigation of high frequency external perturbation effect on flow inside T-shape microchannel was examined. In-phase pulsations of different frequencies were added to both inlets of the T-shaped microchannel to study mixing by means of Micro Laser Induced Fluorescence (μLIF) technique. For all flow regimes studied, mixing enhancement was obtained. Significant enhancement can be achieved at the beginning of the outlet channel operating in steady asymmetric regime (Re=186) by forcing at certain frequency ranges (f = 500Hz, f = 800Hz). Mixing suppression was also observed for two flow regimes (Re = 400, f = 1000Hz) and (Re = 120, f = 700Hz).

  19. Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

    Science.gov (United States)

    Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

    2016-03-01

    Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

  20. Traumatic Testicular Dislocation Associated with Lateral Compression Pelvic Ring Injury and T-Shaped Acetabulum Fracture

    Directory of Open Access Journals (Sweden)

    Daniel Howard Wiznia

    2016-01-01

    Full Text Available We report a case of a unilateral testicular dislocation to the superficial inguinal region associated with a lateral compression type pelvic ring injury (OTA classification 61-C3.3a2, b2, c3 and left T-shaped acetabulum fracture (OTA classification 62-B2 in a 44-year-old male who was in a motorcycle accident. The testicular dislocation was noted during the emergency department primary survey, and its location and viability were verified with ultrasound. The testicle was isolated during surgical stabilization of the left acetabulum through a Pfannenstiel incision and modified-Stoppa approach and returned through the inguinal canal to the scrotum. In follow-up, the patient did not suffer urologic or sexual dysfunction. All motorcycle collision patients presenting with pelvic ring injuries or acetabulum fractures should be worked up for possible testicular dislocation with a scrotal exam. Advanced imaging and a urologic consult may be necessary to detect and treat these injuries.

  1. A compact T-shaped nanodevice for charge sensing of a tunable double quantum dot in scalable silicon technology

    International Nuclear Information System (INIS)

    Tagliaferri, M.L.V.; Crippa, A.; De Michielis, M.; Mazzeo, G.; Fanciulli, M.; Prati, E.

    2016-01-01

    We report on the fabrication and the characterization of a tunable complementary-metal oxide semiconductor (CMOS) system consisting of two quantum dots and a MOS single electron transistor (MOSSET) charge sensor. By exploiting a compact T-shaped design and few gates fabricated by electron beam lithography, the MOSSET senses the charge state of either a single or double quantum dot at 4.2 K. The CMOS compatible fabrication process, the simplified control over the number of quantum dots and the scalable geometry make such architecture exploitable for large scale fabrication of multiple spin-based qubits in circuital quantum information processing. - Highlights: • Charge sensing of tunable, by position and number, quantum dots is demonstrated. • A compact T-shaped design with five gates at a single metalization level is proposed. • The electrometer is a silicon-etched nanowire acting as a disorder tolerant MOSSET.

  2. A compact T-shaped nanodevice for charge sensing of a tunable double quantum dot in scalable silicon technology

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferri, M.L.V., E-mail: marco.tagliaferri@mdm.imm.cnr.it [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); Crippa, A. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); De Michielis, M. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Mazzeo, G.; Fanciulli, M. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); Prati, E. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2016-03-11

    We report on the fabrication and the characterization of a tunable complementary-metal oxide semiconductor (CMOS) system consisting of two quantum dots and a MOS single electron transistor (MOSSET) charge sensor. By exploiting a compact T-shaped design and few gates fabricated by electron beam lithography, the MOSSET senses the charge state of either a single or double quantum dot at 4.2 K. The CMOS compatible fabrication process, the simplified control over the number of quantum dots and the scalable geometry make such architecture exploitable for large scale fabrication of multiple spin-based qubits in circuital quantum information processing. - Highlights: • Charge sensing of tunable, by position and number, quantum dots is demonstrated. • A compact T-shaped design with five gates at a single metalization level is proposed. • The electrometer is a silicon-etched nanowire acting as a disorder tolerant MOSSET.

  3. Experimental study of ionic liquid-water flow in T-shaped microchannels with different aspect ratios

    Science.gov (United States)

    Yagodnitsyna, A. A.; Kovalev, A. V.; Bilsky, A. V.

    2017-09-01

    Flow regimes of immiscible ionic liquid - water flow in T-shaped microchannels with 160 um hydraulic diameter and 1:2 and 1:4 aspect ratios are experimentally studied in the present work. Plug length and velocity were measured using high-speed visualization of the flow. Flow pattern maps were drawn for two channels. Parallel flow was shown to prevail for 1:4 aspect ratio channel in comparison to 1:2.

  4. Design of High Performance Si/SiGe Heterojunction Tunneling FETs with a T-Shaped Gate

    Science.gov (United States)

    Li, Wei; Liu, Hongxia; Wang, Shulong; Chen, Shupeng; Yang, Zhaonian

    2017-03-01

    In this paper, a new Si/SiGe heterojunction tunneling field-effect transistor with a T-shaped gate (HTG-TFET) is proposed and investigated by Silvaco-Atlas simulation. The two source regions of the HTG-TFET are placed on both sides of the gate to increase the tunneling area. The T-shaped gate is designed to overlap with N+ pockets in both the lateral and vertical directions, which increases the electric field and tunneling rate at the top of tunneling junctions. Moreover, using SiGe in the pocket regions leads to the smaller tunneling distance. Therefore, the proposed HTG-TFET can obtain the higher on-state current. The simulation results show that on-state current of HTG-TFET is increased by one order of magnitude compared with that of the silicon-based counterparts. The average subthreshold swing (SS) of HTG-TFET is 44.64 mV/dec when V g is varied from 0.1 to 0.4 V, and the point SS is 36.59 mV/dec at V g = 0.2 V. Besides, this design cannot bring the sever Miller capacitance for the TFET circuit design. By using the T-shaped gate and SiGe pocket regions, the overall performance of the TFET is optimized.

  5. Synthesis and luminescent properties of a novel green-emitting Tb (Ⅲ) complex based on amino-modified fluorine silicone oil and isophorone diisocyanate

    Science.gov (United States)

    Hao, Haixia; Chu, Yang; Yu, Zhenjiang; Xie, Hongde; Seo, Hyo Jin

    2017-10-01

    The novel luminescent polymer-rare earth complexes, denoted as (PFSi-IPDI)-Tb(Ⅲ)-Phen, have been successfully synthesized and can be made into flexible films. Amino-modified fluorine silicone oil-isophorone diisocyanate (PFSi-IPDI) was used as the host macromolecular ligand, and 1, 10-Phenanthroline (Phen) as the secondary small-molecular co-ligand. The luminescent lanthanide complexes were characterized by fourier transform infrared (FITR), scanning electron microscope (SEM), thermogravimetric analysis (TGA). The luminescent properties were investigated through photoluminescence excitation (PLE) and emission (PL) spectroscopy. FTIR analysis verifies the successful preparation and integration of PFSi-IPDI to Tb3+. The comparatively uniform morphological structure can be observed in the images of SEM. The polymer-rare earth complexes display the typical luminescence emission peaks under the excitation wavelength of 330 nm. From the decay curve, the short lifetime (about 0.89 ms) is observed for (PFSi-IPDI)-Tb(Ⅲ)-Phen (0.6 mol/L). Moreover, these luminescent polymer-rare earth complexes possess superior thermal stability (T5 > 195 °C). All the interesting results suggest the potential application of the luminescent polymer-rare earth complexes in green-emitting luminescent materials under high temperature.

  6. Enhancement of the thermoelectric efficiency in a T-shaped quantum dot system in the linear and nonlinear regimes

    Science.gov (United States)

    Gómez-Silva, G.; Orellana, P. A.; Anda, E. V.

    2018-02-01

    In the present work, we investigate the thermoelectric properties of a T-shaped double quantum dot system coupled to two metallic leads incorporating the intra-dot Coulomb interaction. We explore the role of the interference effects and Coulomb blockade on the thermoelectric efficiency of the system in the linear and nonlinear regimes. We studied as well the effect of a Van-Hove singularity of the leads density of states (DOS) at the neighborhood of the Fermi energy, a situation that can be obtained using a carbon nanotube, a graphene nano-ribbon or other contacts with one-dimensional properties. The system is studied above the Kondo temperature. The Coulomb blockade of the electronic charges is studied using the Hubbard III approximation, which properly describes the transport properties of this regime. In the linear response, our results show an enhancement of the thermopower and the figure of merit of the system. For a nonlinear situation, we calculate the thermoelectric efficiency and power output, concluding that the T-shaped double quantum dot is an efficient thermoelectric device. Moreover, we demonstrate the great importance of the DOS Van-Hove singularity at the neighborhood of the Fermi energy to obtain a very significant increase in the thermoelectric efficiency of the system.

  7. Effect of uniaxial strain on the tunnel magnetoresistance of T-shaped graphene nanoribbon based spin-valve

    Science.gov (United States)

    Fouladi, A. Ahmadi

    2016-07-01

    We theoretically investigated the spin-dependent transport through a T-shaped graphene nanoribbon (TsGNR) based spin-valve consisting of armchair graphene sandwiched between two semi-infinite ferromagnetic armchair graphene nanoribbon leads in the presence of an applied uniaxial strain. Based on a tight-binding model and standard nonequilibrium Green's function technique, it is demonstrated that the tunnel magnetoresistance (TMR) for the system can be increased about 98% by tuning the uniaxial strain. Our results show that the absolute values of TMR around the zero bias voltage for compressive strain are larger than tensile strain. In addition, the TMR of the system can be nicely controlled by GNR width.

  8. Design Oriented Model for the Assessment of T-Shaped Beam-Column Joints in Reinforced Concrete Frames

    Directory of Open Access Journals (Sweden)

    Antonio Bossio

    2017-12-01

    Full Text Available Beam-column joints represent very important elements of reinforced concrete (RC structures. In fact, beams and columns, at the boundary, generate internal forces acting on concrete core and on reinforcement bars with a very high gradient. To fully understand the seismic performances and the failure modes of T-shaped beam-column joints (external corner-positioned in RC structures, a simplified analytical model of joint behaviour is proposed and theoretical simulations have been performed. The model is based on the solution of a system of equilibrium equations of cracked joint portions designed to evaluate internal stresses at different values of column shear forces. The main aim of the proposed model is to identify the strength hierarchy. Limit values of different internal stresses allow us to detect the occurrence of different failure modes (namely the failure of the cracked joint, the bond failure of passing through bars, and the flexural/shear failures of columns or beams associated with column shear forces; the smaller one represents the capacity of the joint. The present work, focusing on T-shaped joints, could represent a useful tool for designers to quantify the performance of new structures or of existing ones. In fact, such a tool allows us to push an initial undesired failure mode to a more appropriate one to be evaluated. Finally, some experimental results of tests available in literature are reported, analysed, and compared to the predictions of the proposed model (by means of a worked example and of some international codes. The outcomes confirm that failure modes and corresponding joint capacities require an analytical model, like the proposed one, to be accurately predicted.

  9. Photoactive layer based on T-shaped benzimidazole dyes used for solar cell: from photoelectric properties to molecular design

    Science.gov (United States)

    Xu, Beibei; Li, Yuanzuo; Song, Peng; Ma, Fengcai; Sun, Mengtao

    2017-03-01

    Three benzimidazole-based organic dyes, possessing the same triphenylamine donors and cyanoacrylic acid acceptors with the bithiophene π-bridges combined in different nuclear positions of benzimidazole, were investigated in the utility of dye-sensitizer solar cells. The structure, molecular orbital and energy, absorption spectra and some important parameters (such as light harvesting efficiency (LHE), electron injection driving force, the electron injection time, chemical reactivity parameters, vertical dipole moment as well as interaction models of dye-I2) were obtained according to Newns-Anderson model and DFT calculation. The process and strength of charge transfer and separation were visualized with charge different density and index of spatial extent (S, D and Δq). Current work paid attention to the new T-shaped dyes to reveal the relation between the structure and photoelectric performance. Furthermore, nine dyes (substitution of alkyl chains and π-bridges) have been designed and characterized to screen promising sensitizer candidates with excellent photo-electronic properties.

  10. A PLIC-VOF-Based Simulation of Water-Organic Slug Flow Characteristics in a T-Shaped Microchannel

    Directory of Open Access Journals (Sweden)

    Xian Wang

    2013-01-01

    Full Text Available A water-organic slug flow in a T-shaped microchannel was numerically studied due to its importance in the microreactor system. Various factors affecting the flow mode were studied, for example, channel width, fluid viscosity, interfacial tension, and inlet velocity. The volume of fluid (VOF method was used to track the liquid-liquid interface, and the piecewise-liner interface construction (PLIC technique was adopted to get a sharp interface. The interfacial tension was simulated with continuum surface force (CSF, model and the wall adhesion boundary condition was taken into consideration. The results show that strong vortexes appear in both phases at the meeting sites of main and lateral channels where an organic slug is producing. Inlet velocity influences the slug length and flow mode greatly. The ratio between the slug lengths of two phases in the main channel is almost equal to the ratio between their inlet velocities. If the slug is produced, the interfacial tension and organic viscosity have less effect on the slug length for 200 μm microchannel. The slug producing rate is much higher in a narrow channel than that in a wide channel.

  11. A T-shaped double quantum dot system as a Fano interferometer: Interplay of coherence and correlation upon spin currents

    Science.gov (United States)

    Fernandes, I. L.; Cabrera, G. G.

    2018-05-01

    Based on Keldysh non-equilibrium Green function method, we have investigated spin current production in a hybrid T-shaped device, consisting of a central quantum dot connected to the leads and a side dot which only couples to the central dot. The topology of this structure allows for quantum interference of the different paths that go across the device, yielding Fano resonances in the spin dependent transport properties. Correlation effects are taken into account at the central dot and handled within a mean field approximation. Its interplay with the Fano effect is analyzed in the strong coupling regime. Non-vanishing spin currents are only obtained when the leads are ferromagnetic, the current being strongly dependent on the relative orientation of the lead polarizations. We calculate the conductance (spin and charge) by numerically differentiating the current, and a rich structure is obtained as a manifestation of quantum coherence and correlation effects. Increase of the Coulomb interaction produces localization of states at the side dot, largely suppressing Fano resonances. The interaction is also responsible for the negative values of the spin conductance in some regions of the voltage near resonances, effect which is the spin analog of the Esaki tunnel diode. We also analyze control of the currents via gate voltages applied to the dots, possibility which is interesting for practical operations.

  12. Creating a Minor in Applied Data Science: Case Western Reserve University Engages Business Leaders to Produce T-Shaped Professionals. A BHEF Case Study

    Science.gov (United States)

    Business-Higher Education Forum, 2016

    2016-01-01

    This case study examines how Business-Higher Education Forum (BHEF) member Case Western Reserve University is integrating T-shaped skills into a minor in applied data science. Through the collaboration of its business and higher education members, BHEF launched the National Higher Education and Workforce Initiative to create new undergraduate…

  13. Assessment of T-shape double fascia graft for lower lip deformity from facial paralysis: A questionnaire survey.

    Science.gov (United States)

    Hayashi, Ayato; Yoshizawa, Hidekazu; Natori, Yuhei; Suda, Shunichi; Mochizuki, Mariko; Nishimuta, Yuri; Tanaka, Rica; Mizuno, Hiroshi

    2016-03-01

    There are two main methods to treat lower-lip deformity (LLD) in facial paralysis. The first method is surgical intervention on the side of the paralysis, and the second involves denervating the depressor muscles on the healthy side. It is sometimes difficult for patients to ethically accept the denervating healthy tissue; therefore, we performed the T-shape double fascia graft (TSDFG), which reportedly restores symmetry. In this study, we report our experience with TSDFG and evaluation of the outcomes including the patient questionnaires. Two fascia strips from the thigh, 7 × 70 mm in size, were used; one was grafted horizontally at the lower lip to correct the static position, and the other was grafted obliquely at the lateral side by folding and crossing the horizontal fascia. A total of nine patients were treated by this procedure; three procedures were performed individually and six were performed in combination with another static or reanimation procedure. A questionnaire containing a five-point scoring system for facial appearance in multiple situations and other problems was sent to each patient at least 6 months after the surgery. From the physicians' point of view, all patients achieved an improvement in symmetry of the lower lip, particularly when opening of the mouth; however, assessments from the patients demonstrated much less satisfaction. The main reason for the dissatisfaction was the slight bulkiness of the red lip. There was one comment that noted that with more treatment, the expectations were higher, and, as a result, the patient could not admit satisfaction at the end. TSDFG is a simple and effective procedure for LLD; however, slight modifications may be required. In addition, there were some gaps in the perception of the results between the physicians and patients, and we need to consider these when planning to treat LLD. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All

  14. Construction of three metal-organic frameworks based on multifunctional T-shaped tripodal ligands, H3PyImDC

    KAUST Repository

    Jing, Xuemin

    2010-08-04

    Three novel metal-organic frameworks (MOFs), |(C3H 7NO)2(H2O)|[Zn3(C10H 5N3O4)3(C3H 7NO)2] (1), |(H2O)5(H 3O)(NO3)|[Nd2(C10H5N 3O4)3(H2O)4] (2), and |(H2O)2|[Nd3(C10H5N 3O4)3(C10H4N 3O4)] (3), based on the T-shaped tripodal ligands 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid and 2-(pyridine-3-yl)-1H-4, 5-imidazoledicarboxylic acid (H3PyImDC), have been constructed under solvo-/hydrothermal conditions. The diverse coordination modes of H 3PyImDC ligands have afforded the assembly of three novel compounds. In compound 1, two oxygen atoms and three nitrogen atoms of the H 3PyImDC ligand, a T-shaped linker, coordinate to two zinc centers to form a novel bbm net with two distinct channels along the [100] and [001] directions. In compound 2, H3PyImDC ligands coordinate to neodymium centers to form a ladder-like chain which then interacts with a water molecules chain via hydrogen-bondings to construct a 3D supermolecular structure. In compound 3, H3PyImDC ligands, a T-shaped linker, coordinate to neodymium centers to form a (3,6)-connected net with an ant topology. In compounds 1-3, the two H3PyImDC ligands exhibit different coordination modes with zinc and neodymium centers, which afforded the expected structural diversity. Additionally, all three compounds exhibit strong fluorescence emissions in the solid state at room temperature. © 2010 American Chemical Society.

  15. Analysis of the modulation mechanisms of the electric field and breakdown performance in AlGaN/GaN HEMT with a T-shaped field-plate

    International Nuclear Information System (INIS)

    Mao Wei; Fan Ju-Sheng; Du Ming; Zhang Jin-Feng; Zheng Xue-Feng; Wang Chong; Ma Xiao-Hua; Zhang Jin-Cheng; Hao Yue

    2016-01-01

    A novel AlGaN/GaN high electron mobility transistor (HEMT) with a source-connected T-shaped field-plate (ST-FP HEMT) is proposed for the first time in this paper. The source-connected T-shaped field-plate (ST-FP) is composed of a source-connected field-plate (S-FP) and a trench metal. The physical intrinsic mechanisms of the ST-FP to improve the breakdown voltage and the FP efficiency and to modulate the distributions of channel electric field and potential are studied in detail by means of two-dimensional numerical simulations with Silvaco-ATLAS. A comparison to the HEMT and the HEMT with an S-FP (S-FP HEMT) shows that the ST-FP HEMT could achieve a broader and more uniform channel electric field distribution with the help of a trench metal, which could increase the breakdown voltage and the FP efficiency remarkably. In addition, the relationship between the structure of the ST-FP, the channel electric field, the breakdown voltage as well as the FP efficiency in ST-FP HEMT is analyzed. These results could open up a new effective method to fabricate high voltage power devices for the power electronic applications. (paper)

  16. Analysis of the modulation mechanisms of the electric field and breakdown performance in AlGaN/GaN HEMT with a T-shaped field-plate

    Science.gov (United States)

    Mao, Wei; Fan, Ju-Sheng; Du, Ming; Zhang, Jin-Feng; Zheng, Xue-Feng; Wang, Chong; Ma, Xiao-Hua; Zhang, Jin-Cheng; Hao, Yue

    2016-12-01

    A novel AlGaN/GaN high electron mobility transistor (HEMT) with a source-connected T-shaped field-plate (ST-FP HEMT) is proposed for the first time in this paper. The source-connected T-shaped field-plate (ST-FP) is composed of a source-connected field-plate (S-FP) and a trench metal. The physical intrinsic mechanisms of the ST-FP to improve the breakdown voltage and the FP efficiency and to modulate the distributions of channel electric field and potential are studied in detail by means of two-dimensional numerical simulations with Silvaco-ATLAS. A comparison to the HEMT and the HEMT with an S-FP (S-FP HEMT) shows that the ST-FP HEMT could achieve a broader and more uniform channel electric field distribution with the help of a trench metal, which could increase the breakdown voltage and the FP efficiency remarkably. In addition, the relationship between the structure of the ST-FP, the channel electric field, the breakdown voltage as well as the FP efficiency in ST-FP HEMT is analyzed. These results could open up a new effective method to fabricate high voltage power devices for the power electronic applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61574112, 61334002, 61306017, 61474091, and 61574110) and the Natural Science Basic Research Plan in Shaanxi Province, China (Grant No. 605119425012).

  17. [Case-control study on T-shaped locking internal fixation and external fixation for the treatment of dorsal Barton's fracture].

    Science.gov (United States)

    Chen, Huan-qing; Wen, Xi-le; Li, Yang-ming; Wen, Cong-you

    2015-06-01

    To compare clinical effect of T-shaped locking internal fixation and external fixation in treating dorsal Barton's fracture,and investigate selective strategy of internal fixation. From January 2008 to January 2013, 100 patients with dorsal Barton's fracture were randomly divided into two groups. In treatment group, there were 30 males and 20 females with an average age of (33.8±3.6) years old;30 cases were type B, 20 cases were type C;and treated with T-shaped locking internal fixation. In control group, there were 32 male and 18 females with an average age of (32.9±3.4) years old; 29 cases were type B, 21 cases were type C; and treated with external fixation. Volar tilt, ulnar deviation and radial height at 3 months after operation were detected and compared between two groups. Mechara functional evaluation were used to evaluate postoperative clinical effects. Clinical cure time, postoperative complications,joint mobility and function score were recorded and compared between two groups. In treatment group,volar tilt was (11.9±2.7)°, ulnar deviation was (20.8+ 2.9)°,and radial height was (10.9±1.8) mm; while volar tilt was (9.1±1.6)°, ulnar deviation was (17.1±2.9)°, and radial height was (8.1±1.5) mm in control group. Treatment group was better than control group in volar tilt, ulnar deviation and radial height. Clinical cure time in treatment group was(12.0±2.3) weeks, shorter than control group (18.0±4.1) weeks. The incidence of complications in treatment group was lower than control group. According to Mehara functional evaluation,20 cases got excellent results, 25 good, 3 moderate and 2 poor in treatment group; 16 cases got excellent results, 14 good, 10 moderate and 10 poor in control group. Treatment group was better than control group in clinical effects. T-shaped locking internal fixation with postoperative functional exercise for the treatment of dorsal Barton's fracture fits for biomechanics demands,and has advantages of stable fixation

  18. Mid-infrared emission in InxGa1-xAs/GaAs T-shaped quantum wire lasers and its indium composition dependence

    Science.gov (United States)

    Ridene, Said

    2018-03-01

    In this work, the emission wavelength has been extended out to 1.3, 1.5, and 2.2 μm for InxGa1-xAs/GaAs T-shaped quantum wire (TQWR) using multi-band k.p model and variational formalism. We have investigated the impact of the indium composition on the performance of a series of TQWR through a calculation of the optical gain and transition energies. It is found that the optical gain and the emission wavelength are more influenced taking into account the effect of the indium concentration and persisted up at room temperature (RT). The results could open the way to the development of laser communication systems operating at long wavelengths and fabricated from TQWRs structure.

  19. Switching through symmetry breaking for transmission in a T-shaped photonic waveguide coupled with two identical nonlinear micro-cavities.

    Science.gov (United States)

    Bulgakov, Evgeny; Sadreev, Almas

    2011-08-10

    Using coupled mode theory we consider transmission in a T-shaped waveguide coupled with two identical symmetrically positioned nonlinear micro-cavities with mirror symmetry. For input power injected into the central waveguide we show the existence of a symmetry breaking solution which is a result of mixing of the symmetrical input wave with an antisymmetric standing wave in the Fabry-Pérot interferometer. With growth of the input power, a feature in the form of loops arises in the solution which originates from bistability in the transmission in the output left/right waveguide coupled with the first/second nonlinear cavity. The domains of stability of the solution are found. The breaking of mirror symmetry gives rise to nonsymmetrical left and right outputs. We demonstrate that this phenomenon can be explored for all-optical switching of light transmission from the left output waveguide to the right one by application of input pulses.

  20. Disruption of host-seeking behaviour by the salmon louse, Lepeophtheirus salmonis, using botanically derived repellents.

    Science.gov (United States)

    O'Shea, B; Wadsworth, S; Pino Marambio, J; Birkett, M A; Pickett, J A; Mordue Luntz, A J

    2017-04-01

    The potential for developing botanically derived natural products as novel feed-through repellents for disrupting settlement of the salmon louse, Lepeophtheirus salmonis (Caligidae) upon farmed Atlantic salmon, Salmo salar, was investigated using an established laboratory vertical Y-tube behavioural bioassay for assessing copepodid behaviour. Responses to artificial sea water conditioned with the odour of salmon, or to the known salmon-derived kairomone component, α-isophorone, in admixture with selected botanical materials previously known to interfere with invertebrate arthropod host location were recorded. Materials included oils extracted from garlic, Allium sativum (Amaryllidaceae), rosemary, Rosmarinus officinalis (Lamiaceae), lavender, Lavandula angustifolia (Lamiaceae), and bog myrtle, Myrica gale (Myricaceae), and individual components (diallyl sulphide and diallyl disulphide from garlic; allyl, propyl, butyl, 4-pentenyl and 2-phenylethyl isothiocyanate from plants in the Brassica genus). Removal of attraction to salmon-conditioned water (SCW) or α-isophorone was observed when listed materials were presented at extremely low parts per trillion (ppt), that is picograms per litre or 10 -12 level. Significant masking of attraction to SCW was observed at a level of 10 ppt for diallyl disulphide and diallyl sulphide, and allyl isothiocyanate and butyl isothiocyanate. The potential of very low concentrations of masking compounds to disrupt Le. salmonis copepodid settlement on a host fish has been demonstrated in vitro. © 2016 John Wiley & Sons Ltd.

  1. Efeito da concentração do catalisador acetilacetonato férrico na cura de poliuretano à base de polibutadieno líquido hidroxilado (PBLH e diisocianato de isoforona (IPDI Effect of ferric acetylacetonate catalyst concentration on the cure of polyurethane based on hydroxy terminated polybutadiene and isophorone diisocyanate

    Directory of Open Access Journals (Sweden)

    Willian César Paterlini

    2002-05-01

    Full Text Available The reaction between hydroxy-terminated polybutadiene and isophorone diisocyanate constitutes the base of the curing process of the most composite solid propellant used in the propulsion of solid rocket propellant. In this work, differential scanning calorimetry and viscosity measurements were used to evaluate the effect of the ferric acetylacetonate catalyst concentration on the reaction between HTBR and IPDI. These analyses show one exotherm, which shifts to lower temperatures as the catalyst concentration increases. The viscosity analyses show that the increase of temperature causes, at first, a reduction in the mixture viscosity, reaching a minimum range called gelification region (increasing the crosslinking density.

  2. Formation of T-shaped versus charge-transfer molecular adducts in the reactions between bis(thiocarbonyl) donors and Br2 and I2.

    Science.gov (United States)

    Mancini, Annalisa; Aragoni, M Carla; Bricklebank, Neil; Castellano, Carlo; Demartin, Francesco; Isaia, Francesco; Lippolis, Vito; Pintus, Anna; Arca, Massimiliano

    2013-03-01

    The reactions of 4,5,6,7-tetrathiocino-[1,2-b:3,4-b']-1,3,8,10-tetrasubstituted-diimidazolyl-2,9-dithiones (R(2),R'(2)-todit; 1: R=R'=Et; 2: R=R'=Ph; 3: R=Et, R'=Ph) with Br(2) exclusively afforded 1:1 and 1:2 "T-shaped" adducts, as established by FT-Raman spectroscopy and single-crystal X-ray diffraction in the case of complex 1·2Br(2). On the other hand, the reactions of compounds 1-3 with molecular I(2) provided charge-transfer (CT) "spoke" adducts, among which the solvated species 3·2I(2)·(1-x)I(2)·xCH(2)Cl(2) (x=0.94) and (3)(2)·7I(2)·xCH(2)Cl(2), (x=0.66) were structurally characterized. The nature of all of the reaction products was elucidated based on elemental analysis and FT-Raman spectroscopy and supported by theoretical calculations at the DFT level. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Mechanistic aspects of the reaction between Br2 and chalcogenone donors (LE; E=S, Se): competitive formation of 10-E-3, T-shaped 1:1 molecular adducts, charge-transfer adducts, and [ (LE)2]2+ dications.

    Science.gov (United States)

    Aragoni, M C; Arca, M; Demartin, F; Devillanova, F A; Garau, A; Isaia, F; Lelj, F; Lippolis, V; Verani, G

    2001-07-16

    The synthesis and spectroscopic characterisation of the products obtained by treatment of N,N'-dimethylimidazolidine-2-thione (1), N,N'-dimethylimidazolidine-2-selone (2), N,N'-dimethylbenzoimidazole-2-thione (3) and N,N'-dimethylbenzoimidazole-2-selone (4) with Br2 in MeCN are reported, together with the crystal structures of the 10-E-3, T-shaped adducts 2 . Br2 (12), 3 . Br2 (13) and 4 . Br2 (14). A conductometric and spectrophotometric investigation into the reaction between 1-4 and Br2, carried out in MeCN, allows the equilibria involved in the formation of the isolated 10-E-3 (E = S, Se) hypervalent compounds to be hypothesised. In order to understand the reasons why S and Se donors can give different product types on treatment with Br2 and I2, DFT calculations have been carried out on 1-8, 19 and 20, and on their corresponding hypothetical [LEX]+ cations (L = organic framework; E = S, Se; X = Br, I), which are considered to be key intermediates in the formation of the different products. The results obtained in terms of NBO charge distribution on [LEX]+ species explain the different behaviour of 1-8, 19 and 20 in their reactions with Br2 and I2 fairly well. X-ray diffraction studies show 12-14 to have a T-shaped (10-E-3; E = S, Se) hypervalent chalcogen nature. They contain an almost linear Br-E-Br (E = S, Se) system roughly perpendicular to the average plane of the organic molecules. In 12, the Se atom of each adduct molecule has a short interaction with the Br(1) atom of an adjacent unit, such that the Se atom displays a roughly square planar coordination. The Se-Br distances are asymmetric [2.529(1) vs. 2.608(1) A], the shorter distance being that with the Br(1) atom involved in the short intermolecular contact. In contrast, in the molecular adducts 13 and 14, which lie on a two-fold crystallographic axis, the Br-E-Br system is symmetric and no short intermolecular interactions involving chalcogen and bromine atoms are observed. The adducts are arranged in

  4. Usefulness of T-Shaped Gauze for Precise Dissection of Supra-Pancreatic Lymph Nodes and for Reduced Postoperative Pancreatic Fistula in Patients Undergoing Laparoscopic Gastrectomy for Gastric Cancer.

    Science.gov (United States)

    Matsunaga, Tomoyuki; Saito, Hiroaki; Murakami, Yuki; Kuroda, Hirohiko; Fukumoto, Yoji; Osaki, Tomohiro

    2016-09-01

    Supra-pancreatic lymph node dissection is important in patients undergoing laparoscopic gastrectomy (LG) for gastric cancer. A clear view of the supra-pancreatic area is necessary for precise dissection of supra-pancreatic lymph nodes without injury to the pancreas. This retrospective study assessed the efficacy of T-shaped gauze (TSG) in retracting the pancreas during supra-pancreatic lymph node dissection. The study cohort consisted of 80 patients who underwent LG for gastric cancer. Of these, 44 patients underwent pancreatic retraction with TSG (TSG group) and 36 without TSG (non-TSG group). The efficacy of TSG for pancreatic retraction was evaluated by comparing all grade and Clavien-Dindo grade ≥ III postoperative pancreatic fistula (POPF) and the total number of dissected supra-pancreatic lymph nodes in the TSG and non-TSG groups. The rates of all grade (6.8% vs. 11%) and of Clavien-Dindo grade ≥ III (2.2% vs. 5.5%) POPF were lower in the TSG than in the non-TSG group. The total number of supra-pancreatic lymph nodes harvested by Dissection 1+ (D1+) lymph node dissection was significantly higher in TSG than in non-TSG patients ( P = 0.0078). TSG may be useful for safe and efficient performance of supra-pancreatic lymph node dissection.

  5. Proliferation of human mesenchymal stem cells derived from adipose tissue on polyurethanes with tunable biodegradability

    Directory of Open Access Journals (Sweden)

    Iaci M. Pereira

    2010-01-01

    Full Text Available Polyurethanes (PUs have been considered good candidates to be used in biomedical temporary devices that require mechanical properties comparable to soft tissues. However, toxicity of some PUs is still a concern, since these polyurethanes can contain potential toxic components and residual organic solvents derived from their synthesis. In this work, in vitro tests to measure viability and proliferation of human mesenchymal stem cells (hMSCs in contact with PUs with tunable biodegradability were performed by employing MTT, alkaline phosphatase and collagen secretion assays. PUs were produced in an aqueous environment by employing isophorone diisocyanate/hydrazine (hard segment and poly(caprolactone diol/2,2-bis (hydroxymethyl propionic acid (soft segment as the main reagents. Three series of PUs having different soft segment contents were synthesized. These PUs had their chemical structure, morphology and hydrolytic degradation investigated. The rate of hydrolysis of the obtained PUs was tailored by modifying the soft segment content of the polymers. In vitro results showed that PUs can provide a satisfactory environment for the adhesion and proliferation of hMSCs.

  6. Determination of airborne isocyanates as di-n-butylamine derivatives using liquid chromatography and tandem mass spectrometry

    International Nuclear Information System (INIS)

    Karlsson, Daniel; Dahlin, Jakob; Marand, Aasa; Skarping, Gunnar; Dalene, Marianne

    2005-01-01

    A method for the determination of isocyanates as di-n-butyl amine (DBA) derivatives using tandem mass spectrometry (MS/MS) and electrospray ionisation (ESI) is presented. Multiple-reaction monitoring (MRM) of the protonated molecular ions and corresponding deuterium-labelled d 9 -DBA derivatives resulted in selective quantifications with correlation coefficients >0.998 for the DBA derivatives of isocyanic acid (ICA), methyl isocyanate (MIC), ethyl isocyanate (EIC), propyl isocyanate (PIC), phenyl isocyanate (PhI), 1,6-hexamethylene diisocyanate (HDI), 2,4-, 2,6-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), 4,4'-methylenediphenyl diisocyanate (MDI), 3-ring MDI, 4-ring MDI, HDI-isocyanurate, HDI-diisocyanurate, HDI-biuret and HDI-dibiuret. The instrumental precision for 10 repeated injections of a solution containing 0.1 μg ml -1 of the studied derivatives was + (m/z = 130) from the protonated molecular ion resulted in the lowest detection limits, down to 10 amol (for TDI). Quantification of concentrations below 10 -6 of the occupational exposure limit (OEL) for TDI during 10 min of air sampling was made possible. In an effort to control the formation of alkali adducts, addition of lithium acetate to the mobile phase and monitoring of lithium adducts was evaluated. Having lithium present in the mobile phase resulted in complete domination of [M + Li] + adducts, but detection limits for the studied compounds were not improved. Different deuterium-labelled derivatives as internal standards were evaluated. (1) DBA derivatives of deuterium-labelled isocyanates (d 4 -HDI, d 3 -2,4-TDI, d 3 -2,6-TDI and d 2 -MDI) (2) d 9 -DBA derivatives of the corresponding isocyanates and (3) d 18 -DBA derivatives of the corresponding isocyanates. An increase in number of deuterium in the molecule of the internal standard resulted in an increase in instrumental precision and a decrease in correlation within calibration series

  7. Hemoglobin derivatives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  8. Financial derivatives

    OpenAIRE

    Koutný, Ondřej

    2012-01-01

    1 Abstract/ Financial derivatives The purpose of this thesis is to provide an introduction to financial derivatives which has been, from the legal perspective, described in a not satisfactory manner as quite little literature that can be found about this topic. The main objectives of this thesis are to define the term "financial derivatives" and its particular types and to analyse legal nature of these financial instruments. The last objective is to try to draft future law regulation of finan...

  9. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded and inheren......Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded...

  10. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    ." - Steen Parsholt, Chairman and CEO, Aon Nordic Region. "Andersen has done a wonderful job of developing a comprehensive text that deals with risk management in global markets. I would recommend this book to any student or businessman who has a need to better understand the risks and risk management......""In Global Derivatives: A Strategic Risk Management Perspective", Torben Juul Andersen has succeeded to gather in one book a complete and thorough summary and an easy-to-read explanation of all types of derivative instruments and their background, and their use in modern management of risk...... approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk...

  11. Derivative chameleons

    International Nuclear Information System (INIS)

    Noller, Johannes

    2012-01-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂ μ φ∂ μ φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂ μ φ∂ μ φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type

  12. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    , postgraduate qualification or MBA programme. This book also caters for practicing managers and executives who need to understand current developments in global derivatives markets and require cutting-edge insight on strategic risk management issues. Dr Torben Juul Andersen is currently Associate Professor...... approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk...... management practice. Of particular note is the global and integrated approach chosen in this book which should be of special interest to aspiring managers active in global and international markets." - Dr Jean-Pierre Zigrand, Lecturer in Finance, London School of Economics, UK. More than 90 per cent...

  13. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  14. Electricity derivatives

    OpenAIRE

    Barone-Adesi, Giovanni; Gigli, Andrea

    2006-01-01

    In this paper we propose an algorithm for pricing derivatives written on electricity in an incomplete market setting. A discrete time model for price dynamics which embodies the main features of electricity price revealed by simple time series analysis is considered. We use jointly Binomial and Monte Carlo methods for pricing under a risk-neutral measure of which we prove the existence.

  15. dione derivatives

    Indian Academy of Sciences (India)

    dione derivatives via de-Boc and cyclization reaction in modest yield. Spectroscopic (1H, 13C NMR, and Mass) and analytical techniques have been used to identify and confirm the structure of the products. Keywords. Triflic anhydride; Boc anhydride; Negishi coupling; acid-amine coupling; cyclization reaction; cytotoxicity ...

  16. MULTIBAND MILLIMETER WAVE T-SHAPED ANTENNA WITH ...

    African Journals Online (AJOL)

    The return loss impedance bandwidth of 5GHz for the first band, 8.4GHz for the second band and 5GHz for the third band was obtained. The proposed antenna was analyzed using Ansoft High Frequency Structure Simulator (HFSS) and MATLAB 2013. Radiation characteristics of this patch antenna are observed at various ...

