Готові списки джерел за темами / Transient function

Зміст

Статті в журналах
Дисертації
Книги
Частини книг
Тези доповідей конференцій
Звіти організацій

Добірка наукової літератури з теми "Transient function"

Автор: Grafiati

Опубліковано: 30 травня 2022

Оновлено: 31 травня 2022

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Transient function".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Transient function"

Song, Justin C. W. "Transient wave function twist." Nature Physics 16, no. 1 (November 4, 2019): 6–7. http://dx.doi.org/10.1038/s41567-019-0708-0.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Grubin, H. L. "Transient Wigner Function Studies of DMS Barrier Devices." Advances in Science and Technology 52 (October 2006): 36–41. http://dx.doi.org/10.4028/www.scientific.net/ast.52.36.

Повний текст джерела

Анотація:

Incorporating diluted magnetic semiconductor (DMS) layers within barrier devices offers new device design potential. To study these devices we have generalized an existing time dependent transient algorithm that couples the Wigner transport equation to Poisson’s equation and an external circuit. For electron transport we have studied alterations in the dc and time dependent behavior of resonant tunneling diodes with DMS barriers and wells, have transformed a single barrier structure into a double barrier structure and examined the increased functionality of the devices. We present new results, including some preliminary calculations incorporating holes, discuss transients and the potential role that DMS layers will play in controlling the transient operation of superlattice structures.

Стилі APA, Harvard, Vancouver, ISO та ін.

Fouad, A. A., and V. Vittal. "The transient energy function method." International Journal of Electrical Power & Energy Systems 10, no. 4 (October 1988): 233–46. http://dx.doi.org/10.1016/0142-0615(88)90011-7.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Козир, Олег Васильович, and Юліан Михайлович Туз. "Study of thermocouple transient function models." Information systems, mechanics and control, no. 20 (June 30, 2019): 13–22. http://dx.doi.org/10.20535/2219-3804202019194307.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

ZHAO, J. "Executive function during transient ischemic attacks." Neural Regeneration Research 2, no. 3 (March 2007): 142–45. http://dx.doi.org/10.1016/s1673-5374(07)60032-2.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Christensen, Niels B. "Sensitivity functions of transient electromagnetic methods." GEOPHYSICS 79, no. 4 (July 1, 2014): E167—E182. http://dx.doi.org/10.1190/geo2013-0364.1.

Повний текст джерела

Анотація:

Any geophysical measurement is a filter through which the distribution of a certain physical parameter in the subsurface is seen, and the sensitivity function is a characteristic of the method that reveals the nature of this filter. Insight into the structural pattern of the sensitivity function pertaining to a certain transmitter-receiver configuration provides the geophysicist with an image that allows an immediate qualitative understanding of the characteristics of the method. The assets and shortcomings of different measuring configurations can be discussed and understood, and the sensitivity function permits qualified predictions about resolution characteristics of new configurations and measuring strategies. I evaluated a rapid and accurate method for calculating 3D sensitivity functions of a homogeneous half-space model for a wide variety of transient electromagnetic configurations using the central loop and an airborne offset loop configuration as examples. Computations of 3D sensitivity functions were performed as convolutions in the time domain between the electric fields from the transmitter and the receiver, had it been used as a transmitter. The 2D and 1D sensitivity functions are found through numerical integration of the 3D functions. Beside offering insight into the resolution capability of the measuring configuration, the sensitivity functions lend themselves to rapid calculations of approximate responses and derivatives in various modeling and inversion strategies.

Стилі APA, Harvard, Vancouver, ISO та ін.

Garimella, S. S., and K. Srinivasan. "Transient Response of Repetitive Control Systems." Journal of Dynamic Systems, Measurement, and Control 118, no. 4 (December 1, 1996): 795–97. http://dx.doi.org/10.1115/1.2802360.

Повний текст джерела

Анотація:

Upper bounds on transient response magnitudes for a SISO continuous-time repetitive control system are derived. Limiting the size of these transients is shown to be related to limiting the ∞-norm of a transfer function product of filters used in the repetitive controller. The decay rate of the transients is related to the peak of a function of frequency called the regeneration spectrum, which has previously been shown in the literature to be a measure of the relative stability of the system. Bounds derived here, although conservative, can be useful in the design of the repetitive controller, as illustrated by means of an example.

Стилі APA, Harvard, Vancouver, ISO та ін.

Da-Zhong Fang, T. S. Chung, Yao Zhang, and Wennan Song. "Transient stability limit conditions analysis using a corrected transient energy function approach." IEEE Transactions on Power Systems 15, no. 2 (May 2000): 804–10. http://dx.doi.org/10.1109/59.867177.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Robbins, Matthew S., David M. Breidbart, and Hilary Y. Robbins. "Transient global amnesia complicating pulmonary function testing." Respiratory Medicine CME 3, no. 4 (2010): 230–31. http://dx.doi.org/10.1016/j.rmedc.2009.12.002.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

McDonough, Paul G., and Carlos E. Sueldo. "Transient Liver Function Tests Abnormalities in OHSS." Fertility and Sterility 50, no. 6 (December 1988): 995–96. http://dx.doi.org/10.1016/s0015-0282(16)60392-8.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Дисертації з теми "Transient function"

Watkins, Adam Christopher. "RADIATION INDUCED TRANSIENT PULSE PROPAGATION USING THE WEIBULL DISTRIBUTION FUNCTION." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/811.

Повний текст джерела

Анотація:

In recent years, studying soft errors has become an issue of greater importance. There have been many methods developed that estimate the Soft Error Rate. Those methods are either deterministic or statistical. The proposed deterministic model aims to improve Soft Error Rate estimation by accurately approximating the generated pulse and all subsequent pulses. The generated pulse is approximated by a piecewise function consisting of two Weibull cumulative distribution functions. This method is an improvement over existing methods as it offers high accuracy while requiring less pre-characterization. The proposed algorithm reduces pre-characterization by allowing the beta Weibull parameter to be calculated during runtime using gate parameters such as the gate delay.

Стилі APA, Harvard, Vancouver, ISO та ін.

Katisart, Teeraporn. "Transient receptor potential function in bladder from control and streptozotocin treated rats." Thesis, University of Hertfordshire, 2011. http://hdl.handle.net/2299/6039.

