DISSIPATION PATTERN OF BIFENTHRIN IN TOMATO
Ravi Kumar Katroju; Sreenivasa Rao Cherukuri; Shashi Bushan Vemuri; Narasimha Reddy K
2014-01-01
Field experiment carried out during kharif, 2012 to evaluate the dissipation pattern of most commonly used insecticide bifenthrin 10 EC @ 100 g a.i. ha-1 with two sprays of insecticide first given after fruit initiation and the second spray 10 days later and collecting the fruits at 0, 1, 3, 5, 7, 10, 15, 20 days after last spray, and analysed for residues using the validated QuEChERS method. The initial deposits of bifenthrin were 0.85 mg kg-1 which dissipated to 0.39, 0.15 mg kg-1 by 1st an...
Patterns and Interfaces in Dissipative Dynamics
Pismen, L.M
2006-01-01
Spontaneous pattern formation in nonlinear dissipative systems far from equilibrium is a paradigmatic case of emergent behaviour associated with complex systems. It is encountered in a great variety of settings, both in nature and technology, and has numerous applications ranging from nonlinear optics through solid and fluid mechanics, physical chemistry and chemical engineering to biology. Nature creates its variety of forms through spontaneous pattern formation and self-assembly, and this strategy is likely to be imitated by future biomorphic technologies. This book is a first-hand account by one of the leading players in this field, which gives in-depth descriptions of analytical methods elucidating the complex evolution of nonlinear dissipative systems, and brings the reader to the forefront of current research. The introductory chapter on the theory of dynamical systems is written with a view to applications of its powerful methods to spatial and spatio-temporal patterns. It is followed by two chapters t...
Bifurcations and Patterns in Nonlinear Dissipative Systems
Guenter Ahlers
2005-05-27
This project consists of experimental investigations of heat transport, pattern formation, and bifurcation phenomena in non-linear non-equilibrium fluid-mechanical systems. These issues are studies in Rayleigh-B\\'enard convection, using both pure and multicomponent fluids. They are of fundamental scientific interest, but also play an important role in engineering, materials science, ecology, meteorology, geophysics, and astrophysics. For instance, various forms of convection are important in such diverse phenomena as crystal growth from a melt with or without impurities, energy production in solar ponds, flow in the earth's mantle and outer core, geo-thermal stratifications, and various oceanographic and atmospheric phenomena. Our work utilizes computer-enhanced shadowgraph imaging of flow patterns, sophisticated digital image analysis, and high-resolution heat transport measurements.
Dissipative inertial transport patterns near coherent Lagrangian eddies in the ocean.
Beron-Vera, Francisco J; Olascoaga, María J; Haller, George; Farazmand, Mohammad; Triñanes, Joaquín; Wang, Yan
2015-08-01
Recent developments in dynamical systems theory have revealed long-lived and coherent Lagrangian (i.e., material) eddies in incompressible, satellite-derived surface ocean velocity fields. Paradoxically, observed drifting buoys and floating matter tend to create dissipative-looking patterns near oceanic eddies, which appear to be inconsistent with the conservative fluid particle patterns created by coherent Lagrangian eddies. Here, we show that inclusion of inertial effects (i.e., those produced by the buoyancy and size finiteness of an object) in a rotating two-dimensional incompressible flow context resolves this paradox. Specifically, we obtain that anticyclonic coherent Lagrangian eddies attract (repel) negatively (positively) buoyant finite-size particles, while cyclonic coherent Lagrangian eddies attract (repel) positively (negatively) buoyant finite-size particles. We show how these results explain dissipative-looking satellite-tracked surface drifter and subsurface float trajectories, as well as satellite-derived Sargassum distributions.
Coalbed methane accumulation and dissipation patterns: A Case study of the Junggar Basin, NW China
Li, Xin; Fu, Xuehai; Yang, Xuesong; Ge, Yanyan; Quan, Fangkai
2018-07-01
The Junggar Basin is a potential replacement area of coalbed methane (CBM) development in China. To improve the efficiency of CBM exploration, we investigated CBM accumulation and dissipation patterns of coal profiles located in the northwestern, southern, eastern, and central Junggar Basin based on the following criteria: burial depth, hydrogeological zone, CBM origin, CBM phase, and CBM migration type. We identified four types of CBM accumulation patterns: (1) a self-sourcing CBM pattern containing adsorbed gas of biogenic origin from shallow-depth coal within a weak runoff zone; (2) an endogenic migration pattern containing adsorbed gas of thermogenic origin from the medium and deep coals within a stagnant zone; (3) an exogenic migration pattern containing adsorbed gas of thermogenic origin from deep coal within a stagnant zone; and (4) an exogenic migration pattern containing adsorbed and free gas of thermogenic origin from ultra-deep coal within a stagnant zone. We also identified two types of CBM dissipation patterns: (1) shallow-depth coal within a runoff zone with mixed origin CBM; and (2) shallow and medium-deep coal seams with mixed origin CBM. CBM migration in low-rank coals was more substantial than that adsorbed in high-rank coal. CBM in shallow coal could easily escape, in the absence of closed structures or hydrogeological seals. CBM reservoirs occurred in deep coal where oversaturated gas may accumulate. Future exploration should focus on gas-water sealing structures in shallow coalbeds. CBM that occurred in adsorbed and free phases and other unconventional natural gas dominated by free gas in the coal stratum should be co-explored and co-developed.
Self-Organized Patterns in Gas-Discharge: Particle-Like Behaviour and Dissipative Solitons
Purwins, H.-G.