  17. Determination of airborne isocyanates as di-n-butylamine derivatives using liquid chromatography and tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Daniel [Department of Analytical Chemistry, Work Environment Chemistry, Stockholm University, P.O. Box 460, S-28124 Haessleholm (Sweden); Dahlin, Jakob [Department of Analytical Chemistry, Work Environment Chemistry, Stockholm University, P.O. Box 460, S-28124 Haessleholm (Sweden); Marand, Aasa [Department of Analytical Chemistry, Work Environment Chemistry, Stockholm University, P.O. Box 460, S-28124 Haessleholm (Sweden); Skarping, Gunnar [Department of Analytical Chemistry, Work Environment Chemistry, Stockholm University, P.O. Box 460, S-28124 Haessleholm (Sweden); Dalene, Marianne [Department of Analytical Chemistry, Work Environment Chemistry, Stockholm University, P.O. Box 460, S-28124 Haessleholm (Sweden)

    2005-04-08

    A method for the determination of isocyanates as di-n-butyl amine (DBA) derivatives using tandem mass spectrometry (MS/MS) and electrospray ionisation (ESI) is presented. Multiple-reaction monitoring (MRM) of the protonated molecular ions and corresponding deuterium-labelled d{sub 9}-DBA derivatives resulted in selective quantifications with correlation coefficients >0.998 for the DBA derivatives of isocyanic acid (ICA), methyl isocyanate (MIC), ethyl isocyanate (EIC), propyl isocyanate (PIC), phenyl isocyanate (PhI), 1,6-hexamethylene diisocyanate (HDI), 2,4-, 2,6-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), 4,4'-methylenediphenyl diisocyanate (MDI), 3-ring MDI, 4-ring MDI, HDI-isocyanurate, HDI-diisocyanurate, HDI-biuret and HDI-dibiuret. The instrumental precision for 10 repeated injections of a solution containing 0.1 {mu}g ml{sup -1} of the studied derivatives was <2%. Performing MRM of the product ion [DBA + H]{sup +} (m/z = 130) from the protonated molecular ion resulted in the lowest detection limits, down to 10 amol (for TDI). Quantification of concentrations below 10{sup -6} of the occupational exposure limit (OEL) for TDI during 10 min of air sampling was made possible. In an effort to control the formation of alkali adducts, addition of lithium acetate to the mobile phase and monitoring of lithium adducts was evaluated. Having lithium present in the mobile phase resulted in complete domination of [M + Li]{sup +} adducts, but detection limits for the studied compounds were not improved. Different deuterium-labelled derivatives as internal standards were evaluated. (1) DBA derivatives of deuterium-labelled isocyanates (d{sub 4}-HDI, d{sub 3}-2,4-TDI, d{sub 3}-2,6-TDI and d{sub 2}-MDI) (2) d{sub 9}-DBA derivatives of the corresponding isocyanates and (3) d{sub 18}-DBA derivatives of the corresponding isocyanates. An increase in number of deuterium in the molecule of the internal standard resulted in an increase in instrumental precision

  18. Dimension and deriving manner for derived quantities

    International Nuclear Information System (INIS)

    Zhao Zhixiang

    1993-01-01

    Most physical quantities we are interested in are derived from some directly measured physical quantities. To obtain correct least-square result in derived quantity space, one must pay attention to inconsistencies problem to avoid ppp phenomenon in generating derived quantities and their covariance matrix. The situation is complicated by the problems of dimension and deriving manner for derived quantities. Some more general problems, which are independent of ppp, are discussed

  19. Comparisons of three polyethyleneimine-derived nanoparticles as a gene therapy delivery system for renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Wei Yuquan

    2011-04-01

    Full Text Available Abstract Background Polyethyleneimine (PEI, which can interact with negatively charged DNA through electrostatic interaction to form nanocomplexes, has been widely attempted to use as a gene delivery system. However, PEI has some defects that are not fit for keeping on gene expression. Therefore, some modifications against PEI properties have been done to improve their application value in gene delivery. In this study, three modified PEI derivatives, including poly(ε-caprolactone-pluronic-poly(ε-caprolactone grafted PEI (PCFC-g-PEI, folic acid-PCFC-isophorone diidocyanate-PEI (FA-PEAs and heparin-PEI (HPEI, were evaluated in terms of their cytotoxicity and transfection efficiency in vitro and in vivo in order to ascertain their potential application in gene therapy. Methods MTT assay and a marker GFP gene, encoding green fluorescent protein, were used to evaluate cell toxicity and transfection activity of the three modified PEI in vitro. Renal cell carcinoma (RCC models were established in BALB/c nude mice inoculated with OS-RC-2 cells to detect the gene therapy effects using the three PEI-derived nanoparticles as gene delivery vehicles. The expression status of a target gene Von Hippel-Lindau (VHL in treated tumor tissues was analyzed by semiquantitative RT-PCR and immunohistochemistry. Results Each of three modified PEI-derived biomaterials had an increased transfection efficiency and a lower cytotoxicity compared with its precursor PEI with 25-kD or 2-kD molecule weight in vitro. And the mean tumor volume was obviously decreased 30% by using FA-PEAs to transfer VHL plasmids to treat mice RCC models. The VHL gene expression was greatly improved in the VHL-treated group. While there was no obvious tumor inhibition treated by PCFC-g-PEI:VHL and HPEI:VHL complexes. Conclusions The three modified PEI-derived biomaterials, including PCFC-g-PEI, FA-PEAs and HPEI, had an increased transfection efficiency in vitro and obviously lower toxicities

  20. Interest rate derivatives

    DEFF Research Database (Denmark)

    Svenstrup, Mikkel

    This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered.......This Ph.D. thesis consists of four self-contained essays on valuation of interest rate derivatives. In particular derivatives related to management of interest rate risk care are considered....

  1. Generalized Riemann derivative

    Directory of Open Access Journals (Sweden)

    Sorin Radulescu

    2013-03-01

    Full Text Available Initiated by Marshall Ash in 1966, the study of generalized Riemann derivative draw significant attention of the mathematical community and numerous studies where carried out since then. One of the major areas that benefits from these developments is the numerical analysis, as the use of generalized Riemann derivatives leads to solving a wider class of problems that are not solvable with the classical tools. This article studies the generalized Riemann derivative and its properties and establishes relationships between Riemann generalized derivative and the classical one. The existence of classical derivative implies the existence of the Riemann generalized derivative, and we study conditions necessary for the generalized Riemann derivative to imply the existence of the classical derivative. Furthermore, we provide conditions on the generalized Riemann derivative that are sufficient for the existence of the classical derivative.

  2. Derivatives in emerging markets

    OpenAIRE

    Dubravko Mihaljek; Frank Packer

    2010-01-01

    Turnover of derivatives has grown more rapidly in emerging markets than in developed countries. Foreign exchange derivatives are the most commonly traded of all risk categories, with increasingly frequent turnover in emerging market currencies and a growing share of cross-border transactions. As the global reach of the financial centres in emerging Asia has expanded, the offshore trading of many emerging market currency derivatives has risen as well. Growth in derivatives turnover is positive...

  3. The Ungraded Derived Category

    OpenAIRE

    Stai, Torkil Utvik

    2012-01-01

    By means of the ungraded derived category we prove that the orbit category of the bounded derived category of an iterated tilted algebra with respect to translation is triangulated in such a way that the canonical functor from the bounded derived category to the orbit category becomes a triangle functor.

  4. Higher derivative mimetic gravity

    Science.gov (United States)

    Gorji, Mohammad Ali; Mansoori, Seyed Ali Hosseini; Firouzjahi, Hassan

    2018-01-01

    We study cosmological perturbations in mimetic gravity in the presence of classified higher derivative terms which can make the mimetic perturbations stable. We show that the quadratic higher derivative terms which are independent of curvature and the cubic higher derivative terms which come from curvature corrections are sufficient to remove instabilities in mimetic perturbations. The classified higher derivative terms have the same dimensions but they contribute differently in the background and perturbed equations. Therefore, we can control both the background and the perturbation equations allowing us to construct the higher derivative extension of mimetic dark matter and the mimetic nonsingular bouncing scenarios. The latter can be thought as a new higher derivative effective action for the loop quantum cosmology scenario in which the equations of motion coincide with those suggested by loop quantum cosmology. We investigate a possible connection between the mimetic cosmology and the Randall-Sundrum cosmology.

  5. Taxation of Derivatives

    DEFF Research Database (Denmark)

    Dyppel, Katja Joo

    2013-01-01

    are known as futures, forwards, options and swaps. Derivatives are traded for the purpose of hedging financial or business risk, speculating in future spot prices and taking advantage of arbitrage opportunities. This market has increased tremendously in recent years. The term derivative is not used......The main objective for this thesis is to analyse and systematise the Danish legislation on taxation of derivatives. According to financial terminology, a derivative is a financial instrument. Its value is derived from changes in the value of one or more underlying assets.The most common derivatives...... in the Danish tax legislation. However, contracts known as forwards (terminskontrakter) and options (aftaler om køberetter og salgsretter) are generally included in the term financials contracts covered by the Danish Act on Taxation of Gains and Losses on Claims and Debt. The main part of the analysis deals...

  6. Global Derivatives Market

    Directory of Open Access Journals (Sweden)

    Stankovska Aleksandra

    2017-06-01

    Full Text Available Globalization of financial markets led to the enormous growth of volume and diversification of financial transactions. Financial derivatives were the basic elements of this growth. Derivatives play a useful and important role in hedging and risk management, but they also pose several dangers to the stability of financial markets and thereby the overall economy. Derivatives are used to hedge and speculate the risk associated with commerce and finance.

  7. Numerical derivation in optimization

    International Nuclear Information System (INIS)

    Abadie, J.; Salhi, Y.

    1988-01-01

    Newton's method for function minimization possesses an outstanding property. Its final quadratic convergence under very weak hypothesis, but also some drawbacks, among which (i) the possibility of non convergence when starting far from the solution sought and (ii) the necessity of computing (and then programming) the first and second partial derivatives. We show in this paper how to avoid both difficulties, assuming however that the first partial derivatives are computed by exact formulae. The second partial derivatives are computed by central differences of first derivatives. The difference step h is calculated so as to establish a trade-off between accuracy and computation speed. Encouraging numerical experiments support the proposed method [fr

  8. 4-Aminoquinoline derivatives

    DEFF Research Database (Denmark)

    Singh, Shailja; Agarwal, Drishti; Sharma, Kumkum

    2016-01-01

    Synthetic quinoline derivatives continue to be considered as candidates for new drug discovery if they act against CQ-resistant strains of malaria even after the widespread emergence of resistance to CQ. In this study, we explored the activities of two series of new 4-aminoquinoline derivatives a...

  9. The Dangers of Derivatives.

    Science.gov (United States)

    Blumenstyk, Goldie

    1994-01-01

    Heavy investment in derivatives, whose value derives from the price movement of some underlying security, has meant heavy losses for some colleges and universities despite the fact that institutional investors are required to assure that they understand the risks of such investment. (MSE)

  10. Vitamin D derivatives

    International Nuclear Information System (INIS)

    Deluca, H.F.; Schnoes, H.K.; Napoli, J.L.; Fivizzani, M.A.

    1982-01-01

    The chemical preparation of 26,27-isotopically labelled vitamin D 3 derivatives of high specific activity is described. These labelled vitamin D derivatives are useful in the determination of vitamin D metabolite levels in the blood and tissues of man and animals. (U.K.)

  11. The azobenzene derivatives

    Science.gov (United States)

    Ionita, Ionica; Radulescu, Cristiana; Poinescu, Aurora Anca; Anghelina, Florina Violeta; Bunghez, Raluca; Ion, Rodica-Mariana

    2015-02-01

    Azobenzene derivatives constitute a group of dyes which have photochromic properties and have been investigated as promising systems for diverse applications in the unconventional optic area, their properties can be moulded with help of light.

  12. ASTEROID LIGHTCURVE DERIVED DATA

    Data.gov (United States)

    National Aeronautics and Space Administration — This is a compilation of published rotational parameters derived from lightcurve data for asteroids, based on the Warner et al. (2009) Asteroid Lightcurve Database....

  13. Investigation - Derived Waste Program

    International Nuclear Information System (INIS)

    Beardsley, C.; Anderson, R.

    1998-06-01

    The Investigation-Derived Waste Program is a software application that was developed to identify the groundwater monitoring wells at the Savannah River Site that require containerization and treatment for purge water generated during sampling

  14. Granin-derived peptides.

    Science.gov (United States)

    Troger, Josef; Theurl, Markus; Kirchmair, Rudolf; Pasqua, Teresa; Tota, Bruno; Angelone, Tommaso; Cerra, Maria C; Nowosielski, Yvonne; Mätzler, Raphaela; Troger, Jasmin; Gayen, Jaur R; Trudeau, Vance; Corti, Angelo; Helle, Karen B

    2017-07-01

    The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  16. Molecular Recognition Involving Anthraquinone Derivatives and Molecular Clips

    Science.gov (United States)

    Alaparthi, Madhubabu

    In the past, we have demonstrated that 1,8-anthraquinone-18-crown-5 (1) and its heterocyclic derivatives act as luminescent hosts for a variety of cations of environmental and clinical concern. We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene - 9,10-dione in a 1:1 ratio (2,3, and 6). These sensors bind metal ions in a 1:1 ratio (7 and 8), and the optical properties of the new complexes were examined and the sulfur and selenium analogues show that selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was competitive for Ca(II) ion. Selective reduction of 1 yields secondary alcohols where either one or both of the anthraquinone carbonyl groups has been reduced ( 15 and 9). A new mechanism for the fluorescence detection of metal cations in solution is introduced involving a unique keto-enol tautomerization. Reduction of 1 yields the doubly reduced secondary alcohol, 9. 9 acts as a chemodosimeter for Al(III) ion producing a strong blue emission due to the formation of the anthracene fluorophore, 10, via dehydration of the internal secondary alcohol in DMSO/aqueous solution. The enol form is not the most thermodynamically stable form under these conditions however, and slowly converts to the keto form 11.. Currently we are focusing on cucurbituril derivatives, also described as molecular clips due to their folded geometry used as molecular recognition hosts. We first investigated the synthesis and characterization of aromatic methoxy/catechol terminated cucurbituril units that act as hosts for small solvent molecules, such as CH2Cl2, CH3CN, DMF, and MeOH, through dual pi...H-C T-shaped

  17. Asia Pacific energy derivatives

    International Nuclear Information System (INIS)

    Fusaro, P.C.

    1997-09-01

    Asia Pacific Energy Derivatives, from FT Energy, is the first report of its kind to examine the growth of energy derivatives within Asia Pacific and their increasing importance within this region. It provides a comprehensive overview of the subject, including analysis of: deregulation as a market driver; the impact of privatisation; the future for energy risk management tools; the unique characteristics of the Asia Pacific energy market; the role of futures exchanges in Asia; existing indexes and their performance; the differences between the Asia Pacific markets and their more mature counterparts in London and New York; non-oil derivatives, project finance and cross commodity arbitrage; the thriving Pacific Rim Over the Counter (OTC) markets. (author)

  18. Essays on Derivatives Pricing

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    . With the existence of a liquid market for derivatives with variance as underlying, such as VIX options, VIX futures and a well-developed over-the-counter market for options on variance swaps, it is important to consider models that are able to fit these markets while consistently pricing vanilla options...... financial models, and most importantly, to be aware of their limitations. Following that belief, this thesis consists of three independent and self-contained papers, all dealing with topics in derivatives pricing. The first paper considers the pricing of traffic light options, which are appropriate...... the market for multivariate credit instruments, we take a step back and focus on single-name default modeling and introduce two new model classes for modeling of the default time of a company. Finally, in the third paper we propose a consistent pricing model for index and volatility derivatives...

  19. Gorenstein derived functions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    Over any associative ring R it is standard to derive HomR(􀀀;􀀀) using projective resolutions in the rst variable, or injective resolutions in the second variable, and doing this, one obtains Extn R(􀀀;􀀀) in both cases. We examine the situation where projective an...

  20. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    2007-01-01

    to subordinates, who exercise derived judgment. We call these employees `proxy-entrepreneurs', and ask how the firm's organizational structure - its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating agreements, means of evaluating performance and so on - can...

  1. 78 FR 32191 - Derivatives

    Science.gov (United States)

    2013-05-29

    ...] Counterparty exposure management. [cir] Evaluating liquidity risk. Conduct: [cir] Collateral [cir] Accounting... rate risk. This proposed rule applies to federal credit unions and any federally insured, state... derivatives transactions \\1\\ for the purpose of mitigating interest rate risk (IRR). This proposed authority...

  2. Structural insight into the active site of mushroom tyrosinase using phenylbenzoic acid derivatives.

    Science.gov (United States)

    Oyama, Takahiro; Yoshimori, Atsushi; Takahashi, Satoshi; Yamamoto, Tetsuya; Sato, Akira; Kamiya, Takanori; Abe, Hideaki; Abe, Takehiko; Tanuma, Sei-Ichi

    2017-07-01

    So far, many inhibitors of tyrosinase have been discovered for cosmetic and clinical agents. However, the molecular mechanisms underlying the inhibition in the active site of tyrosinase have not been well understood. To explore this problem, we examined here the inhibitory effects of 4'-hydroxylation and methoxylation of phenylbenzoic acid (PBA) isomers, which have a unique scaffold to inhibit mushroom tyrosinase. The inhibitory effect of 3-PBA, which has the most potent inhibitory activity among the isomers, was slightly decreased by 4'-hydroxylation and further decreased by 4'-methoxylation against mushroom tyrosinase. Surprisingly, 4'-hydroxylation but not methoxylation of 2-PBA appeared inhibitory activity. On the other hand, both 4'-hydroxylation and methoxylation of 4-PBA increased the inhibitory activity against mushroom tyrosinase. In silico docking analyses using the crystallographic structure of mushroom tyrosinase indicated that the carboxylic acid or 4'-hydroxyl group of PBA derivatives could chelate with cupric ions in the active site of mushroom tyrosinase, and that the interactions of Asn260 and Phe264 in the active site with the adequate-angled biphenyl group are involved in the inhibitory activities of the modified PBAs, by parallel and T-shaped π-π interactions, respectively. Furthermore, Arg268 could fix the angle of the aromatic ring of Phe264, and Val248 is supposed to interact with the inhibitors as a hydrophobic manner. These results may enhance the structural insight into mushroom tyrosinase for the creation of novel tyrosinase inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Studies on derivative fluorimetry

    International Nuclear Information System (INIS)

    Gao Jinzhang; He Jiang; Wang Xiwen; Wang Zheming; Bai Guangbi

    1987-01-01

    A method is described for the derivative spectrofluorimetric determination of trace amounts of Sm, Eu and Tb as their ternary complexes with 2-thenoyltrifluoroacetone and diphenylguanidine. These ternary complexes show excitation bands at 345 nm for Sm and Eu and 350 nm for Tb, and fluorescence bands at 645 nm for Sm, 614 nm for Eu and 545 nm for Tb. A mixture of Sm, Eu and Tb can be determined by second-derivative spectrofluorimetry. The calibration graphs are linear over the range 10-100 p.p.m. for Sm, 0.5-50 p.p.m. for Eu and 100-1000 p.p.m. for Tb. (author)

  4. Insulin-derived amyloidosis

    Directory of Open Access Journals (Sweden)

    Yashdeep Gupta

    2015-01-01

    Full Text Available Amyloidosis is the term for diseases caused by the extracellular deposition of insoluble polymeric protein fibrils in tissues and organs. Insulin-derived amyloidosis is a rare, yet significant complication of insulin therapy. Insulin-derived amyloidosis at injection site can cause poor glycemic control and increased insulin dose requirements because of the impairment in insulin absorption, which reverse on change of injection site and/or excision of the mass. This entity should be considered and assessed by histopathology and immunohistochemistry, in patients with firm/hard local site reactions, which do not regress after cessation of insulin injection at the affected site. Search strategy: PubMed was searched with terms "insulin amyloidosis". Full text of articles available in English was reviewed. Relevant cross references were also reviewed. Last search was made on October 15, 2014.

  5. Multifunctional Cinnamic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Aikaterini Peperidou

    2017-07-01

    Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

  6. Computation of Mie derivatives.

    Science.gov (United States)

    Li, Yang; Bowler, Nicola

    2013-07-10

    Analytical expressions are obtained for the derivatives of Mie scattering coefficients with respect to the electrical radius of the spherical scattering particle, and to the relative permittivity and permeability of both the particle and the surrounding medium. Their corresponding approximate expressions are developed to avoid numerical overflow based on the logarithmic derivative of Riccati-Bessel functions. The analytical expressions have been verified by comparing their results with those calculated by analytical expressions developed by Mathematica. Compared with the numerical derivative, the analytical expressions and approximate expressions show a higher accuracy and are 2.0 and 2.8 times, respectively, faster in the case of a single magnetodielectric sphere. Generally, for spheres with an electrical radius in a large range, the approximate expressions can yield acceptable accuracy and computation time up to a high order. This work can be used in the design of nonmetallic metamaterials, and in the retrieval of aerosol properties from remote sensing data. An example calculation is given for the design of an optical, all-dielectric, mu-negative metamaterial consisting of a simple cubic array of tellurium nanoparticles.

  7. Credit derivatives and risk management

    OpenAIRE

    Michael S. Gibson

    2007-01-01

    The striking growth of credit derivatives suggests that market participants find them to be useful tools for risk management. I illustrate the value of credit derivatives with three examples. A commercial bank can use credit derivatives to manage the risk of its loan portfolio. An investment bank can use credit derivatives to manage the risks it incurs when underwriting securities. An investor, such as an insurance company, asset manager, or hedge fund, can use credit derivatives to align its...

  8. Correction for dispersion and Coulombic interactions in molecular clusters with density functional derived methods: Application to polycyclic aromatic hydrocarbon clusters

    Science.gov (United States)

    Rapacioli, Mathias; Spiegelman, Fernand; Talbi, Dahbia; Mineva, Tzonka; Goursot, Annick; Heine, Thomas; Seifert, Gotthard

    2009-06-01

    The density functional based tight binding (DFTB) is a semiempirical method derived from the density functional theory (DFT). It inherits therefore its problems in treating van der Waals clusters. A major error comes from dispersion forces, which are poorly described by commonly used DFT functionals, but which can be accounted for by an a posteriori treatment DFT-D. This correction is used for DFTB. The self-consistent charge (SCC) DFTB is built on Mulliken charges which are known to give a poor representation of Coulombic intermolecular potential. We propose to calculate this potential using the class IV/charge model 3 definition of atomic charges. The self-consistent calculation of these charges is introduced in the SCC procedure and corresponding nuclear forces are derived. Benzene dimer is then studied as a benchmark system with this corrected DFTB (c-DFTB-D) method, but also, for comparison, with the DFT-D. Both methods give similar results and are in agreement with references calculations (CCSD(T) and symmetry adapted perturbation theory) calculations. As a first application, pyrene dimer is studied with the c-DFTB-D and DFT-D methods. For coronene clusters, only the c-DFTB-D approach is used, which finds the sandwich configurations to be more stable than the T-shaped ones.

  9. Original and Derived Judgment

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Klein, Peter G.

    may delegate a wide range of decision rights to subordinates, who exercise derived judgment. We call these employees "proxy-entrepreneurs," and ask how the firm's or-ganizational structure — its formal and informal systems of rewards and punishments, rules for settling disputes and renegotiating...... agreements, means of evaluating perform-ance, and so on — can be designed to encourage forms of proxy-entrepreneurship that increase firm value while discouraging actions that destroy value. Building on key ideas from the entrepreneurship literature, Austrian economics, and the economic theory of the firm we...

  10. Certain legal aspects of derivatives.

    Science.gov (United States)

    Cloney, T J

    1994-01-01

    This article discusses legal characteristics of derivatives that a not-for-profit health care company may use in a conduit financing in which a governmental issuer issues bonds for the benefit of a health care company. This article also presents the Master Agreement promulgated by the International Swaps and Derivatives Association; discusses how to get out of a derivative; discusses the status of a derivative after insolvency of a counterparty; presents disclosure issues relating to documents prepared in connection with an issue of bonds; and describes the treatment of derivatives under commodities regulations. It concludes with a presentation of possible new regulations applying to derivatives.

  11. In defense of derivations

    Science.gov (United States)

    Mungan, Carl E.

    2016-05-01

    At the 2015 AAPT Summer Meeting, I presented four derivations of the formula for motional emf. Such physics derivations involve the construction of explanatory frameworks involving diagrams and mathematical models. Although textbooks devote considerable space to such explanations, many teachers and students spend their time on worksheets, end-of-chapter problems, and the like. The book is reduced to a bank of solved (i.e., example) and unsolved (i.e., homework) questions, along with equations in colored boxes that presumably are to be used to answer those questions. Such an approach encourages fragmentation of knowledge, the view that there is only one right answer to a problem with the goal of physics being to find that answer (neatly boxed of course), and the inability to reason about even a slightly different (much less a novel) situation. If we are to develop scientific literacy, significant course time must be devoted to explaining the structure of and support for the models and equations we use.

  12. Quinazolin-4-one derivatives

    DEFF Research Database (Denmark)

    Mosley, Cara A; Acker, Timothy M; Hansen, Kasper Bø

    2010-01-01

    We describe a new class of subunit-selective antagonists of N-methyl D-aspartate (NMDA)-selective ionotropic glutamate receptors that contain the (E)-3-phenyl-2-styrylquinazolin-4(3H)-one backbone. The inhibition of recombinant NMDA receptor function induced by these quinazolin-4-one derivatives ...... were identified with 50-fold selectivity for recombinant NR2C/D-containing receptors over NR2A/B containing receptors. These compounds represent a new class of noncompetitive subunit-selective NMDA receptor antagonists.......We describe a new class of subunit-selective antagonists of N-methyl D-aspartate (NMDA)-selective ionotropic glutamate receptors that contain the (E)-3-phenyl-2-styrylquinazolin-4(3H)-one backbone. The inhibition of recombinant NMDA receptor function induced by these quinazolin-4-one derivatives...... is noncompetitive and voltage-independent, suggesting that this family of compounds does not exert action on the agonist binding site of the receptor or block the channel pore. The compounds described here resemble CP-465,022 ((S)-3-(2-chlorophenyl)-2-[2-(6-diethylaminomethyl-pyridin-2-yl)-vinyl]-6-fluoro-3H...

  13. Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context

    Science.gov (United States)

    Marinellie, Sally A.; Kneile, Lynn A.

    2012-01-01

    Purpose: This research investigated children's ability to acquire semantic and syntactic knowledge of derived nominals and derived adjectives in the context of short passages. The study also investigated the relation of morphological awareness and the ability to acquire knowledge of derived words in context. Method: A total of 106 children in…

  14. Experts' Understanding of Partial Derivatives Using the Partial Derivative Machine

    Science.gov (United States)

    Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

    2015-01-01

    Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of…

  15. Algae Derived Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  16. Metal borohydrides and derivatives

    DEFF Research Database (Denmark)

    Paskevicius, Mark; Haarh Jepsen, Lars; Schouwink, Pascal

    2017-01-01

    review new synthetic strategies along with structural, physical and chemical properties for metal borohydrides, revealing a number of new trends correlating composition, structure, bonding and thermal properties. These new trends provide general knowledge and may contribute to the design and discovery......A wide variety of metal borohydrides, MBH4, have been discovered and characterized during the past decade, revealing an extremely rich chemistry including fascinating structural flexibility and a wide range of compositions and physical properties. Metal borohydrides receive increasing interest...... major classes of metal borohydride derivatives have also been discovered: anion-substituted compounds where the complex borohydride anion, BH4 -, is replaced by another anion, i.e. a halide or amide ion; and metal borohydrides modified with neutral molecules, such as NH3, NH3BH3, N2H4, etc. Here, we...

  17. SEMANTIC DERIVATION OF BORROWINGS

    Directory of Open Access Journals (Sweden)

    Shigapova, F.F.

    2017-09-01

    Full Text Available The author carried out the contrastive analysis of the word спикер borrowed into Russian from English and the English word speaker. The findings of the analysis include confirm (1 different derivational abilities and functions of the borrowed word and the native word; (2 distinctive features in the definitions, i.e. semantic structures, registered in monolingual non-abridged dictionaries; (3 heterogeneous parameters of frequencies recorded in the National Corpus of the Russian language and the British National Corpus; (4 absence of bilingual equivalent collocations with words спикер and speaker. The collocations with words studied revealed new lexical and connotative senses in the meaning of the word. Relevance of the study conducted is justified by the new facts revealed about the semantic adaptation of the borrowed word in the system of the Russian language and its paradigmatic and syntagmatic connections in the system of the recipient language.

  18. 6-Bromocholesterol derivatives

    International Nuclear Information System (INIS)

    Flanagan, R.J.

    1984-01-01

    Novel 6-bromo derivatives of cholesterol have the formula 3-(R-O-),6-BR,17-((H3C-)2-HC-H2C-H2C-H2C-HC(-CH3)-)-ESTR-5-ENE Such compounds are prepared from the known 6-iodocholesterol by treatment with cuprous bromide. These compounds, labelled with radioisotopes of Br-82 or Br-77, are localized in the adrenal, mammary and ovary tissue of female mammals and in the adrenal or prostate tissue of males when administered to such individuals. This provides a method for imaging adrenal, ovary or prostate tissue which is superior to use of the prior art 6-iodo-cholesterol

  19. Development of credit derivatives trading

    OpenAIRE

    Kunovjánek, Robert

    2015-01-01

    The bachelor thesis is focused on the structure and development of credit derivatives market. The thesis provides a basic summary for insight into credit derivatives market. The first part deals with general specifications of derivatives, their structure, functions and relevant categorization. The main chapter is dedicated to the most frequently used variants of credit derivatives, namely, credit default swap, total return swap and credit-linked note. Predominantly traded credit default swap ...

  20. T-shaped emitter metal heterojunction bipolar transistors for submillimeter wave applications

    Science.gov (United States)

    Fung, Andy; Samoska, Lorene; Velebir, Jim; Siege, Peter; Rodwell, Mark; Paidi, Vamsi; Griffth, Zach; Urteaga, Miguel; Malik, Roger

    2004-01-01

    We report on the development of submillimeter wave transistors at JPL. The goal of the effort is to produce advance-reliable high frequency and high power amplifiers, voltage controlled oscillators, active multipliers, and high-speed mixed-signal circuits for space borne applications. The technology in development to achieve this is based on the Indium Phosphide (InP) Heterojunction Bipolar Transistor (HBT). The HBT is well suited for high speed, high power and uniform (across wafer) performance, due to the ability to tailor the material structure that electrons traverse through by well-controlled epitaxial growth methods. InP with its compatible lattice matched alloys such as indium gallium arsenide (InGaAs) and indium aluminium arsenide (InAlAs) provides for high electron velocities and high voltage breakdown capabilities. The epitaxial methods for this material system are fairly mature, however the implementation of high performance and reliable transistors are still under development by many laboratories. Our most recently fabricated, second generation mesa HBTs at JPL have extrapolated current gain cutoff frequency (FJ of 142GHz and power gain cutoff frequency (Fm,) of approximately 160GHz. This represents a 13% and 33% improvement of Ft and F, respectively, compared to the first generation mesa HBTs [l]. Analysis based on the University of California, Santa Barbara (UCSB) device model, RF device characteristics can be significantly improved by reducing base contact resistance and base metal contact width. We will describe our effort towards increasing transistor performance and yield.

  1. How LeuT shapes our understanding of the mechanisms of sodium-coupled neurotransmitter transporters.

    Science.gov (United States)

    Penmatsa, Aravind; Gouaux, Eric

    2014-03-01

    Neurotransmitter transporters are ion-coupled symporters that drive the uptake of neurotransmitters from neural synapses. In the past decade, the structure of a bacterial amino acid transporter, leucine transporter (LeuT), has given valuable insights into the understanding of architecture and mechanism of mammalian neurotransmitter transporters. Different conformations of LeuT, including a substrate-free state, inward-open state, and competitive and non-competitive inhibitor-bound states, have revealed a mechanistic framework for the transport and transport inhibition of neurotransmitters. The current review integrates our understanding of the mechanistic and pharmacological properties of eukaryotic neurotransmitter transporters obtained through structural snapshots of LeuT.

  2. Flow Characterization in T-Shaped and Cross-Shaped Micromixers

    Czech Academy of Sciences Publication Activity Database

    Ait Mouheb, N.; Montillet, A.; Solliec, C.; Havlica, Jaromír; Legentilhomme, P.; Comiti, J.; Tihon, Jaroslav

    2011-01-01

    Roč. 10, č. 6 (2011), s. 1185-1197 ISSN 1613-4982 Institutional research plan: CEZ:AV0Z40720504 Keywords : micromixers * piv * electrochemical method Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.371, year: 2011

  3. Shear or bending? Experimental results on large t-shaped prestressed conrete beams

    NARCIS (Netherlands)

    Ensink, S.W.H.; Van der Veen, C.; De Boer, A.

    2015-01-01

    Experimental results of four shear tests on two large prestressed concrete beams are compared to nonlinear analysis and design code calculations. The beams have a length of 12 m and a depth of 1.3 m and are reinforced with stirrups and pre-tensioning. The four tests consist of a single point load at

  4. Synthesis of Glucose Spiropiperazinone Derivatives

    OpenAIRE

    Vasiļjevs, D

    2013-01-01

    Piperazinone derivatives аге noticeable peptidometics; therefore, they сап replace peptides, such as RGD and Leu-enkephalin in different biological processes. Some piperazinone derivatives are anticoagulants, others act like neurotransmitters. Herein, we report an approach for the synthesis of поуеl piperazinone ring containing spiro-derivatives of glucose.

  5. Piroxicam derivatives THz classification

    Science.gov (United States)

    Sterczewski, Lukasz A.; Grzelczak, Michal P.; Nowak, Kacper; Szlachetko, Bogusław; Plinska, Stanislawa; Szczesniak-Siega, Berenika; Malinka, Wieslaw; Plinski, Edward F.

    2016-02-01

    In this paper we report a new approach to linking the terahertz spectral shapes of drug candidates having a similar molecular structure to their chemical and physical parameters. We examined 27 newly-synthesized derivatives of a well-known nonsteroidal anti-inflammatory drug Piroxicam used for treatment of inflammatory arthritis and chemoprevention of colon cancer. The testing was carried out by means of terahertz pulsed spectroscopy (TPS). Using chemometric techniques we evaluated their spectral similarity in the terahertz range and attempted to link the position on the principal component analysis (PCA) score map to the similarity of molecular descriptors. A simplified spectral model preserved 75% and 85.1% of the variance in 2 and 3 dimensions respectively, compared to the input 1137. We have found that in 85% of the investigated samples a similarity of the physical and chemical parameters corresponds to a similarity in the terahertz spectra. The effects of data preprocessing on the generated maps are also discussed. The technique presented can support the choice of the most promising drug candidates for clinical trials in pharmacological research.

  6. Hyperlanguage, derivation and genre

    Directory of Open Access Journals (Sweden)

    Maria Marta Furlanetto

    2012-07-01

    Full Text Available The present paper has as its background a research on the trends of derivation in cultivated Brazilian Portuguese, whose partial results have allowed a reflection on the synthesis-theme: the functioning of a hyperlanguage. A hyperlanguage (notion developed by Sylvain Auroux, serves subjects, spatially and temporally, with certain linguistic capacities, immersed in a world in which there are, among other things, technical artifacts as grammars and dictionaries, which have a descriptive, but also a normative role. The result is a constant dispute between stabilization and destabilization (centripetal and centrifugal forces, in Bakhtin. By also using the play structure/event, according to the discursive semantics by Michel Pêcheux, my goal is to further reflect on the issues raised, approaching the historical-discursive provisionality of the identities in the production of meaning effects. From the practical standpoint, I point to the emergence of heterogeneous genres, as those which exploit humor, with indefinite authorship, and I propose the discursive reading of a sample.

  7. Derivative spectrophotometry of cobalt alloys

    International Nuclear Information System (INIS)

    Spitsyn, P.K.

    1985-01-01

    The method of derivative spectrophotometry is briefly described, and derivative absorption spectra are presented for samarium, cobalt, and commercial Sm-Co alloys. It is shown that the use of derivative spectrophotometry not only improves the accuracy and selectivity of element determinations but also simplifies the analysis of alloys. Results of a statistical evaluation of the metrological characteristics of the analytical procedure described here are presented. 8 references

  8. Push-outs of derivations

    Indian Academy of Sciences (India)

    B containing A as an ideal, thereby exploiting (or establishing) hereditary properties. This is usually done using ... space X [Bl, G2], it is exploited that derivations can be extended to the Banach alge- bra B(X) of all ... A derivation is inner if it is of the form a ↦→ a.x − x.a for some x ∈ X. The vector space of all derivations D: A ...

  9. [Urine derivation after radical cystectomy].

    Science.gov (United States)

    Jarabák, J; Zachoval, R; Vik, V

    2014-01-01

    Radical cystectomy, performed both for the treatment of cancer and other conditions, needs to be followed by ensuring the derivation of urine. The aim of this work is to summarize the possibilities of urine derivation after cystectomy, their advantages, disadvantages and long-term results. A review article summarising relevant literature and the team of authors own experience. This work compares advantages and risks of different types of urine derivation following radical cystectomy.

  10. derivatives: Synthesis and antimicrobial evaluation

    Indian Academy of Sciences (India)

    traced to or were inspired by natural products.1 These include natural products, natural product derivatives, synthetic compounds with natural product derived phar- macophores and synthetic compounds designed on the basis of knowledge gained from a natural product.2. Similarly, isocoumarins are an important class of.

  11. Tame-wild dichotomy for derived categories

    OpenAIRE

    Bekkert, Viktor I.; Drozd, Yuriy A.

    2003-01-01

    We prove that every finite dimensional algebra over an algebraically closed field is either derived tame or derived wild. The proof is based on the technique of matrix problems (boxes and reduction algorithm). It implies, in particular, that any degeneration of a derived wild algebra is derived wild; respectively, any deformation of a derived tame algebra is derived tame.

  12. Jordan-H\\"older theorems for derived categories of derived discrete algebras

    OpenAIRE

    Qin, Yongyun

    2015-01-01

    For any positive integer $n$, $n$-derived-simple derived discrete algebras are classified up to derived equivalence. Furthermore, the Jordan-H\\"older theorems for all kinds of derived categories of derived discrete algebras are obtained.

  13. Therapeutic Versatility of Resveratrol Derivatives.

    Science.gov (United States)

    Nawaz, Waqas; Zhou, Zhongqin; Deng, Sa; Ma, Xiaodong; Ma, Xiaochi; Li, Chuangang; Shu, Xiaohong

    2017-10-29

    Resveratrol, a natural phytoalexin, exhibits a remarkable range of biological activities, such as anticancer, cardioprotective, neuroprotective and antioxidant properties. However, the therapeutic application of resveratrol was encumbered for its low bioavailability. Therefore, many researchers focused on designing and synthesizing the derivatives of resveratrol to enhance the bioavailability and the pharmacological activity of resveratrol. During the past decades, a large number of natural and synthetic resveratrol derivatives were extensively studied, and the methoxylated, hydroxylated and halogenated derivatives of resveratrol received particular more attention for their beneficial bioactivity. So, in this review, we will summarize the chemical structure and the therapeutic versatility of resveratrol derivatives, and thus provide the related structure activity relationship reference for their practical applications.