Повний текст джерела

Анотація:

Diabetic cystopathy is a chronic and common complication of diabetes with a classical triad of symptoms; decreased bladder sensation, increased bladder capacity and impaired detrusor muscle contractility (Hunter and Moore, 2003). In animal models of diabetes such as streptozotocin-induced diabetes in the rat, abnormalities of bladder function have been reported (Longhurst and Belis, 1986). The prototypic TRPV channel, TRPV1, is activated by capsaicin, which has been shown to cause contraction of the rat bladder (Saitoh et al., 2007), and this is reduced in STZ-diabetic rat bladder (Pinna et al., 1994). Therefore we hypothesize that TRPV1 function will be reduced in the diabetic bladder. The aim of this study are the following: Firstly, to investigate the effect of the streptozotocin (STZ) model of diabetes on a range of TRP channel functions in the urinary bladder smooth muscle preparation using TRP channel agonists and antagonists and to study the neurotransmitters involved in the contractile or relaxant responses. Some studies were also performed on colon tissues. Secondly, to explore the involvement of cholesterol modudation in TRP channel signalling. Thirdly, to study the change in TRP channel response with time following the treatment with streptozotocin. The results showed that the contractile responses to the TRPV1 agonist capsaicin, TRPV4 agonist 4-α-PDD, and TRPA1 agonist allyl isothiocyanate were significantly reduced in diabetic bladder. The selective TRPV1 antagonist, SB-366791, inhibited the contractile responses to capsaicin confirming the involvement of TRPV1 channels. The effect of diabetes is unlikely to be at the level of contractile machinery since the contractile responses to muscarinic receptor agonist carbachol were not significantly reduced in diabetic tissues. It is reported for the first time that the combination of neurokinin 1 and 2 antagonists GR-205171 and SB-207164 inhibited the contractile responses to capsaicin suggesting that a neurokinin may be the neurotransmitter involved in the capsaicin responses. In addition, the reduction of the responses to capsaicin in STZ-induced diabetic tissues occurred not only in urinary bladder but also in colon. Cholesterol-PEG significantly lowered the maximal contractile responses to capsaicin of rat bladder strips. Methyl-β-cyclodextrin, α-cyclodextrin and β-cyclodextrin at the same concentrations enhanced the contractile responses to capsaicin in the control and diabetic rat bladder strips. These effects of cyclodextrin are specific to capsaicin activated contractions and not seen with TRPA1 activation, suggesting that the effects are not mediated downstream of channel activation. Since α-cyclodextrin does not sequester cholesterol, the enhanced responses to cyclodextrins may not be due to the cholesterol modulations. Instead, theses novel findings may possibly occur by changing the local membrane lipid environment of the TRPV1 channel. As early as 36 hours after induction of diabetes by STZ, the contractile responses to capsaicin were significantly reduced in comparison to those of the controls and this reduction persisted until the eight weeks time point. In contrast, responses to the TRPA1 agonist allyl isothiocyanate were not affected at early time points but were reduced one week after STZ treatment. This detailed time course analysis suggests that there are novel mechanisms of modulation of the TRPV1 channels in this STZ model. In conclusion, in the rat urinary bladder or colon preparations, diabetes mellitus using STZ animal model caused 1) the impairment of a number of TRP channel subfamily functions, TRPV1, TRPV4 and TRPA1 but not TRPM8. The combination of NK1 and NK2 antagonists significantly inhibited the responses to capsaicin. This may suggest the involvement of neurokinin in postsynaptic transmission in rat bladder following the activation of TRPV1 channel, 2) the impairment caused by STZ-induced diabetes occurred very early (within 36 hours after diabetes induction) in TRPV1 channel but not TRPA1 channel. There are specific early effects of STZ treatment on TRPV1 channel function at a time when other afferent nerve terminal channels (TRPA1) are functioning normally, suggesting that early onset of dysfunction in TRPV1 signalling may not merely be the consequence of nerve damage, 3) the mechanism of this impairment may not be the effect of neuropathy on neurotransmitter release or nerve damage. Improving the responsiveness of nerves of bladder in diabetic patients might be of therapeutic benefit. The present studies suggest that it is possible to enhance function using indirect modulators such as bradykinin which potentiated the TRPV1 channel function in diabetic rat bladders.

Стилі APA, Harvard, Vancouver, ISO та ін.

陳偉樂 and Wai-lok Chan. "Multi-function monitoring system for harmonic and transient study of power networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31210727.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Chan, Wai-lok. "Multi-function monitoring system for harmonic and transient study of power networks /." [Hong Kong : University of Hong Kong], 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13418051.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zettner, Erika Maria. "Transient otoacoustic emission suppression tuning curves as a function of psychophysical threshold /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8273.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Myers, Benjamin R. "Genetic and evolutionary approaches to transient receptor potential channel structure and function." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3339199.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Mellechervu, Karthik. "Modeling of Transient Thrust of a Two Phase Propellant Tank." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1231561130.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Shaner, Samuel Christopher. "Transient method of characteristics via the Adiabatic, Theta, and Multigrid Amplitude Function methods." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92092.

Повний текст джерела

Анотація:

Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 147-149).
In this thesis, we investigated the Adiabatic, Theta, and Multigrid Amplitude Function (MAF) methods for solving the Method of Characteristics (MOC) formulation of the time-dependent neutron transport equation. The transient transport versions of the 2D LRA and C5G7 benchmarks were used to assess the performance and accuracy of these methods. We began by deriving the CMFD-accelerated MOC algorithm in 2D steady state form and examining the effects of various MOC and CMFD parameters on eigenvalue convergence. The C5G7 problem showed similar acceleration performance for 2, 4, and 7 CMFD energy group structures. CMFD meshes at or near the pin-cell level resulted in the greatest speedups of 15-45x in run time and 30-240 x in number of MOC iterations for both problems. A relaxation factor on the nonlinear diffusion coefficient was required to maintain stability for both problems with optimum values between 0.4-0.7. A sensitivity study was conducted on the C5G7 and LRA transient problems to understand the effects of time step and spatial mesh sizes on the solution accuracy and run time performance. The shape function time step size had a large effect on the solution accuracy for the MAF and Theta methods in solving the LRA problem. All methods showed moderate sensitivity to the amplitude function step size, where increasing step size shifted the peak power to earlier times. The coarse mesh size did not have a significant effect on solution accuracy, but meshes on the pin-cell level were clearly preferred to reduce run time. The overall run time performance between the three methods was mixed. The MAF and Theta methods displayed ~84% speedup over the Adiabatic method for the LRA problem, but all methods had similar run times for the C5G7 problem. This inconsistency is likely due to the more drastic flux shape change during the LRA transient and the ability of the MAF and Theta methods to more accurately treat the flux shape temporal derivative. These results demonstrate that the Adiabatic, Theta, and MAF methods are computationally efficient methods for solving the time-dependent neutron transport equation and warrant further investigation. There are clear advantages to each method and the optimal method will likely depend on the transient characteristics of the problem being studied.
by Samuel Christopher Shaner.
S.M.