2008-01-01
The understanding of self-organise patterns in spatially extended nonlinear dissipative systems (SOPs) is one of the most challenging subjects in modern natural sciences. In the last 20 years it turned out that research in the field of low temperature gas-discharge can help to obtain insight into important aspect of SOPs. At the same time, due to the practical relevance of plasma systems one might expect interesting applications. In the present paper the focus is on self-organised filamentary patterns in planar dc and ac systems with high ohmic and dielectric barrier, respectively. - In the discharge plane of these systems filaments show up as spots which are also referred to as dissipative solitons (DSs). In many respect experimentally detected DSs exhibit particle-like behaviour. Among other things, isolated stationary or travelling DSs, stationary, travelling or rotating 'molecules' and various kinds of many-body systems have been observed. Also scattering, generation and annihilation of DSs are frequent phenomena. - At least some of these patterns can be described quantitatively in terms of a drift diffusion model. It is also demonstrated that a simple reaction diffusion model allows for an intuitive understanding of many of the observed phenomena. At the same time this model is the basis for a theoretical foundation of the particle picture and the experimentally observed universal behaviour of SOPs. - Finally some hypothetical applications are discussed
Dissipative neurodynamics in perception forms cortical patterns that are stabilized by vortices
Freeman, Walter J.; Vitiello, Giuseppe
2009-06-01
In the engagement of the brain with its environment, large-scale neural interactions in brain dynamics create a mesoscopic order parameter, which is evaluated by measuring brain waves (electrocorticogram, ECoG). Such large-scale interactions emerge from the background activity of the brain that is sustained by mutual excitation in cortical populations and manifest in spatiotemporal patterns of neural activity. Band pass filtering reveals beats in ECoG power that recur at theta rates (3-7 Hz) as null spikes in log10 power. The order parameter transiently approaches zero, and the microscopic activity is both disordered and symmetric. As the null spikes terminate, the order parameter resurges and imposes a mesoscopic spatial pattern of ECoG amplitude modulation that then governs the microscopic gamma activity and retrieves the memory of a stimulus. The brain waves reveal a spatial pattern of phase modulation in the form of a cone. The dissipative many-body model of brain dynamics describes these phase cones as vortices, which are initiated by the null spikes, and which stabilize the amplitude modulated patterns embedded in the turbulent neural noise from which they emerge.
Dissipative neurodynamics in perception forms cortical patterns that are stabilized by vortices
Freeman, Walter J; Vitiello, Giuseppe
2009-01-01
In the engagement of the brain with its environment, large-scale neural interactions in brain dynamics create a mesoscopic order parameter, which is evaluated by measuring brain waves (electrocorticogram, ECoG). Such large-scale interactions emerge from the background activity of the brain that is sustained by mutual excitation in cortical populations and manifest in spatiotemporal patterns of neural activity. Band pass filtering reveals beats in ECoG power that recur at theta rates (3-7 Hz) as null spikes in log 10 power. The order parameter transiently approaches zero, and the microscopic activity is both disordered and symmetric. As the null spikes terminate, the order parameter resurges and imposes a mesoscopic spatial pattern of ECoG amplitude modulation that then governs the microscopic gamma activity and retrieves the memory of a stimulus. The brain waves reveal a spatial pattern of phase modulation in the form of a cone. The dissipative many-body model of brain dynamics describes these phase cones as vortices, which are initiated by the null spikes, and which stabilize the amplitude modulated patterns embedded in the turbulent neural noise from which they emerge.
NMR spin relaxation in proteins: The patterns of motion that dissipate power to the bath
Shapiro, Yury E., E-mail: eva.meirovitch@biu.ac.il, E-mail: yuryeshapiro@gmail.com; Meirovitch, Eva, E-mail: eva.meirovitch@biu.ac.il, E-mail: yuryeshapiro@gmail.com [The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900-02 (Israel)
2014-04-21
We developed in recent years the two-body coupled-rotator slowly relaxing local structure (SRLS) approach for the analysis of NMR relaxation in proteins. The two bodies/rotators are the protein (diffusion tensor D{sub 1}) and the spin-bearing probe, e.g., the {sup 15}N−{sup 1}H bond (diffusion tensor, D{sub 2}), coupled by a local potential (u). A Smoluchowski equation is solved to yield the generic time correlation functions (TCFs), which are sums of weighted exponentials (eigenmodes). By Fourier transformation one obtains the generic spectral density functions (SDFs) which underlie the experimental relaxation parameters. The typical paradigm is to characterize structural dynamics in terms of the best-fit values of D{sub 1}, D{sub 2}, and u. Additional approaches we pursued employ the SRLS TCFs, SDFs, or eigenmodes as descriptors. In this study we develop yet another perspective. We consider the SDF as function of the angular velocity associated with the fluctuating fields underlying NMR relaxation. A parameter called j-fraction, which represents the relative contribution of eigenmode, i, to a given value of the SDF function at a specific frequency, ω, is defined. j-fraction profiles of the dominant eigenmodes are derived for 0 ≤ ω ≤ 10{sup 12} rad/s. They reveal which patterns of motion actuate power dissipation at given ω-values, what are their rates, and what is their relative contribution. Simulations are carried out to determine the effect of timescale separation, D{sub 1}/D{sub 2}, axial potential strength, and local diffusion axiality. For D{sub 1}/D{sub 2} ≤ 0.01 and strong local potential of 15 k{sub B}T, power is dissipated by global diffusion, renormalized (by the strong potential) local diffusion, and probe diffusion on the surface of a cone (to be called cone diffusion). For D{sub 1}/D{sub 2} = 0.1, power is dissipated by mixed eigenmodes largely of a global-diffusion-type or cone-diffusion-type, and a nearly bare renormalized