  14. Deriving belief operators from preferences

    OpenAIRE

    Asheim, Geir B.

    2000-01-01

    A belief operator derived from preferences is presented. It generalizes ‘belief with probability1’ to incomplete preferences and satisfies minimal requirements for belief operators under weak conditions.

  15. Elementary derivation of Kepler's laws

    International Nuclear Information System (INIS)

    Vogt, E.

    1995-02-01

    A simple derivation of all three so-called Kepler Laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian Mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford Scattering Law. (author). 4 refs., 3 figs

  16. Derivatives Trading and Negative Voting

    OpenAIRE

    Spamann, Holger

    2012-01-01

    This paper exposits a model of parallel trading of corporate securities (shares, bonds) and derivatives in which a large trader can sometimes profitably acquire securities with their corporate control rights for the sole purpose of reducing the corporations value and gaining on a net short position created through off-setting derivatives. At other times, the large trader profitably takes a net long position. The large trader requires no private information beyond its own trades. The problem i...

  17. Push-outs of derivations

    Indian Academy of Sciences (India)

    extension as a limit of operators b ↦→ D(ba) − b.D(a), a ∈ A in an appropriate operator topology, the main point in the proof being to show that the limit map is in fact a derivation. In this paper we make clear which part of this approach is analytic and which algebraic by presenting an algebraic scheme that gives derivations ...

  18. Electricity derivatives and risk management

    Energy Technology Data Exchange (ETDEWEB)

    Deng, S.J. [School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0205 (United States); Oren, S.S. [Department of Industrial Engineering and Operations Research, University of California, Berkeley, CA 94720 (United States)

    2006-05-15

    Electricity spot prices in the emerging power markets are volatile, a consequence of the unique physical attributes of electricity production and distribution. Uncontrolled exposure to market price risks can lead to devastating consequences for market participants in the restructured electricity industry. Lessons learned from the financial markets suggest that financial derivatives, when well understood and properly utilized, are beneficial to the sharing and controlling of undesired risks through properly structured hedging strategies. We review different types of electricity financial instruments and the general methodology for utilizing and pricing such instruments. In particular, we highlight the roles of these electricity derivatives in mitigating market risks and structuring hedging strategies for generators, load serving entities, and power marketers in various risk management applications. Finally, we conclude by pointing out the existing challenges in current electricity markets for increasing the breadth, liquidity and use of electricity derivatives for achieving economic efficiency. (author)

  19. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  20. Relieving of Misconceptions of Derivative Concept with Derive

    Science.gov (United States)

    Kaplan, Abdullah; Ozturk, Mesut; Ocal, Mehmet Fatih

    2015-01-01

    The purpose of this study is to determine students' learning levels in derivative subjects and their misconceptions. In addition, this study aims to compared to the effects of the computer based instruction and traditional instruction in resolving these misconceptions. For this purpose, 12th grade 70 students were chosen from high schools in Agri…

  1. Synthesis of 2-phosphaadamantane derivatives

    International Nuclear Information System (INIS)

    Zemlyanoi, V.N.; Aleksandrov, A.M.; Kukhar', V.P.

    1986-01-01

    The authors describe the synthesis and properties of 2-phosphadamantane derivatives. For the synthesis of 2-phosphaadamantane derivatives they decided to use the methodology of the synthesis of 2-thiaadamantane. The IR spectra were determined on CHCl 3 solutions with a Specord 711R spectrometer, the PMR spectra were determined on Tesla BS-467 (60 MHz) and Bruker WP-200 (200 MHz) spectrometers, external standard hexamethyldisiloxane, the 31 P NMR spectra were determined on Tesla BS-487 C (30 MHz) and Bruker WP-200 (81 MHz) spectrometers, external standard 85% phosphoric acid, and the mass spectra were determined on an MS-1302 spectrometer

  2. Derived equivalences for group rings

    CERN Document Server

    König, Steffen

    1998-01-01

    A self-contained introduction is given to J. Rickard's Morita theory for derived module categories and its recent applications in representation theory of finite groups. In particular, Broué's conjecture is discussed, giving a structural explanation for relations between the p-modular character table of a finite group and that of its "p-local structure". The book is addressed to researchers or graduate students and can serve as material for a seminar. It surveys the current state of the field, and it also provides a "user's guide" to derived equivalences and tilting complexes. Results and proofs are presented in the generality needed for group theoretic applications.

  3. Risk Factors in Derivatives Markets

    Directory of Open Access Journals (Sweden)

    Raimonda Martinkutė-Kaulienė

    2015-02-01

    Full Text Available The objective of the article is to analyse and present the classification of risks actual to derivative securities. The analysis is based on classical and modern literature findings and analysis of newest statistical data. The analysis led to the conclusion, that the main risks typical for derivatives contracts and their traders are market risk, liquidity risk, credit and counterparty risk, legal risk and transactions risk. Pricing risk and systemic risk is also quite important. The analysis showed that market risk is the most important kind of risk that in many situations influences the level of remaining risks.

  4. Radiolabeled derivatives of folic acid

    International Nuclear Information System (INIS)

    1980-01-01

    Derivatives of folic acid are described, in which the α-carboxyl group is substituted with an amino compound having an aromatic or heterocyclic ring substituent which is capable of being radiolabelled. Particularly mentioned as a radiolabel is 125 I. (author)

  5. Antileishmanial activity of polycyclic derivatives

    Directory of Open Access Journals (Sweden)

    Sarciron M.E.

    2005-09-01

    Full Text Available 33 polycyclic derivatives have been studied and tested on Leishmania donovani and L. major promastigotes. Their antileishmanial activity was assessed in vitro and an assay of their cytotoxicity was realized on human myelomonocytic cell line. The reference molecules used in the assays were amphotericin B and pentamidine. Among the compounds tested, 29 possess an antileishmanial activity; 25 of those were more active against L. donovani than amphotericin B, and nine were as effective as amphotericin B against L. major. Many synthesized derivatives were more active against L.donovani than against L. major. The cytotoxicity studies have shown that among the thirty-three derivatives tested, 12 molecules have an IC50 towards THP-1 cells about equal than that reference drugs, the 21 other derivatives are much less toxic. A 3D QSAR study was undertaken and has permitted to predict activity against L. donovani and L. major and to highlight critical area to optimize activity against the two species.

  6. Bounded Densities and Their Derivatives

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, V.

    2009-01-01

    This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...

  7. Derivation of Schwinger variational principles

    International Nuclear Information System (INIS)

    Szmytkowski, R.

    2003-01-01

    We present systematic derivations of bilinear and fractional Schwinger variational principles for matrix elements of a generalized transition operator in the context of quantum mechanical potential scattering. The employed method is based on a generalization of the method of Lagrange multipliers

  8. First derivative potentiometric and spectrophotometric ...

    African Journals Online (AJOL)

    This study sets out to provide simple, inexpensive and sensitive analytical techniques for the assay of cimetidine in tablet dosage forms using first derivative potentiometric and UV-spectrophotometric techniques, with a view to providing simple, sensitive and cost-effective analytical methods. Ten brands of cimetidine tablets ...

  9. Alchemical derivatives of reaction energetics

    Science.gov (United States)

    Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O. Anatole

    2010-08-01

    Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts.

  10. Radiological protection optimization using derivatives

    International Nuclear Information System (INIS)

    Freitas Acosta Perez, C. de; Sordi, G.M.A.A.

    2006-01-01

    The aim of this paper is to provide a different approach related to the integral cost-benefit and extended cost-benefit analysis used in the decision-aiding techniques. In the ICRP publication 55 the annual protection cost is envisaged as a set of points, each of them representing an option, linked by a straight line. The detriment cost function is considered a linear function whose angular coefficient is determined by the alpha value. In this paper the uranium mine example considered in the ICRP publication 55 was used. But the potential curve was introduced both in the integral cost benefit analysis and in the extended cost-benefit analysis, which the individual dose distribution attribute is added. The result was obtained using derivatives. The detriment cost, Y, is not necessary because the alpha value is known. The Y derivative dS/dY is the alpha value itself and so, the attention is directed to the derivative -dX/dS on the points that, along with the alpha value, present the optimum option. The results makes clear that the prevailing factor in the optimum option selection is the alpha value imputed, and those a single alpha value, as suggested now, probably as little efficiency on the optimization process. Obtaining a curve for the alpha value and using the derivative technique introduced in this paper, the analytical solution is more convenient and reliable compared to the one used now. (authors)

  11. Novel bisstyryl derivatives of bakuchiol

    DEFF Research Database (Denmark)

    Reddy, Mallepally V; Thota, Niranjan; Sangwan, Payare L

    2010-01-01

    Novel bisstyryl derivatives of bakuchiol using Heck coupling reaction as the key step were synthesized and screened against a panel of six oral cavity pathogens for their antimicrobial activity. Four compounds (9-12) showed two to fourfold and four to eightfold better activity (MIC 0.25-16 microg...

  12. Second derivative spectrophotometric determination of ...

    African Journals Online (AJOL)

    A new, simple, rapid, wide applicable range and reliable second derivative spectrophotometric method has been developed for determination of cyclophosphamide (CP) in bulk and pharmaceutical dosage forms. Calibration graph is linear in the concentration range of 25 - 200 μg/ml of CP with 10 μg/ml of detection limit and ...

  13. Therapeutic Versatility of Resveratrol Derivatives

    OpenAIRE

    Waqas Nawaz; Zhongqin Zhou; Sa Deng; Xiaodong Ma; Xiaochi Ma; Chuangang Li; Xiaohong Shu

    2017-01-01

    Resveratrol, a natural phytoalexin, exhibits a remarkable range of biological activities, such as anticancer, cardioprotective, neuroprotective and antioxidant properties. However, the therapeutic application of resveratrol was encumbered for its low bioavailability. Therefore, many researchers focused on designing and synthesizing the derivatives of resveratrol to enhance the bioavailability and the pharmacological activity of resveratrol. During the past decades, a large number of natural a...

  14. Second derivative spectrophotometric determination of ...

    African Journals Online (AJOL)

    Hemn

    2013-11-13

    Nov 13, 2013 ... olanzapine in pharmaceutical formulation.Int.J.ChemTech. Res.2(1):756-761. Stanisz B, Paszun S, Lesniak M (2009). Validation of UV derivative spectrophotometric method for determination of benazepril hydrochloride in tablets and evaluation of its stability.ActaPoloniaePharmaceutica-Drug Research.

  15. Higher-derivative generalization of conformal mechanics

    Science.gov (United States)

    Baranovsky, Oleg

    2017-08-01

    Higher-derivative analogs of multidimensional conformal particle and many-body conformal mechanics are constructed. Their Newton-Hooke counterparts are derived by applying appropriate coordinate transformations.

  16. Derivatives in energy project finance

    International Nuclear Information System (INIS)

    Spencer, Lloyd

    1999-01-01

    This chapter focuses on risk management of merchant power generation projects and describes project finance as balancing risk and reward over time. The historical background to risk management is traced, and the case for derivatives in energy project finance is put forward with the hedging of forward output, and forwards and power purchase agreements discussed. Current and prospective usage, and the implementation issues of market liquidity, margin calls, letters of credit, derivative counterparty credit risk, and accounting policy are considered. A detailed example of a gas-fired plant in the US is presented with details given of the distribution of project earnings before tax. Oil field operating cashflows are examined, with reserved flow models, leverage effects, and price hedging addressed

  17. Position Estimation Using Image Derivative

    Science.gov (United States)

    Mortari, Daniele; deDilectis, Francesco; Zanetti, Renato

    2015-01-01

    This paper describes an image processing algorithm to process Moon and/or Earth images. The theory presented is based on the fact that Moon hard edge points are characterized by the highest values of the image derivative. Outliers are eliminated by two sequential filters. Moon center and radius are then estimated by nonlinear least-squares using circular sigmoid functions. The proposed image processing has been applied and validated using real and synthetic Moon images.

  18. Financial Derivatives (Based on Two Supports Evaluation

    Directory of Open Access Journals (Sweden)

    Tiberiu Socaciu

    2016-07-01

    Full Text Available In this paper we build a PDE like Black-Scholes equation in hypothesis of a financial derivative that is dependent on two supports (usual is dependent only on one support, like amoption based on gold, when national currency has a great float.Keywords: Financial derivatives, derivatives evaluation, derivatives based on two supports, extended Itō like lemma.

  19. Derived equivalences induced by good silting complexes

    OpenAIRE

    Breaz, Simion; Modoi, George Ciprian

    2017-01-01

    Consider a (possibly big) silting object $U$ in a derived category over a (dg-)algebra $A$. Under some fairly general appropriate hypotheses, we show that it induces derived equivalences between the derived category over $A$ and a localization of the derived category of dg-endomorphism algebra $B$ of $U$. If, in addition, $U$ is small then this localization is the whole derived category over $B$.

  20. Deformable fractional derivative and its applications

    Science.gov (United States)

    Ahuja, Priyanka; Zulfeqarr, Fahed; Ujlayan, Amit

    2017-10-01

    In this paper, we introduce an application of recently proposed deformable derivative which is equivalent to ordinary derivative in the sense that one implies other. The deformable derivative is defined using limit approach as ordinary derivative. Thus it could also be regarded as fractional derivative. The simple nature of this definition allows us for the extension of some classical theorems in calculus like the Rolles, Mean Value and Extended Mean Value theorems. As a theoritical application some fractional differentiable equations are solved.

  1. Development trends of the international derivatives market

    OpenAIRE

    Motorniuk, U.; Terebukh, M.; Kharchuk, V.

    2016-01-01

    The factors forming international derivatives market trends are researched in this article. The history of the formation of the global derivatives market was analyzed, in particular, events which have led to the growth of the derivatives market. Global derivatives market has revealed major changes in its trends and witnessed the gradual transformation of its structure, observed in recent years. Global derivatives market has revealed major changes in its trends and witnessed the gradual transf...

  2. Iron and iron derived radicals

    International Nuclear Information System (INIS)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fast! Think small! In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab

  3. Stable Hemiaminals: 2-Aminopyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Anna Kwiecień

    2015-08-01

    Full Text Available Stable hemiaminals can be obtained in the one-pot reaction between 2-aminopyrimidine and nitrobenzaldehyde derivatives. Ten new hemiaminals have been obtained, six of them in crystal state. The molecular stability of these intermediates results from the presence of both electron-withdrawing nitro groups as substituents on the phenyl ring and pyrimidine ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess a tetrahedral carbon atom constituting a stereogenic centre. As the result of crystallisation in centrosymmetric space groups both enantiomers are present in the crystal structure.

  4. Resorcinol derivatives from Ardisia maculosa.

    Science.gov (United States)

    Zheng, Ying; Wu, Feng-E

    2007-01-01

    Besides a series of known sterols and triterpenoids, a new resorcinol (1) and a known resorcinol (2) have been isolated from ethanol extract of Ardisia maculosa for the first time. The structures of these resorcinol derivatives were elucidated as 2-methyl-5-(Z-heptadec-8-enyl) resorcinol and 5-Z-heptadec-8-enyl) resorcinol by HRESI-MS, NMR ((1)H, (13)C, HSQC, HMBC) experiments. In our in vitro assay, compounds 1 and 2 showed no antimicrobial activities, however, compound 2 exhibited cytotoxity activity against human cancer cell line with GI(50) value of 2.14 x 10(- 4) mmol/ml.

  5. Radioiodination of C60 derivative

    International Nuclear Information System (INIS)

    Li Yuguo; Zhang Xiaodong; Li Qingnuan; Li Wenxin

    2001-01-01

    The water-soluble C 60 derivative was iodo-labelled radioactively with Iodogen method. The labelled yield was measured by Silica GF254 TLC. The effects of pH value, time, temperature and the amount of Iodogen on the labelled yield were studied. 125 I-C 60 (OH) x O y was purified by Sephadex G-25 column chromatography and then the stability of 125 I-C 60 (OH) x O y was examined. The results showed that the radiochemical purity of 125 I-C 60 (OH) x O y solution with 2% benzylalcohol remained 82.7% after 43h

  6. Adipose-Derived Stem Cells

    DEFF Research Database (Denmark)

    Toyserkani, Navid Mohamadpour; Quaade, Marlene Louise; Sheikh, Søren Paludan

    2015-01-01

    Emerging evidence has shown that adipose tissue is the richest and most accessible source of mesenchymal stem cells. Many different therapies for chronic wounds exist with varying success rates. The capacity of adipose-derived stem cells (ASCs) to promote angiogenesis, secrete growth factors......, regulate the inflammatory process, and differentiate into multiple cell types makes them a potential ideal therapy for chronic wounds. The aim of this article was to review all preclinical trials using ASCs in problem wound models. A systematic search was performed and 12 studies were found where different...

  7. Derivative Kernels: Numerics and Applications.

    Science.gov (United States)

    Hosseini, Mahdi S; Plataniotis, Konstantinos N

    2017-10-01

    A generalized framework for numerical differentiation (ND) is proposed for constructing a finite impulse response (FIR) filter in closed form. The framework regulates the frequency response of ND filters for arbitrary derivative-order and cutoff frequency selected parameters relying on interpolating power polynomials and maximally flat design techniques. Compared with the state-of-the-art solutions, such as Gaussian kernels, the proposed ND filter is sharply localized in the Fourier domain with ripple-free artifacts. Here, we construct 2D MaxFlat kernels for image directional differentiation to calculate image differentials for arbitrary derivative order, cutoff level and steering angle. The resulted kernel library renders a new solution capable of delivering discrete approximation of gradients, Hessian, and higher-order tensors in numerous applications. We tested the utility of this library on three different imaging applications with main focus on the unsharp masking. The reported results highlight the high efficiency of the 2D MaxFlat kernel and its versatility with respect to robustness and parameter control accuracy.

  8. Amphiphilic copolymers based on polyoxazoline and grape seed vegetable oil derivatives: self-assemblies and dynamic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Travelet, Christophe, E-mail: Christophe.Travelet@cermav.cnrs.fr [Universite Joseph Fourier (UJF), Institut de Chimie Moleculaire de Grenoble (ICMG-FR 2607 CNRS), PolyNat Carnot institute, Arcane LabEx, domaine universitaire de Grenoble, Centre de Recherches sur les Macromolecules Vegetales - CERMAV-UPR 5301 CNRS (France); Stemmelen, Mylene; Lapinte, Vincent [Universite de Montpellier II, Institut Charles Gerhardt Montpellier (UMR 5253 CNRS-UM2-UM1-ENSCM), equipe ingenierie et architectures macromoleculaires (France); Dubreuil, Frederic [Universite Joseph Fourier (UJF), Institut de Chimie Moleculaire de Grenoble (ICMG-FR 2607 CNRS), PolyNat Carnot institute, Arcane LabEx, domaine universitaire de Grenoble, Centre de Recherches sur les Macromolecules Vegetales - CERMAV-UPR 5301 CNRS (France); Robin, Jean-Jacques [Universite de Montpellier II, Institut Charles Gerhardt Montpellier (UMR 5253 CNRS-UM2-UM1-ENSCM), equipe ingenierie et architectures macromoleculaires (France); and others

    2013-06-15

    The self-assembly in solution of original structures of amphiphilic partially natural copolymers based on polyoxazoline [more precisely poly(2-methyl-2-oxazoline) (POx)] and grape seed vegetable oil derivatives (linear, T-, and trident-structure) is investigated. The results show that such systems are found, using dynamic light scattering (DLS), to spontaneously self-organize into monomodal, narrow-size, and stable nanoparticles in aqueous medium. The obtained hydrodynamic diameters (D{sub h}) range from 8.6 to 32.5 nm. Specifically, such size increases strongly with increasing natural block (i.e., lipophilic species) length due to higher hydrophobic interactions (from 10.1 nm for C{sub 19} to 19.2 nm for C{sub 57}). Furthermore, increasing the polyoxazoline (i.e., hydrophilic block) length leads to a moderate linear increase of the D{sub h}-values. Therefore, the first-order size effect comes from the natural lipophilic block, whereas the characteristic size can be tuned more finely (i.e., in a second-order) by choosing appropriately the polyoxazoline length. The DLS results in terms of characteristic size are corroborated using nanoparticle tracking analysis (NTA), and also by atomic force microscopy (AFM) and transmission electron microscopy (TEM) imaging where well-defined spherical and individual nanoparticles exhibit a very good mechanical resistance upon drying. Moreover, changing the lipophilic block architecture from linear to T-shape, while keeping the same molar mass, generates a branching and thus a shrinking by a factor of 2 of the nanoparticle volume, as observed by DLS. In this paper, it is clearly shown that the self-assemblies of amphiphilic block copolymer obtained from grape seed vegetable oil derivatives (sustainable renewable resources) as well as their tunability are of great interest for biomass valorization at the nanoscale level [continuation of the article by Stemmelen et al. (Polym Chem 4:1445-1458, 2013)].Graphical Abstract

  9. Penetratin and derivatives acting as antifungal agents

    NARCIS (Netherlands)

    Masman, Marcelo F.; Rodriguez, Ana M.; Raimondi, Marcela; Zacchino, Susana A.; Luiten, Paul G. M.; Somlai, Csaba; Kortvelyesi, Tamas; Penke, Botond; Enriz, Ricardo D.

    The synthesis, in vitro evaluation, and conformational study of RQIKTWFQNRRMKWKK-NH(2) (penetratin) and related derivatives acting as antifungal agents are reported. Penetratin and some of its derivatives displayed antifungal activity against the human opportunistic pathogenic standardized ATCC

  10. Derivative Sign Patterns in Two Dimensions

    Science.gov (United States)

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  11. fq-Derivations of G-Algebra

    Directory of Open Access Journals (Sweden)

    Deena Al-Kadi

    2016-01-01

    Full Text Available We introduce the notion of fq-derivation as a new derivation of G-algebra. For an endomorphism map f of any G-algebra X, we show that at least one fq-derivation of X exists. Moreover, for such a map, we show that a self-map dqf of X is fq-derivation of X if X is an associative medial G-algebra. For a medial G-algebra X, dqf is fq-derivation of X if dqf is an outside fq-derivation of X. Finally, we show that if f is the identity endomorphism of X then the composition of two fq-derivations of X is a fq-derivation. Moreover, we give a condition to get a commutative composition.

  12. Surprising Results Using Calculators for Derivatives.

    Science.gov (United States)

    Goetz, Albert; Kahan, Jeremy

    1995-01-01

    Attempts to answer and generalize the question: When is the numerical derivative obtained on the graphing calculator greater than the actual derivative, and when is it smaller? Discusses symmetric difference. (MKR)

  13. Silsesquioxane-derived ceramic fibres

    Science.gov (United States)

    Hurwitz, F. I.; Farmer, S. C.; Terepka, F. M.; Leonhardt, T. A.

    1991-01-01

    Fibers formed from blends of silsesquioxane polymers were characterized to study the pyrolytic conversion of these precursors to ceramics. The morphology of fibers pyrolyzed to 1400 C revealed primarily amorphous glasses whose conversion to beta-SiC is a function of both blend composition and pyrolysis conditions. Formation of beta-SiC crystallites within the glassy phase is favored by higher than stoichiometric C/Si ratios, while carbothermal reduction of Si-O bonds to form SiC with loss of SiO and CO occurs at higher methyl/phenylpropyl silsesquioxane (lower C/Si) ratios. As the carbothermal reduction is assumed to be diffusion controlled, the fibers can serve as model systems to gain understanding of the silsesquioxane pyrolysis behavior, and therefore are useful in the development of polysilsesquioxane-derived ceramic matrices and coatings as well.

  14. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan

    2007-06-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2 . Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b , 2(f1 , and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a , 2(c , 2(d1 , and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  15. Cytotoxicity study of pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Nusrat Binta Ahasan and Md. Rabiul Islam

    2007-12-01

    Full Text Available Pyrazolone heterocyclic compound, 3-methyl-1-phenyl-2-pyrazoline-5-one 2(a was synthesized by condensation reaction between ethyl acetoacetate and phenyl hydrazine and was converted into their corresponding heterocyclic derivatives 2(b to 2(f2. Their cytotoxicity effects were measured by brine shrimp lethality bioassay. Among them the compounds 2(b, 2(f1, and 2(f2 were highly active according to IC50 values 19.50, 19.50 and 20 ppm respectively. The rest of compounds 2(a, 2(c, 2(d1, and 2(d2 having IC50 values 38, 33.50, 37.50, 36, 37.50 and 36 ppm in that order, were moderately active.

  16. Iron and iron derived radicals

    Energy Technology Data Exchange (ETDEWEB)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  17. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  18. Polymer-Derived Ceramic Fibers

    Science.gov (United States)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  19. Bioactive Terpenes from Marine-Derived Fungi

    Directory of Open Access Journals (Sweden)

    Ahmed M. Elissawy

    2015-04-01

    Full Text Available Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years’ reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities.

  20. 40 CFR 721.5913 - Phenothiazine derivative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813) is...

  1. 40 CFR 721.1820 - Bisphenol derivative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Bisphenol derivative. 721.1820 Section... Substances § 721.1820 Bisphenol derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as bisphenol derivative (PMN No. P-92-509) is...

  2. 40 CFR 721.9658 - Thiadiazole derivative.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject to...

  3. 12 CFR 403.4 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Derivative classification. 403.4 Section 403.4 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  4. 28 CFR 17.26 - Derivative classification.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  5. 6 CFR 7.26 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Derivative classification. 7.26 Section 7.26... INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined... already classified, and marking the newly developed material consistent with the classification markings...

  6. 32 CFR 2001.22 - Derivative classification.

    Science.gov (United States)

    2010-07-01

    ... Intelligence. (4) When determining the most restrictive declassification instruction among multiple source... shall appear as: Derived From: Multiple Sources (ii) The derivative classifier shall include a listing... derivatively classified on the basis of a source document that is itself marked “Multiple Sources” shall cite...

  7. 12 CFR 563.172 - Financial derivatives.

    Science.gov (United States)

    2010-01-01

    ... underlying assets, indices, or reference rates. The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage derivative security, such as a collateralized mortgage... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Financial derivatives. 563.172 Section 563.172...

  8. Numerical simulation of liquid-liquid plug formation in a T-shaped cylindrical micro-channel

    Science.gov (United States)

    Chinaud, Maxime; Roumpea, Evangelia; Angeli, Panagiota; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Kahouadji, Lyes; Matar, Omar

    2015-11-01

    We present experimental studies and three-dimensional simulations using the code BLUE for different fluid flow rate combinations in a tubular T-junction. All branches have internal diameters equal to 200 μm. The dispersed phase consists of a water/glycerol solution injected from the side branch of the junction, while the continuous phase is silicon oil injected along the main channel axis. BLUE is a new massively parallel Navier-Stokes solver for multiphase flows. Communication across process threads is handled by MPI message passing procedures. The method for the treatment of the fluid phase interfaces and, in particular, capillary forces uses a hybrid Front Tracking/Level Set technique which defines the interface both by a discontinuous density field as well as by a local triangular Lagrangian mesh. This structure allows the interface to undergo large deformations including rupture or coalescence of fluid interfaces. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  9. Photoactive layer based on T-shaped benzimidazole dyes used for solar cell: from photoelectric properties to molecular design

    OpenAIRE

    Beibei Xu; Yuanzuo Li; Peng Song; Fengcai Ma; Mengtao Sun

    2017-01-01

    Three benzimidazole-based organic dyes, possessing the same triphenylamine donors and cyanoacrylic acid acceptors with the bithiophene ?-bridges combined in different nuclear positions of benzimidazole, were investigated in the utility of dye-sensitizer solar cells. The structure, molecular orbital and energy, absorption spectra and some important parameters (such as light harvesting efficiency (LHE), electron injection driving force, the electron injection time, chemical reactivity parameter...

  10. Educating T-Shaped professionals to meet substitution challenges and developing business models for substitution and recycling

    Science.gov (United States)

    Arroyo, Ana; Mendibil Eguiluz, Javier; Sánchez Cupido, Laura

    2018-03-01

    One strategy to overcome the challenges related to critical raw materials (CRMs) is their substitution and recycling. However, the bright scientific idea, proof of concept or laboratory demonstration need to cross the valley of death in order to become stated as ‘a substitute’ instead of ‘a potential substitute’. Most PhD students and Post Docs specialize within a given thematic area; for example on specific materials or on substitution in a certain application. This specialization could limit the ability to generate innovations and profitable business models if there are not enough tools and skills to transform new knowledge and research results into an appealing value proposition towards customers and to a business opportunity for the current markets. The project proposes a framework for developing substitution and recycling related cross-sectorial skills and tools. These are applied for training business-related competences e.g. teamwork, management, communication, value proposition and business models design, especially within RTOs and industries. The proposed learning itinerary can radically improve the path from scientific proof of concept into innovation and lean start up or industrial market launch. The developed framework is tested by a pilot group having several topics within the areas of substitution and recycling of critical raw materials.

  11. Deriving the bond pricing equation

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available Given the recent focus on Eurozone debt crisis and the credit rating downgrade not only of US debt, but that of other countries and many UK major banking institutions, this paper aims to explain the concept of bond yield, its different measures and bond pricing equation. Yields on capital market instruments are rarely quoted on the same basis, which makes direct comparison between different as investment choices impossible. Some debt instruments are quoted on discount basis, whilst coupon-bearing ones accrue interest differently, offer different compounding opportunities, have different coupon payment frequencies, and manage non-business day maturity dates differently. Moreover, rules governing debt vary across countries, markets and currencies, making yield calculation and comparison a rather complex issue. Thus, some fundamental concepts applicable to debt instrument yield measurement, with focus on bond equation, are presented here. In addition, bond equation expressed in annuity form and used to apply Newton-Raphson algorithm to derive true bond yield is also shown.

  12. The estimation of derived limits

    International Nuclear Information System (INIS)

    Harrison, N.T.; Bryant, P.M.; Clarke, R.H.; Morley, F.

    1979-08-01

    In practical radiation protection, it is often necessary to calculate limits of intake of radionuclides associated with various quantities; such limits are needed, for example, to assess the adequacy of the control of environmental contamination. In publication 26 of the International Commission on Radiological Protection (ICRP), these limits, when related to the basic limits of dose-equivalent by a defined model, are referred to as Derived Limits (DLs). In the present report the principles to be adopted by the Board in calculating DLs to be recommended for general application within the United Kingdom are outlined. DLs will be recommended for a wide range of radionuclides and for circumstances relevant to the workplace, and, more frequently, the general environment. The latter will include DLs in foodstuffs and associated environmental materials, such as soil and grass, and DLs for discharges from stacks. DLs will be related to dose equivalents for workers or members of the public for stochastic or non-stochastic effects as appropriate. Consideration will be given to relevant data on radiosensitivity, metabolism and dosimetry for children and to the physicochemical forms of radionuclides. (author)

  13. Option Derivatives in Electricity Hedging

    Directory of Open Access Journals (Sweden)

    P. Pavlátka

    2010-01-01

    Full Text Available Despite the high volatility of electricity prices, there is still little demand for electricity power options, and the liquidity on the power exchanges of these power derivatives is quite low. One of the reasons is the uncertainty about how to evaluate these electricity options and about finding the right fair value of this product. Hedging of electricity is associated mainly with products such as futures and forwards. However, due to new trends in electricity trading and hedging, it is also useful to think more about options and the principles for working with them in hedging various portfolio positions and counterparties. We can quite often encounter a situation when we need to have a perfect hedge for our customer’s (end user consuming electricity portfolio, or we have to evaluate the volumetric risk (inability of a customer to predict consumption, which is very similar to selling options. Now comes the moment to compare the effects of using options or futures to hedge these open positions. From a practical viewpoint, the Black-Scholes prices appear to be the best available and the simplest method for evaluating option premiums, but there are some limitations that we have to consider.

  14. Speeding up Derivative Configuration from Product Platforms

    Directory of Open Access Journals (Sweden)

    Ruben Heradio

    2014-06-01

    Full Text Available To compete in the global marketplace, manufacturers try to differentiate their products by focusing on individual customer needs. Fulfilling this goal requires that companies shift from mass production to mass customization. Under this approach, a generic architecture, named product platform, is designed to support the derivation of customized products through a configuration process that determines which components the product comprises. When a customer configures a derivative, typically not every combination of available components is valid. To guarantee that all dependencies and incompatibilities among the derivative constituent components are satisfied, automated configurators are used. Flexible product platforms provide a big number of interrelated components, and so, the configuration of all, but trivial, derivatives involves considerable effort to select which components the derivative should include. Our approach alleviates that effort by speeding up the derivative configuration using a heuristic based on the information theory concept of entropy.

  15. Perturbative reduction of derivative order in EFT

    Science.gov (United States)

    Glavan, Dražen

    2018-02-01

    Higher derivative corrections are ubiquitous in effective field theories, which seemingly introduces new degrees of freedom at successive orders. This is actually an artefact of the implicit local derivative expansion defining effective field theories. We argue that higher derivative corrections that introduce additional degrees of freedom should be removed and their effects captured either by lower derivative corrections, or special combinations of higher derivative corrections not propagating extra degrees of freedom. Three methods adapted for this task are examined and field redefinitions are found to be most appropriate. First order higher derivative corrections in a scalar tensor theory are removed by field redefinition and it is found that their effects are captured by a subset of Horndeski theories. A case is made for restricting the effective field theory expansions in principle to only terms not introducing additional degrees of freedom.

  16. Conformable derivative approach to anomalous diffusion

    Science.gov (United States)

    Zhou, H. W.; Yang, S.; Zhang, S. Q.

    2018-02-01

    By using a new derivative with fractional order, referred to conformable derivative, an alternative representation of the diffusion equation is proposed to improve the modeling of anomalous diffusion. The analytical solutions of the conformable derivative model in terms of Gauss kernel and Error function are presented. The power law of the mean square displacement for the conformable diffusion model is studied invoking the time-dependent Gauss kernel. The parameters related to the conformable derivative model are determined by Levenberg-Marquardt method on the basis of the experimental data of chloride ions transportation in reinforced concrete. The data fitting results showed that the conformable derivative model agrees better with the experimental data than the normal diffusion equation. Furthermore, the potential application of the proposed conformable derivative model of water flow in low-permeability media is discussed.

  17. Weather Derivatives – Origin, Types and Application

    Directory of Open Access Journals (Sweden)

    Piotr Binkowski

    2008-01-01

    Full Text Available The number of companies that are exposed to the revenues loss risk caused by weather variability is still increasing. The businesses that are mostly exposed to weather risk are following: energy, agriculture, constructions and transport. That situation has initiated dynamic growth of weather derivatives markets as well as the awareness of the weather risk among the market participants. Presently, the weather derivatives markets evaluate rapidly in all the mature economies: USA, Asia and Europe. Constructing weather derivatives relies on qu- antifying climate factors in the form of indexes, what is quite simple task, more difficultly can be gathering precise historical data of required climate factors. Taking into consideration so far development of derivatives especially the financial derivatives based on different types of indexes financial market has at disposal wide range of different types of proved derivatives (futures, forward, options, swaps, which can be successfully utilised on the weather-driven markets both for hedging weather risk and speculating.

  18. Derivative markets in emerging economies: a survey

    OpenAIRE

    Atılgan, Yiğit; Atilgan, Yigit; Demirtaş, Özgür; Demirtas, Ozgur; Şimşek, Koray Deniz; Simsek, Koray Deniz

    2016-01-01

    We review the literature on derivatives in emerging markets. This young but booming literature appears to be concentrated on a few countries, but is quite rich in terms of subject coverage. We classify these topics based on the generally recognized functions of derivative markets and restrict the review to the set of top journals in finance and those that specialize on emerging markets or derivatives.

  19. Transchromosomally derived Ig heavy chains

    Energy Technology Data Exchange (ETDEWEB)

    Knight, K.L.; Kingzette, M.; Crane, M.A. [Loyola Univ. Chicago, Maywood, IL (United States)] [and others

    1995-07-15

    During an immune response, activated B cells undergo isotype switching and begin to express isotypes other than IgM and IgD. Isotype switching occurs when downstream C{gamma}, C{alpha}, or C{epsilon} genes are rearranged into the S{mu} chromosomal region, resulting in the deletion of the region in between. These rearrangements usually occur in cis, i.e., intrachromosomally. In previous studies, we analyzed allotypic specificities of rabbit secretory IgA and identified a substantial number of IgA heavy chains with V{sub h} and C{alpha} allotypes that were encoded by V{sub h} and C{alpha} genes in trans. In those studies, however, we could not determine whether the trans association of V{sub H} and C{alpha} occurred during VDJ gene rearrangement or during isotype switching. Here, we cloned rabbit cDNA which encodes these trans IgA heavy chains and determined the chromosomal origin of the V{sub H}, J{sub H}, and C{alpha} regions. To determine whether the trans association occurred during VDJ gene rearrangement, we analyzed the nucleotide polymorphism of the J{sub H} region and the V{sub H} allotype encoded by the cDNA. We found that the V{sub H} and J{sub H} genes used in the VDJ gene rearrangements were from the same chromosome, indicating that the V{sub H}, D, and J{sub H} gene rearrangements occurred in cis. Furthermore, we analyzed the DNA polymorphisms of J{sub H} and C{alpha} and showed that the VDJ and C{alpha} genes encoding the trans IgA molecules were derived from different parental chromosomes. We suggest that the trans association occurred during isotype switching. This study shows that V{sub H} and C{sub H} can associate transchromosomally as part of a normal immune response. 34 refs., 5 figs.

  20. OLS ANALOG DERIVED LIGHTNING V11

    Data.gov (United States)

    National Aeronautics and Space Administration — The OLS Analog Derived Lightning dataset consists of global lightning signatures from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System...

  1. Heteropolyacids in synthesis of benzoyl hydrazone derivatives

    Directory of Open Access Journals (Sweden)

    Sodeh Sadjadi

    2009-12-01

    Full Text Available Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid hydrazide and aldehyde and ketone derivatives. The synthesis of N-acetyl and N-benzoyl derivatives has also been performed by the reaction of obtained benzoyl hydrazones with acylcholorides in presence of this kind of heteropolyacids.

  2. Molecular dynamics of a proguanil derivative

    African Journals Online (AJOL)

    pc

    ABSTRACT. Proguanil is a prophylactic antimalarial drug t stopping the malaria parasites from reprod molecular dynamics of a derivative of Progua benzene ring of the molecule of Proguanil derivative. The molecular geometries of chemical calculations at the Restricted Hatre. 31G(d,p) and 6-31++G. Also, Density Func.

  3. "Nonmorphological Derivations" and the Four Main English ...

    African Journals Online (AJOL)

    This article addresses the problem of "nonmorphological derivations" in English and its consequences for pedagogical lexicography, i.e. learner's dictionaries. The term "nonmorphological derivation" refers to cases such as sun — solar, moon — lunar, cat — feline, and in general to all cases where instead of, or in addition ...