Стилі APA, Harvard, Vancouver, ISO та ін.

Waldenborg, Micael. "Echocardiographic measurements at Takotsubo cardiomyopathy : transient left ventricular dysfunction." Doctoral thesis, Örebro universitet, Institutionen för hälsovetenskap och medicin, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-35798.

Повний текст джерела

Анотація:

Takotsubo cardiomyopathy (TTC) is a disease characterized by transient left ventricular (LV) dysfunction and typical wall motion abnormalities in apical parts, without obvious signs of coronary influence. Due to its elusive natural cause and the lack of clarified pathology, further studies are needed. Thirteen patients presented with an episode of TTC, and referred to Örebro University Hospital (USÖ), were prospectively included and investigated by comparisons made at onset (acute phase) against at follow-up three months later (recovery phase). Including echocardiographic measurements, focused on biventricular systolic long-axis function and conventional diastolic function (DF) variables. Systolic improvement was shown, while most DF data were unchanged, suggesting that TTC is mainly a systolic disease affecting both ventricles. Diagnosis should include multidisciplinary engagement, as TTC associates both with emotional stress and pathological markers of physiological stress. In this thesis, such approach was offered to the aforementioned patients; to see if a common denominator could be found, thus, contributing to better handling. Emotional state was assessed, along with an array of cardiac investigations in addition to echocardiography. Acutely, imbalance in the autonomic cardiac control was shown, as well as a trend toward posttraumatic stress, but specific findings allowing conclusions on differential diagnosis could not be demonstrated. By adding another 15 TTC patients (i.e. 28 in total), through collaboration with observers from USA, a retrospective echocardiographic analysis could be done to further study DF; concluding that TTC associates with impairment of conventional DF variables which tends to parallel the systolic recovery, in contrary to the initial result but in line with other causesof LV dysfunction. Magnetic resonance imaging (MRI) is another method of choice at TTC. The USÖ patients had cardiac MRI, thus, a retrospective analysis was done to investigate the effect on LV geometry, both echocardiographic and by MRI; suggesting that TTC is consistently associated with increased LV mass, due to a local impact that seems to follow the change in LVconcentric wall motion.

Стилі APA, Harvard, Vancouver, ISO та ін.

Al, Marhoon Hussain Hassan. "A Practical Method for Power Systems Transient Stability and Security." ScholarWorks@UNO, 2011. http://scholarworks.uno.edu/td/114.

Повний текст джерела

Анотація:

Stability analysis methods may be categorized by two major stability analysis methods: small-signal stability and transient stability analyses. Transient stability methods are further categorized into two major categories: numerical methods based on numerical integration, and direct methods. The purpose of this thesis is to study and investigate transient stability analysis using a combination of step-by-step and direct methods using Equal Area Criterion. The proposed method is extended for transient stability analysis of multi machine power systems. The proposed method calculates the potential and kinetic energies for all machines in a power system and then compares the largest group of kinetic energies to the smallest groups of potential energies. A decision based on the comparison can be made to determine stability of the power system. The proposed method is used to simulate the IEEE 39 Bus system to verify its effectiveness by comparison to the results obtained by pure numerical methods.

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Книги з теми "Transient function"

Vijay, Vittal, ed. Power system transient stability analysis using the transient energy function method. Englewood Cliffs, N.J: Prentice Hall, 1992.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux Green's function analysis for transient spectral radiation in a composite. Reston, VA: American Institute of Aeronautics and Astronautics, 1996.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux Green's function analysis for transient spectral radiation in a composite. Reston, VA: American Institute of Aeronautics and Astronautics, 1996.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux Green's function analysis for transient spectral radiation in a composite. Reston, VA: American Institute of Aeronautics and Astronautics, 1996.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux and Green's function method for transient radiative transfer in a semitransparent layer. [Washington, D.C: National Aeronautics and Space Administration, 1995.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux and Green's function method for transient radiative transfer in a semitransparent layer. [Washington, D.C: National Aeronautics and Space Administration, 1995.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Siegel, Robert. Two-flux and Green's function method for transient radiative transfer in a semitransparent layer. [Washington, D.C: National Aeronautics and Space Administration, 1995.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

O'Reilly, Andrew M. A method for simulating transient ground-water recharge in deep water-table settings in central Florida by using a simple water-balance/transfer-function model. Reston, Va: U.S. Geological Survey, 2004.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Tygel, M. Transient waves in layered media. Amsterdam: Elsevier, 1987.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Частини книг з теми "Transient function"

Noben-Trauth, Konrad. "The TRPML3 Channel: From Gene to Function." In Transient Receptor Potential Channels, 229–37. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-94-007-0265-3_13.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Bollimuntha, Sunitha, Senthil Selvaraj, and Brij B. Singh. "Emerging Roles of Canonical TRP Channels in Neuronal Function." In Transient Receptor Potential Channels, 573–93. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-94-007-0265-3_31.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Rychkov, Grigori Y., and Gregory J. Barritt. "Expression and Function of TRP Channels in Liver Cells." In Transient Receptor Potential Channels, 667–86. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-94-007-0265-3_35.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Kumar, Pradeep G., and Mohammed Shoeb. "The Role of TRP Ion Channels in Testicular Function." In Transient Receptor Potential Channels, 881–908. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-94-007-0265-3_46.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Turner, H., K. A. del Carmen, and A. Stokes. "Link Between TRPV Channels and Mast Cell Function." In Transient Receptor Potential (TRP) Channels, 457–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-34891-7_27.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Brinkmeier, Heinrich. "TRP Channels in Skeletal Muscle: Gene Expression, Function and Implications for Disease." In Transient Receptor Potential Channels, 749–58. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-94-007-0265-3_39.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Kemp, D. T., and M. Souter. "CM and OAE Changes Following Transient Efferent Excitation." In Cochlear Mechanisms: Structure, Function, and Models, 307–14. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-5640-0_35.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhang, D., and C. S. Desai. "Viscoplastic Model with Generalized Yield Function." In Transient/Dynamic Analysis and Constitutive Laws for Engineering Materials, 747–55. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3655-3_82.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Liu, Yutian, Xiaodong Chu, Yuanyuan Sun, and Li Li. "Transient Stability Assessment Using Radial Basis Function Networks." In Lecture Notes in Computer Science, 581–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-28648-6_93.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Rode, Andrei V., Davide Boschetto, Thomas Garl, and Antoine Rousse. "Transient Dielectric Function of Fs-Laser Excited Bismuth." In Springer Series in Chemical Physics, 217–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-95946-5_70.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Transient function"