Print-to-pattern dry film photoresist lithography
Garland, Shaun P; Murphy, Terrence M Jr; Pan, Tingrui
2014-01-01
Here we present facile microfabrication processes, referred to as print-to-pattern dry film photoresist (DFP) lithography, that utilize the combined advantages of wax printing and DFP to produce micropatterned substrates with high resolution over a large surface area in a non-cleanroom setting. The print-to-pattern methods can be performed in an out-of-cleanroom environment making microfabrication much more accessible to minimally equipped laboratories. Two different approaches employing either wax photomasks or wax etchmasks from a solid ink desktop printer have been demonstrated that allow the DFP to be processed in a negative tone or positive tone fashion, respectively, with resolutions of 100 µm. The effect of wax melting on resolution and as a bonding material was also characterized. In addition, solid ink printers have the capacity to pattern large areas with high resolution, which was demonstrated by stacking DFP layers in a 50 mm × 50 mm woven pattern with 1 mm features. By using an office printer to generate the masking patterns, the mask designs can be easily altered in a graphic user interface to enable rapid prototyping. (technical note)
Special Pattern of Hydraulic Dissipation System used for Isolation of Bridges against Earthquakes
Fanel Dorel Scheaua
2017-11-01
Full Text Available The construction sector experienced a constant evolution over time, so that today structures can be made to withstand earthquakes of considerable magnitude. This can be achieved by using various methods to counteract the direct earthquake destructive action on the construction. The methods consist of using insulation systems or earthquake energy dissipation devices that have occurred in time, being in constant development and improvement. In this paper it is presented a model of a hydraulic dissipation device as an assembly of a linear motor with fluid, which can be mounted to the structural frame of a bridge, in order to take some of the earthquake energy when it occurs, so that the bridge superstructure is protected against from high magnitude damages
Shabeer T P, Ahammed; Girame, Rushali; Hingmire, Sandip; Banerjee, Kaushik; Sharma, Ajay Kumar; Oulkar, Dasharath; Utture, Sagar; Jadhav, Manjusha
2015-02-01
A residue analysis method was validated for trace level estimation of pyraclostrobin by liquid chromatography-mass spectrometry and metiram (analyzed as CS2) by gas chromatography mass spectrometry in grapes and raisin matrix. Dissipation of their residues and processing factors (PFs) during raisin making were evaluated through field studies with applications at single dose (SD) and double dose (DD). Residue data during drying process were best fitted to first + first-order kinetics model giving half-life ranging between 6 and 7 days for pyroclostrobin and 4 days for metiram. PFs for metiram and pyraclostrobin related to washing and oil dipping were 0.47 and 0.41, and 0.78 and 0.63 at single dose (SD) and double dose (DD), respectively. PF value of >1 for drying (1.01 and 1.31 for metiram and 1.34 and 1.10 for pyraclostrobin) indicates concentration of the residues during the drying process. The dietary exposure corresponding to average daily consumption of 0.0043 kg raisin per day on each sampling day was less than the respective maximum permissible intake at both the doses.
Buddidathi, Radhika; Mohapatra, Soudamini; Siddamallaiah, Lekha; Manikrao, Gourishankar; Hebbar, Shibara Shankara
2016-01-01
This investigation was undertaken to compare the dissipation pattern of flubendiamide in capsicum fruits under poly-house and open field after giving spray applications at the recommended and double doses of 48 g a.i. ha(-1) and 96 g a.i. ha(-1). Extraction and purification of capsicum fruit samples were carried out by the QuEChERS method. Residues of flubendiamide and its metabolite, des-iodo flubendiamide, were analyzed by high-performance liquid chromatography-photodiode array, and confirmed by liquid chromatography-mass spectrometry/mass spectrometry. Limit of quantification of the method was 0.05 mg kg(-1), and recovery of the insecticides was in the range of 89.6-104.3%, with relative standard deviation being 4.5-11.5%. The measurement uncertainty of the analytical method was in the range of 10.7-15.7%. Initial residue deposits of flubendiamide on capsicum fruits grown under poly-house conditions were (0.977 and 1.834 mg kg(-1)) higher than that grown in the field (0.665 and 1.545 mg kg(-1)). Flubendiamide residues persisted for 15 days in field-grown and for 25 days in poly-house-grown capsicum fruits. The residues were degraded with the half-lives of 4.3-4.7 and 5.6-6.6 days in field and poly-house respectively. Des-iodo flubendiamide was not detected in capsicum fruits or soil. The residues of flubendiamide degraded to below the maximum residue limit notified by Codex Alimentarius Commission (FAO/WHO) after 1 and 6 days in open field, and 3 and 10 days in poly-house. The results of the study indicated that flubendiamide applied to capsicum under controlled environmental conditions required longer pre-harvest interval to allow its residues to dissipate to the safe level.
Standing crop dry matter accumulation and quality patterns of ...
Nine-week production curves and quality values of eight subtropical pasture species were studied under supplemental spray irrigation to characterize their productive capacity, periodicity and quality.All species exhibited a slow dry matter regrowth rate for two to three weeks after defoliation to 7,5 or 10 cm height. Thereafter ...