  4. Synthesis of Lipophilic Guanine N-9 Derivatives

    DEFF Research Database (Denmark)

    Wamberg, Michael C; Pedersen, Pernille L; Löffler, Philipp M G

    2017-01-01

    the synthesis of five new guanine-N9 derivatives bearing alkyl chains with different attachment chemistries, exploiting a synthesis pathway that allows a flexible choice of hydrophobic anchor moiety. In this study, these guanine derivatives were functionalized with C10 chains for insertion into decanoic acid...

  5. Adsorption and desorption of cellulose derivatives

    NARCIS (Netherlands)

    Hoogendam, C.W.

    1998-01-01

    Cellulose derivatives, in particular carboxymethyl cellulose (CMC) are used in many (industrial) applications. The aim of this work is to obtain insight into the adsorption mechanism of cellulose derivatives on solid-liquid interfaces.

    In chapter

  6. Few Fractional Order Derivatives and Their Computations

    Science.gov (United States)

    Bhatta, D. D.

    2007-01-01

    This work presents an introductory development of fractional order derivatives and their computations. Historical development of fractional calculus is discussed. This paper presents how to obtain computational results of fractional order derivatives for some elementary functions. Computational results are illustrated in tabular and graphical…

  7. Stabilization of biomass-derived pyrolysis oils

    NARCIS (Netherlands)

    Venderbosch, R. H.; Ardiyanti, A. R.; Wildschut, J.; Oasmaa, A.; Heeres, H. J.

    BACKGROUND: Biomass is the only renewable feedstock containing carbon, and therefore the only alternative to fossil-derived crude oil derivatives. However, the main problems concerning the application of biomass for biofuels and bio-based chemicals are related to transport and handling, the limited

  8. Understanding the Derivative through the Calculus Triangle

    Science.gov (United States)

    Weber, Eric; Tallman, Michael; Byerley, Cameron; Thompson, Patrick W.

    2012-01-01

    Typical treatments of the derivative do not clearly convey the idea that the derivative function represents the original function's rate of change. Revealing the relationship between a function and its rate-of-change function for static values of "x" does not facilitate productive ways of thinking about generating the rate-of-change function or…

  9. 45 CFR 601.5 - Derivative classification.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Derivative classification. 601.5 Section 601.5... CLASSIFICATION AND DECLASSIFICATION OF NATIONAL SECURITY INFORMATION § 601.5 Derivative classification. Distinct from “original” classification is the determination that information is in substance the same as...

  10. 46 CFR 503.55 - Derivative classification.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Derivative classification. 503.55 Section 503.55... Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 12958... developed material consistent with the classification markings that apply to the source information, is...

  11. 5 CFR 2500.5 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as the...

  12. 17 CFR 200.506 - Derivative classification.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases...

  13. 22 CFR 9.6 - Derivative classification.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Derivative classification. 9.6 Section 9.6... classification. (a) Definition. Derivative classification is the incorporating, paraphrasing, restating or... with the classification of the source material. Duplication or reproduction of existing classified...

  14. "Nonmorphological Derivations" and the Four Main English ...

    African Journals Online (AJOL)

    rbr

    Abstract: This article addresses the problem of "nonmorphological derivations" in English and its consequences for pedagogical lexicography, i.e. learner's dictionaries. The term "nonmorpholo- gical derivation" refers to cases such as sun — solar, moon — lunar, cat — feline, and in general to all cases where instead of, ...

  15. Deriving force field parameters for coordination complexes

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Brandt, Peter

    2001-01-01

    The process of deriving molecular mechanics force fields for coordination complexes is outlined. Force field basics are introduced with an emphasis on special requirements for metal complexes. The review is then focused on how to set up the initial model, define the target, refine the parameters......, and validate the final force field, Alternatives to force field derivation are discussed briefly....

  16. Weyl and Marchaud Derivatives: A Forgotten History

    Directory of Open Access Journals (Sweden)

    Fausto Ferrari

    2018-01-01

    Full Text Available In this paper, we recall the contribution given by Hermann Weyl and André Marchaud to the notion of fractional derivative. In addition, we discuss some relationships between the fractional Laplace operator and Marchaud derivative in the perspective to generalize these objects to different fields of the mathematics.

  17. Weyl and Marchaud derivatives: a forgotten history

    OpenAIRE

    Ferrari, Fausto

    2017-01-01

    In this paper, we recall the contribution given by Hermann Weyl and André Marchaud to the notion of fractional derivative. In addition, we discuss some relationships between the fractional Laplace operator and Marchaud derivative in the perspective to generalize these objects to different fields of the mathematics.

  18. The Option Value in Timing Derivative Trades

    NARCIS (Netherlands)

    Drost, Feico; van der Heijden, T.G.E.; Werker, Bas

    Risk-neutral traders executing derivative trades on behalf of portfolio managers maximize their expected profit compared to trading at pre-determined times by timing trades, using the quickly changing risk exposures of derivative baskets. The optimal order submission strategy is a sequence of stop

  19. Heteropolyacids in synthesis of benzoyl hydrazone derivatives ...

    African Journals Online (AJOL)

    Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid hydrazide and aldehyde and ketone derivatives. The synthesis of N-acetyl and N-benzoyl derivatives has also been performed by the reaction of obtained benzoyl ...

  20. Derivatives and the non-executive director

    NARCIS (Netherlands)

    van der Nat, M.; Buckley, A.A.

    2003-01-01

    Do non-executive directors have the wherewithal to overview a corporation's integrity, quality of performance and management in the area of derivatives policy? In a survey of the understanding and monitoring of derivatives in a small sample of quoted companies, we found disturbing levels of

  1. Generalized Fractional Derivative Anisotropic Viscoelastic Characterization

    Directory of Open Access Journals (Sweden)

    Harry H. Hilton

    2012-01-01

    Full Text Available Isotropic linear and nonlinear fractional derivative constitutive relations are formulated and examined in terms of many parameter generalized Kelvin models and are analytically extended to cover general anisotropic homogeneous or non-homogeneous as well as functionally graded viscoelastic material behavior. Equivalent integral constitutive relations, which are computationally more powerful, are derived from fractional differential ones and the associated anisotropic temperature-moisture-degree-of-cure shift functions and reduced times are established. Approximate Fourier transform inversions for fractional derivative relations are formulated and their accuracy is evaluated. The efficacy of integer and fractional derivative constitutive relations is compared and the preferential use of either characterization in analyzing isotropic and anisotropic real materials must be examined on a case-by-case basis. Approximate protocols for curve fitting analytical fractional derivative results to experimental data are formulated and evaluated.

  2. Drug laws and the 'derivative' problem.

    Science.gov (United States)

    King, Leslie A; Ujváry, István; Brandt, Simon D

    2014-01-01

    The concept of a 'derivative' is used widely in chemistry, where its precise meaning depends on the circumstances. However, numerous examples of derivative also occur in domestic drugs legislation, some of which stem from the 1961 United Nations Single Convention on Narcotic Drugs. There is a commonly held view that only 'first-order' derivatives should be considered: substances that can be created from a parent structure in a single chemical reaction. In other words, 'derivatives of derivatives' are excluded. However, some substances related to ecgonine (e.g. 2-carbomethoxytropinone) are clearly convertible to cocaine, even though this may require more than one reaction step. It follows that 2-carbomethoxytropinone is a controlled drug, a situation that most chemists would regard as perverse. A more extreme example of the complexity of 'derivative' is shown by the conversion of thebaine to buprenorphine. Even though this requires six or more stages, the US Drug Enforcement Administration successfully argued in a 1986 case that for the purposes of the Controlled Substances Act, the number of steps required was irrelevant; buprenorphine was a derivative of thebaine. Because the term derivative is rarely defined in statutes, the legal status of some substances, such as 2-bromo-LSD, is uncertain. Although a number of definitions of derivative can be found in the chemical literature, no single definition is adequate to describe all situations where it occurs in legislation. Unless qualified, it is suggested that the term derivative should be avoided in any future legislation. Copyright © 2013 John Wiley & Sons, Ltd.

  3. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid...

  4. Four New Citrinin Derivatives from a Marine-Derived Penicillium sp. Fungal Strain

    OpenAIRE

    Wang, Mei; Lu, Chun; Xu, Qing; Song, Si; Hu, Zhi; Zheng, Zhong

    2013-01-01

    Four new citrinin derivatives, including two citrinin dimers and two citrinin monomer derivatives, were isolated and identified from a marine-derived fungal strain Penicillium sp. ML226 along with six known related compounds. Their structures were elucidated by spectroscopic and chemical methods. The new compounds showed modest cytotoxic activity against HepG-2 cell line and weak antimicrobial activity against Staphylococcus aureus.

  5. Risk management, derivatives and shariah compliance

    Science.gov (United States)

    Bacha, Obiyathulla Ismath

    2013-04-01

    Despite the impressive growth of Islamic Banking and Finance (IBF), a number of weaknesses remain. The most important of this is perhaps the lack of shariah compliant risk management tools. While the risk sharing philosophy of Islamic Finance requires the acceptance of risk to justify returns, the shariah also requires adherents to avoid unnecessary risk-maysir. The requirement to avoid maysir is in essence a call for the prudent management of risk. Contemporary risk management revolves around financial engineering, the building blocks of which are financial derivatives. Despite the proven efficacy of derivatives in the management of risk in the conventional space, shariah scholars appear to be suspicious and uneasy with their use in IBF. Some have imposed outright prohibition of their use. This paper re-examines the issue of contemporary derivative instruments and shariah compliance. The shariah compatibility of derivatives is shown in a number of ways. First, by way of qualitative evaluation of whether derivatives can be made to comply with the key prohibitions of the sharia. Second, by way of comparing the payoff profiles of derivatives with risk sharing finance and Bai Salam contracts. Finally, the equivalence between shariah compliant derivatives like the IPRS and Islamic FX Currency Forwards with conventional ones is presented.

  6. Derivation of GFDM Based on OFDM Principles

    Energy Technology Data Exchange (ETDEWEB)

    Hussein Moradi; Behrouz Farhang-Boroujeny

    2015-06-01

    This paper starts with discussing the principle based on which the celebrated orthogonal frequency division multiplexing (OFDM) signals are constructed. It then extends the same principle to construct the newly introduced generalized frequency division multiplexing (GFDM) signals. This novel derivation sheds light on some interesting properties of GFDM. In particular, our derivation seamlessly leads to an implementation of GFDM transmitter which has significantly lower complexity than what has been reported so far. Our derivation also facilitates a trivial understanding of how GFDM (similar to OFDM) can be applied in MIMO channels.

  7. Vulnerable Derivatives and Good Deal Bounds

    DEFF Research Database (Denmark)

    Murgoci, Agatha

    2013-01-01

    a new restriction in the arbitrage free model by setting upper bounds on the Sharpe ratios (SRs) of the assets. The potential prices that are eliminated represent unreasonably good deals. The constraint on the SR translates into a constraint on the stochastic discount factor. Thus, tight pricing bounds......We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modelled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes...... in a consistent way. Finally, we numerically analyse the behaviour of the good deal pricing bounds....

  8. Derived Categories and Zero-Brane Stability

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, Albion

    2001-07-25

    We define a particular class of topological field theories associated to open strings and prove the resulting D-branes and open strings form the bounded derived category of coherent sheaves. This derivation is a variant of some ideas proposed recently by Douglas. We then argue that any 0-brane on any Calabi-Yau threefold must become unstable along some path in the Kahler moduli space. As a byproduct of this analysis we see how the derived category can be invariant under a birational transformation.

  9. Particle production in higher derivative theory

    Indian Academy of Sciences (India)

    Lemaitre–Robertson–Walker cosmological model during the early stages of the universe is analysed in the framework of higher derivative theory. The universe has been considered as an open thermodynamic system where particle production ...

  10. Battery failure model derived from flaw theory

    Science.gov (United States)

    Schulman, I.

    1981-01-01

    A previously derived failure model for battery lifetime is discussed in terms of growth rate of the flaw, distribution of flaw sizes, and number of flaws. Equations are presented for determining the failure model for a nickel cadmium battery.

  11. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    Science.gov (United States)

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  12. SYNTHESIS OF SUBSTITUTED FLAVONE DERIVATIVES AS ...

    African Journals Online (AJOL)

    Preferred Customer

    results showed that this skeletal framework exhibited marked potency as antimicrobial agents. KEY WORDS. KEY WORDS: Chalcone ... It showed significant role in pharmaceutical effects [1] including leishmanicidal activity, oviposter ... new substituted flavone derivative as potent antimicrobial agent. EXPERIMENTAL.

  13. Langmuir-Blodgett Films of Graphene Derivatives

    DEFF Research Database (Denmark)

    Petersen, Søren Vermehren

    The work presented in this PhD thesis can be divided into two main categories: 1) Syn-thesis and Langmuir-Blodgett assembly of graphene derivatives and 2) Application and characterization of graphene derivatives as an interface material in molecular electron-ics. While the first category could...... be divided further, the synthesis and Langmuir-Blodgett results are intertwined in such a way that it would be more confusing to pre-sent them separately. The Langmuir-Blodgett deposition also played a crucial, but more isolated, part in the investigation of graphene derivatives as interface material....... Solution processable graphene in the form of chemically derived graphene has been synthesized through the modified Hummers method with subsequent reduction into reduced graphene oxide with hydrazine. The completeness of oxidation, the effect of the refinement steps and the reduction of the graphene oxide...

  14. Generalized Back Propagation for Training Pattern Derivatives

    Czech Academy of Sciences Publication Activity Database

    Šíma, Jiří

    1994-01-01

    Roč. 4, č. 1 (1994), s. 91-98 ISSN 1210-0552 Grant - others:ALTEC(XE) IC-1000 Keywords : back propagation * smoothness constraints * multi-layered network * expert system * explicite kulle * trainning pattern derivatives * generalization

  15. Anodic selective functionalization of cyclic amine derivatives

    OpenAIRE

    Onomura, Osamu

    2012-01-01

    Anodic reactions are desirable methods from the viewpoint of Green Chemistry, since no toxic oxidants are necessary for the oxidation of organic molecules. This review introduces usefulness of anodic oxidation and successive reaction for selective functionalization of cyclic amine derivatives.

  16. Proteomics Applications in Dental Derived Stem Cells.

    Science.gov (United States)

    Li, Jie; Tian, Weidong; Song, Jinlin

    2017-07-01

    At present, the existence of a variety of dental derived stem cells has been documented. These cells displayed promising clinical application potential not only for teeth and its surrounding tissue regeneration, but also for other tissues, such as nerve and bone regeneration. Proteomics is an unbiased, global informatics tool that provides information on all protein expression levels as well as post-translational modification in cells or tissues and is applicable to dental derived stem cells research. Over the last decade, considerable progress has been made to study the global proteome, secrotome, and membrane proteome of dental derived stem cells. Here, we present an overview of the proteomics studies in the context of stem cell research. Particular attention is given to dental derived stem cell types as well as current challenges and opportunities. J. Cell. Physiol. 232: 1602-1610, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Synthesis and reactions of ferrocene derived hydroxymethyl ...

    Indian Academy of Sciences (India)

    Administrator

    racemic phosphines and their sulphides having hydroxymethyl and morpholinomethyl substituents on the phosphorus. Use of ferrocene-derived hydroxymethyl phosphine sulphide as a potential precursor for making organometallic spirocyclic compounds with inorganic heterocycles is studied. Reference. 1. Goodwin N J ...

  18. Patient-Derived Antibody Targets Tumor Cells

    Science.gov (United States)

    An NCI Cancer Currents blog on an antibody derived from patients that killed tumor cells in cell lines of several cancer types and slowed tumor growth in mouse models of brain and lung cancer without evidence of side effects.

  19. An application of the Ruscheweyh derivatives

    Directory of Open Access Journals (Sweden)

    Shigeyoshi Owa

    1986-01-01

    Full Text Available Let Dαf(z be the Ruscheweyh derivative defined by using the Hadamard product of f(z and z/(1−z1+α. Certain new classes Sα* and Kα are introduced by virtue of the Ruscheweyh derivative. The object of the present paper is to establish several interesting properties of Sα* and Kα. Further, some results for integral operator Jc(f of f(z are shown.

  20. Computer derivation of some dolphin echolocation signals.

    Science.gov (United States)

    Altes, R A

    1971-09-03

    Recent advances in radar theory have given rise to a straightforward method of sonar signal design. The method involves computer maximization of a signal-to-interference ratio. The procedure has been used to derive sonar signals that can accurately measure target velocity. When two dolphins were placed in a situation conducive to the utilization of such signals, their waveforms were similar to those that had been theoretically derived.

  1. Higher-derivative Lee-Wick unification

    International Nuclear Information System (INIS)

    Carone, Christopher D.

    2009-01-01

    We consider gauge coupling unification in Lee-Wick extensions of the Standard Model that include higher-derivative quadratic terms beyond the minimally required set. We determine how the beta functions are modified when some Standard Model particles have two Lee-Wick partners. We show that gauge coupling unification can be achieved in such models without requiring the introduction of additional fields in the higher-derivative theory and we comment on possible ultraviolet completions.

  2. Financial derivatives in power marketing: The basics

    International Nuclear Information System (INIS)

    Ramesh, V.C.; Ghosh, K.

    1996-01-01

    With the ongoing changes in the power industry worldwide, electricity is beginning to be traded like other commodities. The use of financial derivative instruments in power markets is on the rise. The purpose of this paper is to explain the role of these derivatives in risk management which is vital for survival in the increasingly competitive industry. Starting with the familiar cash markets, the paper discusses the basics of futures, options, and swap markets as applied to electric energy trading

  3. Power cocentralizing generalized derivations on prime rings

    Indian Academy of Sciences (India)

    ring it follows that [R,R] ⊆ L. This follows from pp. 4–5 in [6], Lemma 2 and Proposition 1 in [4] and Theorem 4 in [8]. 2. The case of inner generalized derivations on prime rings. We dedicate this section to prove the theorem in case both the generalized derivations. H and G are inner, that is there exist b, c, p, q ∈ U such that ...

  4. Molluscicidal and trypanocidal activities of lapachol derivatives.

    Science.gov (United States)

    Santos, A F; Ferraz, P A; de Abreu, F C; Chiari, E; Goulart, M O; Sant'Ana, A E

    2001-02-01

    The activity of the potassium salt of lapachol against the snail Biomphalaria glabrata and its egg masses was tested. The obtained IC50 values (2.70 ppm and 1.43 ppm, respectively) are indicative of a strong activity. Lapachol derivatives were also assayed against infective trypomastigote blood forms of T. cruzi and the triacetoxy derivative of reduced lapachol showed relevant trypanocidal activity, killing 95.7% of the parasites at the concentration of 42 microg/mL.

  5. Weather Derivatives – Origin, Types and Application

    OpenAIRE

    Piotr Binkowski

    2008-01-01

    The number of companies that are exposed to the revenues loss risk caused by weather variability is still increasing. The businesses that are mostly exposed to weather risk are following: energy, agriculture, constructions and transport. That situation has initiated dynamic growth of weather derivatives markets as well as the awareness of the weather risk among the market participants. Presently, the weather derivatives markets evaluate rapidly in all the mature economies: USA, Asia and Europ...

  6. Synthesis of Pharmacological Heterocyclic Derivatives Based Surfactants.

    Science.gov (United States)

    El-Sayed, Refat; Fadda, Ahmed A

    2016-01-01

    Synthesis of chromenopyrimidine derivatives and the related fused system carried out by the reaction of chromene derivative 1 with various reagents under suitable reaction conditions. Condensation of stearoyl chloride with these heterocycles, then, propoxylated the products using propylene oxide to produce surface active agents having a twofold capacity as surface and antimicrobial dynamic specialists which may be served in the production of medications, pesticides, beautifying agents or may be utilized as an antimicrobial. Some of the surface properties and antimicrobial activity were resolved.

  7. A note on derivations in semiprime rings

    Directory of Open Access Journals (Sweden)

    Joso Vukman

    2005-01-01

    Full Text Available We prove in this note the following result. Let n>1 be an integer and let R be an n!-torsion-free semiprime ring with identity element. Suppose that there exists an additive mapping D:R→R such that D(xn=∑j=1nxn−jD(xxj−1 is fulfilled for all x∈R. In this case, D is a derivation. This research is motivated by the work of Bridges and Bergen (1984. Throughout, R will represent an associative ring with center Z(R. Given an integer n>1, a ring R is said to be n-torsion-free if for x∈R, nx=0 implies that x=0. Recall that a ring R is prime if for a,b∈R, aRb=(0 implies that either a=0 or b=0, and is semiprime in case aRa=(0 implies that a=0. An additive mapping D:R→R is called a derivation if D(xy=D(xy+xD(y holds for all pairs x,y∈R and is called a Jordan derivation in case D(x2=D(xx+xD(x is fulfilled for all x∈R. Every derivation is a Jordan derivation. The converse is in general not true. A classical result of Herstein (1957 asserts that any Jordan derivation on a prime ring with characteristic different from two is a derivation. A brief proof of Herstein's result can be found in 1988 by Brešar and Vukman. Cusack (1975 generalized Herstein's result to 2-torsion-free semiprime rings (see also Brešar (1988 for an alternative proof. For some other results concerning derivations on prime and semiprime rings, we refer to Brešar (1989, Vukman (2005, Vukman and Kosi-Ulbl (2005.

  8. Structures of engineered Clostridium botulinum neurotoxin derivatives

    International Nuclear Information System (INIS)

    Masuyer, Geoffrey; Stancombe, Patrick; Chaddock, John A.; Acharya, K. Ravi

    2011-01-01

    The crystal structures of engineered C. botulinum neurotoxin–SNARE derivatives have been and exhibit strong stability of the LHn fragment. Targeted secretion inhibitors (TSIs) are a new class of engineered biopharmaceutical molecules derived from the botulinum neurotoxins (BoNTs). They consist of the metalloprotease light chain (LC) and translocation domain (Hn) of BoNT; they thus lack the native toxicity towards motor neurons but are able to target soluble N-ethylmaleimide-sensitive fusion protein attachment receptor (SNARE) proteins. These functional fragment (LHn) derivatives are expressed as single-chain proteins and require post-translational activation into di-chain molecules for function. A range of BoNT derivatives have been produced to demonstrate the successful use of engineered SNARE substrate peptides at the LC–Hn interface that gives these molecules self-activating capabilities. Alternatively, recognition sites for specific exoproteases can be engineered to allow controlled activation. Here, the crystal structures of three LHn derivatives are reported between 2.7 and 3.0 Å resolution. Two of these molecules are derivatives of serotype A that contain a SNARE peptide. Additionally, a third structure corresponds to LHn serotype B that includes peptide linkers at the exoprotease activation site. In all three cases the added engineered segments could not be modelled owing to disorder. However, these structures highlight the strong interactions holding the LHn fold together despite the inclusion of significant polypeptide sequences at the LC–Hn interface

  9. Resolution enhancement in second-derivative spectra.

    Science.gov (United States)

    Czarnecki, Mirosław A

    2015-01-01

    Derivative spectroscopy is a powerful tool for the resolution enhancement in infrared, near-infrared, Raman, ultraviolet-visible, nuclear magnetic resonance, electron paramagnetic resonance, and fluorescence spectroscopy. Despite its great significance in analytical chemistry, not all aspects of the applications of this method have been explored as yet. This is the first systematic study of the parameters that influence the resolution enhancement in the second derivative spectra. The derivative spectra were calculated with the Savitzky-Golay method with different window size (5, 15, 25) and polynomial order (2, 4). The results obtained in this work show that the resolution enhancement in the second derivative spectra strongly depends on the data spacing in the original spectra, window size, polynomial order, and peak profile. As shown, the resolution enhancement is related to variations in the width of the peaks upon the differentiation. The present study reveals that in order to maximize the separation of the peaks in the second derivative spectra, the original spectra should be recorded at high resolution and differentiated using a small window size and high polynomial order. However, working with the real spectra one has to compromise between the noise reduction and optimization of the resolution enhancement in the second derivative spectra.

  10. Quadratic forms and Clifford algebras on derived stacks

    OpenAIRE

    Vezzosi, Gabriele

    2013-01-01

    In this paper we present an approach to quadratic structures in derived algebraic geometry. We define derived n-shifted quadratic complexes, over derived affine stacks and over general derived stacks, and give several examples of those. We define the associated notion of derived Clifford algebra, in all these contexts, and compare it with its classical version, when they both apply. Finally, we prove three main existence results for derived shifted quadratic forms over derived stacks, define ...

  11. Introduction of Credit Derivatives and Valuation of Credit Default Swap

    OpenAIRE

    Han, Lu

    2006-01-01

    The credit derivative market was established at the beginning of the 1990s since the emergence of credit derivatives fits the rapid development of the whole derivatives market. However, compare to other derivative market, this market is still small and incomplete. As with other derivatives, credit derivatives can be used to either take more risk or hedge it, hence various credit derivatives instruments are accepted and widely used by market participants such as banks, insurance companies, etc...

  12. Analytic computation of energy derivatives - Relationships among partial derivatives of a variationally determined function

    Science.gov (United States)

    King, H. F.; Komornicki, A.

    1986-01-01

    Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.

  13. Four New Citrinin Derivatives from a Marine-Derived Penicillium sp. Fungal Strain

    Directory of Open Access Journals (Sweden)

    Zhong Hui Zheng

    2013-05-01

    Full Text Available Four new citrinin derivatives, including two citrinin dimers and two citrinin monomer derivatives, were isolated and identified from a marine-derived fungal strain Penicillium sp. ML226 along with six known related compounds. Their structures were elucidated by spectroscopic and chemical methods. The new compounds showed modest cytotoxic activity against HepG-2 cell line and weak antimicrobial activity against Staphylococcus aureus.

  14. Numerical derivative techniques for trajectory optimization

    Science.gov (United States)

    Hallman, Wayne P.

    1990-01-01

    The adoption of robust numerical optimization techniques in trajectory simulation programs has resulted in powerful design and analysis tools. These trajectory simulation/optimization programs are widely used, and a representative list includes the GTS system, the POST program, and newer collocation methods such as OTIS and FONPAC. All of these programs rely on optimization algorithms which require objective function and constraint gradient data during the iteration process. However, most trajectory optimization problems lack simple analytical expressions for these derivatives. In the general case a function evaluation involves integrating aerodynamic, propulsive, and gravity forces over multiple trajectory phases with complex control models. With the newer collocation methods, the integration is replaced by defect constraints and cubic approximations for the state. While analytic gradient expressions can sometimes be derived for trajectory optimization problems, the derivation is cumbersome, time consuming, and prone to mistakes. Fortunately, an alternate method exists for the gradient evaluation, namely finite difference approximations. In this paper some finite difference gradient techniques developed for use with the GTS system are presented. These techniques include methods for computing first and second partial derivatives of single and multiple sets of functions. A key feature of these methods is an error control mechanism which automatically adjusts the perturbation size to obtain accurate derivative values.

  15. Multiscale analysis of the CMB temperature derivatives

    Science.gov (United States)

    Marcos-Caballero, A.; Martínez-González, E.; Vielva, P.

    2017-02-01

    We study the Planck CMB temperature at different scales through its derivatives up to second order, which allows one to characterize the local shape and isotropy of the field. The problem of having an incomplete sky in the calculation and statistical characterization of the derivatives is addressed in the paper. The analysis confirms the existence of a low variance in the CMB at large scales, which is also noticeable in the derivatives. Moreover, deviations from the standard model in the gradient, curvature and the eccentricity tensor are studied in terms of extreme values on the data. As it is expected, the Cold Spot is detected as one of the most prominent peaks in terms of curvature, but additionally, when the information of the temperature and its Laplacian are combined, another feature with similar probability at the scale of 10o is also observed. However, the p-value of these two deviations increase above the 6% when they are referred to the variance calculated from the theoretical fiducial model, indicating that these deviations can be associated to the low variance anomaly. Finally, an estimator of the directional anisotropy for spinorial quantities is introduced, which is applied to the spinors derived from the field derivatives. An anisotropic direction whose probability is <1% is detected in the eccentricity tensor.

  16. PROCEDURES FOR THE DERIVATION OF EQUILIBRIUM ...

    Science.gov (United States)

    This equilibrium partitioning sediment benchmark (ESB) document describes procedures to derive concentrations for 32 nonionic organic chemicals in sediment which are protective of the presence of freshwater and marine benthic organisms. The equilibrium partitioning (EqP) approach was chosen because it accounts for the varying biological availability of chemicals in different sediments and allows for the incorporation of the appropriate biological effects concentration. This provides for the derivation of benchmarks that are causally linked to the specific chemical, applicable across sediments, and appropriately protective of benthic organisms. EqP can be used to calculate ESBs for any toxicity endpoint for which there are water-only toxicity data; it is not limited to any single effect endpoint. For the purposes of this document, ESBs for 32 nonionic organic chemicals, including several low molecular weight aliphatic and aromatic compounds, pesticides, and phthalates, were derived using Final Chronic Values (FCV) from Water Quality Criteria (WQC) or Secondary Chronic Values (SCV) derived from existing toxicological data using the Great Lakes Water Quality Initiative (GLI) or narcosis theory approaches. These values are intended to be the concentration of each chemical in water that is protective of the presence of aquatic life. For nonionic organic chemicals demonstrating a narcotic mode of action, ESBs derived using the GLI approach specifically for fres

  17. A New Truncated M-Fractional Derivative Type Unifying Some Fractional Derivative Types with Classical Properties

    Directory of Open Access Journals (Sweden)

    J. Vanterler da C. Sousa

    2018-01-01

    Full Text Available We introduce a truncated $M$-fractional derivative type for $\\alpha$-differentiable functions that generalizes four other fractional derivatives types recently introduced by Khalil et al., Katugampola and Sousa et al., the so-called conformable fractional derivative, alternative fractional derivative, generalized alternative fractional derivative and $M$-fractional derivative, respectively. We denote this new differential operator by $_{i}\\mathscr{D}_{M}^{\\alpha,\\beta }$, where the parameter $\\alpha$, associated with the order of the derivative is such that $ 0 <\\alpha<1 $, $\\beta>0$ and $ M $ is the notation to designate that the function to be derived involves the truncated Mittag-Leffler function with one parameter.The definition of this truncated $M$-fractional derivative type satisfies the properties of the integer-order calculus. We also present, the respective fractional integral from which emerges, as a natural consequence, the result, which can be interpreted as an inverse property. Finally, we obtain the analytical solution of the $M$-fractional heat equation and present a graphical analysis.

  18. Adaptive synchronization of the complex dynamical network with non-derivative and derivative coupling

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yuhua, E-mail: yuhuaxu2004@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China) and Department of Maths, Yunyang Teachers' College, Hubei 442000 (China); Zhou Wuneng, E-mail: wnzhou@163.co [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Fang Jian' an [College of Information Science and Technology, Donghua University, Shanghai 201620 (China); Sun Wen [School of Mathematics and Information, Yangtze University, Hubei Jingzhou 434023 (China)

    2010-04-05

    This Letter investigates the synchronization of a general complex dynamical network with non-derivative and derivative coupling. Based on LaSalle's invariance principle, adaptive synchronization criteria are obtained. Analytical result shows that under the designed adaptive controllers, a general complex dynamical network with non-derivative and derivative coupling can asymptotically synchronize to a given trajectory, and several useful criteria for synchronization are given. What is more, the coupling matrix is not assumed to be symmetric or irreducible. Finally, simulations results show the method is effective.

  19. 32 CFR 2400.14 - Use of derivative classification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Use of derivative classification. 2400.14... SECURITY PROGRAM Derivative Classification § 2400.14 Use of derivative classification. (a) Derivative... person who applies derivative classification markings believes that the paraphrasing, restating, or...

  20. Gateaux and Frechet Derivative in Intuitionistic Fuzzy Normed Linear spaces

    OpenAIRE

    Dinda, B.; Samanta, T. K.; Bera, U. K.

    2010-01-01

    Intuitionistic Fuzzy derivative, Intuitionistic Fuzzy Gateaux derivative, Intuitionistic Fuzzy Fr\\'{e}chet derivative are defined and a few of their properties are studied. The relation between Intuitionistic Fuzzy Gateaux derivative and Intuitionistic Fuzzy Fr\\'{e}chet derivative are emphasized.

  1. Synthesis of azido derivatives of mucobromic acid

    Directory of Open Access Journals (Sweden)

    N. Mbebe

    2013-04-01

    Full Text Available Mucobromic acid is a highly reactive multicentered molecule. It was converted to its corresponding but unstable diazido derivative by reaction with two equivalents of sodium azide. The resultant 3,4-diazido-5-hydroxyfuran-2(5H-one was obtained in moderate yield (42% but decomposed readily even at low temperatures. Its more stable analogue 3,4-diazido-5-methoxyfuran-2(5H-one was obtained in excellent yield after reacting 5-methoxy-3,4-dibromofuranone with two equivalents of sodium azide. The 4,5-dibromopyridazinones which are in effect masked mucobromic acid derivatives, underwent nucleophilic substitution reactions with various nucleophiles, including azides and afforded corresponding azidopyridazinones in good yields. The synthesized azido-furanone and pyridazinone derivatives are earmarked for click reactions.DOI: http://dx.doi.org/10.4314/bcse.v27i1.17

  2. Additive derivations on algebras of measurable operators

    International Nuclear Information System (INIS)

    Ayupov, Sh.A.; Kudaybergenov, K.K.

    2009-08-01

    Given a von Neumann algebra M we introduce the so-called central extension mix(M) of M. We show that mix(M) is a *-subalgebra in the algebra LS(M) of all locally measurable operators with respect to M, and this algebra coincides with LS(M) if and only if M does not admit type II direct summands. We prove that if M is a properly infinite von Neumann algebra then every additive derivation on the algebra mix(M) is inner. This implies that on the algebra LS(M), where M is a type I ∞ or a type III von Neumann algebra, all additive derivations are inner derivations. (author)

  3. Dielectric transition of polyacrylonitrile derived carbon nanofibers

    International Nuclear Information System (INIS)

    Li, Jiangling; Su, Shi; Abbot, Andrew M; Ye, Haitao; Zhou, Lei

    2014-01-01

    The dielectric behavior of polyacrylonitrile derived carbon nanofibers formed at different carbonization temperatures was investigated using impedance spectroscopy. The impedance data are presented in the form of Cole–Cole plots and four equivalent electrical circuits are derived. It is found that by increasing carbonization temperature from 500 to 800 °C, a strong capacitive element in the parallel equivalent circuit is transformed into an inductive element, while the contact resistance and parallel resistance are significantly decreased. Along with the morphological and chemical structural evolution, respectively witnessed by scanning electron microscopy and Raman spectroscopy, the dielectric transition deduced from the transformation of electrical circuits can be correlated to the proposed microstructural changes of polyacrylonitrile derived carbon nanofibers and the interaction/interference among them. (paper)

  4. Analytics of Quinine and its Derivatives.

    Science.gov (United States)

    Kluska, Mariusz; Marciniuk-Kluska, Anna; Prukała, Dorota; Prukała, Wiesław

    2016-01-01

    The objective of this study was to perform a synthesis and analysis of the most important information on quinine and its derivatives, which are still very important in the treatment of malaria. The analysis of stereoisomers of quinine and its derivatives was conducted using two techniques, high-performance liquid chromatography and capillary electrophoresis. Particularly noteworthy is the technique used for the determination of isotachophoresis, referred to as one of the so-called green chemistry techniques. Particular attention was paid to properties and the use of quinine and its derivatives in the treatment of malaria. The analytical part will supplement knowledge about quinidine, quinine, and cinchonidine, and will contribute to the growth of research on the so-much-needed drugs against malaria.

  5. Azobenzene derivatives carrying a nitroxide radical.

    Science.gov (United States)

    Nakatsuji, Shin'ichi; Fujino, Masahiro; Hasegawa, Satoko; Akutsu, Hiroki; Yamada, Jun-ichi; Gurman, Vladimir S; Kh Vorobiev, Andrey

    2007-03-16

    Several trans-azobenzene derivatives carrying a nitroxide (aminoxyl) radical (2a, 6a-12a) were prepared, and their photoisomerization reactions to the corresponding cis-isomers were investigated. Although no fruitful results could be obtained for the photoisomerizations of the derivatives with para-subsituents (9a-12a), the unsubstututed derivatives at the para-position (2a, 6a, 7a, 8a) were found to show photoisomerizations by irradiation to give the corresponding cis-isomers (2b, 6b, 7b, 8b), being isolated as relatively stable solid materials, and the change of the intermolecular magnetic interactions was apparently observed by the structural change for each photochromic couple.

  6. Funding climate adaptation strategies with climate derivatives

    Directory of Open Access Journals (Sweden)

    L. Richard Little

    2015-01-01

    Full Text Available Climate adaptation requires large capital investments that could be provided not only by traditional sources like governments and banks, but also by derivatives markets. Such markets would allow two parties with different tolerances and expectations about climate risks to transact for their mutual benefit and, in so doing, finance climate adaptation. Here we calculate the price of a derivative called a European put option, based on future sea surface temperature (SST in Tasmania, Australia, with an 18 °C strike threshold. This price represents a quantifiable indicator of climate risk, and forms the basis for aquaculture industries exposed to the risk of higher SST to finance adaptation strategies through the sale of derivative contracts. Such contracts provide a real incentive to parties with different climate outlooks, or risk exposure to take a market assessment of climate change.

  7. FINANCIAL DERIVATIVES - MEANINGS BEYOND SUBPRIME CRISIS STIGMA

    Directory of Open Access Journals (Sweden)

    FELICIA RAMONA BIRĂU

    2012-12-01

    Full Text Available Derivatives are designed as complex financial instruments and their main aim is to manage the risk associated with the underlying asset, in order to ensure against fluctuations in value, or to profit from periods of inactivity, instability or decline. In recent years financial derivatives have experienced a fulminant development and also they have been perceived as an effective lever of the modern economy. The subprime crisis was triggered by a quite significant financial infrastructure glitch, which coalesced around certain factors influence, such as : highly permissive regulation of financial markets, speculative bubbles, underperforming risk management, liquidity injections and structural imbalances. Despite the fact that is a innovative segment and quite difficult affordable as understanding level of the operation mechanisms, financial derivatives were only the tool triggering this global dimension crisis.

  8. Langmuir-Blodgett Films of Graphene Derivatives

    DEFF Research Database (Denmark)

    Petersen, Søren Vermehren

    The work presented in this PhD thesis can be divided into two main categories: 1) Syn-thesis and Langmuir-Blodgett assembly of graphene derivatives and 2) Application and characterization of graphene derivatives as an interface material in molecular electron-ics. While the first category could....... Solution processable graphene in the form of chemically derived graphene has been synthesized through the modified Hummers method with subsequent reduction into reduced graphene oxide with hydrazine. The completeness of oxidation, the effect of the refinement steps and the reduction of the graphene oxide...... immobilization of the monolayered graphene oxide via the Langmuir-Blodgett deposition technique prior to a three step reduction scheme involving hydrazine reduc-tion, sulfuric acid de-oxygenation, and thermal annealing. This method resulted in wrin-kle-free reduced graphene oxide with a negligible oxygen content...