C.M, Khan, Chanda C.K, and Konar S.C. "Study Of Transient Stability By Transient Energy Function." In National Conference on Advancement of Computing in Engineering Research. Academy & Industry Research Collaboration Center (AIRCC), 2013. http://dx.doi.org/10.5121/csit.2013.3235.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Chengjun Xia, Yao Zhang, and Huijun Hu. "Equivalent machine transient energy function method for transient stability assessment." In 7th IET International Conference on Advances in Power System Control, Operation and Management (APSCOM 2006). IEE, 2006. http://dx.doi.org/10.1049/cp:20061979.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Fang Da-Zhong. "Corrected transient energy function and its application to transient stability margin assessment." In APSCOM-97. International Conference on Advances in Power System Control, Operation and Management. IEE, 1997. http://dx.doi.org/10.1049/cp:19971850.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Lin, Y. Z., Z. X. Cai, and Q. Mo. "Transient stability analysis of AC/DC power system based on transient energy function." In 2008 Third International Conference on Electric Utility Deregulation and Restructuring and Power Technologies. IEEE, 2008. http://dx.doi.org/10.1109/drpt.2008.4523572.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Huang Yan, Li Hua-qiang, Li Qian, and Zheng Guo. "Branch transient vulnerability assessment based on the transient energy function and complex network." In 2014 International Conference on Power System Technology (POWERCON). IEEE, 2014. http://dx.doi.org/10.1109/powercon.2014.6993529.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Watkins, Adam, and Spyros Tragoudas. "Transient pulse propagation using the Weibull distribution function." In 2012 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFT). IEEE, 2012. http://dx.doi.org/10.1109/dft.2012.6378209.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Acciani, G., E. Chiarantoni, G. Fornarelli, and S. Vergura. "A homotopy function for transient analysis of switching circuits." In Proceedings of the IEEE International Symposium on Industrial Electronics. IEEE, 2005. http://dx.doi.org/10.1109/isie.2005.1528984.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ghezzehei, Teamrat, and Ammar Albalasmeh. "TRANSIENT STRUCTURE OF THE RHIZOSPHERE: IT FORMATION AND FUNCTION." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-288058.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Tang, Meng-meng, Bo Wang, Di-chen Liu, and Zhong-wei He. "Application of Transient Energy Function in Regional Power Grig." In 2nd International Conference on Electronic and Mechanical Engineering and Information Technology. Paris, France: Atlantis Press, 2012. http://dx.doi.org/10.2991/emeit.2012.459.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhang, Yuyue, Yimu Fu, Dong Liu, Ying Mu, Jianing Zhang, and Donglei Sun. "Influence of OPC Function on Transient Stability of Power System." In 2020 Chinese Control And Decision Conference (CCDC). IEEE, 2020. http://dx.doi.org/10.1109/ccdc49329.2020.9164795.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Transient function"

Cameron, Arthur, Shimshon Ben-Yehoshua, and Rebecca Hernandez. Design and Function of Modified Atmosphere Packaging Systems for Fresh Produce: a Unified Approach for Optimizing Oxygen, Carbon Dioxide and Relative Humidity. United States Department of Agriculture, January 1996. http://dx.doi.org/10.32747/1996.7613019.bard.

Повний текст джерела

Анотація:

Oxygen uptake, CO2 production and respiratory quotient (RQ) of strawberry, raspberry and cherry were measured as functions of temperature and oxygen level. The effect of cultivar was studied in strawberry ('Honey' and 'Allstar'). The effect of harvest date was studied for raspberry. The lower O2 limit increased markedly with incraqsing temperature for all fruits studied. Red bell pepper O2 uptake was measured as a function of O2 at 20o C. Lowering the inpackage humidity using NaCl reduced decay of bell pepper sealed in low-density polyethylene packages when stored at 8o C. Analyses of a model developed for MA-packaged red bell pepper fruit demonstrated that when RQ was near one and when CO2 exceeded O2 permeability, transient CO2 levels increased to a maximum before dropping to steady-state levels. An isothermal model of O2, CO2 and water vapor exchange in MA packages was developed for red bell pepper and tested empirically. A comprehensive model was developed for small fruits that also incorporated water vapor and the effects of changing temperature. Variation in package O2 levels was measured and modeled as a function of variation in respiration and film permeability.

Стилі APA, Harvard, Vancouver, ISO та ін.

Schaffer, Arthur, Jack Preiss, Marina Petreikov, and Ilan Levin. Increasing Starch Accumulation via Genetic Modification of the ADP-glucose Pyrophosphorylase. United States Department of Agriculture, October 2009. http://dx.doi.org/10.32747/2009.7591740.bard.