Dotov, D G; Kim, S; Frank, T D
2015-02-01
We derive explicit expressions for the non-equilibrium thermodynamical variables of a canonical-dissipative limit cycle oscillator describing rhythmic motion patterns of active systems. These variables are statistical entropy, non-equilibrium internal energy, and non-equilibrium free energy. In particular, the expression for the non-equilibrium free energy is derived as a function of a suitable control parameter. The control parameter determines the Hopf bifurcation point of the deterministic active system and describes the effective pumping of the oscillator. In analogy to the equilibrium free energy of the Landau theory, it is shown that the non-equilibrium free energy decays as a function of the control parameter. In doing so, a similarity between certain equilibrium and non-equilibrium phase transitions is pointed out. Data from an experiment on human rhythmic movements is presented. Estimates for pumping intensity as well as the thermodynamical variables are reported. It is shown that in the experiment the non-equilibrium free energy decayed when pumping intensity was increased, which is consistent with the theory. Moreover, pumping intensities close to zero could be observed at relatively slow intended rhythmic movements. In view of the Hopf bifurcation underlying the limit cycle oscillator model, this observation suggests that the intended limit cycle movements were actually more similar to trajectories of a randomly perturbed stable focus. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Survey of Ophthalmologists Regarding Practice Patterns for Dry Eye and Sjogren Syndrome.
Bunya, Vatinee Y; Fernandez, Karen B; Ying, Gui-Shuang; Massaro-Giordano, Mina; Macchi, Ilaria; Sulewski, Michael E; Hammersmith, Kristin M; Nagra, Parveen K; Rapuano, Christopher J; Orlin, Stephen E
2018-01-15
To survey ophthalmologists about current practice patterns regarding the evaluation of dry eye patients and referrals for a Sjogren syndrome (SS) workup. An online survey was sent to ophthalmologists affiliated with the Scheie Eye Institute or Wills Eye Hospital using REDCap in August 2015. Descriptive statistics were used to summarize the data. Four hundred seventy-four survey invitations were sent out and 101 (21%) ophthalmologists completed the survey. The common traditional dry eye test performed was corneal fluorescein staining (62%) and the most common newer dry eye test performed was tear osmolarity (18%). Half of respondents (51%) refer fewer than 5% of their dry eye patients for SS workups, with 18% reporting that they never refer any patients. The most common reasons for referrals included positive review of systems (60%), severe dry eye symptoms (51%) or ocular signs (47%), or dry eye that is refractory to treatment (42%). The majority (83%) felt that there is a need for an evidence-based standardized screening tool for dry eye patients to decide who should be referred for evaluation for SS. Ophthalmologists continue to prefer the use of traditional dry eye tests in practice, with the most common test being corneal fluorescein staining. There is an underreferral of dry eye patients for SS workups, which is contributing to the continued underdiagnosis of the disease. Most respondents felt that there was a need for an evidence-based standardized screening tool to decide which dry eye patients should be referred for SS evaluations.
Gecko Adhesion on Wet and Dry Patterned Substrates.
Alyssa Y Stark
Full Text Available Perhaps one of the most astounding characteristics of the gecko adhesive system is its versatility. Geckos can locomote across complex substrates in a variety of conditions with apparent ease. In contrast, many of our synthetic pressure sensitive adhesives fail on substrates that are dirty, wet or rough. Although many studies have investigated the effect of environmental challenges on performance, the interaction of multiple, potentially compromising variables is studied less often. Here we focus on substrate structure and surface water, both of which are highly relevant to the biological system and to synthetic design. To do this we utilized a highly controlled, patterned substrate (Sharklet®, by Sharklet® Technologies Inc.. This allowed us to test independently and jointly the effects of reduced surface area substrates, with a defined pattern, on adhesion in both air and water. Our results show that adhesion is not significantly impaired in air, whereas surface area and pattern significantly affect adhesion in water. These findings highlight the need to study multiple parameters that are relevant to the gecko adhesive system to further improve our understanding of the biological system and to design better, more versatile synthetics.