  9. 5-Nitroimidazole Derivatives and their Antimicrobial Activity

    International Nuclear Information System (INIS)

    Khan, K.M.; Salar, U.; Yousuf, S.; Naz, F.

    2016-01-01

    5-Nitroimidazole derivatives 2-8 were synthesized from secnidazole. The syntheses were accomplished in two steps which start from the oxidation of secnidazole to the secnidazolone 1. Secnidazolone 1 was converted into its hydrazone derivative 2-8 by treating with different substituted acid hydrazide. Compounds 2-8 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, compounds 3 and 4 showed the significant activity against Staphylococcus epidermidis, however, compound 2 showed good inhibitions against Corynebacterium diphtheria when compared with the standard. Compound 3 showed good inhibitory potential against tested Gram-negative bacterial strains i.e. Enterobacter aerogene, Escherichia coli, Salmonella typhi, Salmonella paratyphi A, Shigella flexeneri and Vibrio choleriae. All synthetic derivatives were also tested against eight fungal stains, however, they were weekly active against Aspergillus flavus and Candida albican. The synthesized compounds were characterized by different spectroscopy techniques. (author)

  10. Development of chitosan derivatives with anhydride maleic

    International Nuclear Information System (INIS)

    Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da

    2015-01-01

    Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

  11. Modelling Environment Changes for Pricing Weather Derivatives

    Directory of Open Access Journals (Sweden)

    Kabaivanov Stanimir

    2017-12-01

    Full Text Available This paper focuses on modelling environment changes in a way that allows to price weather derivatives in a flexible and efficient way. Applications and importance of climate and weather contracts extends beyond financial markets and hedging as they can be used as complementary tools for risk assessment. In addition, option-based approach toward resource management can offer very special insights on rare-events and allow to reuse derivative pricing methods to improve natural resources management. To demonstrate this general concept, we use Monte Carlo and stochastic modelling of temperatures to evaluate weather options. Research results are accompanied by R and Python code.

  12. Ethanolamine derivatives of dysprosium and holmium

    International Nuclear Information System (INIS)

    Gharia, K.S.; Singh, M.; Mathur, S.; Sankhla, B.S.

    1981-01-01

    The preparation and properties of dysprosium and holmium derivatives of mono-, di- and tri-ethanolamine derivatives are described. Compounds of general formulae: Ln(OPrsup(i)) 2 (mea), Ln(OPrsup(i))(mea) 2 , Ln(mea) 3 , Ln(OPrsup(i))(dea), Ln 2 (dea) 3 , Ln(dea)(deaH) and Ln(tea) (where Ln = Dy or Ho and mea, dea and tea are the anions of respective ethanolamine) were obtained and characterized by elemental analysis and IR spectra. (author)

  13. Special relativity derived from spacetime magma.

    Directory of Open Access Journals (Sweden)

    Fred Greensite

    Full Text Available We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally.

  14. Special relativity derived from spacetime magma.

    Science.gov (United States)

    Greensite, Fred

    2014-01-01

    We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally.

  15. Derivation of Mayer Series from Canonical Ensemble

    International Nuclear Information System (INIS)

    Wang Xian-Zhi

    2016-01-01

    Mayer derived the Mayer series from both the canonical ensemble and the grand canonical ensemble by use of the cluster expansion method. In 2002, we conjectured a recursion formula of the canonical partition function of a fluid (X.Z. Wang, Phys. Rev. E 66 (2002) 056102). In this paper we give a proof for this formula by developing an appropriate expansion of the integrand of the canonical partition function. We further derive the Mayer series solely from the canonical ensemble by use of this recursion formula. (paper)

  16. Derivation of Mayer Series from Canonical Ensemble

    Science.gov (United States)

    Wang, Xian-Zhi

    2016-02-01

    Mayer derived the Mayer series from both the canonical ensemble and the grand canonical ensemble by use of the cluster expansion method. In 2002, we conjectured a recursion formula of the canonical partition function of a fluid (X.Z. Wang, Phys. Rev. E 66 (2002) 056102). In this paper we give a proof for this formula by developing an appropriate expansion of the integrand of the canonical partition function. We further derive the Mayer series solely from the canonical ensemble by use of this recursion formula.

  17. Elevation Derivatives for Mojave Desert Tortoise Habitat

    Science.gov (United States)

    Wallace, Cynthia S.A.; Gass, Leila

    2008-01-01

    This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

  18. Deriving High-Precision Radial Velocities

    Science.gov (United States)

    Figueira, Pedro

    This chapter describes briefly the key aspects behind the derivation of precise radial velocities. I start by defining radial velocity precision in the context of astrophysics in general and exoplanet searches in particular. Next I discuss the different basic elements that constitute a spectrograph, and how these elements and overall technical choices impact on the derived radial velocity precision. Then I go on to discuss the different wavelength calibration and radial velocity calculation techniques, and how these are intimately related to the spectrograph's properties. I conclude by presenting some interesting examples of planets detected through radial velocity, and some of the new-generation instruments that will push the precision limit further.

  19. Derivation of Darcy's Law using Homogenization Method

    OpenAIRE

    Kannanut Chamsri

    2013-01-01

    Darcy’s Law is a well-known constitutive equation describing the flow of a fluid through a porous medium. The equation shows a relationship between the superficial or Darcy velocity and the pressure gradient which was first experimentally observed by Henry Darcy in 1855-1856. In this study, we apply homogenization method to Stokes equation in order to derive Darcy’s Law. The process of deriving the equation is complicated, especially in multidimensional domain. Thus, for the sake of simplicit...

  20. Quantum mechanics of 4-derivative theories

    CERN Document Server

    Salvio, Alberto

    2016-01-01

    A renormalizable theory of gravity is obtained if the dimension-less 4-derivative kinetic term of the graviton, which classically suffers from negative unbounded energy, admits a sensible quantisation. We find that a 4-derivative degree of freedom involves a canonical coordinate with unusual time-inversion parity, and that a correspondingly unusual representation must be employed for the relative quantum operator. The resulting theory has positive energy eigenvalues, normalisable wave functions, unitary evolution in a negative-norm configuration space. We present a formalism for quantum mechanics with a generic norm.

  1. Geometric derivation of the quantum speed limit

    International Nuclear Information System (INIS)

    Jones, Philip J.; Kok, Pieter

    2010-01-01

    The Mandelstam-Tamm and Margolus-Levitin inequalities play an important role in the study of quantum-mechanical processes in nature since they provide general limits on the speed of dynamical evolution. However, to date there has been only one derivation of the Margolus-Levitin inequality. In this paper, alternative geometric derivations for both inequalities are obtained from the statistical distance between quantum states. The inequalities are shown to hold for unitary evolution of pure and mixed states, and a counterexample to the inequalities is given for evolution described by completely positive trace-preserving maps. The counterexample shows that there is no quantum speed limit for nonunitary evolution.

  2. Scale up of proteoliposome derived Cochleate production.

    Science.gov (United States)

    Zayas, Caridad; Bracho, Gustavo; Lastre, Miriam; González, Domingo; Gil, Danay; Acevedo, Reinaldo; del Campo, Judith; Taboada, Carlos; Solís, Rosa L; Barberá, Ramón; Pérez, Oliver

    2006-04-12

    Cochleate are highly stable structures with promising immunological features. Cochleate structures are usually obtaining from commercial lipids. Proteoliposome derived Cochleate are derived from an outer membrane vesicles of Neisseria meningitidis B. Previously, we obtained Cochleates using dialysis procedures. In order to increase the production process, we used a crossflow system (CFS) that allows easy scale up to obtain large batches in an aseptic environment. The raw material and solutions used in the production process are already approved for human application. This work demonstrates that CFS is very efficient process to obtain Cochleate structures with a yield of more than 80% and the immunogenicity comparable to that obtained by dialysis membrane.

  3. Electronic absorption spectra of antiviral aminophenol derivatives

    Science.gov (United States)

    Belkov, M. V.; Ksendzova, G. A.; Raichyonok, T. F.; Skornyakov, I. V.; Sorokin, V. L.; Tolstorozhev, G. B.; Shadyro, O. I.

    2011-03-01

    Electronic absorption spectra of aminophenol derivatives in solutions have been studied. A general property of the absorption spectra of these compounds, the dependence of the maximum of a long-wavelength absorption band on the solvent polarity, is revealed. As a rule, the absorption band maximum of compounds possessing pharmacological properties shows a greater shift to short wavelength with an increase in the medium polarity than that of inactive compounds. Absorption measurements of solutions of aminophenol derivatives can be used for a tentative estimation of their antiviral activity.

  4. Structure-activity relationships of bumetanide derivatives

    DEFF Research Database (Denmark)

    Pedersen, Kasper Lykke; Töllner, Kathrin; Römermann, Kerstin

    2015-01-01

    , the effect of a series of diuretically active bumetanide derivatives was investigated on human NKCC2 variant A (hNKCC2A) expressed in Xenopus laevis oocytes. KEY RESULTS: Bumetanide blocked hNKCC2A transport with an IC50 of 4 μM. There was good correlation between the diuretic potency of bumetanide and its...... derivatives in dogs and their inhibition of hNKCC2A (r(2) = 0.817; P ... of the structural requirements that determine relative potency of loop diuretics on human NKCC2 splice variants, and may lead to the discovery of novel high-ceiling diuretics....

  5. New coumarin derivatives as carbonic anhydrase inhibitors.

    Science.gov (United States)

    Karataş, Mert Olgun; Alici, Bülent; Cakir, Umit; Cetinkaya, Engin; Demir, Dudu; Ergün, Adem; Gençer, Nahit; Arslan, Oktay

    2014-06-01

    In the current study, a series of 4-chloromethyl-7-hydroxy-coumarin derivatives containing imidazolium, benzimidazolium, bisbenzimidazolium and quaternary ammonium salts were synthesized, characterized and the inhibition effects of the derivatives on human carbonic anhydrases (hCA I and hCA II) were investigated as in vitro. Structures of these coumarins were confirmed by FT-IR, (1)H NMR, (13)C NMR and LC-MS analyses. Structure activity relationship study showed that 3d (IC50: 79 μM for hCA I and 88 μM for hCA II) performed higher inhibitory activity than others.

  6. 76 FR 3697 - Risk Management Requirements for Derivatives Clearing Organizations

    Science.gov (United States)

    2011-01-20

    ... Derivatives Clearing Organizations; Proposed Rule #0;#0;Federal Register / Vol. 76 , No. 13 / Thursday... RIN 3038-AC98 Risk Management Requirements for Derivatives Clearing Organizations AGENCY: Commodity... regulatory standards for compliance with derivatives clearing organization (DCO) Core Principles C...

  7. 18 CFR 367.2440 - Account 244, Derivative instrument liabilities.

    Science.gov (United States)

    2010-04-01

    ..., Derivative instrument liabilities. This account must include the change in the fair value of all derivative instrument liabilities not designated as cash flow or fair value hedges. Account 426.5, Other deductions... the fair value of the derivative instrument. ...

  8. Recurrence relations for the Cartesian derivatives of the Zernike polynomials.

    Science.gov (United States)

    Stephenson, Philip C L

    2014-04-01

    A recurrence relation for the first-order Cartesian derivatives of the Zernike polynomials is derived. This relation is used with the Clenshaw method to determine an efficient method for calculating the derivatives of any linear series of Zernike polynomials.

  9. Effects of oxyresveratrol and its derivatives on cultured P19-derived ...

    African Journals Online (AJOL)

    Purpose: To modify the structure of oxyresveratrol and evaluate the obtained derivatives for effects on neuronal cells. Methods: Electron-withdrawing groups were selectively introduced to the aromatic ring of the core stilbene structure. Oxyresveratrol and derivatives were then evaluated for their ability to enhance the ...

  10. A class of constitutive relations with internal variable derivatives. Derivation from homogenization and initial value problem

    International Nuclear Information System (INIS)

    Andrieux, S.; Joussemet, M.; Lorentz, E.

    1996-01-01

    A general framework for deriving and using a class of constitutive laws incorporating spatial gradients of internal variables is presented. It uses two basic ingredients: a derivation of such models by homogenization techniques and a reformulation of the evolution equation at the scale of the whole structure. (orig.)

  11. Cretan Hydronyms Derived from Settlement Names

    Directory of Open Access Journals (Sweden)

    Elwira Kaczyńska

    2017-03-01

    Full Text Available The paper discusses 284 Cretan river names, presumably derived from settlement names. This group of hydronyms represents 6.1% among all the modern hydronyms of the island (4 666 names collected by the author from written sources and, at a lesser degree, during fieldwork, its biggest part being attested only from the 20th century. The names studied in this paper were formed either by metonymic transfer of settlement names to bodies of water (134 units or by morphological derivation (suffixation and, in some cases, regressive derivation (150 units. To establish the direction of derivation, the author analyses the semantic features of the names and the chronology of their attestation in written sources. As to the morphological structure of the analyzed river names, the author distinguishes 85 simple names (29.9%, 128 compound names (45.1% and 71 elliptical ones (25%. This enables a structural analysis of the differentiating elements in the compound names and in the elliptical names formed by omitting a hydrograhical term. The morphological structure of some hydronyms allows to retrieve valuable information on lost or decayed settlements of Crete. The author also shows that some items demonstrate the onomastic contuinity in the island from antiquity to the present day.

  12. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    New substituted trichostatic acid derivatives have been synthesized and evaluated for their biological activities towards the H661 non-small lung cancer cell line. These syntheses were achieved by alkylation of propiophenones to introduce the side chain with a terminal precursor of hydroxamic acid and aminobenzamide ...

  13. Formal Derivation of Concurrent Garbage Collectors

    NARCIS (Netherlands)

    Pavlovic, Dusko; Pepper, Peter; Smith, Douglas R.

    Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the

  14. synthesis and characterization of novel sulfonamides derivatives ...

    African Journals Online (AJOL)

    Newer sulfonamides and their derivatives has obtained great attention in pharmaceutical field in order to compete life threatening issues caused by drug resistant strains of bacteria, i.e. Methicillin resistance as they have unusual ability of acclimatization against stress caused by antibiotics [12]. Disease causing organisms ...

  15. Derived Transformation of Children's Pregambling Game Playing

    Science.gov (United States)

    Dymond, Simon; Bateman, Helena; Dixon, Mark R.

    2010-01-01

    Contemporary behavior-analytic perspectives on gambling emphasize the impact of verbal relations, or derived relational responding and the transformation of stimulus functions, on the initiation and maintenance of gambling. Approached in this way, it is possible to undertake experimental analysis of the role of verbal/mediational variables in…

  16. Structural features of bionanocomposite derived from novel ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 36; Issue 2. Structural features of bionanocomposite derived from novel designed poly(ester-imide) based on natural amino acids with hydroxyl segments tailored for better dispersion of TiO2 nanofiller. Shadpour Mallakpour Parvin Asadi. Volume 36 Issue 2 April 2013 ...

  17. Inequalities for a Polynomial and its Derivative

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 110; Issue 2. Inequalities for a Polynomial and its Derivative. V K Jain. Volume 110 Issue 2 May 2000 pp 137- ...

  18. Hamiltonian path integral formalism with higher derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Natividade, C.P. (Rio de Janeiro Univ. (Brazil). Inst. de Fisica)

    1991-07-01

    We study the Hamiltonian path integral formalism for systems containing higher derivatives. First we show the consistency of the formalism in applications involving only scalar fields. Later we use the Maxwell electromagnetic theory with a higher order regularization term to show that the Batalin-Fradkin-Vilkovisky (BFV) theory can also be consistently described. (orig.).

  19. Characterization of sugar beet pulp derived oligosaccharides

    NARCIS (Netherlands)

    Leijdekkers, M.

    2015-01-01

    Abstract This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp. Hydrophilic interaction chromatography with on-line evaporative light scattering

  20. Derivation of Stochastic Equations for Computational Uncertainties ...

    African Journals Online (AJOL)

    ADOWIE PERE

    physical parameters using the relative standard deviations techniques (σ). These equations also known as ... define the maximum level of uncertainty that can be tolerated in any independent variable if the maximum uncertainty to be ... standard deviations, partial derivatives, degree of accuracy, empirical models. LIST OF ...

  1. Biodegradable polymers derived from amino acids.

    Science.gov (United States)

    Khan, Wahid; Muthupandian, Saravanan; Farah, Shady; Kumar, Neeraj; Domb, Abraham J

    2011-12-08

    In the past three decades, the use of polymeric materials has increased dramatically for biomedical applications. Many α-amino acids derived biodegradable polymers have also been intensely developed with the main goal to obtain bio-mimicking functional biomaterials. Polymers derived from α-amino acids may offer many advantages, as these polymers: (a) can be modified further to introduce new functions such as imaging, molecular targeting and drugs can be conjugated chemically to these polymers, (b) can improve on better biological properties like cell migration, adhesion and biodegradability, (c) can improve on mechanical and thermal properties and (d) their degradation products are expected to be non-toxic and readily metabolized/excreted from the body. This manuscript focuses on biodegradable polymers derived from natural amino acids, their synthesis, biocompatibility and biomedical applications. It is observed that polymers derived from α-amino acids constitute a promising family of biodegradable materials. These provide innovative multifunctional polymers possessing amino acid side groups with biological activity and with innumerous potential applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Novel hydroquinone derivatives alleviate algesia, inflammation and ...

    African Journals Online (AJOL)

    The in silico studies predicted high binding affinity of the hydroquinone derivatives to the active site of the cyclooxygenase 2 (COX-2) enzyme. Conclusion: The synthesized hydroquinone compounds possess analgesic, antipyretic and antiinflammatory properties with low gastric-ulcerogenic potential. This may be credited to ...

  3. Synthesis of Trishomocubane Amino Acid Derivatives | Govender ...

    African Journals Online (AJOL)

    The synthesis of four novel trishomocubane amino acid derivatives is described. The hydantoin precursor and bis-Boc protected hydantoin (>95% yield) were previously reported. A mild hydrolysis of the bis-Boc hydantoin with lithium hydroxide at room temperature quantitatively yielded the corresponding novel cage amino ...

  4. Glycosylation of a Newly Functionalized Orthoester Derivative

    Directory of Open Access Journals (Sweden)

    Kohei Kawa

    2014-02-01

    Full Text Available Tandem glycosylation of the 6-O-Fmoc-substituted benzyl orthoester derivative 2a was carried out in moderate yields by electrogenerated acid (EGA. The Fmoc group was effectively removed under mild basic conditions, and the product was submitted to the subsequent glycosylation.

  5. Antifungal activity of naphthothiazoles derived from Lawsone ...

    African Journals Online (AJOL)

    A series of Naphtho [2,3-d] thiazole-4, 9-diones was prepared by the condensation of bromolawsone with thiosemicarbazones derived from the aldehydes and ketones in dry dimethyl formamide (DMF). The products are also obtained by the cyclization of the intermediate 2-chlorobenzaldehyde thiosemicarbazone of 1 ...

  6. Particle production in higher derivative theory

    Indian Academy of Sciences (India)

    Abstract. The effect of particle production on the evolution of the spatially flat Friedmann–. Lemaitre–Robertson–Walker cosmological model during the early stages of the universe is analysed in the framework of higher derivative theory. The universe has been considered as an open thermo- dynamic system where particle ...

  7. Microscopic Derivation of Ginzburg-Landau Theory

    DEFF Research Database (Denmark)

    Frank, Rupert; Hainzl, Christian; Seiringer, Robert

    2012-01-01

    We give the first rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Close to the critical temperature, GL arises as an effective theory on the macroscopic scale. The relevant scaling limit is semiclassical...

  8. Pharmacological characterization of tachykinin tetrabranched derivatives.

    Science.gov (United States)

    Ruzza, Chiara; Rizzi, Anna; Malfacini, Davide; Cerlesi, Maria Camilla; Ferrari, Federica; Marzola, Erika; Ambrosio, Caterina; Gro, Cristina; Severo, Salvadori; Costa, Tommaso; Calo, Girolamo; Guerrini, Remo

    2014-09-01

    Peptide welding technology (PWT) is a novel chemical strategy that allows the synthesis of multibranched peptides with high yield, purity and reproducibility. Using this technique, we have synthesized and pharmacologically characterized the tetrabranched derivatives of the tachykinins, substance P (SP), neurokinin A (NKA) and B (NKB). The following in vitro assays were used: calcium mobilization in cells expressing human recombinant NK receptors, BRET studies of G-protein - NK1 receptor interaction, guinea pig ileum and rat urinary bladder bioassays. Nociceptive behavioural response experiments were performed in mice following intrathecal injection of PWT2-SP. In calcium mobilization studies, PWT tachykinin derivatives behaved as full agonists at NK receptors with a selectivity profile similar to that of the natural peptides. NK receptor antagonists display similar potency values when tested against PWT2 derivatives and natural peptides. In BRET and bioassay experiments PWT2-SP mimicked the effects of SP with similar potency, maximal effects and sensitivity to aprepitant. After intrathecal administration in mice, PWT2-SP mimicked the nociceptive effects of SP, but with higher potency and a longer-lasting action. Aprepitant counteracted the effects of PWT2-SP in vivo. The present study has shown that the PWT technology can be successfully applied to the peptide sequence of tachykinins to generate tetrabranched derivatives characterized with a pharmacological profile similar to the native peptides. In vivo, PWT2-SP displayed higher potency and a marked prolongation of action, compared with SP. © 2014 The British Pharmacological Society.

  9. Deriving force field parameters for coordination complexes

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Brandt, Peter

    2001-01-01

    The process of deriving molecular mechanics force fields for coordination complexes is outlined. Force field basics are introduced with an emphasis on special requirements for metal complexes. The review is then focused on how to set up the initial model, define the target, refine the parameters...

  10. Nanomaterials derived from metal-organic frameworks

    Science.gov (United States)

    Dang, Song; Zhu, Qi-Long; Xu, Qiang

    2018-01-01

    The thermal transformation of metal-organic frameworks (MOFs) generates a variety of nanostructured materials, including carbon-based materials, metal oxides, metal chalcogenides, metal phosphides and metal carbides. These derivatives of MOFs have characteristics such as high surface areas, permanent porosities and controllable functionalities that enable their good performance in sensing, gas storage, catalysis and energy-related applications. Although progress has been made to tune the morphologies of MOF-derived structures at the nanometre scale, it remains crucial to further our knowledge of the relationship between morphology and performance. In this Review, we summarize the synthetic strategies and optimized methods that enable control over the size, morphology, composition and structure of the derived nanomaterials. In addition, we compare the performance of materials prepared by the MOF-templated strategy and other synthetic methods. Our aim is to reveal the relationship between the morphology and the physico-chemical properties of MOF-derived nanostructures to optimize their performance for applications such as sensing, catalysis, and energy storage and conversion.

  11. reaction-diffusion system with fractional derivatives

    Directory of Open Access Journals (Sweden)

    Kamel Haouam

    2006-01-01

    Full Text Available We give some necessary conditions for local and global existence of a solution to reaction-diffusion system of type (FDS with temporal and spacial fractional derivatives. As in the case of single equation of type (STFE studied by M. Kirane et al. (2005, we prove that these conditions depend on the behavior of initial conditions for large |x|.

  12. Characterization of sugar beet pulp derived oligosaccharides

    NARCIS (Netherlands)

    Leijdekkers, M.

    2015-01-01

    Abstract

    This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp.

    Hydrophilic interaction chromatography with on-line evaporative

  13. arene derivatives containing multiple aromatic groups

    Indian Academy of Sciences (India)

    ... two novel thiacalix[4]arene derivatives containing multiple aromatic groups in yields of 86% and 90%. Their complexation properties for four organic dyes were investigated by liquid-liquid extraction experiments, complexation UV-Vis spectra and mass spectrum. The highest extraction percentage was 97% for Neutral red.

  14. Derivation of Stochastic Equations for Computational Uncertainties ...

    African Journals Online (AJOL)

    This paper presents a simple mathematical algorithm or procedure for computing the uncertainties at the various percent of data input, using the stochastic approach of simulating the input variables to compute the output variables. A simple algorithm was used to derive stochastic equations for some selected petrophysical ...

  15. Resveratrol derivatives: a patent review (2009 - 2012).

    Science.gov (United States)

    Pezzuto, John M; Kondratyuk, Tamara P; Ogas, Talysa

    2013-12-01

    There is currently a wealth of information on the effects of resveratrol and its derivatives in therapeutic, cosmetic and nutraceutical patent applications. Structure-activity studies of the resveratrol scaffold provide a foundation for the development of new analogs with potent activity or other beneficial properties. Ongoing research has yielded promising results and potential use in the treatment of various diseases. This review provides analysis of patents published from January 2009 to April 2013. There is a focus on different approaches for the production of resveratrol derivatives, combinations of new derivatives with old drugs, and applications in therapeutic areas, nutraceutical compositions and cosmetics. The ability of resveratrol to interact with a disparate array of subcellular targets is uncanny. Nonetheless, even though limited or no toxicity is apparent, the molecule is not a panacea due to lack of potency and issues with bioavailability. Thus, as witnessed by a number of patents, a large assortment of derivatives have been synthesized under the guise of having superior characteristics for treating or preventing various diseases or for use as neutraceutics and cosmetics. Some of these suppositions are probably correct, but evidence-based applications are essentially nil due to a lack of commitment in terms of investing the resources necessary for the conduct of obligatory clinical trials. Current usage is largely based on anecdotes and publicity. Hopefully, at some point in time, it will be possible to follow a standard protocol with a predicable outcome.

  16. Waste-wood-derived fillers for plastics

    Science.gov (United States)

    Brent English; Craig M. Clemons; Nicole Stark; James P. Schneider

    1996-01-01

    Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts. Such thermoplastics are usually provided to the end-user as a precompounded, pelletized feedstock. Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper...

  17. Enabling quaternion derivatives: the generalized HR calculus.

    Science.gov (United States)

    Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C; Mandic, Danilo P

    2015-08-01

    Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis.

  18. Temperature stochastic modeling and weather derivatives pricing ...

    African Journals Online (AJOL)

    ... over a sufficient period to apply a stochastic process that describes the evolution of the temperature. A numerical example of a swap contract pricing is presented, using an approximation formula as well as Monte Carlo simulations. Keywords: Weather derivatives, temperature stochastic model, Monte Carlo simulation.

  19. Immunochemical analysis of apamin and its derivatives

    International Nuclear Information System (INIS)

    Vasilenko, S.V.; Kolesnikova, I.N.; Miroshnikov, A.I.; Komissarenko, S.V.

    1981-01-01

    The radioimmunologic analysis of apamin (neurotoxin of the venom of Apis mellifica honey bee) is carried out using its derivatives which have modifications of various aminoacidic remnants and antibodies against apamin. The curves of 125 J apamin binding with antiserum against apamin and the curves of inhibition with various nonlabelled binding effectors of 125 J-apamin with antiserum are obtained

  20. quinoxaline dyes derived from Anthraquinone f

    Indian Academy of Sciences (India)

    chemsci

    to increase the solubility of the target molecules and later, the 5–methylated isatin derivatives were reacted with 1,2- diaminoathraquinone in acetic acid for 1–2h to produce the desired cyclocondensed product. The five target com- pounds were obtained in good yield (72–78%) as deep red solids. The identity and purity of ...

  1. Undesired Plant-Derived Components in Food

    NARCIS (Netherlands)

    Dusemund, Birgit; Rietjens, Ivonne M.C.M.; Abraham, Klaus; Cartus, Alexander; Schrenk, Dieter

    2017-01-01

    Among the various chemical compounds, the class of natural plant-derived substances in the modern food chain is generating increasing concern. Adverse effects encountered may be various and pose risks of acute, subchronic, or chronic toxicity. The underlying mechanisms of toxicity may be

  2. Nitration of Thiacalix[4]arene Derivatives

    Czech Academy of Sciences Publication Activity Database

    Lhoták, P.; Svoboda, J.; Stibor, I.; Sýkora, Jan

    2002-01-01

    Roč. 43, č. 41 (2002), s. 7413-7417 ISSN 0040-4039 R&D Projects: GA ČR GA104/00/1722 Keywords : derivatives * nitation of thiacalix[4]arene Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.357, year: 2002

  3. Orchard navigation using derivative free Kalman filtering

    DEFF Research Database (Denmark)

    Hansen, Søren; Bayramoglu, Enis; Andersen, Jens Christian

    2011-01-01

    This paper describes the use of derivative free filters for mobile robot localization and navigation in an orchard. The localization algorithm fuses odometry and gyro measurements with line features representing the surrounding fruit trees of the orchard. The line features are created on basis of 2...

  4. Ineffective higher derivative black hole hair

    Science.gov (United States)

    Goldstein, Kevin; Mashiyane, James Junior

    2018-01-01

    Inspired by the possibility that the Schwarzschild black hole may not be the unique spherically symmetric vacuum solution to generalizations of general relativity, we consider black holes in pure fourth order higher derivative gravity treated as an effective theory. Such solutions may be of interest in addressing the issue of higher derivative hair or during the later stages of black hole evaporation. Non-Schwarzschild solutions have been studied but we have put earlier results on a firmer footing by finding a systematic asymptotic expansion for the black holes and matching them with known numerical solutions obtained by integrating out from the near-horizon region. These asymptotic expansions can be cast in the form of trans-series expansions which we conjecture will be a generic feature of non-Schwarzschild higher derivative black holes. Excitingly we find a new branch of solutions with lower free energy than the Schwarzschild solution, but as found in earlier work, solutions only seem to exist for black holes with large curvatures, meaning that one should not generically neglect even higher derivative corrections. This suggests that one effectively recovers the nonhair theorems in this context.

  5. Methodology for deriving optimal exploration target zones

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2010-03-01

    Full Text Available This research describes a quantitive methodology for deriving optimal exploration target zones based on a probalistic mineral prospectivity map.The Rodalquilar mineral district is located in the Sierra del Cabo de Gata volcanic field, in the south...

  6. MEAN OF MEDIAN ABSOLUTE DERIVATION TECHNIQUE MEAN ...

    African Journals Online (AJOL)

    eobe

    The accurate estimation of noise variance in an image is the first important stage ... lung image was lung image was developed. developed. developed. The development of mean of median absolute derivation technique development of mean of median absolute .... that are non-real numbers during initial processing.

  7. Deriving Process Congruences from Reaction Rules

    DEFF Research Database (Denmark)

    Sobocinski, Pawel

    This thesis is concerned with the development of a theory which, given a formalism with a reduction semantics, allows the derivation of a canonical labelled transition system on which bisimilarity as well as other other equiv� alences are congruences; provided that the contexts of the formalism f...

  8. Econometric Analysis of Financial Derivatives : An overview

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael)

    2014-01-01

    markdownabstract__Abstract__ One of the fastest growing areas in empirical finance, and also one of the least rigorously analyzed, especially from a financial econometrics perspective, is the econometric analysis of financial derivatives, which are typically complicated and difficult to analyze.

  9. Econometric Analysis of Financial Derivatives: An Overview

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael)

    2014-01-01

    markdownabstract__Abstract__ One of the fastest growing areas in empirical finance, and also one of the least rigorously analyzed, especially from a financial econometrics perspective, is the econometric analysis of financial derivatives, which are typically complicated and difficult to analyze.

  10. Visualization of enhancer-derived noncoding RNA

    CSIR Research Space (South Africa)

    Shibayama, Y

    2017-01-01

    Full Text Available Enhancers are principal regulators that allow spatiotemporal tissue-specifi c control of gene expression. While mounting evidence suggests that enhancer-derived long noncoding RNAs (long ncRNAs), including enhancer RNAs (eRNAs), are an important...

  11. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  12. Access to new antimicrobial 4-methylumbelliferone derivatives

    Indian Academy of Sciences (India)

    pounds did not show any activity against P. huttiensis and only compound 8 exhibited a low activity towards. A. tumefasciens (IZ=7.5 mm). Pyrazole and pyrrole derivatives 10-12 were found to be active towards A. tumefasciens. The activity of com- pounds 11 and 12 could be explained by the presence in each one of the ...

  13. A topological derivative method for topology optimization

    DEFF Research Database (Denmark)

    Norato, J.; Bendsøe, Martin P.; Haber, RB

    2007-01-01

    We propose a fictitious domain method for topology optimization in which a level set of the topological derivative field for the cost function identifies the boundary of the optimal design. We describe a fixed-point iteration scheme that implements this optimality criterion subject to a volumetric...

  14. A Graphical Introduction to the Derivative

    Science.gov (United States)

    Samuels, Jason

    2017-01-01

    Calculus has frequently been called one the greatest intellectual achievements of humankind. As a key transitional course to college mathematics, it combines such elementary ideas as rate with new abstract ideas--such as infinity, instantaneous change, and limit--to formulate the derivative and the integral. Most calculus texts begin with the…

  15. Actuarial risk measures for financial derivative pricing

    NARCIS (Netherlands)

    Goovaerts, M.J.; Laeven, R.J.A.

    2008-01-01

    We present an axiomatic characterization of price measures that are superadditive and comonotonic additive for normally distributed random variables. The price representation derived involves a probability measure transform that is closely related to the Esscher transform, and we call it the

  16. Testing Expected Shortfall Models for Derivative Positions

    NARCIS (Netherlands)

    Kerkhof, F.L.J.; Melenberg, B.; Schumacher, J.M.

    2003-01-01

    In this paper we test several risk management models for computing expected shortfall for one-period hedge errors of hedged derivatives positions.Contrary to value-at-risk, expected shortfall cannot be tested using the standard binomial test, since we need information of the distribution in the

  17. 5 CFR 1312.7 - Derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 1312.7 Section 1312.7 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Classification and...

  18. NMR Analysis of Some Pentacycloundecanedione Derivatives ...

    African Journals Online (AJOL)

    The completeNMRelucidation of four pentacycloundecanedione (PCUdione) derivatives is described. Major proton shifts occur when additions are performed on the carbonyl carbons. Some of the carbon signals are also transposed. Despite the fact that the signals of the methine protons on the cage skeleton experience ...

  19. Initial value formulation of higher derivative gravity

    International Nuclear Information System (INIS)

    Noakes, D.R.

    1983-01-01

    The initial value problem is considered for the conformally coupled scalar field and higher derivative gravity, by expressing the equations of each theory in harmonic coordinates. For each theory it is shown that the (vacuum) equations can take the form of a diagonal hyperbolic system with constraints on the initial data. Consequently these theories possess well-posed initial value formulations

  20. Interest Rate Derivative Pricing with Stochastic Volatility

    NARCIS (Netherlands)

    Chen, B.

    2012-01-01

    One purpose of exotic derivative pricing models is to enable financial institutions to quantify and manage their financial risk, arising from large books of portfolios. These portfolios consist of many non-standard exotic financial products. Risk is managed by means of the evaluation of sensitivity

  1. Synthesis and characterization of novel sulfonamides derivatives ...

    African Journals Online (AJOL)

    Five novel sulfonamides derivatives HR5-HR8 and HR14 were synthesized by sulfonylation of primary or secondary amine in the presence of base through nucleophilic substitution reaction. Structural elucidation was carried out through FT-IR, UV, 1H NMR, MS and elemental analysis. Prepared compounds were evaluated ...

  2. Sol-Gel Derived Hafnia Coatings

    Science.gov (United States)

    Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

    2002-01-01

    Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

  3. Derivation of the Ideal Gas Law

    Science.gov (United States)

    Laugier, Alexander; Garai, Jozsef

    2007-01-01

    Undergraduate and graduate physics and chemistry books usually state that combining the gas laws results in the ideal gas law. Leaving the derivation to the students implies that this should be a simple task, most likely a substitution. Boyle's law, Charles's law, and the Avogadro's principle are given under certain conditions; therefore, direct…

  4. Particle production in higher derivative theory

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Permanent link: http://www.ias.ac.in/article/fulltext/pram/054/05/0729-0736. Keywords. Cosmological models; particle production; higher derivative theory of gravitation. Abstract. The effect of particle production on the evolution of the spatially flat Friedmann–Lemaitre–Robertson–Walker cosmological model ...

  5. Measurements of brain-derived neurotrophic factor

    DEFF Research Database (Denmark)

    Trajkovska, Viktorija; Klein, Anders Bue; Vinberg, Maj

    2007-01-01

    Although numerous studies have dealt with changes in blood brain-derived neurotrophic factor (BDNF), methodological issues about BDNF measurements have only been incompletely resolved. We validated BDNF ELISA with respect to accuracy, reproducibility and the effect of storage and repeated freezing...

  6. Contact allergy to isoeugenol and its derivatives

    DEFF Research Database (Denmark)

    Tanaka, Susumu; Royds, C; Buckley, Christopher D

    2004-01-01

    A total of 2261 (808 male, 1453 female) consecutive patients attending contact dermatitis clinics were patch tested to isoeugenol and its derivatives listed in the EU Inventory of Fragrance Ingredients. Positive reactions were found to isoeugenol in 40, transisoeugenol in 40, isoeugenyl acetate i...

  7. Higher-Derivative Supergravity and Moduli Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Ciupke, David; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Louis, Jan [Hamburg Univ. (Germany). Fachberich Physik; Hamburg Univ. (Germany). Zentrum fuer Mathematische Physik

    2015-05-15

    We review the ghost-free four-derivative terms for chiral superfields in N=1 supersymmetry and supergravity. These terms induce cubic polynomial equations of motion for the chiral auxiliary fields and correct the scalar potential. We discuss the different solutions and argue that only one of them is consistent with the principles of effective field theory. Special attention is paid to the corrections along flat directions which can be stabilized or destabilized by the higher-derivative terms. We then compute these higher-derivative terms explicitly for the type IIB string compactified on a Calabi-Yau orientifold with fluxes via Kaluza-Klein reducing the (α'){sup 3}R{sup 4} corrections in ten dimensions for the respective N=1 Kaehler moduli sector. We prove that together with flux and the known (α'){sup 3}-corrections the higher-derivative term stabilizes all Calabi-Yau manifolds with positive Euler number, provided the sign of the new correction is negative.

  8. Supersymmetric higher derivative couplings and their applications

    NARCIS (Netherlands)

    Lodato, I.|info:eu-repo/dai/nl/357520890

    2014-01-01

    After an elementary introduction on black hole physics, supersymmetry and effective theories, which motivates the importance of higher derivative couplings in supergravity, we give an exhaustive treatment of the covariant phase space formalism with many examples explicitly worked out. This sets the

  9. INVESTIGATION OF ANTIFUNGAL ACTIVITY OF QUINOLINIUM DERIVATIVES

    Directory of Open Access Journals (Sweden)

    G. A. Alexandrova

    2013-01-01

    Full Text Available Abstract. Antifungal activity (Candida albicans, Candida krusei of some substituted quinolinium derivatives has been investigated. It was established that the most perspective compound for detail investigation of antifungal activity by labeled biomarkers method was N-phenylbenzoquinaldinium tetrafluoroborate.

  10. Solventless Synthesis of Quinoline Derivatives: Acceleration of ...

    African Journals Online (AJOL)

    NICO

    ABSTRACT. Different Keggin type heteropoly acids (HPAs) and supported ones on solids with different nature and textural properties were used in ... Friedländer reaction, quinoline derivatives, heteropoly compound, supported catalysts, solvent-free condition. 1. ... mechanical properties.7 Different procedures such as the.