Повний текст джерела

Анотація:

The overall objective of the research project was to utilize biochemical insights together with both classical and molecular genetic strategies to improve tomato starch accumulation. The proposal was based on the observation that the transient starch accumulation in the immature fruit serves as a reservoir for carbohydrate and soluble sugar content in the mature fruit, thereby impacting on fruit quality. The general objectives were to optimize AGPase function and activity in developing fruit in order to increase its transient starch levels. The specific research objectives were to: a) perform directed molecular evolution of the limiting enzyme of starch synthesis, AGPase, focussing on the interaction of its regulatory and catalytic subunits; b) determine the mode of action of the recently identified allelic variant for the regulatory subunit in tomato fruit that leads to increased AGPase activity and hence starch content. During the course of the research project major advances were made in understanding the interaction of the small and large subunits of AGPase, in particular the regulatory roles of the different large subunits, in determining starch synthesis. The research was performed using various experimental systems, including bacteria and Arabidopsis, potato and tomato, allowing for broad and meaningful conclusions to be drawn. A novel discovery was that one of the large subunits of tomato AGPase is functional as a monomer. A dozen publications describing the research were published in leading biochemical and horticultural journals. The research results clearly indicated that increasing AGPase activity temporally in the developing fruit increase the starch reservoir and, subsequently, the fruit sugar content. This was shown by a comparison of the carbohydrate balance in near-isogenic tomato lines differing in a gene encoding for the fruit-specific large subunit (LS1). The research also revealed that the increase in AGPase activity is due to a temporal extension of LS1 gene expression in the developing fruit which in turn stabilizes the limiting heterotetrameric enzyme, leading to sustained starch synthesis. This genetic variation can successfully be utilized in the breeding of high quality tomatoes.

Стилі APA, Harvard, Vancouver, ISO та ін.

Aadithya, Karthik, Eric Keiter, and Ting Mei. DAGSENS: Directed Acyclic Graph Based Direct and Adjoint Transient Sensitivity Analysis for Event-Driven Objective Functions. Office of Scientific and Technical Information (OSTI), August 2017. http://dx.doi.org/10.2172/1761808.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Halker Singh, Rashmi B., Juliana H. VanderPluym, Allison S. Morrow, Meritxell Urtecho, Tarek Nayfeh, Victor D. Torres Roldan, Magdoleen H. Farah, et al. Acute Treatments for Episodic Migraine. Agency for Healthcare Research and Quality (AHRQ), December 2020. http://dx.doi.org/10.23970/ahrqepccer239.

Повний текст джерела

Анотація:

Objectives. To evaluate the effectiveness and comparative effectiveness of pharmacologic and nonpharmacologic therapies for the acute treatment of episodic migraine in adults. Data sources. MEDLINE®, Embase®, Cochrane Central Registrar of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO®, Scopus, and various grey literature sources from database inception to July 24, 2020. Comparative effectiveness evidence about triptans and nonsteroidal anti-inflammatory drugs (NSAIDs) was extracted from existing systematic reviews. Review methods. We included randomized controlled trials (RCTs) and comparative observational studies that enrolled adults who received an intervention to acutely treat episodic migraine. Pairs of independent reviewers selected and appraised studies. Results. Data on triptans were derived from 186 RCTs summarized in nine systematic reviews (101,276 patients; most studied was sumatriptan, followed by zolmitriptan, eletriptan, naratriptan, almotriptan, rizatriptan, and frovatriptan). Compared with placebo, triptans resolved pain at 2 hours and 1 day, and increased the risk of mild and transient adverse events (high strength of the body of evidence [SOE]). Data on NSAIDs were derived from five systematic reviews (13,214 patients; most studied was ibuprofen, followed by diclofenac and ketorolac). Compared with placebo, NSAIDs probably resolved pain at 2 hours and 1 day, and increased the risk of mild and transient adverse events (moderate SOE). For other interventions, we included 135 RCTs and 6 comparative observational studies (37,653 patients). Compared with placebo, antiemetics (low SOE), dihydroergotamine (moderate to high SOE), ergotamine plus caffeine (moderate SOE), and acetaminophen (moderate SOE) reduced acute pain. Opioids were evaluated in 15 studies (2,208 patients).Butorphanol, meperidine, morphine, hydromorphone, and tramadol in combination with acetaminophen may reduce pain at 2 hours and 1 day, compared with placebo (low SOE). Some opioids may be less effective than some antiemetics or dexamethasone (low SOE). No studies evaluated instruments for predicting risk of opioid misuse, opioid use disorder, or overdose, or evaluated risk mitigation strategies to be used when prescribing opioids for the acute treatment of episodic migraine. Calcitonin gene-related peptide (CGRP) receptor antagonists improved headache relief at 2 hours and increased the likelihood of being headache-free at 2 hours, at 1 day, and at 1 week (low to high SOE). Lasmiditan (the first approved 5-HT1F receptor agonist) restored function at 2 hours and resolved pain at 2 hours, 1 day, and 1 week (moderate to high SOE). Sparse and low SOE suggested possible effectiveness of dexamethasone, dipyrone, magnesium sulfate, and octreotide. Compared with placebo, several nonpharmacologic treatments may improve various measures of pain, including remote electrical neuromodulation (moderate SOE), magnetic stimulation (low SOE), acupuncture (low SOE), chamomile oil (low SOE), external trigeminal nerve stimulation (low SOE), and eye movement desensitization re-processing (low SOE). However, these interventions, including the noninvasive neuromodulation devices, have been evaluated only by single or very few trials. Conclusions. A number of acute treatments for episodic migraine exist with varying degrees of evidence for effectiveness and harms. Use of triptans, NSAIDs, antiemetics, dihydroergotamine, CGRP antagonists, and lasmiditan is associated with improved pain and function. The evidence base for many other interventions for acute treatment, including opioids, remains limited.

Стилі APA, Harvard, Vancouver, ISO та ін.

Delmer, Deborah P., Douglas Johnson, and Alex Levine. The Role of Small Signal Transducing Gtpases in the Regulation of Cell Wall Deposition Patterns in Plants. United States Department of Agriculture, August 1995. http://dx.doi.org/10.32747/1995.7570571.bard.

Повний текст джерела

Анотація:

The combined research of the groups of Delmer, Levine and Johnson has led to a number of interesting findings with respect to the function of the small GTPase Rac in plants and also opened up new leads for future research. The results have shown: 1) The Rac13 protein undergoes geranylgeranlyation and is also translocated to the plasma membrane as found for Rac in mammals; 2) When cotton Rac13 is highly- expressed in yeast, it leads to an aberrant phenotype reminiscent of mutants impaired in actin function, supporting a role for Rac13 in cytoskeletal organization; 3) From our searches, there is no strong evidence that plants contain homologs of the related CDC42 genes found in yeast and mammals; 4) We have identified a rather unique Rac gene in Arabidopsis that has unusual extensions at both the N- and C-terminal portions of the protein; 5) New evidence was obtained that an oxidative burst characterized by substantial and sustained production of H202 occurs coincident with the onset of secondary wall synthesis in cotton fibers. Further work indicates that the H202 produced may be a signal for the onset of this phase of development and also strongly suggests that Rac plays an important role in signaling for event. Since the secondary walls of plants that contain high levels of lignin and cellulose are the major source of biomass on earth, understanding what signals control this process may well in the future have important implications for manipulating the timing and extent of secondary wall deposition. 6) When the cotton Rac13 promoter is fused to the reporter gene GUS, expression patterns in Arabidopsis indicate very strong and specific expression in developing trichomes and in developing xyelm. Since both of these cell types are engaged in secondary wall synthesis, this further supports a role for Rac in signaling for onset of this process. Since cotton fibers are anatomically defined as trichomes, these data may also be quite useful for future studies in which the trichomes of Arabidopsis may serve as a model for cotton fiber development; the Rac promoter can therefore be useful to drive expression of other genes proposed to affect fiber development and study the effects on the process; 7) The Rac promoter has also been shown to be the best so far tested for use in development of a system for transient transformation of developing cotton fibers, a technique that should have many applications in the field of cotton biotechnology; 8) One candidate protein that may interact with Rac13 to be characterized further in the future is a protein kinase that may be analogous to the PAK kinase that is known to interact with Rac in mammals.

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhao, Bingyu, Saul Burdman, Ronald Walcott, and Gregory E. Welbaum. Control of Bacterial Fruit Blotch of Cucurbits Using the Maize Non-Host Disease Resistance Gene Rxo1. United States Department of Agriculture, September 2013. http://dx.doi.org/10.32747/2013.7699843.bard.

Повний текст джерела

Анотація:

The specific objectives of this BARD proposal were: (1) To determine whether Rxol can recognize AacavrRxo1 to trigger BFB disease resistance in stable transgenic watermelon plants. (2) To determine the distribution of Aac-avrRxo1 in a global population of Aae and to characterize the biological function of Aac-avrRxo1. (3) To characterize other TIS effectors of Aae and to identify plant R gene(s) that can recognize conserved TIS effectors of this pathogen. Background to the topic: Bacterial fruit blotch (BFB) of cucurbits, caused by Acidovorax avenae subsp. citrulli (Aae), is a devastating disease that affects watermelon (Citrullus lanatus) and melon (Cucumis melo) production worldwide, including both Israel and USA. Two major groups of Aae strains have been classified based on their virulence on host plants, genetics and biochemical properties. Thus far, no effective resistance genes have been identified from cucurbit germplasm. In this project, we assessed the applicability of a non-host disease resistance gene, Rxol, to control BFB in watermelon. We also tried to identify Aae type III secreted (TIS) effectors that can be used as molecular probes to identify novel disease resistance genes in both cucurbits and Nieotianatabaeum. Major conclusions, solutions, achievements: We generated five independent transgenic watermelon (cv. Sugar Babay) plants expressing the Rxol gene. The transgenic plants were evaluated with Aae strains AAC001 and M6 under growth chamber conditions. All transgenic plants were found to be susceptible to both Aae strains. It is possible that watermelon is missing other signaling components that are required for Rxol-mediated disease resistance. In order to screen for novel BFB resistance genes, we inoculated two Aae strains on 60 Nieotiana species. Our disease assay revealed Nicotiana tabaeum is completely resistant to Aae, while its wild relative N. benthamiana is susceptible to Aae. We further demonstrated that Nieotiana benthamiana can be used as a surrogate host for studying the mechanisms of pathogenesis of Aae. We cloned 11 TIS effector genes including the avrRxolhomologues from the genomes of 22 Aae strains collected worldwide. Sequencing analysis revealed that functional avrRxol is conserved in group" but not group I Aae strains. Three effector genes- Aave_1548, Aave_2166 and Aave_2708- possessed the ability to trigger an HR response in N. tabacum when they were transiently expressed by Agrobaeterium. We conclude that N. tabacum carries at least three different non-host resistance genes that can specifically recognize AaeTIS effectors to trigger non-host resistance. Screening 522 cucurbits genotypes with two Aae strains led us to identify two germplasm (P1536473 and P1273650) that are partially resistant to Aae. Interestingly, transient expression of the TIS effector, Aave_1548, in the two germplasms also triggered HR-Iike cell death, which suggests the two lines may carry disease resistance genes that can recognize Aave_1548. Importantly, we also demonstrated that this effector contributes to the virulence of the bacterium in susceptible plants. Therefore, R genes that recognize effector Aave1548 have great potential for breeding for BFB resistance. To better understand the genome diversity of Aae strains, we generated a draft genome sequence of the Israeli Aae strain, M6 (Group I) using Iliumina technology. Comparative analysis of whole genomes of AAC001, and M6 allowed us to identify several effectors genes that differentiate groups I and II. Implications, both scientific and agricultural: The diversity of TIS effectors in group I and II strains of Aae suggests that a subset of effectors could contribute to the host range of group I and II Aae strains. Analysis of these key effectors in a larger Aae population may allow us to predict which cucurbit hosts may be at risk to BFB. Additionally, isolation of tobacco and cucurbit Rgenes that can recognize Aae type III effectors may offer new genetic resources for controlling BFB.

Стилі APA, Harvard, Vancouver, ISO та ін.

Lers, Amnon, E. Lomaniec, S. Burd, A. Khalchitski, L. Canetti, and Pamela J. Green. Analysis of Senescence Inducible Ribonuclease in Tomato: Gene Regulation and Function. United States Department of Agriculture, February 2000. http://dx.doi.org/10.32747/2000.7570563.bard.