Stonecipher KG
2013-10-01
Full Text Available Karl G Stonecipher,1 Jenny Chia,2 Ahunna Onyenwenyi,2 Linda Villanueva,2 David A Hollander2 1TLC Laser Eye Centers, Greensboro, NC, 2Allergan, Inc., Irvine, CA, USA Background: Dry eye is a multifactorial, symptomatic disease associated with ocular surface inflammation and tear film hyperosmolarity. This study was designed to assess patterns of topical cyclosporine ophthalmic emulsion 0.05% (Restasis® use in dry eye patients and determine if there were any differences in use based on whether dry eye is physician-coded as a primary or nonprimary diagnosis. Methods: Records for adult patients with a diagnosis of dry eye at an outpatient visit from January 1, 2008 to December 31, 2009 were selected from Truven Health MarketScan® Research Databases. The primary endpoint was percentage of patients with at least one primary versus no primary dry eye diagnosis who filled a topical cyclosporine prescription. Data analyzed included utilization of topical corticosteroids, oral tetracyclines, and punctal plugs. Results: The analysis included 576,416 patients, accounting for 875,692 dry eye outpatient visits: 74.7% were female, 64.2% were ages 40-69 years, and 84.4% had at least one primary dry eye diagnosis. During 2008–2009, 15.9% of dry eye patients with a primary diagnosis versus 6.5% with no primary diagnosis filled at least one cyclosporine prescription. For patients who filled at least one prescription, the mean months’ supply of cyclosporine filled over 12 months was 4.44. Overall, 33.9% of dry eye patients filled a prescription for topical cyclosporine, topical corticosteroid, or oral tetracycline over 2 years. Conclusion: Patients with a primary dry eye diagnosis were more likely to fill a topical cyclosporine prescription. Although inflammation is key to the pathophysiology of dry eye, most patients seeing a physician for dry eye may not receive anti-inflammatory therapies. Keywords: corticosteroids, cyclosporine, dry eye syndromes
Stonecipher, Karl G; Chia, Jenny; Onyenwenyi, Ahunna; Villanueva, Linda; Hollander, David A
2013-01-01
Background Dry eye is a multifactorial, symptomatic disease associated with ocular surface inflammation and tear film hyperosmolarity. This study was designed to assess patterns of topical cyclosporine ophthalmic emulsion 0.05% (Restasis®) use in dry eye patients and determine if there were any differences in use based on whether dry eye is physician-coded as a primary or nonprimary diagnosis. Methods Records for adult patients with a diagnosis of dry eye at an outpatient visit from January 1, 2008 to December 31, 2009 were selected from Truven Health MarketScan® Research Databases. The primary endpoint was percentage of patients with at least one primary versus no primary dry eye diagnosis who filled a topical cyclosporine prescription. Data analyzed included utilization of topical corticosteroids, oral tetracyclines, and punctal plugs. Results The analysis included 576,416 patients, accounting for 875,692 dry eye outpatient visits: 74.7% were female, 64.2% were ages 40–69 years, and 84.4% had at least one primary dry eye diagnosis. During 2008–2009, 15.9% of dry eye patients with a primary diagnosis versus 6.5% with no primary diagnosis filled at least one cyclosporine prescription. For patients who filled at least one prescription, the mean months’ supply of cyclosporine filled over 12 months was 4.44. Overall, 33.9% of dry eye patients filled a prescription for topical cyclosporine, topical corticosteroid, or oral tetracycline over 2 years. Conclusion Patients with a primary dry eye diagnosis were more likely to fill a topical cyclosporine prescription. Although inflammation is key to the pathophysiology of dry eye, most patients seeing a physician for dry eye may not receive anti-inflammatory therapies. PMID:24179335
Stonecipher, Karl G; Chia, Jenny; Onyenwenyi, Ahunna; Villanueva, Linda; Hollander, David A
2013-01-01
Dry eye is a multifactorial, symptomatic disease associated with ocular surface inflammation and tear film hyperosmolarity. This study was designed to assess patterns of topical cyclosporine ophthalmic emulsion 0.05% (Restasis®) use in dry eye patients and determine if there were any differences in use based on whether dry eye is physician-coded as a primary or nonprimary diagnosis. Records for adult patients with a diagnosis of dry eye at an outpatient visit from January 1, 2008 to December 31, 2009 were selected from Truven Health MarketScan® Research Databases. The primary endpoint was percentage of patients with at least one primary versus no primary dry eye diagnosis who filled a topical cyclosporine prescription. Data analyzed included utilization of topical corticosteroids, oral tetracyclines, and punctal plugs. The analysis included 576,416 patients, accounting for 875,692 dry eye outpatient visits: 74.7% were female, 64.2% were ages 40-69 years, and 84.4% had at least one primary dry eye diagnosis. During 2008-2009, 15.9% of dry eye patients with a primary diagnosis versus 6.5% with no primary diagnosis filled at least one cyclosporine prescription. For patients who filled at least one prescription, the mean months' supply of cyclosporine filled over 12 months was 4.44. Overall, 33.9% of dry eye patients filled a prescription for topical cyclosporine, topical corticosteroid, or oral tetracycline over 2 years. Patients with a primary dry eye diagnosis were more likely to fill a topical cyclosporine prescription. Although inflammation is key to the pathophysiology of dry eye, most patients seeing a physician for dry eye may not receive anti-inflammatory therapies.
Stonecipher, Karl G; Chia, Jenny; Onyenwenyi, Ahunna; Villanueva, Linda; Hollander, David A
2013-01-01
Karl G Stonecipher,1 Jenny Chia,2 Ahunna Onyenwenyi,2 Linda Villanueva,2 David A Hollander2 1TLC Laser Eye Centers, Greensboro, NC, 2Allergan, Inc., Irvine, CA, USA Background: Dry eye is a multifactorial, symptomatic disease associated with ocular surface inflammation and tear film hyperosmolarity. This study was designed to assess patterns of topical cyclosporine ophthalmic emulsion 0.05% (Restasis®) use in dry eye patients and determine if there were any differences in use based o...
Seasonal Patterns of Dry Deposition at a High-Elevation Site in the Colorado Rocky Mountains
Oldani, Kaley M.; Mladenov, Natalie; Williams, Mark W.; Campbell, Cari M.; Lipson, David A.