  11. Phenotypic Characterization of Derivative 22 Syndrome: Case ...

    Indian Academy of Sciences (India)

    DEEPTI

    E-mail: shubharaophadke@gmail.com. Conflict of Interest Statement: There is no conflict of interest among the authors. Key words: Emanuel syndrome; derivative chromosome 22; microarray; intellectual disability; chromosomal rearrangement. Abstract. Emanuel syndrome is characterized by severe intellectual disability, ...

  12. New lycosinine derivative from Hippeastrum breviflorum

    Directory of Open Access Journals (Sweden)

    Camila Sebben

    Full Text Available AbstractA new lycosinine derivative, 9-O-demethyllycosinine B, was isolated from the native Brazilian Hippeastrum breviflorumHerb., Amaryllidaceae, along with the well-known alkaloids lycosinine B and lycorine. The structure of the new compound was established by physical and spectroscopic methods. 9-O-demethyllycosinine B is the third lycosinine variant identified in the Amaryllidaceae family.

  13. Surface tree languages and parallel derivation trees

    NARCIS (Netherlands)

    Engelfriet, Joost

    1976-01-01

    The surface tree languages obtained by top-down finite state transformation of monadic trees are exactly the frontier-preserving homomorphic images of sets of derivation trees of ETOL systems. The corresponding class of tree transformation languages is therefore equal to the class of ETOL languages.

  14. Risk Management and Financial Derivatives: An Overview

    NARCIS (Netherlands)

    S.M. Hammoudeh (Shawkat); M.J. McAleer (Michael)

    2012-01-01

    textabstractRisk management is crucial for optimal portfolio management. One of the fastest growing areas in empirical finance is the expansion of financial derivatives. The purpose of this special issue on “Risk Management and Financial Derivatives” is to highlight some areas in which novel

  15. Fundamentals of futures, options, basis and derivatives

    International Nuclear Information System (INIS)

    Jones, D.

    1997-01-01

    Characteristic features of futures and options contracts, basis differentials and derivatives were defined and explained. A futures contract refers to an exchange-traded supply contract between a buyer and a seller where the buyer is obligated to take delivery and the seller is obligated to provide delivery of a fixed amount of a commodity at a predetermined price at a specified location. In contrast, an option contract gives the purchaser the right, but not the obligation, to buy or sell the underlying commodity at a certain price on or before an agreed date. Basis differential refers to the discount between two distinct delivery points to reflect the relative value of a commodity, such as natural gas, at those points. Advantages and disadvantages of futures and options contacts, the factors affecting options pricing, and basis differentials, and the methods of calculating basis differentials were described. The nature and intricacies of derivatives, their benefits, in particular their use as a tool for the effective management of the volatilities associated with the oil and gas industry were explained. Their shortcomings such as the high liquidity risk, were also described. Examples of derivative transactions were provided to illustrate the interrelationships of futures/options/derivatives, and their role in financial risk management

  16. Genetic enrichment of cardiomyocytes derived from mouse ...

    African Journals Online (AJOL)

    Pluripotent embryonic stem cells (ESC) have the ability to differentiate into a variety of cell lineages in vitro, including cardiomyocytes. Successful applications of ESC-derived cardiomyocytes in cell therapy and tissue engineering were limited by difficulties in selecting the desired cells from the heterogeneous cell population ...

  17. Familial Follicular-Cell Derived Carcinoma

    Directory of Open Access Journals (Sweden)

    Eun Ju eSon

    2012-05-01

    Full Text Available Follicular cell-derived well-differentiated thyroid cancer, papillary (PTC and follicular thyroid carcinomas (FTC compose 95% of all thyroid malignancies. Familial follicular cell-derived well-differentiated thyroid cancers contribute to 5% of those cases. These familial follicular cell derived carcinomas or non-medullary thyroid carcinomas (NMTC divide into two clinical-pathological groups. One group, syndromic-associated, composed by predominately non-thyroidal tumors, is comprised of Pendred syndrome, Warner syndrome, Carney complex type 1, PTEN-hamartoma tumor syndrome (Cowden disease; PHTS, familial adenomatous polyposis (FAP/Gardner syndrome. Additionally other less established links correlated to the development of follicular cell-derived tumors have also included Ataxia-teleangiectasia syndrome, McCune Albright syndrome, and Peutz-Jeghers syndrome. The subsequent group encompasses syndromes typified by non-medullary thyroid carcinomas or NMTC, as well as, pure familial (f PTC with or without oxyphilia, fPTC with multinodular goiter and fPTC with papillary renal cell carcinoma. This heterogeneous group of diseases has not a established genotype-phenotype correlation as the well-known genetic events identified in the familial C-cell-derived tumors or medullary thyroid carcinomas (MTC. Clinicians should be have the knowledge to identify the likelihood of a patient presenting with thyroid cancer having an additional underlying familial syndrome stemming from characteristics through morphological findings that would alert the pathologist to have the patient undergo subsequent molecular genetics evaluations. This review will discuss the clinical and pathological findings of the patients with familial papillary thyroid carcinoma, such as familial adenomatous polyposis, Carney complex, Werner syndrome, and Pendred syndrome and the heterogeneous group of familial papillary thyroid carcinoma.

  18. WEATHER INDEX- THE BASIS OF WEATHER DERIVATIVES

    Directory of Open Access Journals (Sweden)

    Botos Horia Mircea

    2011-07-01

    Full Text Available This paper approaches the subject of Weather Derivatives, more exactly their basic element the weather index. The weather index has two forms, the Heating Degree Day (HDD and the Cooling Degree Day (CDD. We will try to explain their origin, use and the relationship between the two forms of the index. In our research we started from the analysis of the weather derivatives and what they are based on. After finding out about weather index, we were interested in understanding exactly how they work and how they influence the value of the contract. On the national level the research in the field is scares, but foreign materials available. The study for this paper was based firstly on reading about Weather Derivative, and then going in the meteorogical field and determining the way by which the indices were determined. After this, we went to the field with interest in the indices, such as the energy and gas industries, and figured out how they determined the weather index. For the examples we obtained data from the weather index database, and calculated the value for the period. The study is made on a period of five years, in 8 cities of the European Union. The result of this research is that we can now understand better the importance of the way the indices work and how they influence the value of the Weather Derivatives. This research has an implication on the field of insurance, because of the fact that weather derivative are at the convergence point of the stock markets and the insurance market. The originality of the paper comes from the personal touch given to the theoretical aspect and through the analysis of the HDD and CDD index in order to show their general behaviour and relationship.

  19. Modelling ocean-colour-derived chlorophyll a

    Science.gov (United States)

    Dutkiewicz, Stephanie; Hickman, Anna E.; Jahn, Oliver

    2018-01-01

    This article provides a proof of concept for using a biogeochemical/ecosystem/optical model with a radiative transfer component as a laboratory to explore aspects of ocean colour. We focus here on the satellite ocean colour chlorophyll a (Chl a) product provided by the often-used blue/green reflectance ratio algorithm. The model produces output that can be compared directly to the real-world ocean colour remotely sensed reflectance. This model output can then be used to produce an ocean colour satellite-like Chl a product using an algorithm linking the blue versus green reflectance similar to that used for the real world. Given that the model includes complete knowledge of the (model) water constituents, optics and reflectance, we can explore uncertainties and their causes in this proxy for Chl a (called derived Chl a in this paper). We compare the derived Chl a to the actual model Chl a field. In the model we find that the mean absolute bias due to the algorithm is 22 % between derived and actual Chl a. The real-world algorithm is found using concurrent in situ measurement of Chl a and radiometry. We ask whether increased in situ measurements to train the algorithm would improve the algorithm, and find a mixed result. There is a global overall improvement, but at the expense of some regions, especially in lower latitudes where the biases increase. Not surprisingly, we find that region-specific algorithms provide a significant improvement, at least in the annual mean. However, in the model, we find that no matter how the algorithm coefficients are found there can be a temporal mismatch between the derived Chl a and the actual Chl a. These mismatches stem from temporal decoupling between Chl a and other optically important water constituents (such as coloured dissolved organic matter and detrital matter). The degree of decoupling differs regionally and over time. For example, in many highly seasonal regions, the timing of initiation and peak of the spring bloom in

  20. A New Grünwald-Letnikov Derivative Derived from a Second-Order Scheme

    Directory of Open Access Journals (Sweden)

    B. A. Jacobs

    2015-01-01

    Full Text Available A novel derivation of a second-order accurate Grünwald-Letnikov-type approximation to the fractional derivative of a function is presented. This scheme is shown to be second-order accurate under certain modifications to account for poor accuracy in approximating the asymptotic behavior near the lower limit of differentiation. Some example functions are chosen and numerical results are presented to illustrate the efficacy of this new method over some other popular choices for discretizing fractional derivatives.

  1. Synthesis of metronidazole derivatives as antigiardiasis agents

    Directory of Open Access Journals (Sweden)

    Khabnadideh S.

    2007-04-01

    Full Text Available Metronidazole (MTZ and its derivatives have been extensively used to treat infections caused by protozoa and anaerobic bacteria. In this investigation several novel imidazole and nitroimidazol derivatives namely: 2-(1H-1-imidazolyl-1-phenyl-1-ethanol 1a, 2-(2-methyl-1H-1-imidazolyl-1-phenyl-1-ethanol 1b, 2-(2-methyl-4-nitro-1H-1-imidazolyl-1-phenyl-1-ethanol 1c, 2-(1H-1-imidazolyl-1-cyclohexanol 2d and 2-(2-methyl-4-nitro-1H-1-imidazolyl-1-cyclohexanol 2e were prepared by the reaction of the corresponding imidazoles with styrene oxide or cyclohexene oxide respectively and their biological activity against Giardia lamblia cyst in compareison with MTZ were determined by flotation technique based on Bingham method. These compounds were less active than metronidazole but showed significant antigiardiasis activity.

  2. Inconsistency of Minkowski higher-derivative theories

    Energy Technology Data Exchange (ETDEWEB)

    Aglietti, Ugo G. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); Anselmi, Damiano [Universita di Pisa, Dipartimento di Fisica ' ' Enrico Fermi' ' , Pisa (Italy); INFN, Sezione di Pisa, Pisa (Italy)

    2017-02-15

    We show that Minkowski higher-derivative quantum field theories are generically inconsistent, because they generate nonlocal, non-hermitian ultraviolet divergences, which cannot be removed by means of standard renormalization procedures. By ''Minkowski theories'' we mean theories that are defined directly in Minkowski spacetime. The problems occur when the propagators have complex poles, so that the correlation functions cannot be obtained as the analytic continuations of their Euclidean versions. The usual power counting rules fail and are replaced by much weaker ones. Self-energies generate complex divergences proportional to inverse powers of D'Alembertians. Three-point functions give more involved nonlocal divergences, which couple to infrared effects. We illustrate the violations of the locality and hermiticity of counterterms in scalar models and higher-derivative gravity. (orig.)

  3. Proprioceptive derivation concept-Implications in dentistry

    Directory of Open Access Journals (Sweden)

    Ajay Bhambhal

    2013-01-01

    Full Text Available Dentists and dental students often assume awkward physical positions while providing treatment to (a get a better view of the intraoral cavity; (b provide a more comfortable position for the patient; and/or (c operate equipment and reach for instruments and supplies. Posture isn′t the only concern. New technologies and changes aims to give the dentist new concepts to give greater comfort and better health. This review emphasizes on a new technology: proprioceptive derivation concept.Proprioceptive derivation concept helps dentists to discover new ways of positioning themselves, and working comfortably and effectively, which makes it possible for dentists to adopt a more neutral, less awkward working posture.

  4. Rational Models for Inflation-Linked Derivatives

    DEFF Research Database (Denmark)

    Dam, Henrik; Macrina, Andrea; Skovmand, David

    2018-01-01

    We construct models for the pricing and risk management of inflation-linked derivatives. The model is rational in the sense that affine payoffs written on the consumer price index have prices that are rational functions of the state variables. The nominal pricing kernel is constructed in a multip......We construct models for the pricing and risk management of inflation-linked derivatives. The model is rational in the sense that affine payoffs written on the consumer price index have prices that are rational functions of the state variables. The nominal pricing kernel is constructed...... in a multiplicative manner that allows for closed-form pricing of vanilla inflation products suchlike zero-coupon swaps, caps and floors, year-on-year swaps, caps and floors, and the exotic limited price index swap. The model retains the attractive features of a nominal multi-curve interest rate model such as closed...

  5. Electrochemical Behavior of Biologically Important Indole Derivatives

    Directory of Open Access Journals (Sweden)

    Cigdem Karaaslan

    2011-01-01

    Full Text Available Voltammetric techniques are most suitable to investigate the redox properties of a new drug. Use of electrochemistry is an important approach in drug discovery and research as well as quality control, drug stability, and determination of physiological activity. The indole nucleus is an essential element of a number of natural and synthetic products with significant biological activity. Indole derivatives are the well-known electroactive compounds that are readily oxidized at carbon-based electrodes, and thus analytical procedures, such as electrochemical detection and voltammetry, have been developed for the determination of biologically important indoles. This paper explains some of the relevant and recent achievements in the electrochemistry processes and parameters mainly related to biologically important indole derivatives in view of drug discovery and analysis.

  6. Two Constraints on Tonal Derivation in Chinese

    Directory of Open Access Journals (Sweden)

    Hui-chuan Hsu

    2005-12-01

    Full Text Available This paper aims to further examine two working constraints on tonal derivation proposed in some recent generative studies on Changting, namely One Step Principle (OSP and Moving Windows Constraint (MWC. Our extension of the scope of discussion to other Chinese dialects leads to the necessity of proposing the more general Domain Constraint (DC which subsumes the MWC. The comparison and contrast between OSP and DC exhibits a see-saw battle at present. Both successfully account for Dongshi Hakka, Tianjin, and Yaoping. OSP wins in Changting (Chen 2003, Chen et al. 2004 and fast speeches in Xuzhou and Standard Mandarin. Different form the above-mentioned cases, Tianjin fast speech demonstrates a dual nature in regard to both constraints. Furthermore, DC receives non-Sinitic support from Hakha Lai; segmental derivation of fanqie languages reveals an OSP counterpart. How these two constraints behave in African tone languages awaits further study.

  7. Photocatalytic Based Degradation Processes of Lignin Derivatives

    Directory of Open Access Journals (Sweden)

    Colin Awungacha Lekelefac

    2015-01-01

    Full Text Available Photocatalysis, belonging to the advanced oxidation processes (AOPs, is a potential new transformation technology for lignin derivatives to value added products (e.g., phenol, benzene, toluene, and xylene. Moreover, lignin represents the only viable source to produce aromatic compounds as fossil fuel alternative. This review covers recent advancement made in the photochemical transformation of industrial lignins. It starts with the photochemical reaction principle followed by results obtained by varying process parameters. In this context, influences of photocatalysts, metal ions, additives, lignin concentration, and illumination intensity and the influence of pH are presented and discussed. Furthermore, an overview is given on several used process analytical methods describing the results obtained from the degradation of lignin derivatives. Finally, a promising concept by coupling photocatalysis with a consecutive biocatalytic process was briefly reviewed.

  8. Algebraic theory of locally nilpotent derivations

    CERN Document Server

    Freudenburg, Gene

    2017-01-01

    This book explores the theory and application of locally nilpotent derivations, a subject motivated by questions in affine algebraic geometry and having fundamental connections to areas such as commutative algebra, representation theory, Lie algebras and differential equations. The author provides a unified treatment of the subject, beginning with 16 First Principles on which the theory is based. These are used to establish classical results, such as Rentschler's Theorem for the plane and the Cancellation Theorem for Curves. More recent results, such as Makar-Limanov's theorem for locally nilpotent derivations of polynomial rings, are also discussed. Topics of special interest include progress in classifying additive actions on three-dimensional affine space, finiteness questions (Hilbert's 14th Problem), algorithms, the Makar-Limanov invariant, and connections to the Cancellation Problem and the Embedding Problem. A lot of new material is included in this expanded second edition, such as canonical factoriza...

  9. Fundamentals and advanced techniques in derivatives hedging

    CERN Document Server

    Bouchard, Bruno

    2016-01-01

    This book covers the theory of derivatives pricing and hedging as well as techniques used in mathematical finance. The authors use a top-down approach, starting with fundamentals before moving to applications, and present theoretical developments alongside various exercises, providing many examples of practical interest. A large spectrum of concepts and mathematical tools that are usually found in separate monographs are presented here. In addition to the no-arbitrage theory in full generality, this book also explores models and practical hedging and pricing issues. Fundamentals and Advanced Techniques in Derivatives Hedging further introduces advanced methods in probability and analysis, including Malliavin calculus and the theory of viscosity solutions, as well as the recent theory of stochastic targets and its use in risk management, making it the first textbook covering this topic. Graduate students in applied mathematics with an understanding of probability theory and stochastic calculus will find this b...

  10. Noise-compliant tip-shape derivation

    Science.gov (United States)

    Williams, P. M.; Davies, M. C.; Roberts, C. J.; Tendler, S. J. B.

    Wide use of the blind tip-derivation procedure has lead to the realization of the problem of noise in experimental image data. A modification to the algorithm by which the probe shape is extracted from image data is described. By consideration of the possible levels of noise in an image, a realistic estimate of the probe geometry can be derived from unfiltered experimental image data. The new procedure is demonstrated by its application to a test image that has been deliberately degraded through the addition of random noise. The results are compared with those from the current technique. The technique has significant application in metrology through the compensation of both lateral and vertical measurement errors.

  11. Sensitivity derivatives for flexible sensorimotor learning.

    Science.gov (United States)

    Abdelghani, M N; Lillicrap, T P; Tweed, D B

    2008-08-01

    To learn effectively, an adaptive controller needs to know its sensitivity derivatives--the variables that quantify how system performance depends on the commands from the controller. In the case of biological sensorimotor control, no one has explained how those derivatives themselves might be learned, and some authors suggest they are not learned at all but are known innately. Here we show that this knowledge cannot be solely innate, given the adaptive flexibility of neural systems. And we show how it could be learned using forms of information transport that are available in the brain. The mechanism, which we call implicit supervision, helps explain the flexibility and speed of sensorimotor learning and our ability to cope with high-dimensional work spaces and tools.

  12. Arbitrage-free valuation of energy derivatives

    International Nuclear Information System (INIS)

    Amin, K.; Ng, V.; Pirrong, C.

    1999-01-01

    This chapter focuses on techniques available for valuing energy-contingent claims and develops an arbitrage-free framework to value energy derivatives. The relationship between the spot, forward and futures prices is explained. Option valuation with deterministic convenience yields is discussed using an extension of the Black (1976) framework, and details of the risk-neutral valuation of European options, and valuation of American and European-style options are given. Option valuations with stochastic convenience yields, the evolution of the term structure of convenience yield, and a tree approach to valuing American and other options are discussed. Applications and limitations of the models for pricing energy derivative products are considered. The stochastic differential equation for the futures prices when the convenience yields are stochastic is presented in an appendix

  13. A generalization of the Lie derivative

    International Nuclear Information System (INIS)

    Dolan, P.

    1984-01-01

    If X=xisup(i)deltasub(i) and Y=etasup(i)deltasub(i) are vector fields then it is well-known that the Lie derivative Poundsub(X)Y equivalent to [X,Y] (xisup(s)deltasub(s) etasup(s)deltasub(s)xisup(i))deltasub(i) is also a vector field under general coordinate transformations. A generalization of this result, due to previous workers, allows a definition of Poundsub(F)G, where F,G are arbitrary contravariant tensor fields. The formulae are linear in the first partial derivatives of F and G. An application to the theory of Killing-Yano tensor fields on Riemannian manifolds is given. (author)

  14. Eisenhart lift for higher derivative systems

    Energy Technology Data Exchange (ETDEWEB)

    Galajinsky, Anton, E-mail: galajin@tpu.ru; Masterov, Ivan, E-mail: masterov@tpu.ru

    2017-02-10

    The Eisenhart lift provides an elegant geometric description of a dynamical system of second order in terms of null geodesics of the Brinkmann-type metric. In this work, we attempt to generalize the Eisenhart method so as to encompass higher derivative models. The analysis relies upon Ostrogradsky's Hamiltonian. A consistent geometric description seems feasible only for a particular class of potentials. The scheme is exemplified by the Pais–Uhlenbeck oscillator.

  15. On butterfly effect in higher derivative gravities

    Energy Technology Data Exchange (ETDEWEB)

    Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Davody, Ali; Naseh, Ali; Taghavi, Seyed Farid [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2016-11-07

    We study butterfly effect in D-dimensional gravitational theories containing terms quadratic in Ricci scalar and Ricci tensor. One observes that due to higher order derivatives in the corresponding equations of motion there are two butterfly velocities. The velocities are determined by the dimension of operators whose sources are provided by the metric. The three dimensional TMG model is also studied where we get two butterfly velocities at generic point of the moduli space of parameters. At critical point two velocities coincide.

  16. Alkylation of Zwitterionic Thiooxalic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Manfred Michalik

    2001-05-01

    Full Text Available The new S-alkyl thiooxal-1-hydrazono-2-amidrazonium halides 2-4 were synthesized by reaction of the corresponding zwitterionic thiooxalic acid derivatives 1 with alkyl halides in methanol. The structures of compounds 4b and 4d were proven by X-ray structural analysis. Both compounds form an interesting intermolecular network of hydrogen bonds in the solid state.

  17. Schwinger model with higher derivative couplings

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Natividade, C.P. (Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Fisica)

    1991-02-01

    We study a version of the Schwinger model where fermion and gauge fields are coupled by means of higher derivatives. We show that, regardless of possible existence of ghosts and non-unitarity, the model is completely soluble and the anomalous axial divergence and the mass generated for the photon field are the same as in the usual model. The confinement of the electric charge is also discussed. (orig.).

  18. Strong commutativity preserving generalized derivations on ...

    African Journals Online (AJOL)

    Let R be a non-commutative prime ring of characteristic different from 2, with right Utumi quotient ring U and extended centroid C and let F and G be generalized derivations of R such that F(x)G(y)-F(y)G(x) = [x; y], for all x; y ∈ S, where S is a subset of R. Here we will discuss the following cases: (a) S = [R;R];. b) S = L, where ...

  19. Derivation of plutonium-239 materials disposition categories

    International Nuclear Information System (INIS)

    Brough, W.G.

    1995-01-01

    At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report

  20. Literature Review of Polymer Derived Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Reuben James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-25

    Polymer Derived Ceramics (PDCs), also known as preceramic polymers, are valuable coating agents that are used to produce surface barriers on substrates such as stainless steel. These barriers protect against a multitude of environmental threats, and have been used since their research and development in 19772. This paper seeks to review and demonstrate the remarkable properties and versatility that PDCs have to offer, while also giving a brief overview of the processing techniques used today.

  1. Higher derivative super Yang-Mills theories

    NARCIS (Netherlands)

    Bergshoeff, E.; Rakowski, M.; Sezgin, E.

    1987-01-01

    The most general higher derivative Yang-Mills actions of the type (F^2 + α^2F^4) which are globally supersymmetric up to order α^2 in six- and ten-dimensional spacetimes are given. The F^4-terms turn out to occur in the combination α^2[tr F^4 - ¼(tr F^2)^2], where the trace is over the Lorentz

  2. Cholestane derivatives as antitumor and antiangiogenic drugs

    Czech Academy of Sciences Publication Activity Database

    Hoffmannová, L.; Steigerová, J.; Oklešťková, J.; Kohout, Ladislav; Chodounská, Hana; Hniličková, Jaroslava; Kasal, Alexander; Černý, Ivan; Kolář, Z.; Strnad, M.

    2010-01-01

    Roč. 35, SA (2010), s. 205-205 ISSN 0377-8282. [EFMC-ISMC 2010. International Symposium on Medicinal Chemistry /21./. 05.09.2010-09.09.2010, Brussels] R&D Projects: GA MŠk(CZ) LC06077; GA AV ČR KAN200200651 Institutional research plan: CEZ:AV0Z40550506 Keywords : cholestane derivatives * anticancer drugs Subject RIV: CC - Organic Chemistry

  3. Derived length for arbitrary topological spaces

    Directory of Open Access Journals (Sweden)

    A. J. Jayanthan

    1992-01-01

    Full Text Available The notion of derived length is as old as that of ordinal numbers itself. It is also known as the Cantor-Bendixon length. It is defined only for dispersed (that is scattered spaces. In this paper this notion has been extended in a natural way for all topological spaces such that all its pleasing properties are retained. In this process we solve a problem posed by V. Kannan. ([1] Page 158.

  4. Covariant derivatives of the Berezin transform

    Czech Academy of Sciences Publication Activity Database

    Engliš, Miroslav; Otáhalová, R.

    2011-01-01

    Roč. 363, č. 10 (2011), s. 5111-5129 ISSN 0002-9947 R&D Projects: GA AV ČR IAA100190802 Keywords : Berezin transform * Berezin symbol * covariant derivative Subject RIV: BA - General Mathematics Impact factor: 1.093, year: 2011 http://www.ams.org/journals/tran/2011-363-10/S0002-9947-2011-05111-1/home.html

  5. The Brain Derived Neurotrophic Factor and Personality

    OpenAIRE

    Christian Montag

    2014-01-01

    The study of the biological basis of personality is a timely research endeavor, with the aim of deepening our understanding of human nature. In recent years, a growing body of research has investigated the role of the brain derived neurotrophic factor (BDNF) in the context of individual differences across human beings, with a focus on personality traits. A large number of different approaches have been chosen to illuminate the role of BDNF for personality, ranging from the measurement of BDNF...

  6. Eosinophil secretion of granule-derived cytokines

    Directory of Open Access Journals (Sweden)

    Lisa A Spencer

    2014-10-01

    Full Text Available Eosinophils are tissue-dwelling leukocytes, present in the thymus, and gastrointestinal and genitourinary tracts of healthy individuals at baseline, and recruited, often in large numbers, to allergic inflammatory foci and sites of active tissue repair. The biological significance of eosinophils is vast and varied. In health, eosinophils support uterine and mammary gland development, and maintain bone marrow plasma cells and adipose tissue alternatively activated macrophages, while in response to tissue insult eosinophils function as inflammatory effector cells, and, in the wake of an inflammatory response, promote tissue regeneration and wound healing. One common mechanism driving many of the diverse eosinophil functions is the regulated and differential secretion of a vast array of eosinophil-derived cytokines. Eosinophils are distinguished from most other leukocytes in that many, if not all, of the over three dozen eosinophil-derived cytokines are pre-synthesized and stored within intracellular granules, poised for very rapid, stimulus-induced secretion. Eosinophils engaged in cytokine secretion in situ utilize distinct pathways of cytokine release that include: classical exocytosis, whereby granules themselves fuse with the plasma membrane and release their entire contents extracellularly; piecemeal degranulation, whereby granule-derived cytokines are selectively mobilized into vesicles that emerge from granules, traverse the cytoplasm and fuse with the plasma membrane to release discrete packets of cytokines; and eosinophil cytolysis, whereby intact granules are extruded from eosinophils, and deposited within tissues. In this latter scenario, extracellular granules can themselves function as stimulus-responsive secretory-competent organelles within the tissue. Here we review the distinctive processes of differential secretion of eosinophil granule-derived cytokines.

  7. Econometric Analysis of Financial Derivatives: An Overview

    OpenAIRE

    Chang, Chia-Lin; McAleer, Michael

    2014-01-01

    One of the fastest growing areas in empirical finance, and also one of the least rigorously analyzed, especially from a financial econometrics perspective, is the econometric analysis of financial derivatives, which are typically complicated and difficult to analyze. The purpose of this special issue of the journal on “Econometric Analysis of Financial Derivatives” is to highlight several areas of research by leading academics in which novel econometric, financial econometric, mathematical fi...

  8. Derivative processes for modelling metabolic fluxes

    Science.gov (United States)

    Žurauskienė, Justina; Kirk, Paul; Thorne, Thomas; Pinney, John; Stumpf, Michael

    2014-01-01

    Motivation: One of the challenging questions in modelling biological systems is to characterize the functional forms of the processes that control and orchestrate molecular and cellular phenotypes. Recently proposed methods for the analysis of metabolic pathways, for example, dynamic flux estimation, can only provide estimates of the underlying fluxes at discrete time points but fail to capture the complete temporal behaviour. To describe the dynamic variation of the fluxes, we additionally require the assumption of specific functional forms that can capture the temporal behaviour. However, it also remains unclear how to address the noise which might be present in experimentally measured metabolite concentrations. Results: Here we propose a novel approach to modelling metabolic fluxes: derivative processes that are based on multiple-output Gaussian processes (MGPs), which are a flexible non-parametric Bayesian modelling technique. The main advantages that follow from MGPs approach include the natural non-parametric representation of the fluxes and ability to impute the missing data in between the measurements. Our derivative process approach allows us to model changes in metabolite derivative concentrations and to characterize the temporal behaviour of metabolic fluxes from time course data. Because the derivative of a Gaussian process is itself a Gaussian process, we can readily link metabolite concentrations to metabolic fluxes and vice versa. Here we discuss how this can be implemented in an MGP framework and illustrate its application to simple models, including nitrogen metabolism in Escherichia coli. Availability and implementation: R code is available from the authors upon request. Contact: j.norkunaite@imperial.ac.uk; m.stumpf@imperial.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24578401

  9. Synthesis and pharmacological activity of diterpenylnaphthoquinone derivatives.

    Science.gov (United States)

    Pertino, Mariano Walter; Theoduloz, Cristina; Palenzuela, Jose Antonio; Afonso, Maria del Mar; Yesilada, Erdem; Monsalve, Francisco; González, Paulo; Droguett, Daniel; Schmeda-Hirschmann, Guillermo

    2011-10-13

    New diterpenylquinones, combining a diterpene diacid and a naphthoquinone, were prepared from junicedric acid and lapachol. The new derivatives were assessed as gastroprotective agents by the HCl-EtOH-induced gastric lesions model in mice as well as for basal cytotoxicity on the following human cell lines: Normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), and hepatocellular carcinoma (Hep G2). Several of the new compounds were significantly active as antiulcer agents and showed selective cytotoxicity against AGS cells.

  10. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  11. Synthesis and anticonvulsant properties of tetrahydroisoquinoline derivatives.

    Science.gov (United States)

    Gitto, Rosaria; Caruso, Roberta; Orlando, Valerie; Quartarone, Silvana; Barreca, Maria Letizia; Ferreri, Guido; Russo, Emilio; De Sarro, Giovambattista; Chimirri, Alba

    2004-01-01

    As a follow up of our previous structure-activity relationship and molecular modeling studies, we synthesized a novel series of 1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives as potential non-competitive AMPA receptor antagonists. When tested for their ability to prevent sound-induced seizures in DBA/2 mice, some of these novel compounds showed high anticonvulsant potency.

  12. Parallel Aircraft Trajectory Optimization with Analytic Derivatives

    Science.gov (United States)

    Falck, Robert D.; Gray, Justin S.; Naylor, Bret

    2016-01-01

    Trajectory optimization is an integral component for the design of aerospace vehicles, but emerging aircraft technologies have introduced new demands on trajectory analysis that current tools are not well suited to address. Designing aircraft with technologies such as hybrid electric propulsion and morphing wings requires consideration of the operational behavior as well as the physical design characteristics of the aircraft. The addition of operational variables can dramatically increase the number of design variables which motivates the use of gradient based optimization with analytic derivatives to solve the larger optimization problems. In this work we develop an aircraft trajectory analysis tool using a Legendre-Gauss-Lobatto based collocation scheme, providing analytic derivatives via the OpenMDAO multidisciplinary optimization framework. This collocation method uses an implicit time integration scheme that provides a high degree of sparsity and thus several potential options for parallelization. The performance of the new implementation was investigated via a series of single and multi-trajectory optimizations using a combination of parallel computing and constraint aggregation. The computational performance results show that in order to take full advantage of the sparsity in the problem it is vital to parallelize both the non-linear analysis evaluations and the derivative computations themselves. The constraint aggregation results showed a significant numerical challenge due to difficulty in achieving tight convergence tolerances. Overall, the results demonstrate the value of applying analytic derivatives to trajectory optimization problems and lay the foundation for future application of this collocation based method to the design of aircraft with where operational scheduling of technologies is key to achieving good performance.

  13. Diphosphorus-substituted derivatives of ketones

    International Nuclear Information System (INIS)

    Novikova, Z.S.; Kurkin, A.N.; Lutsenko, I.F.

    1986-01-01

    The structure of C,0-diphosphorus-substituted derivatives of ketones formed in the phosphorylation of sodium enolates of C-phosphorus-substituted ketones depends on the structure of the phosphorus-containing group in the molecule of the original ketone; increase in the electron-acceptor power of the substituents on the phosphorus atom and rise in its valence favor the formation of β-phosphorus-containing vinyl esters of phosphorus acids

  14. Lie n-derivations on 7 -subspace lattice algebras

    Indian Academy of Sciences (India)

    all x ∈ K and all A ∈ Alg L. Based on this result, a complete characterization of linear n-Lie derivations on Alg L is obtained. Keywords. J -subspace lattice algebras; Lie derivations; Lie n-derivations; derivations. 2010 Mathematics Subject Classification. 47B47, 47L35. 1. Introduction. Let A be an algebra. Recall that a linear ...

  15. On Functional Inequalities Originating from Module Jordan Left Derivations

    Directory of Open Access Journals (Sweden)

    Kang Sheon-Young

    2008-01-01

    Full Text Available Abstract We first examine the generalized Hyers-Ulam stability of functional inequality associated with module Jordan left derivation (resp., module Jordan derivation. Secondly, we study the functional inequality with linear Jordan left derivation (resp., linear Jordan derivation mapping into the Jacobson radical.

  16. On Functional Inequalities Originating from Module Jordan Left Derivations

    Directory of Open Access Journals (Sweden)

    Ick-Soon Chang

    2008-06-01

    Full Text Available We first examine the generalized Hyers-Ulam stability of functional inequality associated with module Jordan left derivation (resp., module Jordan derivation. Secondly, we study the functional inequality with linear Jordan left derivation (resp., linear Jordan derivation mapping into the Jacobson radical.

  17. Higher-derivative massive actions from dimensional reduction

    Science.gov (United States)

    Joung, Euihun; Mkrtchyan, Karapet

    2013-02-01

    A procedure to obtain higher-derivative free massive actions is proposed. It consists in dimensional reduction of conventional two-derivative massless actions, where solutions to constraints bring in higher derivatives. We apply this procedure to derive the arbitrary dimensional generalizations of (linearized) New Massive Gravity and New Topologically Massive Gravity.

  18. 17 CFR 240.16a-4 - Derivative securities.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Derivative securities. 240.16a....16a-4 Derivative securities. (a) For purposes of section 16 of the Act, both derivative securities and... securities, except that the acquisition or disposition of any derivative security shall be separately...

  19. 14 CFR 1203.501 - Applying derivative classification markings.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Applying derivative classification markings... INFORMATION SECURITY PROGRAM Derivative Classification § 1203.501 Applying derivative classification markings. Persons who apply derivative classification markings shall: (a) Observe and respect original...

  20. 32 CFR 2400.16 - Derivative classification markings.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Derivative classification markings. 2400.16... SECURITY PROGRAM Derivative Classification § 2400.16 Derivative classification markings. (a) Documents..., as described in § 2400.12 of this part, the information may not be used as a basis for derivative...

  1. 17 CFR 200.507 - Declassification dates on derivative documents.

    Science.gov (United States)

    2010-04-01

    ... derivative documents. 200.507 Section 200.507 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... of National Security Information and Material § 200.507 Declassification dates on derivative... derivative document that derives its classification from the approved use of the classification guide of...

  2. 45 CFR 1630.12 - Applicability to derivative income.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Applicability to derivative income. 1630.12... CORPORATION COST STANDARDS AND PROCEDURES § 1630.12 Applicability to derivative income. (a) Derivative income... activity. (b) Derivative income which is allocated to the LSC fund in accordance with paragraph (a) of this...

  3. 14 CFR 1203.500 - Use of derivative classification.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Use of derivative classification. 1203.500... PROGRAM Derivative Classification § 1203.500 Use of derivative classification. The application of derivative classification markings is a responsibility of those who incorporate, paraphrase, restate, or...

  4. 7-oxygenated Derivatives of Dehydroepiandrosterone and Obesity

    Directory of Open Access Journals (Sweden)

    B. Sedláčková

    2012-01-01

    Full Text Available 7-hydroxy/oxo derivatives of dehydroepiandrosterone are potential regulators of the local cortisol activity due to their competition in the cortisolcortisone balance mediated by 11β-hydroxysteroid dehydrogenase. 7-hydroxydehydroepiandrosterone is marketed as anti-obesity medication, though no clinical study aimed at the benefit of administering 7-oxygenated derivatives of dehydroepiandrosterone has appeared until now. We tried to show whether there exist differences in levels of circulating 7-hydroxy/oxo-dehydroepiandrosterone derivatives between lean and obese boys and girls. From a cohort of adolescents investigated within the frame of anti-obesity programme 10 obese boys and 10 obese girls were compared with age-matched lean boys and girls in their anthropometric data, and concentrations of both epimers of 7-hydroxydehydroepiandrosterone and 7-oxo-dehydroepiandrosterone were determined by the RIA method. The basal levels of 7α-hydroxy-dehydroepiandrosterone were significantly higher in obese boys than in lean boys but not in girls. The association was found for anthropometric parameters and 7α-hydroxy-dehydroepiandrosterone, however again only in boys and not in girls. Higher levels of 7α-hydroxydehydroepiandrosterone its positive association with anthropometric data in obese boys may serve as a sign that, at least in boys, 7-oxygenated 5-ene-steroids may take part in regulating the hormonal signal for fat formation or distribution.

  5. Novel isoquinoline derivatives as antimicrobial agents.

    Science.gov (United States)

    Galán, Abraham; Moreno, Laura; Párraga, Javier; Serrano, Ángel; Sanz, Ma Jesús; Cortes, Diego; Cabedo, Nuria

    2013-06-01

    The wide variety of potent biological activities of natural and synthetic isoquinoline alkaloids encouraged us to develop novel antimicrobial isoquinoline compounds. We synthesized a variety of differently functionalized 1-pentyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (THIQs), including dihydroisoquinolinium salts (2 and 5), methyl pentanoate-THIQ (6), 1-pentanol-THIQ (7), ester derivatives (8-15) and carbamate derivatives (16-23). We employed classic intramolecular Bischler-Napieralski cyclodehydration to generate the isoquinoline core. All the structures were characterized by nuclear magnetic resonance and mass spectrometry. The bactericide and fungicide activities were evaluated for all the synthesized compounds and structure-activity relationships were established. Many compounds exhibited high and broad-range bactericidal activity. Fluorophenylpropanoate ester 13 and the halogenated phenyl- (17, 18) and phenethyl carbamates (21, 22) exerted the most remarkable bactericidal activity. However, few compounds displayed antifungal activity against most of the fungi tested. Among them, chlorinated derivatives like chlorobenzoate and chlorophenylpropanoate esters (10 and 14, respectively) and chlorophenethyl carbamate 22, exhibited the greatest antifungal activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  7. Generalised derived limits for radioisotopes of plutonium

    International Nuclear Information System (INIS)

    Simmonds, J.R.; Harrison, N.T.; Linsley, G.S.