Повний текст джерела

Анотація:

Natural leaf senescence has a negative influence on yield. Postharvest induced senescence contributes to the losses of quality in flowers, foliage, and vegetables. Strategies designed to control the senescence process in crop plants could therefore have great applied significance. Senescence is regulated by differential gene expression yet, functional characterization of the genes specifically induced and study of their expression control, is still in its infancy. Study of senescence-specific genes is required to allow identification of regulatory elements participating in senescence-induced expression and thus provide insights into the genetic regulation of senescence. A main feature of senescence is the hydrolysis of macromolecules by hydrolases of various types such as RNases and proteases. This study was aimed a analysis of senescence-inducible RNases in tomato with the following objectives: Isolation of senescence-inducible RNase cDNA clones; Expression analyses of RNase genes during senescence; Identification of sequences required for senescence-induced gene expression; Functional analyses of senescence-inducible RNases. We narrowed our aims somewhat to focus on the first three objectives because the budget we were awarded was reduced from that requested. We have expanded our research for identification senescence-related RNase/nuclease activities as we thought it will direct us to new RNase/nuclease genes. We have also carried out research in Arabidopsis and parsley, which enabled us to draw mire general conclusions. We completed the first and second objectives and have made considerable progress on the remaining two. We have defined growth conditions suitable for this research and defined the physiological and biochemical parameters characteristic to the advance of leaf senescence. In tomato and arabidopsis we have focused on natural leaf senescence. Parsley was used mainly for study of postharvest senescence in detached leaves. We have identified a 41-kD a tomato nuclease, LeNUCI, specifically induced during senescence which can degrade both RNA and DNA. This activity could be induced by ethylene in young leaves and was subjected to detailed analysis, which enabled its classification as Nuclease I enzyme. LeNUCI may be involved in nucleic acid metabolism during tomato leaf senescence. In parsley senescing leaves we identified 2 main senescence-related nuclease activities of 41 and 39-kDa. These activities were induced in both naturally or artificially senescing leaves, could degrade both DNA and RNA and were very similar in their characteristics to the LeNUCI. Two senescence-induced RNase cDNAs were cloned from tomato. One RNase cDNA was identical to the tomato LX RNase while the second corresponded to the LE RNase. Both were demonstrated before to be induced following phosphate starvation of tomato cell culture but nothing was known about their expression or function in plants. LX gene expression was much more senescence specific and ethylene could activate it in detached young leaves. LE gene expression, which could be transiently induced by wounding, appeared to be activated by abscisic acid. We suggest that the LX RNase has a role in RNA catabolism in the final stage of senescence, and LE may be a defense-related protein. Transgenic plants were generated for altering LX gene expression. No major visible alterations in the phenotype were observed so far. Detailed analysis of senescence in these plants is performed currently. The LX promoter was cloned and its analysis is performed currently for identification of senescence-specific regulatory elements. In Arabidopsis we have identified and characterized a senescence-associated nuclease 1 gene, BFN1, which is highly expressed during leaf and stem senescence. BFN1, is the first example of a senescence- associated gene encoding a nuclease I enzyme as well as the first nuclease I cloned and characterized from Arabidopsis. Our progress should provide excellent tools for the continued analysis of regulation and function of senescence-inducible ribonucleases and nucleases in plants. The cloned genes can be used in reverse genetic approaches, already initiated, which can yield a more direct evidence for the function of these enzymes. Another contribution of this research will be in respect to the molecular mechanism, which controls senescence. We had already initiated in this project and will continue to identify and characterize regulatory elements involved in senescence-specific expression of the genes isolated in this work.

Стилі APA, Harvard, Vancouver, ISO та ін.

Snyder, Victor A., Dani Or, Amos Hadas, and S. Assouline. Characterization of Post-Tillage Soil Fragmentation and Rejoining Affecting Soil Pore Space Evolution and Transport Properties. United States Department of Agriculture, April 2002. http://dx.doi.org/10.32747/2002.7580670.bard.

Повний текст джерела

Анотація:

Tillage modifies soil structure, altering conditions for plant growth and transport processes through the soil. However, the resulting loose structure is unstable and susceptible to collapse due to aggregate fragmentation during wetting and drying cycles, and coalescense of moist aggregates by internal capillary forces and external compactive stresses. Presently, limited understanding of these complex processes often leads to consideration of the soil plow layer as a static porous medium. With the purpose of filling some of this knowledge gap, the objectives of this Project were to: 1) Identify and quantify the major factors causing breakdown of primary soil fragments produced by tillage into smaller secondary fragments; 2) Identify and quantify the. physical processes involved in the coalescence of primary and secondary fragments and surfaces of weakness; 3) Measure temporal changes in pore-size distributions and hydraulic properties of reconstructed aggregate beds as a function of specified initial conditions and wetting/drying events; and 4) Construct a process-based model of post-tillage changes in soil structural and hydraulic properties of the plow layer and validate it against field experiments. A dynamic theory of capillary-driven plastic deformation of adjoining aggregates was developed, where instantaneous rate of change in geometry of aggregates and inter-aggregate pores was related to current geometry of the solid-gas-liquid system and measured soil rheological functions. The theory and supporting data showed that consolidation of aggregate beds is largely an event-driven process, restricted to a fairly narrow range of soil water contents where capillary suction is great enough to generate coalescence but where soil mechanical strength is still low enough to allow plastic deforn1ation of aggregates. The theory was also used to explain effects of transient external loading on compaction of aggregate beds. A stochastic forInalism was developed for modeling soil pore space evolution, based on the Fokker Planck equation (FPE). Analytical solutions for the FPE were developed, with parameters which can be measured empirically or related to the mechanistic aggregate deformation model. Pre-existing results from field experiments were used to illustrate how the FPE formalism can be applied to field data. Fragmentation of soil clods after tillage was observed to be an event-driven (as opposed to continuous) process that occurred only during wetting, and only as clods approached the saturation point. The major mechanism of fragmentation of large aggregates seemed to be differential soil swelling behind the wetting front. Aggregate "explosion" due to air entrapment seemed limited to small aggregates wetted simultaneously over their entire surface. Breakdown of large aggregates from 11 clay soils during successive wetting and drying cycles produced fragment size distributions which differed primarily by a scale factor l (essentially equivalent to the Van Bavel mean weight diameter), so that evolution of fragment size distributions could be modeled in terms of changes in l. For a given number of wetting and drying cycles, l decreased systematically with increasing plasticity index. When air-dry soil clods were slightly weakened by a single wetting event, and then allowed to "age" for six weeks at constant high water content, drop-shatter resistance in aged relative to non-aged clods was found to increase in proportion to plasticity index. This seemed consistent with the rheological model, which predicts faster plastic coalescence around small voids and sharp cracks (with resulting soil strengthening) in soils with low resistance to plastic yield and flow. A new theory of crack growth in "idealized" elastoplastic materials was formulated, with potential application to soil fracture phenomena. The theory was preliminarily (and successfully) tested using carbon steel, a ductile material which closely approximates ideal elastoplastic behavior, and for which the necessary fracture data existed in the literature.

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhang, Renduo, and David Russo. Scale-dependency and spatial variability of soil hydraulic properties. United States Department of Agriculture, November 2004. http://dx.doi.org/10.32747/2004.7587220.bard.