2017-10-01
In the Colorado Rocky Mountains, high-elevation barren soils are deficient in carbon (C) and phosphorus (P) and enriched in nitrogen (N). The seasonal variability of dry deposition and its contributions to alpine elemental budgets is critical to understanding how dry deposition influences biogeochemical cycling in high-elevation environments. In this 2 year study, we evaluated dry and wet deposition inputs to the Niwot Ridge Long Term Ecological Research (NWT LTER) site in the Colorado Rocky Mountains. The total organic C flux in wet + dry (including soluble and particulate C) deposition was >30 kg C ha-1 yr-1 and represents a substantial input for this C-limited environment. Our side-by-side comparison of dry deposition collectors with and without marble insert indicated that the insert improved retention of dry deposition by 28%. Annual average dry deposition fluxes of water-soluble organic carbon (4.25 kg C ha-1 yr-1) and other water-soluble constituents, including ammonium (0.16 kg NH4+ha-1 yr-1), nitrate (1.99 kg NO3- ha-1 yr-1), phosphate (0.08 kg PO43- ha-1 yr-1), and sulfate (1.20 kg SO42- ha-1 yr-1), were comparable to those in wet deposition, with highest values measured in the summer. Backward trajectory analyses implicate air masses passing through the arid west and Four Corners, USA, as dominant source areas for dry deposition, especially in spring months. Synchronous temporal patterns of deposition observed at the NWT LTER site and a distant Rocky Mountain National Park Clean Air Status and Trends Network site indicate that seasonal dry deposition patterns are regional phenomena with important implications for the larger Rocky Mountain region.
Vischer, D. L; Hager, Willi H; Hager, W. H
1995-01-01
.... the book comprises chapters in farious fields such as hydraulic jump, stilling basins, ski jumps and plunge pools but introduces also a general account on various methods of dissipation, as well...
Ransijn, Johannes; Damgaard, Christian; Schmidt, Inger K
2015-01-01
Plant community patterns in space and time may be explained by the interactions between competing plant species. The presented study investigates this in a nutrient and species poor ecosystem. The study presents a methodology for inferring competitive interactions from yearly vegetation inventories...... to predict the community dynamics of C. vulgaris and D. flexuosa. This was compared with the observed plant community structure at 198 Danish dry heathland sites. Interspecific competition will most likely lead to competitive exclusion of D. flexuosa at the observed temporal and spatial scale...... and uses this to assess the outcome of competitive interactions and to predict community patterns and dynamics in a Northwest-European dry heathland. Inferred competitive interactions from five consecutive years of measurements in permanent vegetation frames at a single dry heathland site were used...
Pan, Rong; Chen, Hong-Ping; Zhang, Ming-Lu; Wang, Qing-Hua; Jiang, Ying; Liu, Xin
2015-01-01
Residue levels of dimethoate and its oxon metabolite (omethoate) during tea planting, manufacturing, and brewing were investigated using a modified QuEChERS sample preparation and gas chromatography. Dissipation of dimethoate and its metabolite in tea plantation followed the first-order kinetic with a half-life of 1.08–1.27 d. Tea manufacturing has positive effects on dimethoate dissipation. Processing factors of dimethoate are in the range of 2.11–2.41 and 1.41–1.70 during green tea and black tea manufacturing, respectively. Omethoate underwent generation as well as dissipation during tea manufacturing. Sum of dimethoate and omethoate led to a large portion of 80.5–84.9% transferring into tea infusion. Results of safety evaluation indicated that omethoate could bring higher human health risk than dimethoate due to its higher hazard quotient by drinking tea. These results would provide information for the establishment of maximum residue limit and instruction for the application of dimethoate formulation on tea crop. PMID:26406463
Rong Pan
Full Text Available Residue levels of dimethoate and its oxon metabolite (omethoate during tea planting, manufacturing, and brewing were investigated using a modified QuEChERS sample preparation and gas chromatography. Dissipation of dimethoate and its metabolite in tea plantation followed the first-order kinetic with a half-life of 1.08-1.27 d. Tea manufacturing has positive effects on dimethoate dissipation. Processing factors of dimethoate are in the range of 2.11-2.41 and 1.41-1.70 during green tea and black tea manufacturing, respectively. Omethoate underwent generation as well as dissipation during tea manufacturing. Sum of dimethoate and omethoate led to a large portion of 80.5-84.9% transferring into tea infusion. Results of safety evaluation indicated that omethoate could bring higher human health risk than dimethoate due to its higher hazard quotient by drinking tea. These results would provide information for the establishment of maximum residue limit and instruction for the application of dimethoate formulation on tea crop.
DeSimone, A.; Kružík, Martin
2013-01-01
Roč. 8, č. 2 (2013), s. 481-499 ISSN 1556-1801 R&D Projects: GA ČR(CZ) GAP201/12/0671 Institutional support: RVO:67985556 Keywords : hysteresis * shape memory Subject RIV: BA - General Mathematics Impact factor: 0.952, year: 2013 http://library.utia.cas.cz/separaty/2013/MTR/kruzik-domain patterns and hysteresis in phase-transforming solids analysis and numerical simulations of a sharp interface dissipative model via phase-field approximation.pdf
Y. Zeng
2009-06-01
Full Text Available Located in western Inner Mongolia, the Badain Jaran Desert is the second largest desert in China and consists of a regular series of stable megadunes, among which over 70 permanent lakes exist. The unexpected lakes in desert attracted research interests on exploring the hydrological process under this particular landscape; however, a very few literatures exist on the diurnal and spatial variation of the drying front in this area, which is the main issue in the desert hydrological process to characterize the movement of water in soil. In order to understand the drying front in the Badain Jaran Desert, a field campaign was conducted by the observations of soil physical parameters and micrometeorological parameters. With the field data, the performance of a vadose zone soil water balance model, the HYDRUS, was verified and calibrated. Then, the HYDRUS was used to produce the spatial and temporal information of coupled water, water vapour and heat transport in sand to characterize the variation pattern of the drying front before, during and after the rainfall. Finally, the deepest drying front was applied to determine the effective infiltration, which is defined as the amount of soil water captured by the sand beneath the deepest drying front by infiltrating water of an incident rainfall event.