    1982-01-01

    Generalised Derived Limits (GDLs) are evaluated for plutonium isotopes in materials from the terrestrial and aquatic environments and for discharge to atmosphere. They are intended for use as convenient reference levels against which the results of environmental monitoring can be compared and atmospheric discharges assessed. GDLs are calculated using assumptions concerning the habits and location of the critical group of exposed individuals in the population. They are intended for use when the environmental contamination or discharge to atmosphere is less than about 5% of the GDL. If the level of environmental contamination or discharge to the atmosphere exceeds this percentage of the GDL it does not necessarily mean that the dose equivalents to members of the public are approaching the dose equivalent limit. It is rather an indication that it may be appropriate to obtain a more specific derived limit for the particular situation by reviewing the values of the parameters involved in the calculation. GDL values are specified for plutonium radionuclides in air, water, soil, sediments and various foodstuffs derived from the terrestrial and aquatic environments. GDLs are also given for plutonium radionuclides on terrestrial surfaces and for their discharge to atmosphere. (author)

  8. Generalised derived limits for radioisotopes of iodine

    International Nuclear Information System (INIS)

    Hughes, J.S.; Haywood, S.M.; Simmonds, J.R.

    1984-04-01

    Generalised Derived Limits (GDLs) are evaluated for iodine-125,129,131,132,133,134,135 in selected materials from the terrestrial and aquatic environments and for discharge to atmosphere. They are intended for use as convenient reference levels against which the results of environmental monitoring can be compared and atmospheric discharges assessed. GDLs are intended for use when the environmental contamination or discharge to atmosphere is less than about 5% of the GDL. If the level of environmental contamination or discharge to the atmosphere exceeds this percentage of the GDL it does not necessarily mean that the dose equivalents to members of the public are approaching the dose equivalent limit. It is rather an indication that it may be appropriate to obtain a more specific derived limit for the particular situation by reviewing the values of the parameters involved in the calculation. GDL values are specified for iodine radionuclides in water, soil, grass, sediments and various foodstuffs derived from the terrestrial and aquatic environments. GDLs are also given for iodine radionuclides on terrestrial surfaces and for their discharge to atmosphere. (author)

  9. Price models for oil derivates in Slovenia

    International Nuclear Information System (INIS)

    Nemac, F.; Saver, A.

    1995-01-01

    In Slovenia, a law is currently applied according to which any change in the price of oil derivatives is subject to the Governmental approval. Following the target of getting closer to the European Union, the necessity has arisen of finding ways for the introduction of liberalization or automated approach to price modifications depending on oscillations of oil derivative prices on the world market and the rate of exchange of the American dollar. It is for this reason that at the Agency for Energy Restructuring we made a study for the Ministry of Economic Affairs and Development regarding this issue. We analysed the possible models for the formation of oil derivative prices for Slovenia. Based on the assessment of experiences of primarily the west European countries, we proposed three models for the price formation for Slovenia. In future, it is expected that the Government of the Republic of Slovenia will make a selection of one of the proposed models to be followed by enforcement of price liberalization. The paper presents two representative models for price formation as used in Austria and Portugal. In the continuation the authors analyse the application of three models that they find suitable for the use in Slovenia. (author)

  10. P-Splines Using Derivative Information

    KAUST Repository

    Calderon, Christopher P.

    2010-01-01

    Time series associated with single-molecule experiments and/or simulations contain a wealth of multiscale information about complex biomolecular systems. We demonstrate how a collection of Penalized-splines (P-splines) can be useful in quantitatively summarizing such data. In this work, functions estimated using P-splines are associated with stochastic differential equations (SDEs). It is shown how quantities estimated in a single SDE summarize fast-scale phenomena, whereas variation between curves associated with different SDEs partially reflects noise induced by motion evolving on a slower time scale. P-splines assist in "semiparametrically" estimating nonlinear SDEs in situations where a time-dependent external force is applied to a single-molecule system. The P-splines introduced simultaneously use function and derivative scatterplot information to refine curve estimates. We refer to the approach as the PuDI (P-splines using Derivative Information) method. It is shown how generalized least squares ideas fit seamlessly into the PuDI method. Applications demonstrating how utilizing uncertainty information/approximations along with generalized least squares techniques improve PuDI fits are presented. Although the primary application here is in estimating nonlinear SDEs, the PuDI method is applicable to situations where both unbiased function and derivative estimates are available.

  11. Bio-Detergent oil derivative used frying

    Directory of Open Access Journals (Sweden)

    Alfonso Jesús Torres Ortega

    2011-04-01

    Full Text Available Currently, the global trend towards sustainable development for environmental friendly products such as biosurfactants shows an excellent performance. Anionic surface active agents can be produced from renewable natural raw materials such as vegetable oils mainly derived from palm oil. Methyl ester sulfonate is an active component of highly biodegradable detergents, one advantage compared with detergents derived from petrochemicals which generate a high pollutant load. This paper proposes the study of sulfonation with sulfur trioxide of esters derived from waste cooking oil which main component is palm oil. The falling film reactor allows determining the conditions of the process at pilot scale. The experimentation allowed an enhancement of empirical equations in the equipment implemented for this purpose and to determine some physicochemical properties. The comparison obtained for this same process with petrochemicals compounds indicates that the model could be applied to any film sulfonation but adjusting the parameters and specific conditions, such as the physicochemical properties of the compounds used, since the sulfonation process described in this work is one of the more complicated cases. The technological development presented here seeks to contribute with the industrial needs to promote green chemical industry for the production of biosurfactant from waste frying oil.

  12. Synthesis and Evaluation of Essential Oil-Derived β-Methoxyacrylate Derivatives as High Potential Fungicides

    Directory of Open Access Journals (Sweden)

    Haihuan Su

    2017-05-01

    Full Text Available Essential oils (EOs are plant-derived aroma compounds with a wide range of biological activity, but their actions are slow, and they are typically unstable to light or heat, difficult to extract and so on. To find highly potential fungicides derived from natural EOs, a series of essential oil-based β-methoxyacrylate derivatives have been designed and synthesized. The target compounds have been screened for their potential fungicidal activity against eleven species of plant pathogen fungi, including Alternaria alternata, Phomopsis adianticola, Pestalotiopsis theae, Sclerotinia sclerotiorum, etc. Compared with intermediates I, the parent essential oils and azoxystrobin, almost all of essential oil-based β-methoxyacrylate derivatives exhibited significantly better fungicidal activity. Further investigation revealed that some compounds showed remarkable inhibitory activities against Pestalotiopsis theae, Phomopsis adianticola, Sclerotinia sclerotiorum and Magnapothe grisea at different concentrations in contrast to the commercial product azoxystrobin. Compound II-8 exhibited particularly significant fungicidal activity.

  13. SYNTHESIS OF FLAVANONE-6-CARBOXYLIC ACID DERIVATIVES FROM SALICYLIC ACID DERIVATIVE

    OpenAIRE

    Mardjan, Muhammad Idham Darussalam; Ambarwati, Retno; Matsjeh, Sabirin; Wahyuningsih, Tutik Dwi; Haryadi, Winarto

    2012-01-01

    Synthesis of flavanone-6-carboxylic acid derivatives had been conducted via the route of chalcone. The synthesis was carried out from salicylic acid derivative, i.e. 4-hydroxybenzoic acid, via esterification, Fries rearrangement, Claisen-Schmidt condensation and 1,4-nucleophilic addition reactions. Structure elucidation of products was performed using FT-IR, 1H-NMR, GC-MS and UV-Vis spectrometers. Reaction of 4-hydroxybenzoic acid with methanol catalyzed with sulfuric acid produced methyl 4-h...

  14. Resveratrol derivatives: an updated patent review (2012-2015).

    Science.gov (United States)

    Li, Chang; Xu, Xiaofei; Tao, Zhihao; Sun, Cuirong; Pan, Yuanjiang

    2016-08-04

    Resveratrol is a well-studied natural small molecule that possesses diverse bioactivities. Chemical derivation based on the resveratrol scaffold is of great importance to overcome the drawbacks of resveratrol and to improve its therapeutic potential. Continuous efforts have been established to develop resveratrol derivatives that target different therapeutic applications. This review covers patents published from 2012 to 2015. All resveratrol derivatives discussed are classified based on its derivation strategy as simple derivatives, conjugated derivatives and miscellaneous derivatives. Their therapeutic related activities are reviewed and discussed. Chemical derivation is an effective strategy to enhance the benefits of resveratrol and ameliorate its disadvantages. Recent studies on resveratrol derivatives have made great progress in the treatment of cancer and neurodegenerative diseases to name a few, demonstrating improved activity compared with resveratrol. Notably, its bioavailability was also improved in some cases. However, the 'next generation' of resveratrol derivatives still requires the development of new strategies and techniques.

  15. MODERN TRENDS OF DEVELOPMENT OF INTERNATIONAL DERIVATIVES MARKET

    Directory of Open Access Journals (Sweden)

    V. Shelydko

    2014-09-01

    Full Text Available Article is devoted to analysis of structure and peculiarities of development of the international derivatives market. The history of formation of the international derivatives market is investigated. The nature, functions and advantages of use of derivatives, and also their role in the modern international securities market are defined. Classification of financial derivatives is considered. Product lines of financial derivatives are analyzed. The regional structure of the international derivatives market and dynamics of its development are investigated. The comparative characteristic of volumes and structure of exchange and over-the-counter segments of international derivatives market are carried out. Dynamics and structure of international markets of interest-bearing derivatives and currency derivatives are analyzed. The fundamental trends of development of the modern international derivatives market are defined.

  16. Performance of small-scale aero-derivative industrial gas turbines derived from helicopter engines

    Directory of Open Access Journals (Sweden)

    Barinyima Nkoi

    2013-12-01

    Full Text Available This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines. More particularly, investigation was made of technical performance of the small-scale aero-derivative engine cycles based on existing and projected cycles for applications in industrial power generation, combined heat and power concept, rotating equipment driving, and/or allied processes. The investigation was done by carrying out preliminary design and performance simulation of a simple cycle (baseline two-spool small-scale aero-derivative turboshaft engine model, and some advanced counterpart aero-derivative configurations. The advanced configurations consist of recuperated and intercooled/recuperated engine cycles of same nominal power rating of 1.567 MW. The baseline model was derived from the conversion of an existing helicopter engine model. In doing so, design point and off-design point performances of the engine models were established. In comparing their performances, it was observed that to a large extent, the advanced engine cycles showed superior performance in terms of thermal efficiency, and specific fuel consumption. In numerical terms, thermal efficiencies of recuperated engine cycle, and intercooled/recuperated engine cycles, over the simple cycle at DP increased by 13.5%, and 14.5% respectively, whereas specific fuel consumption of these cycles over simple cycle at DP decreased by 12.5%, and 13% respectively. This research relied on open access public literature for data.

  17. Antioxidant and intestinal anti-inflammatory effects of plant-derived coumarin derivatives.

    Science.gov (United States)

    Witaicenis, Aline; Seito, Leonardo Noboru; da Silveira Chagas, Alexandre; de Almeida, Luiz Domingues; Luchini, Ana Carolina; Rodrigues-Orsi, Patrícia; Cestari, Silvia Helena; Di Stasi, Luiz Claudio

    2014-02-15

    Coumarins, also known as benzopyrones, are plant-derived products with several pharmacological properties, including antioxidant and anti-inflammatory activities. Based on the wide distribution of coumarin derivatives in plant-based foods and beverages in the human diet, our objective was to evaluate both the antioxidant and intestinal anti-inflammatory activities of six coumarin derivatives of plant origin (scopoletin, scoparone, fraxetin, 4-methyl-umbeliferone, esculin and daphnetin) to verify if potential intestinal anti-inflammatory activity was related to antioxidant properties. Intestinal inflammation was induced by intracolonic instillation of TNBS in rats. The animals were treated with coumarins by oral route. The animals were killed 48 h after colitis induction. The colonic segments were obtained after laparotomy and macroscopic and biochemical parameters (determination of glutathione level and myeloperoxidase and alkaline phosphatase activities) were evaluated. The antioxidant properties of these coumarins were examined by lipid peroxidation and DPPH assays. Treatment with esculin, scoparone and daphnetin produced the best protective effects. All coumarin derivatives showed antioxidant activity in the DPPH assay, while daphnetin and fraxetin also showed antioxidant activity by inhibiting lipid peroxidation. Coumarins, except 4-methyl-umbeliferone, also showed antioxidant activity through the counteraction of glutathione levels or through the inhibition of myeloperoxidase activity. The intestinal anti-inflammatory activity of coumarin derivatives were related to their antioxidant properties, suggesting that consumption of coumarins and/or foods rich in coumarin derivatives, particularly daphnetin, esculin and scoparone, could prevent intestinal inflammatory disease. Copyright © 2013 Elsevier GmbH. All rights reserved.

  18. Hydration of urea and alkylated urea derivatives

    Science.gov (United States)

    Kaatze, Udo

    2018-01-01

    Compressibility data and broadband dielectric spectra of aqueous solutions of urea and some of its alkylated derivatives have been evaluated to yield their numbers Nh of hydration water molecules per molecule of solute. Nh values in a broad range of solute concentrations are discussed and are compared to hydration numbers of other relevant molecules and organic ions. Consistent with previous results, it is found that urea differs from other solutes in its unusually small hydration number, corresponding to just one third of the estimated number of nearest neighbor molecules. This remarkable hydration behavior is explained by the large density φH of hydrogen bonding abilities offered by the urea molecule. In terms of currently discussed models of reorientational motions and allied dynamics in water and related associating liquids, the large density φH causes a relaxation time close to that of undisturbed water with most parts of water encircling the solute. Therefore only a small part of disturbed ("hydration") water is left around each urea molecule. Adding alkyl groups to the basic molecule leads to Nh values which, within the series of n-alkylurea derivatives, progressively increase with the number of methyl groups per solute. With n-butylurea, Nh from dielectric spectra, in conformity with many other organic solutes, slightly exceeds the number of nearest neighbors. Compared to such Nh values, hydration numbers from compressibility data are substantially smaller, disclosing incorrect assumptions in the formula commonly used to interpret the experimental compressibilities. Similar to other series of organic solutes, effects of isomerization have been found with alkylated urea derivatives, indicating that factors other than the predominating density φH of hydrogen bond abilities contribute also to the hydration properties.

  19. Studies in higher-derivative gravitation

    International Nuclear Information System (INIS)

    Dutt, S.K.

    1987-01-01

    In this work two formulations of gravitation in which the action includes the second-derivatives of the metric in a non-trivial fashion are investigated. In the first part, the gauge theory of gravitation proposed by Yang in 1974 is investigated. The implications of coupling the pure space equations to matter sources via the action principle proposed by Yang is studied. It is shown that this action principle does not couple to matter sources in a satisfactory fashion. An earlier study by Fairchild along similar lines is critically examined. It is argued that Fairchild's action functional, and his objections to Yang's gauge approach to gravitation, arise from a not very meaningful analogy with the case of a general gauge field. Also, a conjecture originated in that work is refuted. A modification of Yang's action functional is provided which leads to both the Einstein and Yang field-equations. This system is shown to have non-trivial solutions in the presence of matter. An additional advantage is that the unphysical solutions of the pure space equations can be ruled out. It is shown that the joint system of Einstein and Yang field-equations leads to a physically viable cosmological model based on the Robertson-Walker metric, which satisfies both sets of field-equations. In the second part of this work, the Hamiltonian for pure gravity in Einstein's theory is obtained directly from the Hilbert Lagrangian. Since the Lagrangian depends upon the second-derivatives of the metric tensor, first the Hamiltonian formulation for a Lagrangian which may, in general depend upon the Nth-order time derivatives of the dynamical variables is developed

  20. Biologic rhythms derived from Siberian mammoths' hairs.

    Science.gov (United States)

    Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

    2011-01-01

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  1. Biologic rhythms derived from Siberian mammoths' hairs.

    Directory of Open Access Journals (Sweden)

    Mike Spilde

    Full Text Available Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios, which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  2. Derivation of an applied nonlinear Schroedinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, Todd Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Laine, Mark Richard [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Schwarz, Jens [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rambo, Patrick K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    We derive from first principles a mathematical physics model useful for understanding nonlinear optical propagation (including filamentation). All assumptions necessary for the development are clearly explained. We include the Kerr effect, Raman scattering, and ionization (as well as linear and nonlinear shock, diffraction and dispersion). We explain the phenomenological sub-models and each assumption required to arrive at a complete and consistent theoretical description. The development includes the relationship between shock and ionization and demonstrates why inclusion of Drude model impedance effects alters the nature of the shock operator. Unclassified Unlimited Release

  3. New cytotoxic phloroglucinol derivatives from Agrimonia pilosa.

    Science.gov (United States)

    Tang, Lan; Fu, Lulu; Lu, Chenghua; Hou, Xiaorong; Shan, Weiguang; Zhan, Zhajun

    2017-04-01

    Three new phloroglucinol derivatives, namely agripinol A-C (1-3), were isolated from Agrimonia pilosa Ledeb, along with two known ones (4-5). Their structures were characterized by spectroscopic methods, including MS and NMR spectroscopic techniques. The absolute configurations of the new compounds were unambiguously established by single crystal X-ray diffraction analyses. In the cytotoxicity assay, all compounds exhibited more potent cytotoxic activities against HCT-116, MDA-MB-231 and PC-3, as compared with the positive control fluorouracil. Copyright © 2017. Published by Elsevier B.V.

  4. Superspace higher derivative terms in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Farakos, Fotis [Dipartimento di Fisica “Galileo Galilei”, Università di Padova,Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova,Via Marzolo 8, 35131 Padova (Italy); Kočí, Pavel; Unge, Rikard von [Institute for Theoretical Physics, Masaryk University,611 37 Brno (Czech Republic)

    2017-04-03

    We study (2,2) and (4,4) supersymmetric theories with superspace higher derivatives in two dimensions. A characteristic feature of these models is that they have several different vacua, some of which break supersymmetry. Depending on the vacuum, the equations of motion describe different propagating degrees of freedom. Various examples are presented which illustrate their generic properties. As a by-product we see that these new vacua give a dynamical way of generating non-linear realizations. In particular, our 2D (4,4) example is the dimensional reduction of a 4D N=2 model, and gives a new way for the spontaneous breaking of extended supersymmetry.

  5. Bootstrapping Density-Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    Employing the "small bandwidth" asymptotic framework of Cattaneo, Crump, and Jansson (2009), this paper studies the properties of a variety of bootstrap-based inference procedures associated with the kernel-based density-weighted averaged derivative estimator proposed by Powell, Stock, and Stoker...... (1989). In many cases validity of bootstrap-based inference procedures is found to depend crucially on whether the bandwidth sequence satisfies a particular (asymptotic linearity) condition. An exception to this rule occurs for inference procedures involving a studentized estimator employing a "robust...

  6. Black holes in higher derivative gravity.

    Science.gov (United States)

    Lü, H; Perkins, A; Pope, C N; Stelle, K S

    2015-05-01

    Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.

  7. Deriving GENERIC from a Generalized Fluctuation Symmetry

    Science.gov (United States)

    Kraaij, Richard; Lazarescu, Alexandre; Maes, Christian; Peletier, Mark

    2018-02-01

    Much of the structure of macroscopic evolution equations for relaxation to equilibrium can be derived from symmetries in the dynamical fluctuations around the most typical trajectory. For example, detailed balance as expressed in terms of the Lagrangian for the path-space action leads to gradient zero-cost flow. We expose a new such fluctuation symmetry that implies GENERIC, an extension of gradient flow where a Hamiltonian part is added to the dissipative term in such a way as to retain the free energy as Lyapunov function.

  8. Steroid derivatives and their use in radioimmunoassays

    International Nuclear Information System (INIS)

    Varma, R.K.; Chao, S.T.

    1983-01-01

    Radioimmunoassay techniques have been used to determine the concentration in body fluids of various endogenous and exogenous steroids. In the development of radioimmunoassays for the various steroids, the preparation of an antigen labelled with iodine-125 is of primary concern. The chemical structure of steroids is such that it is generally not possible to radioiodinate them directly. It is necessary to utilize as a precursor of the radiolabeled antigen a derivative of the steroid to be assayed which can be readily iodinatd. The process by which steroids are chosen and structurally modified is given

  9. Biochemical activity of fullerenes and related derivatives

    International Nuclear Information System (INIS)

    Huczko, A.; Lange, H.; Calko, E.

    1999-01-01

    An astonishing scientific interest, embodied in over 15000 research articles so far, has been encountered since 1985 when fullerenes were discovered. From new superconductors to a rich electrochemistry and reaction chemistry, fullerene nanostructures continue to excite the scientific world, and new findings continue at record pace. This review presents many examples of the biochemical activities of fullerenes and derivatives, e. g. cytotoxic activity, selective DNA cleavage and antiviral activity against HIV. We also present some results of our testing which show that, despite its chemical and biochemical activity, fullerene matter does not present any health hazard directly related to skin irritation and allergic risks. (author)

  10. A NOVEL ACRYLONITRILE DERIVATIVE HAVING PHOTOVOLTAIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Cigdem Yorur-Goreci

    2016-10-01

    Full Text Available A new acrylonitrile derivative 3 (BPCPFA which offer potential application as organic solar cell material was synthesized with three steps. The structures of the molecules synthesized in these steps were characterized using various spectral analyses. BPCPFA was investigated as an electron acceptor molecule in next generation organic solar cells. Theoretical prediction and experimental studies for photovoltaic performance were performed. Based on these results, it is concluded that BPCPFA with extended conjugated system has good and promising photovoltaic performance with Voc value as 0.96 V.

  11. Boundary layer heights derived from velocity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hoejstrup, J.; Barthelmie, R.J. [Risoe National Lab., Roskilde (Denmark); Kaellstrand, B. [Univ. of Uppsala, Uppsala (Sweden)

    1997-10-01

    It is a well-known fact that the height of the mixed layer determines the size of the largest and most energetic eddies that can be observed in the unstable boundary layer, and consequently a peak can be observed in the power spectra of the along-wind velocity component at scales comparable to the mixed layer depth. We will now show how the mixed layer depth can be derived from the u-specta and the results will be compared with direct measurements using pibal and tethersonde measurements. (au)

  12. Photoelectrochemical Properties of Graphene and Its Derivatives

    Science.gov (United States)

    Adán-Más, Alberto; Wei, Di

    2013-01-01

    Graphene and its derivatives combine a numerous range of supreme properties that can be useful in many applications. The purpose of this review is to analyse the photoelectrochemical properties of pristine graphene, graphene oxide (GO) and reduced graphene oxide (rGO) and their impact on semiconductor catalysts/quantum dots. The mechanism that this group of materials follows to improve their performance will be cleared by explaining how those properties can be exploited in several applications such as photo-catalysts (degradation of pollutants) and photovoltaics (solar cells). PMID:28348339

  13. Unedoside derivatives in Nuxia and their biosynthesis

    DEFF Research Database (Denmark)

    Jensen, Søren Rosendal; Ravnkilde, Lene; Schripsema, Jan

    1998-01-01

    An investigation of two species of Nuxia showed that this genus is characterized by the presence of the eight-carbon iridoid glucoside unedoside and/or its derivatives. From N. floribunda unedoside, nuxioside (6-O-alpha-L-rhamnopyranosyl-unedoside) and 2 "-acetyl-3 "-cinnamoyl-nuxioside were...... isolated, while from N. oppositifolia 2 "-acetyl-3 "-benzoyl-nuxioside was obtained. Both plants contained verbascoside. The biosynthesis of unedoside in N. floribunda was investigated and deoxyloganic acid was found to be a precursor, similar to wh;lt was found for the eight-carbon iridoids in Thunbergia...

  14. Nonextensive entropies derived from Gauss' principle

    International Nuclear Information System (INIS)

    Wada, Tatsuaki

    2011-01-01

    Gauss' principle in statistical mechanics is generalized for a q-exponential distribution in nonextensive statistical mechanics. It determines the associated stochastic and statistical nonextensive entropies which satisfy Greene-Callen principle concerning on the equivalence between microcanonical and canonical ensembles. - Highlights: → Nonextensive entropies are derived from Gauss' principle and ensemble equivalence. → Gauss' principle is generalized for a q-exponential distribution. → I have found the condition for satisfying Greene-Callen principle. → The associated statistical q-entropy is found to be normalized Tsallis entropy.

  15. [Antidiuretic activity of dithiocarbamic acid derivatives].

    Science.gov (United States)

    Korablec, M V; Evets, M A

    1977-01-01

    Chemically pure dithiocarbamates, thiuramsulphides and ethylene-bis-dithiocarbamates display a well-marked antidiuretic action. They materially reduce diuresis, natri- and kaliuresis in rats (1/5 LD(50) per 1 kg into the stomach) and in dogs (sodium N, N-diethyl-dithiocarbamate-into renal artery). Without changing the tubular reabsorption DEDTC inhibits the glomerular filtration of the dogs' kidneys. Furosemide (lasix) prevents the development of the an antidiuletic anidiuretic effect and reduction of the sodium and potassium excretion provoked in rats with DEDTC, zinc N, N', N"-tetraethylthiuram-disulphide and ethylene-bis-dithiocarbamate. Furosemide is recommended for the treatment of acute poisonings with dithiocarbaminic acid derivatives.

  16. Photoelectrochemical Properties of Graphene and Its Derivatives

    Directory of Open Access Journals (Sweden)

    Alberto Adán-Más

    2013-07-01

    Full Text Available Graphene and its derivatives combine a numerous range of supreme properties that can be useful in many applications. The purpose of this review is to analyse the photoelectrochemical properties of pristine graphene, graphene oxide (GO and reduced graphene oxide (rGO and their impact on semiconductor catalysts/quantum dots. The mechanism that this group of materials follows to improve their performance will be cleared by explaining how those properties can be exploited in several applications such as photo-catalysts (degradation of pollutants and photovoltaics (solar cells.

  17. Molecular Recognition Studies on Naphthyridine Derivatives

    Directory of Open Access Journals (Sweden)

    José Carlos Iglesias-Sánchez

    2010-03-01

    Full Text Available The association constants Kb of three hosts I–III designed to have both enhanced hydrogen bonding donor strength and conformational preorganization with biotin analogues 1–5 are reported. 1H-NMR titrations under two different concentration conditions have been employed to determine the association constants Kb. A statistical analysis using a presence absence matrix has been applied to calculate the different contributions. Hydrogen bond interactions make naphthyridine derivatives II and III potent binders and effective receptors for (+-biotin methyl ester (1, due to the complex stabilization by additional hydrogen bonds.

  18. Derivative expansion and renormalisation group flows

    CERN Document Server

    Litim, Daniel F

    2001-01-01

    We study the convergence of the derivative expansion for flow equations. The convergence strongly depends on the choice for the infrared regularisation. Based on the structure of the flow, we explain why optimised regulators lead to better physical predictions. This is applied to O(N)-symmetric real scalar field theories in 3d, where critical exponents are computed for all N. In comparison to the sharp cut-off regulator, an optimised flow improves the leading order result up to 10%. An analogous reasoning is employed for a proper time renormalisation group. We compare our results with those obtained by other methods.

  19. Derivatives Trading, Climate Science and Human Rights

    DEFF Research Database (Denmark)

    Haigh, Matthew

    the élites of science and privately managed capital. Its outcomes have been disastrous in terms of climate management. Published rankings of corporations' climate-readiness bear tenuous linkages with scientific data. The linking of corporate revenues to corporate carbon emissions data has represented...... the heaviest polluters as contributing to carbon-minimised investment portfolios. Assets owned by privately managed pension funds have remained materially exposed to risks posed by climate change. In public finance, a narrow range of financial instruments centred on derivatives trading has entrenched global...

  20. Arctic seabirds transport marine-derived contaminants.

    Science.gov (United States)

    Blais, Jules M; Kimpe, Lynda E; McMahon, Dominique; Keatley, Bronwyn E; Mallory, Mark L; Douglas, Marianne S V; Smol, John P

    2005-07-15

    Long-range atmospheric transport of pollutants is generally assumed to be the main vector for arctic contamination, because local pollution sources are rare. We show that arctic seabirds, which occupy high trophic levels in marine food webs, are the dominant vectors for the transport of marine-derived contaminants to coastal ponds. The sediments of ponds most affected by seabirds had 60 times higher DDT, 25 times higher mercury, and 10 times higher hexachlorobenzene concentrations than nearby control sites. Bird guano greatly stimulates biological productivity in these extreme environments but also serves as a major source of industrial and agricultural pollutants in these remote ecosystems.

  1. Contact allergy to isoeugenol and its derivatives

    DEFF Research Database (Denmark)

    Tanaka, Susumu; Royds, C; Buckley, Christopher D

    2004-01-01

    in 19, isoeugenyl benzoate in 4, isoeugenyl phenylacetate in 16, isoeugenyl methyl ether in 6 and benzyl isoeugenyl ether in 2 patients. There was a concomitant reaction to isoeugenol in 36/40 of those positive to transisoeugenol, 13/19 of those to isoeugenyl acetate, 3/4 of those to isoeugenyl benzoate...... and 15/16 of those to isoeugenyl phenylacetate but in none of those 6 positive to isoeugenyl methyl ether and in neither of those 2 positive to benzyl isoeugenyl ether. Concomitant contact allergy between isoeugenol and its derivatives may occur through chemical cross-reactivity or local skin metabolism...

  2. Enhancer-derived RNA: A Primer.

    Science.gov (United States)

    Liu, Feng

    2017-06-01

    Enhancer-derived RNAs (eRNAs) are a group of RNAs transcribed by RNA polymerase II from the domain of transcription enhancers, a major type of cis-regulatory elements in the genome. The correlation between eRNA production and enhancer activity has stimulated studies on the potential role of eRNAs in transcriptional regulation. Additionally, eRNA has also served as a marker for global identification of enhancers. Here I review the brief history and fascinating properties of eRNAs. Copyright © 2017 The Author. Production and hosting by Elsevier B.V. All rights reserved.

  3. Enhancer-derived RNA: A Primer

    Directory of Open Access Journals (Sweden)

    Feng Liu

    2017-06-01

    Full Text Available Enhancer-derived RNAs (eRNAs are a group of RNAs transcribed by RNA polymerase II from the domain of transcription enhancers, a major type of cis-regulatory elements in the genome. The correlation between eRNA production and enhancer activity has stimulated studies on the potential role of eRNAs in transcriptional regulation. Additionally, eRNA has also served as a marker for global identification of enhancers. Here I review the brief history and fascinating properties of eRNAs.

  4. Synthesis and Pharmacological Activity of Diterpenylnaphthoquinone Derivatives

    Directory of Open Access Journals (Sweden)

    Guillermo Schmeda-Hirschmann

    2011-10-01

    Full Text Available New diterpenylquinones, combining a diterpene diacid and a naphthoquinone, were prepared from junicedric acid and lapachol. The new derivatives were assessed as gastroprotective agents by the HCl-EtOH-induced gastric lesions model in mice as well as for basal cytotoxicity on the following human cell lines: Normal lung fibroblasts (MRC-5, gastric epithelial adenocarcinoma (AGS, and hepatocellular carcinoma (Hep G2. Several of the new compounds were significantly active as antiulcer agents and showed selective cytotoxicity against AGS cells.

  5. Statistical Analysis of Asian WeatherDerivatives

    OpenAIRE

    Jiao, Yue

    2009-01-01

    Since last decade, weather derivatives have been traded by Chicago Mercantile Exchange(CME) to hedge the weather risk. In addition to HDD,CDD and CAT, which are index written on the temperature in U.S. and Europe, Pacific Rim Index is newly developed and actively traded nowadays. In terms of the great value of research on this new instrument, we study the temperature dynamics of 4 cities in Asia: Tokyo, Osaka, Taipei and Beijing by a continuous-time autoregressive process. We further inferred...

  6. Quinoxaline derivatives: a patent review (2006--present).

    Science.gov (United States)

    González, Mercedes; Cerecetto, Hugo

    2012-11-01

    Quinoxaline scaffold is included in a large number of therapeutic agents because of its physicochemical properties that make the difference between them and the carbono analogue, naphthalene. This review of patented products presents the quinoxaline heterocycle as part of the structural patent claims from a medicinal chemistry perspective. We centred our discussion in the various drug patent applications of the quinoxaline and its derivatives. The applications are based firstly in the specific enzyme target with very low development in the disease treatment. Only for cancer and antimicrobial agents they were specifically determined but little is mentioned in order to insight in the last development activities.

  7. Current-induced forces: a simple derivation

    DEFF Research Database (Denmark)

    Todorov, Tchavdar N.; Dundas, Daniel; Lü, Jing-Tao

    2014-01-01

    We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that-with the help of background literature-should be accessible to physics undergraduates. The discussion...... aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current-the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant...

  8. Stemness is derived from thyroid cancer cells

    Directory of Open Access Journals (Sweden)

    Risheng eMa

    2014-07-01

    Full Text Available Background: One hypothesis for thyroid cancer development is its derivation from thyroid cancer stem cells (CSCs. Such cells could arise via different paths including from mutated resident stem cells within the thyroid gland or via epithelial to mesenchymal transition (EMT from malignant cells since EMT is known to confer stem-like characteristics. Methods: To examine the status of stemness in thyroid papillary cancer we employed a murine model of thyroid papillary carcinoma and examined the expression of stemness and EMT using qPCR and histochemistry in mice with a thyroid-specific knock-in of oncogenic Braf (LSL-Braf(V600E/TPO-Cre. This construct is only activated at the time of thyroid peroxidase (TPO expression in differentiating thyroid cells and cannot be activated by undifferentiated stem cells which do not express TPO.Results: There was decreased expression of thyroid specific genes such as Tg and NIS and increased expression of stemness markers such as Oct4, Rex1, CD15 and Sox2 in the thyroid carcinoma tissue from 6 week old BRAFV600E mice. The decreased expression of the epithelial marker E-cadherin and increased EMT regulators including Snail, Slug, and TGF-β1 and TGF-β3, and the mesenchymal marker vimentin demonstrated the simultaneous progression of EMT and the CSC-like phenotype. Stemness was also found in a derived cancer thyroid cell line in which overexpression of Snail caused up-regulation of vimentin expression and up regulation of stemness markers Oct4, Rex1, CD15 with enhanced migration ability of the cells. Conclusions: Our findings support our earlier hypothesis that stemness in thyroid cancer is derived via EMT rather than from resident thyroid stem cells. In mice with a thyroid-specific knock-in of oncogenic Braf (LSL-Braf(V600E/TPO-Cre the neoplastic changes were dependent on thyroid cell differentiation and the onset of stemness must have been derived from differentiated thyroid epithelial cells.

  9. Zero birefringence films of pullulan ester derivatives

    Science.gov (United States)

    Danjo, Takahiro; Enomoto, Yukiko; Shimada, Hikaru; Nobukawa, Shogo; Yamaguchi, Masayuki; Iwata, Tadahisa

    2017-04-01

    High-performance films with almost zero-birefringence and zero-wavelength dispersion were succeeded to prepare from pullulan esters derivatives (PLEs) without any additives. Optical transmittance analysis, birefringence measurement of PLE cast film and hot stretched films, and infrared dichroism analysis were conducted to characterize optical properties of PLE films comparing with cellulose triacetate which is commercially used as low-birefringence in optical devices. The aims of this study, characterization of optical properties of pullulan esters, can develop a deep understanding of the fundamental knowing and applicability of polysaccharides. Accordingly, authors believe this paper will open the gate for researches in the application of polysaccharides.

  10. SYNTHESIS OF FLAVANONE-6-CARBOXYLIC ACID DERIVATIVES FROM SALICYLIC ACID DERIVATIVE

    Directory of Open Access Journals (Sweden)

    Muhammad Idham Darussalam Mardjan

    2012-02-01

    Full Text Available Synthesis of flavanone-6-carboxylic acid derivatives had been conducted via the route of chalcone. The synthesis was carried out from salicylic acid derivative, i.e. 4-hydroxybenzoic acid, via esterification, Fries rearrangement, Claisen-Schmidt condensation and 1,4-nucleophilic addition reactions. Structure elucidation of products was performed using FT-IR, 1H-NMR, GC-MS and UV-Vis spectrometers. Reaction of 4-hydroxybenzoic acid with methanol catalyzed with sulfuric acid produced methyl 4-hydroxybenzoate in 87% yield. The acid-catalyzed-acetylation of the product using acetic anhydride gave methyl 4-acetoxybenzoate in 75% yield. Furthermore, solvent-free Fries rearrangement of methyl 4-acetoxybenzoate in the presence of AlCl3 produced 3-acetyl-4-hydroxybenzoic acid as the acetophenone derivatives in 67% yield. Then, Claisen-Schmidt condensation of the acetophenone and benzaldehyde derivatives of p-anisaldehyde and veratraldehyde in basic condition gave 2'-hydroxychalcone-5'-carboxylic acid derivatives  in 81 and 71 % yield, respectively. Finally, the ring closure reaction of the chalcone yielded the corresponding flavanone-6-carboxylic acids in 67 and 59% yield, respectively.

  11. Synthesis and anticancer evaluation of imidazolinone and benzoxazole derivatives

    Directory of Open Access Journals (Sweden)

    Heba A. El-Hady

    2017-05-01

    Full Text Available A series of imidazolinone and benzoxazole derivatives (3 and 5 have been synthesized by the condensation of oxazolinone derivatives (2a–c with aniline and 2-hydroxyaniline. Acetyl derivatives (4, 6 and 7 were prepared via acetylation of compounds 3 and 5 with acetic anhydride and chloroacetyl chloride. The results revealed that imidazolinone and benzoxazole derivatives are potent against the cancer cell lines MCF-7 and HePG2. In particular, benzoxazole derivatives are more potent than imidazolinone derivatives.

  12. Platelet-Derived Microvesicles in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Maria T. K. Zaldivia

    2017-11-01

    Full Text Available Microvesicles (MVs circulating in the blood are small vesicles (100–1,000 nm in diameter derived from membrane blebs of cells such as activated platelets, endothelial cells, and leukocytes. A growing body of evidence now supports the concept that platelet-derived microvesicles (PMVs, the most abundant MVs in the circulation, are important regulators of hemostasis, inflammation, and angiogenesis. Compared with healthy individuals, a large increase of circulating PMVs has been observed, particularly in patients with cardiovascular diseases. As observed in MVs from other parent cells, PMVs exert their biological effects in multiple ways, such as triggering various intercellular signaling cascades and by participating in transcellular communication by the transfer of their “cargo” of cytoplasmic components and surface receptors to other cell types. This review describes our current understanding of the potential role of PMVs in mediating hemostasis, inflammation, and angiogenesis and their consequences on the pathogenesis of cardiovascular diseases, such as atherosclerosis, myocardial infarction, and venous thrombosis. Furthermore, new developments of the therapeutic potential of PMVs for the treatment of cardiovascular diseases will be discussed.