Повний текст джерела

Анотація:

Water resources assessment and protection requires quantitative descriptions of field-scale water flow and contaminant transport through the subsurface, which, in turn, require reliable information about soil hydraulic properties. However, much is still unknown concerning hydraulic properties and flow behavior in heterogeneous soils. Especially, relationships of hydraulic properties changing with measured scales are poorly understood. Soil hydraulic properties are usually measured at a small scale and used for quantifying flow and transport in large scales, which causes misleading results. Therefore, determination of scale-dependent and spatial variability of soil hydraulic properties provides the essential information for quantifying water flow and chemical transport through the subsurface, which are the key processes for detection of potential agricultural/industrial contaminants, reduction of agricultural chemical movement, improvement of soil and water quality, and increase of agricultural productivity. The original research objectives of this project were: 1. to measure soil hydraulic properties at different locations and different scales at large fields; 2. to develop scale-dependent relationships of soil hydraulic properties; and 3. to determine spatial variability and heterogeneity of soil hydraulic properties as a function of measurement scales. The US investigators conducted field and lab experiments to measure soil hydraulic properties at different locations and different scales. Based on the field and lab experiments, a well-structured database of soil physical and hydraulic properties was developed. The database was used to study scale-dependency, spatial variability, and heterogeneity of soil hydraulic properties. An improved method was developed for calculating hydraulic properties based on infiltration data from the disc infiltrometer. Compared with the other methods, the proposed method provided more accurate and stable estimations of the hydraulic conductivity and macroscopic capillary length, using infiltration data collected atshort experiment periods. We also developed scale-dependent relationships of soil hydraulic properties using the fractal and geostatistical characterization. The research effort of the Israeli research team concentrates on tasks along the second objective. The main accomplishment of this effort is that we succeed to derive first-order, upscaled (block effective) conductivity tensor, K'ᵢⱼ, and time-dependent dispersion tensor, D'ᵢⱼ, i,j=1,2,3, for steady-state flow in three-dimensional, partially saturated, heterogeneous formations, for length-scales comparable with those of the formation heterogeneity. Numerical simulations designed to test the applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots suggested that even in this complicated case, the upscaling methodology essentially compensated for the loss of sub-grid-scale variations of the velocity field caused by coarse discretization of the flow domain. These results have significant implications with respect to the development of field-scale solute transport models capable of simulating complex real-world scenarios in the subsurface, and, in turn, are essential for the assessment of the threat posed by contamination from agricultural and/or industrial sources.

Стилі APA, Harvard, Vancouver, ISO та ін.

Meir, Shimon, Michael S. Reid, Cai-Zhong Jiang, Amnon Lers, and Sonia Philosoph-Hadas. Molecular Studies of Postharvest Leaf and Flower Senescence. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592657.bard.

Повний текст джерела

Анотація:

Original objectives: To understand the regulation of abscission by exploring the nature of changes of auxin-related gene expression in tomato (Lycopersicon esculatumMill) abscission zones (AZs) following organ removal, and by analyzing the function of these genes. Our specific goals were: 1) To complete the microarray analyses in tomato flower and leaf AZs, for identifying genes whose expression changes early in response to auxin depletion; 2) To examine, using virus-induced gene silencing (VIGS), the effect of silencing target genes on ethylene sensitivity and abscission competence of the leaf and flower AZs; 3) To isolate and characterize promoters from AZ-specific genes to be used in functional analysis; 4) To generate stable transgenic tomato plants with selected genes silenced with RNAi, under the control of an AZ-specific promoter, for further characterization of their abscission phenotypes. Background: Abscission, the separation of organs from the parent plant, results in postharvest quality loss in many ornamentals and other fresh produce. The process is initiated by changes in the auxin gradient across the AZ, and is triggered by ethylene. Although changes in gene expression have been correlated with the ethylene-mediated execution of abscission, there is almost no information on the initiation of the abscission process, as the AZ becomes sensitized to ethylene. The present project was focused on elucidating these early molecular regulatory events, in order to gain a better control of the abscission process for agricultural manipulations. Major conclusions, solutions, achievements: Microarray analyses, using the Affymetrix Tomato GeneChip®, revealed changes in expression, occurring early in abscission, of many genes with possible regulatory functions. These included a range of auxin- and ethylene-related transcription factors (TFs), other TFs that are transiently induced just after flower removal, and a set of novel AZ-specific genes. We also identified four different defense-related genes, including: Cysteine-type endopeptidase, α- DOX1, WIN2, and SDF2, that are newly-associated with the late stage of the abscission process. This supports the activation of different defense responses and strategies at the late abscission stages, which may enable efficient protection of the exposed tissue toward different environmental stresses. To facilitate functional studies we implemented an efficient VIGS system in tomato, and isolated two abscission-specific promoters (pTAPG1 and pTAPG4) for gene silencing in stable transformation. Using the VIGS system we could demonstrate the importance of TAPGs in abscission of tomato leaf petioles, and evaluated the importance of more than 45 genes in abscission. Among them we identified few critical genes involved in leaf and flower abscission. These included: PTRP-F1, PRP, TKN4, KNOTTED-like homeobox TF, KD1, and KNOX-like homeodomain protein genes, the silencing of which caused a striking retardation of pedicel abscission, and ERF1, ERF4, Clavata-like3 protein, Sucrose transporter protein, and IAA10 genes, the silencing of which delayed petiole abscission. The importance of PRPand KD1 genes in abscission was confirmed also by antisense–silencing using pTAPG4. Experiments testing the effects of RNAi silencing of few other genes are still in progress, The analysis of the microarray results of flower and leaf AZs allowed us to establish a clear sequence of events occurring during acquisition of tissue sensitivity to ethylene, and to confirm our hypothesis that acquisition of ethylene sensitivity in the AZ is associated with altered expression of auxin-regulated genes in both AZs. Implication, both scientific and agricultural: Our studies had provided new insights into the regulation of the abscission process, and shaded light on the molecular mechanisms that drive the acquisition of abscission competence in the AZ. We pointed out some critical genes involved in regulation of abscission, and further expanded our knowledge of auxin-ethylene cross talk during the abscission process. This permits the development of novel techniques for manipulating abscission, and thereby improving the postharvest performance of ornamentals and other crops.

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!