Sparkle L. Malone; Paula J. Fornwalt; Mike A. Battaglia; Marin E. Chambers; Jose M. Iniguez; Carolyn H. Sieg
2018-01-01
We examined spatial patterns of post-fire regenerating conifers in a Colorado, USA, dry conifer forest 11-12 years following the reintroduction of mixed-severity fire. We mapped and measured all post-fire regenerating conifers, as well as all other post-fire regenerating trees and all residual (i.e., surviving) trees, in three 4-ha plots following the 2002 Hayman Fire...
Sujata Tarafdar
2018-01-01
Full Text Available This review is devoted to the simple process of drying a multicomponent droplet of a complex fluid which may contain salt or other inclusions. These processes provide a fascinating subject for study. The explanation of the rich variety of patterns formed is not only an academic challenge but also a problem of practical importance, as applications are growing in medical diagnosis and improvement of coating/printing technology. The fundamental scientific problem is the study of the mechanism of micro- and nanoparticle self-organization in open systems. The specific fundamental problems to be solved, related to this system, are the investigation of the mass transfer processes, the formation and evolution of phase fronts, and the identification of mechanisms of pattern formation. The drops of liquid containing dissolved substances and suspended particles are assumed to be drying on a horizontal solid insoluble smooth substrate. The chemical composition and macroscopic properties of the complex fluid, the concentration and nature of the salt, the surface energy of the substrate, and the interaction between the fluid and substrate which determines the wetting all affect the final morphology of the dried film. The range of our study encompasses the fully wetting case with zero contact angle between the fluid and substrate to the case where the drop is levitated in space, so there is no contact with a substrate and angle of contact can be considered as 180°.
Singh, Yadwinder; Mandal, Kousik; Singh, Balwinder
2015-10-01
The present study was carried out to observe the dissipation pattern of triazophos on capsicum and risk assessment of its residues on human beings and to suggest a waiting period for the safety of consumers. Following two applications of triazophos (Truzo 40 EC) at 500 and 1000 g a.i. ha(-1), the average initial deposits were found to be 3.61 and 6.26 mg kg(-1), respectively. These residues dissipated below the limit of quantification (LOQ) of 0.05 mg kg(-1) in 10 and 15 days at the recommended and double the recommended dosages, respectively. The calculated values of half-life were 2.31 and 2.14 days at recommended and double the recommended dosages, respectively. Theoretical maximum residue contribution (TMRC) values were found to be 28.8 and 41.6 μg person(-1) day(-1) at 500 and 1000 g a.i. ha(-1), respectively, and found to be below the maximum permissible intake on capsicum fruit on the 7th day. Therefore, a waiting period of 7 days is suggested for consumption of capsicum sprayed with triazophos at the recommended dosages.
Mehmet Camurdan
1998-01-01
are coupled by appropriate trace operators. This overall model differs from those previously studied in the literature in that the elastic chamber floor is here more realistically modeled by a hyperbolic Kirchoff equation, rather than by a parabolic Euler-Bernoulli equation with Kelvin-Voight structural damping, as in past literature. Thus, the hyperbolic/parabolic coupled system of past literature is replaced here by a hyperbolic/hyperbolic coupled model. The main result of this paper is a uniform stabilization of the coupled PDE system by a (physically appealing boundary dissipation.
von Schiller, Daniel; Barberá, Gonzalo G.; Díaz, Angela M.; Arce, Maria Isabel; del Campo, Rubén; Tockner, Klement
2018-01-01
In the present study, we examined the effects of different drying conditions on the composition, structure and function of benthic invertebrate assemblages. We approached this objective by comparing invertebrate assemblages in perennial and intermittent sites along two intermittent Mediterranean streams with contrasting predictability, duration, and spatial patterns of drying: Fuirosos (high predictability, short duration, downstream drying pattern) and Rogativa (low predictability, long duration, patchy drying pattern). Specifically, we quantified the contribution of individual taxa to those differences, the degree of nestedness, and shifts in the composition, structure and function of benthic invertebrate assemblages along flow intermittence gradients. We observed greater effects of drying on the benthic invertebrate composition in Fuirosos than in Rogativa, resulting in a higher dissimilarity of assemblages between perennial and intermittent sites, as well as a lower degree of nestedness. Furthermore, a higher number of biotic metrics related to richness, abundance and biological traits were significantly different between perennial and intermittent sites in Fuirosos, despite a shorter dry period compared to Rogativa. At the same time, slightly different responses were detected during post-drying (autumn) than pre-drying (spring) conditions in this stream. In Rogativa, shifts in benthic invertebrate assemblages along increasing gradients of flow intermittence were found for three metrics (Ephemeroptera, Plecoptera and Trichoptera (EPT) and Odonata, Coleoptera and Heteroptera (OCH) abundances and aerial active dispersal. Furthermore, we demonstrated that combined gradients of dry period duration and distance to nearest perennial reach can generate complex, and different, responses of benthic invertebrate assemblages, depending on the flow intermittence metric. Our study advances the notion that special attention should be paid to the predictability, duration and
Quintana, Catalina; Girardello, Marco; Barfod, Anders
2016-01-01
Aims We studied diversity, patterns of endemism and turnover of vegetation composition in dry inter-Andean valleys (DIAVs) where little is known about the influence of the abiotic drivers controlling plant species composition and occurrences, and the life forms that contribute most to α- and β...... species with low abundance (e.g. 30 individuals ha−1), including four endemic species. Most of the endemic species were locally rare, and most of them were restricted to southern valleys...... results further highlight the influence of disturbance, water availability and low temperature on plant species composition and occurrence. We also found significant, contrasting patterns in responses to environmental drivers, when analyzing our data separately by life form. Our results show...