  13. Waste derived bioeconomy in India: A perspective.

    Science.gov (United States)

    S, Venkata Mohan; P, Chiranjeevi; Dahiya, Shikha; A, Naresh Kumar

    2018-01-25

    Environmental and climatic change issues, population explosion, rapid urbanisation, depletion of fossil reserves, need for energy security, huge waste generation, etc. are some of the inherent issues associated with the fossil based linear economy which need greater attention. In this context, the world is gradually transforming from fossil-based economy to a sustainable circular bio-economy. The biogenic waste which is generated in enormous quanties in India can be considered as potential feedstock for structuring the bio-based economy. This communication depicts the need for developing waste derived bioeconomy in the Indian perspective. Waste is now being perceived as a resource with value and believed to supplement petroleum feedstock to a great extent if properly utilized. The necessity to introduce waste as the core element for the future economic models which also allows sustainable development is discussed. The review also establishes drivers for the bioeconomy and structures the waste derived bioeconomy in a sustainable format to address the futuristic needs, scope and opportunities envisaged in the business and economic realm. The enabling technologies/processes that can be applied for biogenic wastes valorisation are elaborated. Circularizing the economy in a waste biorefinery model for the production of biobased products including bioenergy is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Antitumor Effect of Burchellin Derivatives Against Neuroblastoma.

    Science.gov (United States)

    Kurita, Masahiro; Takada, Tomomi; Wakabayashi, Noriko; Asami, Satoru; Ono, Shinichi; Uchiyama, Taketo; Suzuki, Takashi

    2018-02-01

    Neuroblastoma is one of the most commonly encountered malignant solid tumors in the pediatric age group. We examined the antitumor effects of five burchellin derivatives against human neuroblastoma cell lines. We evaluated cytotoxicity by the MTT assay for four human neuroblastoma and two normal cell lines. We also performed analysis of the apoptotic induction effect by flow cytometry, and examined the expression levels of apoptosis- and cell growth-related proteins by western blot analysis. We found that one of the burchellin derivatives (compound 4 ) exerted cytotoxicity against the neuroblastoma cell lines. Compound 4 induced caspase-dependent apoptosis via a mitochondrial pathway. The apoptosis mechanisms induced by compound 4 involved caspase-3, -7 and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, compound 4 induced cell death through inhibition of the cell growth pathway (via extracellular signal-regulated kinase 1 and 2, AKT8 virus oncogene cellular homolog, and signal transducer and activator of transcription 3). Compound 4 exerted cellular cytotoxicity against neuroblastoma cells via induction of caspase-dependent apoptosis, and may offer promise for further development as a useful drug for the treatment of advanced neuroblastoma. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  15. Derivative Securities on Romanian Capital Market

    Directory of Open Access Journals (Sweden)

    Ramona Maria GOGONCEA

    2011-12-01

    Full Text Available This study aimed to investigate whether the world wide agreed models of valuation of derivates may be properly applied to the Romanian capital market, obtaining reliable results for decision makers. The most common valuation models take into account market data such as, interest and exchange rates, volatilities and the price of the underlying instrument. The procedures for valuation must clearly define the nature of the market data to be taken into consideration (for example the zero-coupon curve for the valuation of swaps and the independent reference base to be used (Reuters at a given time, bid/offer or mid price, broker. In order to be able to obtain the results, I based my study on a self-developed software which can calculate the price and characteristics for different types of derivatives securities once the primary data are filled in. I compared the results obatined usig the valuation models with the actual prices on the Romanian capital market. I expected that the results obtained to be more accurate as the parameters used in the calculation models properly reflect market data as at that date being as widely as possible.. These assumptions were only supported for certain value orientations. In conclusion, explanations for these results are given and limitations for this study are discussed. Also, suggestions for future research are presented in the final part of the article.

  16. A One Line Derivation of EGARCH

    Directory of Open Access Journals (Sweden)

    Michael McAleer

    2014-06-01

    Full Text Available One of the most popular univariate asymmetric conditional volatility models is the exponential GARCH (or EGARCH specification. In addition to asymmetry, which captures the different effects on conditional volatility of positive and negative effects of equal magnitude, EGARCH can also accommodate leverage, which is the negative correlation between returns shocks and subsequent shocks to volatility. However, the statistical properties of the (quasi- maximum likelihood estimator of the EGARCH parameters are not available under general conditions, but rather only for special cases under highly restrictive and unverifiable conditions. It is often argued heuristically that the reason for the lack of general statistical properties arises from the presence in the model of an absolute value of a function of the parameters, which does not permit analytical derivatives, and hence does not permit (quasi- maximum likelihood estimation. It is shown in this paper for the non-leverage case that: (1 the EGARCH model can be derived from a random coefficient complex nonlinear moving average (RCCNMA process; and (2 the reason for the lack of statistical properties of the estimators of EGARCH under general conditions is that the stationarity and invertibility conditions for the RCCNMA process are not known.

  17. PUFA-derived endocannabinoids: an overview.

    Science.gov (United States)

    Cascio, Maria Grazia

    2013-11-01

    Following on from the discovery of cannabinoid receptors, of their endogenous agonists (endocannabinoids) and of the biosynthetic and metabolic enzymes of the endocannabinoids, significant progress has been made towards the understanding of the role of the endocannabinoid system in both physiological and pathological conditions. Endocannabinoids are mainly n-6 long-chain PUFA (LCPUFA) derivatives that are synthesised by neuronal cells and inactivated via a two-step process that begins with their transport from the extracellular to the intracellular space and culminates in their intracellular degradation by hydrolysis or oxidation. Although the enzymes responsible for the biosynthesis and metabolism of endocannabinoids have been well characterised, the processes involved in their cellular uptake are still a subject of debate. Moreover, little is yet known about the roles of endocannabinoids derived from n-3 LCPUFA such as EPA and DHA. Here, I provide an overview of what is currently known about the mechanisms for the biosynthesis and inactivation of endocannabinoids, together with a brief analysis of the involvement of the endocannabinoids in both food intake and obesity. Owing to limited space, recent reviews will be often cited instead of original papers.

  18. DRAFT METHODOLOGY FOR DERIVATION OF WATER ...

    Science.gov (United States)

    Development and body functions of many organisms are directed by the endocrine system. Endocrine Disrupting Chemicals (EDCs), are those exogenous (and endogenous) compounds that may interfere with this regulatory function because they may either mimic or suppress the action of the body’s natural hormones. Because these chemicals are increasingly present in the environment as a result of human activities and they only require tiny amounts to disrupt endocrine functions, EDCs may have major impacts on ecology and particularly aquatic life as evidenced by the abundance of field observations verified by both laboratory and controlled in situ experiments. The Clean Water Act § 304(a)(1) authorizes the Administrator to develop and publish criteria for water quality that are protective of aquatic life. Traditionally, ambient water quality criteria for the protection of aquatic life have been derived using the 1985 Guidelines (Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Life and Their Uses). These guidelines have comprehensive data requirements for toxicity tests using a variety of aquatic taxa, thus ensuring protection of the existing aquatic assemblage, and helping to ensure a goal of protecting and restoring “ecological integrity”. Some “Pharmaceuticals and Personal Care Products” (PPCPs), particularly those exhibiting endocrine disrupting activity, have two unique features, which distinguish them from

  19. Chromoionophoric Recognition of Alkylamines by Nitro Derivative

    International Nuclear Information System (INIS)

    Kim, Ju Hee; Hwang, Ah Ran; Choe, Jong In; Chang, Suk Kyu

    2004-01-01

    The molecular design of efficient and selective chromogenic and fluorogenic ionophore systems for the sensing of chemically and biologically important ionic guests has attracted much attention in the past decade. Many of the compounds are based on the well-known molecular framework of crown ethers, calixarenes, and other EDTA type efficient chelating compounds. Among them the calix[4]arenes are particularly attractive for their selective ionophoric properties toward many of interesting organic ammonium guests. Particularly, the calix[4]arene-crown ethers are known to have unique binding properties toward some of alkali, alkaline earth metal ions, and biogenic amines. Many of the chromogenic sensing materials are developed by conjugating molecular framework of calix[4]- arene-crown ethers with suitable signaling functions of azophenols, thiazoles, and indophenols. Quite unexpectedly, however, the ionophoric properties of simple nitro derivative of calix[4]arene-crown ethers were not reported, except for the closely related structure having ester-ether functions in crown moiety, in spite of their synthetically easy availability and expectedly efficient ionophoric properties toward organic amine guests. In this paper, we report the ionophoric properties of dinitro derivative of calix[4]arene-crown-5 ether 1 toward representative alkylammonium ions aiming for the development of efficient and selective chromogenic sensing material for the biologically important organic amine guests. The Ba 2+ -selective chromogenic behavior of 1 over the representative alkali and alkaline earth metal ions has been reported earlier.

  20. Effects of titanium dioxide nanoparticles derived from ...

    Science.gov (United States)

    Increased manufacture of TiO2 nano-products has caused concern about the potential toxicity of these products to the environment and in public health. Identification and confirmation of the presence of TiO2 nanoparticles derived from consumer products as opposed to industrial TiO2 NPs warrants examination in exploring the significance of their release and resultant impacts on the environment. To this end we examined the significance of the release of these particles and their toxic effect on the marine diatom algae Thalassiosira pseudonana. Our results indicate that nano-TiO2 sunscreen and toothpaste exhibit more toxicity in comparison to industrial TiO2, and inhibited the growth of the marine diatom Thalassiosira pseudonana. This inhibition was proportional to the exposure time and concentrations of nano-TiO2. Our findings indicate a significant effect, and therefore further research is warranted in evaluation and assessment of the toxicity of modified nano-TiO2 derived from consumer products and their physicochemical properties. Submit to journal Environmental Science and Pollution Research.

  1. Automatic approach to deriving fuzzy slope positions

    Science.gov (United States)

    Zhu, Liang-Jun; Zhu, A.-Xing; Qin, Cheng-Zhi; Liu, Jun-Zhi

    2018-03-01

    Fuzzy characterization of slope positions is important for geographic modeling. Most of the existing fuzzy classification-based methods for fuzzy characterization require extensive user intervention in data preparation and parameter setting, which is tedious and time-consuming. This paper presents an automatic approach to overcoming these limitations in the prototype-based inference method for deriving fuzzy membership value (or similarity) to slope positions. The key contribution is a procedure for finding the typical locations and setting the fuzzy inference parameters for each slope position type. Instead of being determined totally by users in the prototype-based inference method, in the proposed approach the typical locations and fuzzy inference parameters for each slope position type are automatically determined by a rule set based on prior domain knowledge and the frequency distributions of topographic attributes. Furthermore, the preparation of topographic attributes (e.g., slope gradient, curvature, and relative position index) is automated, so the proposed automatic approach has only one necessary input, i.e., the gridded digital elevation model of the study area. All compute-intensive algorithms in the proposed approach were speeded up by parallel computing. Two study cases were provided to demonstrate that this approach can properly, conveniently and quickly derive the fuzzy slope positions.

  2. Human umbilical cord derivatives regenerate intervertebral disc.

    Science.gov (United States)

    Beeravolu, Naimisha; Brougham, Jared; Khan, Irfan; McKee, Christina; Perez-Cruet, Mick; Chaudhry, G Rasul

    2016-09-30

    Intervertebral disc (IVD) degeneration is characterized by the loss of nucleus pulposus (NP), which is a common cause for lower back pain. Although, currently, there is no cure for the degenerative disc disease, stem cell therapy is increasingly being considered for its treatment. In this study, we investigated the feasibility and efficacy of human umbilical cord mesenchymal stem cells (MSCs) and chondroprogenitor cells (CPCs) derived from those cells to regenerate damaged IVD in a rabbit model. Transplanted cells survived, engrafted and dispersed into NP in situ. Significant improvement in the histology, cellularity, extracellular matrix proteins, and water and glycosaminoglycan contents in IVD recipients of CPCs was observed compared to MSCs. In addition, IVDs receiving CPCs exhibited higher expression of NP-specific human markers, SOX9, aggrecan, collagen 2, FOXF1 and KRT19. The novelty of the study is that in vitro differentiated CPCs derived from umbilical cord MSCs, demonstrated far greater capacity to regenerate damaged IVDs, which provides basis and impetus for stem cell based clinical studies to treat degenerative disc disease. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Primer on electricity futures and other derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.

    1998-01-01

    Increased competition in bulk power and retail electricity markets is likely to lower electricity prices, but will also result in greater price volatility as the industry moves away from administratively determined, cost-based rates and encourages market-driven prices. Price volatility introduces new risks for generators, consumers, and marketers. Electricity futures and other derivatives can help each of these market participants manage, or hedge, price risks in a competitive electricity market. Futures contracts are legally binding and negotiable contracts that call for the future delivery of a commodity. In most cases, physical delivery does not take place, and the futures contract is closed by buying or selling a futures contract on or near the delivery date. Other electric rate derivatives include options, price swaps, basis swaps, and forward contracts. This report is intended as a primer for public utility commissioners and their staff on futures and other financial instruments used to manage price risks. The report also explores some of the difficult choices facing regulators as they attempt to develop policies in this area.

  4. Primer on electricity futures and other derivatives

    International Nuclear Information System (INIS)

    Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.

    1998-01-01

    Increased competition in bulk power and retail electricity markets is likely to lower electricity prices, but will also result in greater price volatility as the industry moves away from administratively determined, cost-based rates and encourages market-driven prices. Price volatility introduces new risks for generators, consumers, and marketers. Electricity futures and other derivatives can help each of these market participants manage, or hedge, price risks in a competitive electricity market. Futures contracts are legally binding and negotiable contracts that call for the future delivery of a commodity. In most cases, physical delivery does not take place, and the futures contract is closed by buying or selling a futures contract on or near the delivery date. Other electric rate derivatives include options, price swaps, basis swaps, and forward contracts. This report is intended as a primer for public utility commissioners and their staff on futures and other financial instruments used to manage price risks. The report also explores some of the difficult choices facing regulators as they attempt to develop policies in this area

  5. Derivative-free and blackbox optimization

    CERN Document Server

    Audet, Charles

    2017-01-01

    This book is designed as a textbook, suitable for self-learning or for teaching an upper-year university course on derivative-free and blackbox optimization.  The book is split into 5 parts and is designed to be modular; any individual part depends only on the material in Part I.  Part I of the book discusses what is meant by Derivative-Free and Blackbox Optimization, provides background material, and early basics while Part II focuses on heuristic methods (Genetic Algorithms and Nelder-Mead).  Part III presents direct search methods (Generalized Pattern Search and Mesh Adaptive Direct Search) and Part IV focuses on model-based methods (Simplex Gradient and Trust Region).  Part V discusses dealing with constraints, using surrogates, and bi-objective optimization. End of chapter exercises are included throughout as well as 15 end of chapter projects and over 40 figures.  Benchmarking techniques are also presented in the appendix.

  6. New butenolide derivatives from the marine sponge-derived fungus Aspergillus terreus.

    Science.gov (United States)

    Sun, Yating; Liu, Jingtang; Li, Lei; Gong, Chi; Wang, Shuping; Yang, Fan; Hua, Huiming; Lin, Houwen

    2017-12-22

    Two new butenolide derivatives (±)-asperteretal D ((±)-1) and asperteretal E (2) containing rare 2-benzyl-3-phenyl substituted lactone core, together with nine known analogues (3-11) were obtained from a fungus Aspergillus terreus derived from the marine sponge Phakellia fusca. All the structures were elucidated on the basis of extensive NMR spectroscopic data. The chiral chromatography analyses allowed the separation of the (±)-asperteretal D, of which the absolute configurations were determined by comparing the experimental to calculated electronic circular dichroic (ECD) spectra. Compounds (±)-1, 2-5, and 7 exhibited potent inhibitory activities against α-glucosidase with IC 50 values ranging from 8.65 to 20.3 µM (positive control acarbose with an IC 50 value of 320 µM). In addition, derivatives 5-8 also showed moderate antioxidant activities. Copyright © 2017. Published by Elsevier Ltd.

  7. Two new cytochalasan derivatives from Chaetomium globosum SNSHI-5, a fungus derived from extreme environment.

    Science.gov (United States)

    Wang, Xiao-Yan; Yan, Xia; Fang, Mei-Juan; Wu, Zhen; Wang, Dong; Qiu, Ying-Kun

    2017-07-01

    Two new cytochalasan derivatives, isochaetoglobosin D b (1) and cytoglobosin A b (2), were isolated from an ethyl acetate extract of Chaetomium globosum SNSHI-5, a fungus derived from extreme environment. The structures of the new compounds were comprehensively characterized by HR-ESI-MS, 1 H NMR, 13 C NMR and 2D-NMR. Cytotoxic activity against H292 human lung cancer cell of the new compounds was tested. Isochaetoglobosin D b (1) showed potent cytotoxicity with IC 50 of 3.5 μM, while cytoglobosin A b was inactive (IC 50  > 10 μM).

  8. Cytotoxic anthranilic acid derivatives from deep sea sediment-derived fungus Penicillium paneum SD-44.

    Science.gov (United States)

    Li, Chun-Shun; Li, Xiao-Ming; Gao, Shu-Shan; Lu, Yan-Hua; Wang, Bin-Gui

    2013-08-21

    Five new anthranilic acid derivatives, penipacids A-E (1-5), together with one known analogue (6), which was previously synthesized, were characterized from the ethyl acetate extract of the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analysis. The cytotoxicity and antimicrobial activity of the isolated compounds were evaluated. Compounds 1, and 5 exhibited inhibitory activity against human colon cancer RKO cell line, while compound 6 displayed cytotoxic activity against Hela cell line.

  9. Cytotoxic Anthranilic Acid Derivatives from Deep Sea Sediment-Derived Fungus Penicillium paneum SD-44

    Directory of Open Access Journals (Sweden)

    Bin-Gui Wang

    2013-08-01

    Full Text Available Five new anthranilic acid derivatives, penipacids A–E (1–5, together with one known analogue (6, which was previously synthesized, were characterized from the ethyl acetate extract of the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analysis. The cytotoxicity and antimicrobial activity of the isolated compounds were evaluated. Compounds 1, and 5 exhibited inhibitory activity against human colon cancer RKO cell line, while compound 6 displayed cytotoxic activity against Hela cell line.

  10. A conformational study of proline derivatives

    Directory of Open Access Journals (Sweden)

    M.E. Kamwaya

    2002-12-01

    Full Text Available From the study of the structures and molecular conformations of a number of proline derivatives, some conclusions were drawn. The widening effect of angle Cα-C'-N' is caused by steric repulsion between a hydrogen atom at Cα of the preceding prolyl residue with any other at either Cα or Cδ of the pyrrolidine ring cis to it. This effect is influenced by the distance between the said hydrogen atoms: the nearer this distance is, the greater is the steric repulsion and the wider is the angle of steric repulsion. The ratio of the angle of steric repulsion to the distance between Cα and the following Cα (or Cδ cis to it is approximately 40 and 41 for peptides with trans and cis configurations, respectively. The torsion angle ranges for χ1, χ3, χ 4, θ and φ in these derivatives are widened more than usual. The highest vibration, which more often takes place at either the Cβ or Cγ of the pyrrolidine ring, does so not necessarily at the one that is puckered. A Δ&psi -relationship is established, for the determination of α-helixity or collageneity, also in small peptides and amino acids that contain proline. The Δ&psi-relationship is versatile and gives about +180o and –180o for the two categories, respectively. The distance between the carbonyl and hydroxyl (or otherwise terminal end atoms is minimal (2.2 Å and constant, for all peptides. The ratios of the angles at the carbonyl carbons (O'-C'-N' or (O'-C'-O' to this distance is also constant: 56 and 57 for the cis and trans confirgurations, respectively; i.e. a proline O'-C'-N'- (or O'-C'-O'-test, hereinafter called the CT-test, has been established for the determination of cis and trans configurations. It is also established in these proline derivatives, that whereas puckering takes place at Cβ for the CS form, it does so at Cγ for the C2 form.

  11. Biologic Rhythms Derived from Siberian Mammoths Hairs

    Energy Technology Data Exchange (ETDEWEB)

    M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

    2011-12-31

    Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

  12. On an Inequality Concerning the Polar Derivative of a Polynomial

    Indian Academy of Sciences (India)

    Abstract. In this paper, we present a correct proof of an -inequality concerning the polar derivative of a polynomial with restricted zeros. We also extend Zygmund's inequality to the polar derivative of a polynomial.

  13. ASTEROID LIGHTCURVE DERIVED DATA REFERENCES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This file contains the full text of the references cited by identification code in the Asteroid Lightcurve Derived Data dataset (EAR-A-5-DDR-DERIVED-LIGHTCURVE-V1.0).

  14. Metallocenes and metallocene derivatives having a radioactive central atom

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, M.; Langheim, D.

    1977-06-07

    Radioactive metallocenes and metallocene derivatives are prepared by heating a non-radioactive metallocene or metallocene derivative with a radioactive metal salt, e.g., /sup 103/RuCl/sub 3/, at 140 to 250/sup 0/C.

  15. Simple derivations of Kepler's first law: use of complex variables

    International Nuclear Information System (INIS)

    Xu Donghui

    2012-01-01

    By making use of complex variables, simple derivations of Kepler's first law are introduced. Such derivations might be of interest for undergraduate students in an introductory physics course. (paper)

  16. On an inequality concerning the polar derivative of a polynomial

    Indian Academy of Sciences (India)

    Abstract. In this paper, we present a correct proof of an -inequality concerning the polar derivative of a polynomial with restricted zeros. We also extend Zygmund's inequality to the polar derivative of a polynomial.

  17. Selenium- or tellurium- containing bile acids and derivatives thereof

    International Nuclear Information System (INIS)

    Monks, R.; Riley, A.L.M.

    1981-01-01

    This invention relates to the preparation of selenium and tellurium derivatives, particularly γ-emitting radioactive derivatives of bile acids and bile salts. Such compounds are valuable in the examination of body function, especially small bowel function. (author)

  18. Design, synthesis and antidiabetic evaluation of oxazolone derivatives

    Indian Academy of Sciences (India)

    one derivatives were syn- thesized and assayed in vivo to investigate their antidiabetic activities by streptozotocin-induced model in rat. These derivatives showed considerable biological efficacy when compared to rosiglitazone, a potent and ...

  19. Reaction between chloromercurocobaltcarborane and undecaborate anion derivatives

    International Nuclear Information System (INIS)

    Lobanova, I.A.; Khitrova, O.M.; Petrovskij, P.V.; Bregadze, V.I.

    2004-01-01

    Interaction of Cs + C 2 B 9 H 12 - and exo-nido-5,6,10-[Cl(Ph 3 P) 2 RU]-5,6,10-(μ-H) 3 -10-H-7,8-C 2 B 9 H 8 with 9-chloromercurocobaltcarborane derivative - 3-(η 5 -Cp)-9-ClHg-3,1,2-CoC 2 B 9 H 10 (η 5 -Cp = cyclopentadiene) in mixed solvent tetrahydrofuran-water-ethanol at room temperature was studied using the methods of elementary analysis and 1 H, 31 P, 11 B NMR. Asymmetric metallocarborane cluster, in which exo-nido-ruthenacarborane and closo-cobalt- or dicarbo-nido-undecaborate fragments are bound via mercury atom, were prepared [ru

  20. Autocrine Effects of Tumor-Derived Complement

    Directory of Open Access Journals (Sweden)

    Min Soon Cho

    2014-03-01

    Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

  1. The Brain Derived Neurotrophic Factor and Personality

    Directory of Open Access Journals (Sweden)

    Christian Montag

    2014-01-01

    Full Text Available The study of the biological basis of personality is a timely research endeavor, with the aim of deepening our understanding of human nature. In recent years, a growing body of research has investigated the role of the brain derived neurotrophic factor (BDNF in the context of individual differences across human beings, with a focus on personality traits. A large number of different approaches have been chosen to illuminate the role of BDNF for personality, ranging from the measurement of BDNF in the serum/plasma to molecular genetics to (genetic brain imaging. The present review provides the reader with an overview of the current state of affairs in the context of BDNF and personality.

  2. Ecotoxicology a derivative of encyclopedia of ecology

    CERN Document Server

    Fath, Brian D

    2010-01-01

    The compilation of the articles in this derivative emphasizes ecological components and fundamental paradigms of ecotoxicology. The alphabetical listing of toxic substances and chemicals in Part B and C serves as a quick reference for professionals. Additionally, the international focus of Ecotoxicology and the range of toxins it covers will make it an indispensable resource to scientists. The password protected companion website will contain Estimation of Ecotoxicological Parameters (EEP) software developed by the author. EEP allows users to get ecotoxicological properties of chemicals in data bases or they can estimate them (there are only a few percentages in the data base). There are very specific estimation methods that only estimate for instance the properties for halogenated aromatic compounds or there are very general estimation methods. EEP covers the very general methods and is fast to use but gives in general estimation of higher uncertainty than the very specific methods.

  3. On Derivations of Operator Algebras with Involution

    Directory of Open Access Journals (Sweden)

    Širovnik Nejc

    2014-12-01

    Full Text Available The purpose of this paper is to prove the following result. Let X be a complex Hilbert space, let L(X be an algebra of all bounded linear operators on X and let A(X ⊂ L(X be a standard operator algebra, which is closed under the adjoint operation. Suppose there exists a linear mapping D : A(X → L(X satisfying the relation 2D(AA*A = D(AA*A + AA*D(A + D(AA*A + AD(A*A for all A ∈ A(X. In this case, D is of the form D(A = [A,B] for all A ∈ A(X and some fixed B ∈ L(X, which means that D is a derivation.

  4. Grafting of chitosan with fatty acyl derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Chiandotti, Roberto S.; Rodrigues, Paula C.; Akcelrud, Leni, E-mail: leni@leniak.ne [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept de Quimica

    2010-07-01

    The internal plasticization of chitosan with covalently linked long aliphatic branches, typically 12C, was accomplished through the condensation of the amino groups of chitosan with acidic derivatives of lauric acid, as lauroyl anhydride or lauroyl chloride, that are more reactive than the fatty acid itself. The chemical pathway led to selective N-acylation. The degree of substitution was quantitatively determined by FTIR and {sup 1}H NMR and varied between 3 and 35%. The FTIR quantitative analysis was based in a calibration method with good accuracy. The modified chitosan products were soluble in neutral water and/or DMF according to the degree of substitution. The modified chitosan films were more flexible than the pristine, non-modified ones. (author)

  5. Selective Oxidation of Biomass-Derived Chemicals

    DEFF Research Database (Denmark)

    Modvig, Amalie Elise

    . The objective of this dissertation was to develop new, alternative and sustainable methods for oxidative catalytic upgrading of biomass-derived compounds, with focus on oxidation of glycolaldehyde and simple alcohols as model substrates for larger sugars. Supported gold nanoparticle were studied...... for the selective oxidation of glycolaldehyde to glycolic acid, which has found applications in various industries. Limitations by competing reactions and catalyst deactivation was observed, affording up to 68% of glycolic acid at mild and aqueous conditions. The green oxidant, molecular oxygen, was applied...... for these oxidations and the reaction took place under base-free conditions. Oxidation of glycolaldehyde was further studied in the formation of formic acid. Efficient release of hydrogen from formic acid has proven formic acid a viable precursor for hydrogen, facilitating safe transportation and storage. Hydrogen has...

  6. A Shuttle Derived Vehicle launch system

    Science.gov (United States)

    Tewell, J. R.; Buell, D. N.; Ewing, E. S.

    1982-01-01

    This paper describes a Shuttle Derived Vehicle (SDV) launch system presently being studied for the NASA by Martin Marietta Aerospace which capitalizes on existing Shuttle hardware elements to provide increased accommodations for payload weight, payload volume, or both. The SDV configuration utilizes the existing solid rocket boosters, external tank and the Space Shuttle main engines but replaces the manned orbiter with an unmanned, remotely controlled cargo carrier. This cargo carrier substitution more than doubles the performance capability of the orbiter system and is realistically achievable for minimal cost. The advantages of the SDV are presented in terms of performance and economics. Based on these considerations, it is concluded that an unmanned SDV offers a most attractive complement to the present Space Transportation System.

  7. Radon-Nikodym derivatives of quantum operations

    International Nuclear Information System (INIS)

    Raginsky, Maxim

    2003-01-01

    Given a completely positive (CP) map T, there is a theorem of the Radon-Nikodym type [W. B. Arveson, Acta Math. 123, 141 (1969); V. P. Belavkin and P. Staszewski, Rep. Math. Phys. 24, 49 (1986)] that completely characterizes all CP maps S such that T-S is also a CP map. This theorem is reviewed, and several alternative formulations are given along the way. We then use the Radon-Nikodym formalism to study the structure of order intervals of quantum operations, as well as a certain one-to-one correspondence between CP maps and positive operators, already fruitfully exploited in many quantum information-theoretic treatments. We also comment on how the Radon-Nikodym theorem can be used to derive norm estimates for differences of CP maps in general, and of quantum operations in particular

  8. Higher derivative super Yang-Mills theories

    International Nuclear Information System (INIS)

    Bergshoeff, E.; Rakowski, M.; Sezgin, E.

    1986-11-01

    The most general higher derivative Yang-Mills actions of the type (F 2 +α2F 4 ) which are globally supersymmetric up to order α 2 in six and ten dimensional spacetimes are given. The F 4 -terms turn out to occur in the combination α 2 (tr F 4 - 1/4(tr F 2 ) 2 ), where the trace is over the Lorentz indices. This result agrees with the low energy limit of the open superstring in ten dimensions, where α is the string tension. Surprisingly, the transformation rules of the Yang-Mills multiplet receive order α 2 corrections even in the off-shell formulation. For the case of Abelian Yang-Mills group, the action is expressed in Born-Infeld form with a metric generically given by (1+α 2 F 2 +...). (author)

  9. Derivation of the optical constants of anisotropic

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.; Strong, P. F.

    1985-07-01

    This report concerns the development of methods for obtaining the optical constants of anisotropic crystals of the triclinic and monoclinic systems. The principal method used, classical dispersion theory, is adapted to these crystal systems by extending the Lorentz line parameters to include the angles characterizing the individual resonances, and by replacing the dielectric constant by a dielectric tensor. The sample crystals are gypsium, orthoclase and chalcanthite. The derived optical constants are shown to be suitable for modeling the optical properties of particulate media in the infrared spectral region. For those materials where suitable size single crystals are not available, an extension of a previously used method is applied to alabaster, a polycrystalline material of the monoclinic crystal system.

  10. Functionalized carbon nanomaterials derived from carbohydrates.

    Science.gov (United States)

    Jagadeesan, Dinesh; Eswaramoorthy, Muthusamy

    2010-02-01

    A tremendous growth in the field of carbon nanomaterials has led to the emergence of carbon nanotubes, fullerenes, mesoporous carbon and more recently graphene. Some of these materials have found applications in electronics, sensors, catalysis, drug delivery, composites, and so forth. The high temperatures and hydrocarbon precursors involved in their synthesis usually yield highly inert graphitic surfaces. As some of the applications require functionalization of their inert graphitic surface with groups like -COOH, -OH, and -NH(2), treatment of these materials in oxidizing agents and concentrated acids become inevitable. More recent works have involved using precursors like carbohydrates to produce carbon nanostructures rich in functional groups in a single-step under hydrothermal conditions. These carbon nanostructures have already found many applications in composites, drug delivery, materials synthesis, and Li ion batteries. The review aims to highlight some of the recent developments in the application of carbohydrate derived carbon nanostructures and also provide an outlook of their future prospects.

  11. Fluorescein Derivatives in Intravital Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Michael S. Roberts

    2013-08-01

    Full Text Available Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples.

  12. Proteoliposome derived cochleate as novel adjuvant.

    Science.gov (United States)

    Bracho, Gustavo; Lastre, Miriam; del Campo, Judith; Zayas, Caridad; González, Domingo; Gil, Danay; Acevedo, Reinaldo; Taboada, Carlos; Solís, Rosa L; Pérez, Oliver

    2006-04-12

    Cochleate structures (CS) consist in a highly stable lipid structures that have been reported to be a good antigen delivery system. The incorporation of pathogen associated molecular pattern (PAMP) from bacterial membranes into CS became in a promising approach to develop adjuvants, particularly mucosal adjuvants. Therefore, we prepare CS from proteoliposome (PL) obtained from Neisseria meningitidis B (PLCS) and evaluated it for its capability to stimulate the immune system as well as the adjuvant activity. The ability of PLCS to induce Thl polarization was also explored. The results and the easy capability for new antigen incorporation on CS support its use as adjuvant for immunization with a large variety of pathogen derived antigens and different routes of immunization.

  13. Melilotoside Derivatives from Artemisia splendens (Asteraceae

    Directory of Open Access Journals (Sweden)

    Fariba H. Afshar

    2017-01-01

    Full Text Available A combination of solid-phase-extraction (SPE and reversed-phase preparative high-performance liquid chromatography (prep-HPLC of the methanolic extract of the aerial parts of Artemisia splendens (common name: “Asia Minor Wormwood”, an endemic Iranian species, afforded Z- and E-melilotosides (1 and 2, Z- and E-4-methoxy-melilotosides (3 and 4, and a new dimer, bis-ortho-Z-melilotoside (5, named: splendenoside. Whilst the structures of these compounds (1-5 were elucidated unequivocally by spectroscopic means, the in vitro free-radical-scavenging property of 1-5 was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH assay. This is the first report on the occurrence of any melilotoside derivatives in the genus Artemisia. Artemisia splendens, Asteraceae, 2,2-diphenyl-1-picrylhydrazyl (DPPH, free-radical scavenger, melilotoside, splendenoside

  14. Crown ether derivatives of EDTA: Pt. 6

    International Nuclear Information System (INIS)

    Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

    1988-01-01

    EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

  15. Platelet-Derived Serotonin Mediates Liver Regeneration

    Science.gov (United States)

    Lesurtel, Mickael; Graf, Rolf; Aleil, Boris; Walther, Diego J.; Tian, Yinghua; Jochum, Wolfram; Gachet, Christian; Bader, Michael; Clavien, Pierre-Alain

    2006-04-01

    The liver can regenerate its volume after major tissue loss. In a mouse model of liver regeneration, thrombocytopenia, or impaired platelet activity resulted in the failure to initiate cellular proliferation in the liver. Platelets are major carriers of serotonin in the blood. In thrombocytopenic mice, a serotonin agonist reconstituted liver proliferation. The expression of 5-HT2A and 2B subtype serotonin receptors in the liver increased after hepatectomy. Antagonists of 5-HT2A and 2B receptors inhibited liver regeneration. Liver regeneration was also blunted in mice lacking tryptophan hydroxylase 1, which is the rate-limiting enzyme for the synthesis of peripheral serotonin. This failure of regeneration was rescued by reloading serotonin-free platelets with a serotonin precursor molecule. These results suggest that platelet-derived serotonin is involved in the initiation of liver regeneration.

  16. Determination of phosphorus using derivative neutron activation

    International Nuclear Information System (INIS)

    Scindia, Y.M.; Nair, A.G.C.; Reddy, A.V.R.; Manohar, S.B.

    2002-01-01

    For the determination of phosphorus in different matrices, the derivative neutron activation analysis is especially applicable to aqueous samples, since the conventional neutron activation analysis is not useful for the determination of phosphorus. Phosphorus when reacted with ammonium molybdate 4 hydrate and ammonium metavanadate forms molybdo vanado phosphoric acid. This complex is preconcentrated by extracting into methyl isobutyl ketone. The organic phase containing the molybdo vanado phosphoric acid is neutron activated and the phosphorus is determined through the activation product of 52 V. Preparation of this complex, its stoichiometry, application to trace level determination of phosphorus and improved detection limit are discussed. This method was applied for the analysis of industrial effluent samples. (author)

  17. Visualization of Enhancer-Derived Noncoding RNA.

    Science.gov (United States)

    Shibayama, Youtaro; Fanucchi, Stephanie; Mhlanga, Musa M

    2017-01-01

    Enhancers are principal regulators that allow spatiotemporal tissue-specific control of gene expression. While mounting evidence suggests that enhancer-derived long noncoding RNAs (long ncRNAs), including enhancer RNAs (eRNAs), are an important component of enhancer function, their expression has not been broadly analyzed at a single cell level via imaging techniques. This protocol describes a method to image eRNA in single cells by in situ hybridization followed by tyramide signal amplification (TSA). The procedure can be multiplexed to simultaneously visualize both eRNA and protein-coding transcript at the site of transcriptional elongation, thereby permitting analysis of dynamics between the two transcript species in single cells. Our approach is not limited to eRNAs, but can be implemented on other transcripts.

  18. Cysteine sulfoxide derivatives in Petiveria alliacea.

    Science.gov (United States)

    Kubec, R; Musah, R A

    2001-11-01

    Two diastereomers of S-benzyl-L-cysteine sulfoxide have been isolated from fresh roots of Petiveria alliacea. Their structures and absolute configurations have been determined by NMR, MALDI-HRMS, IR and CD spectroscopy and confirmed by comparison with authentic compounds. Both the R(S) and S(S) diastereomers of the sulfoxide are present in all parts of the plant (root, stem, and leaves) with the latter diastereomer being predominant. Their total content greatly varied in different parts of the plant between 0.07 and 2.97 mg g(-1) fr. wt, being by far the highest in the root. S-Benzylcysteine has also been detected in trace amounts (<10 microg g(-1) fr. wt) in all parts of the plant. This represents the first report of the presence of S-benzylcysteine derivatives in nature.

  19. Chaotic inflation in higher derivative gravity theories

    Energy Technology Data Exchange (ETDEWEB)

    Myrzakul, Shynaray; Myrzakulov, Ratbay; Sebastiani, Lorenzo [Eurasian National University, Department of General and Theoretical Physics, Eurasian Center for Theoretical Physics, Astana (Kazakhstan)

    2015-03-01

    In this paper, we investigate chaotic inflation from a scalar field subjected to a potential in the framework of f(R{sup 2}, P, Q)-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar R{sup 2}, the contraction of the Ricci tensor P, and the contraction of the Riemann tensor Q. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the e-fold number, and the spectral indices. Several explicit examples are furnished; namely, we will consider the cases of a massive scalar field and a scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. A viable approach to inflation according with observations is analyzed. (orig.)

  20. Synthesis and conformational analysis of naphthylnaphthoxazine derivatives

    Science.gov (United States)

    Tóth, Diána; Szatmári, István; Heydenreich, Matthias; Koch, Andreas; Kleinpeter, Erich; Fülöp, Ferenc

    2009-07-01

    Four new primary aminonaphthols ( 4, 5, 9 and 10) were synthesized from 1- or 2-naphthol and 1- or 2-naphthaldehyde via naphthoxazines in modified Mannich condensations. Simple ring-closure reactions of these aminonaphthols with paraformaldehyde, 4-nitrobenzaldehyde, phosgene or 4-chlorophenyl isothiocyanate led to new heterocyclic derivatives. In these transformations, either an sp 2 or an sp 3 carbon was inserted between the hydroxy and amino groups. The effects of substituents and the naphthyl ring on the conformation were investigated by means of NMR measurements, employing both dipolar and scalar couplings. The structures were confirmed by DFT quantum chemical calculations involving computed coupling constants, intramolecular distances between nuclei and the relative energies of the preferred conformers.