Petr Vladimirovich Lebedev-Stepanov, Dr.
2018-02-01
Full Text Available Motivation: It is important to develop the high-precision computerized methods for medical rapid diagnostic which is generalizing the unique clinical experience obtained in the past decade as specialized solutions for diagnostic problems of control of specific diseases and, potentially, for a wide health monitoring of virtually healthy population, identify the reserves of human health and take the actions to prevent of these reserves depletion. In this work we present one of the new directions in bioinformatics, i.e. medical diagnostics by automated expert system on basis of morphology analysis of digital image of biological liquid dried pattern. Results: Proposed method is combination of bioinformatics and biochemistry approaches for obtaining diagnostic information from a morphological analysis of standardized dried patterns of biological liquid sessile drop. We have carried out own research in collaboration with medical diagnostic centers and formed the electronic database for recognition the following types of diseases: candidiasis; neoplasms; diabetes mellitus; diseases of the circulatory system; cerebrovascular disease; diseases of the digestive system; diseases of the genitourinary system; infectious diseases; factors relevant to the work; factors associated with environmental pollution; factors related to lifestyle. The laboratory setup for diagnostics of the human body in pathology states is developed. The diagnostic results are considered. Availability: Access to testing the software can be obtained on request to the contact email below.
Sparkle L. Malone
2018-01-01
Full Text Available We examined spatial patterns of post-fire regenerating conifers in a Colorado, USA, dry conifer forest 11–12 years following the reintroduction of mixed-severity fire. We mapped and measured all post-fire regenerating conifers, as well as all other post-fire regenerating trees and all residual (i.e., surviving trees, in three 4-ha plots following the 2002 Hayman Fire. Residual tree density ranged from 167 to 197 trees ha−1 (TPH, and these trees were clustered at distances up to 30 m. Post-fire regenerating conifers, which ranged in density from 241 to 1036 TPH, were also clustered at distances up to at least 30 m. Moreover, residual tree locations drove post-fire regenerating conifer locations, with the two showing a pattern of repulsion. Topography and post-fire sprouting tree species locations further drove post-fire conifer regeneration locations. These results provide a foundation for anticipating how the reintroduction of mixed-severity fire may affect long-term forest structure, and also yield insights into how historical mixed-severity fire may have regulated the spatially heterogeneous conditions commonly described for pre-settlement dry conifer forests of Colorado and elsewhere.
Claes, N.; Or, D.
2012-04-01
Soil hosts unparalleled diversity of microbial life that is constantly challenged by the vagaries of fluctuating ambient conditions. Desiccation stresses play a key role not only by directly affecting individual bacterial cells, but also by shaping diffusion pathways and cell dispersion. The gradual thinning and fragmentation of the aqueous environment during drying have led to different survival mechanisms including dormancy and sporulation, resulting in a highly resistive state capable of surviving extreme and prolonged environmental stresses until conditions improve in the future. Our aim is to investigate how temporal changes in hydration status shape microbial communities over time, based on simple survival strategy rules for each individual bacterium. The two survival strategies considered are dormancy and sporulation. Dormancy is the state in which bacterial cells significantly reduce their metabolism with minor morphological adaptations. The required energy and time for attaining this state are low relative to sporulation costs. Sporulation involves several morphological and biochemical changes that result in a resistive capsule that endures extreme stresses over long periods of time. The working hypothesis is that different micro-ecological conditions and community compositions would result from temporal patterns and magnitude of desiccation stresses. An Individual Based Model (IBM) considering habitats on rough soil surfaces and local effects of micro-hydrological conditions on dispersion and nutrient diffusion would enable systematic study of emerging communities over extended periods. Different population compositions are expected to emerge based on low and high frequency, duration and amplitudes of wetting-drying cycles reflecting relative success or failure of survival strategy.
Deep UV patterning of acrylic masters for molding biomimetic dry adhesives
Sameoto, D; Menon, C
2010-01-01
We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance
Dry limit to photosynthesis and cyanobacterial spatial pattern in the Atacama Desert
Warren-Rhodes, K. A.; Pointing, S. B.; Ewing, S.; Lacap, D.; Gomez-Silva, B.; Amundson, R.; Friedmann, E. I.; McKay, C. P.
2005-12-01
Hypolithic autotrophs inhabit translucent rocks in the world`'s most extreme hot and cold deserts. Across a rainfall gradient in the Atacama, we measured a three-fold decline in the molecular diversity of cyanobacterial communities and a drop in their abundance from 28% in relatively wet sites to 0.08% in the driest core. Like plants, hypoliths appear to exhibit traits of self-organized patchiness (aggregated spatial patterns) that tightly correlate with rainfall. Rare cyanobacteria in the core live slowly (3,200 y turnover times) and survive in spatially isolated patches of self-augmented fertility, with the dry limit to their survival occurring at ~Mars but may have existed in rare oases in the past. The spatial distributions of terrestrial desert microbes should be considered in the remote search for life on Mars.
Kusaka, Yasuyuki; Ushijima, Hirobumi; Sugihara, Kazuyoshi; Koutake, Masayoshi
2017-01-01
A process for reflowing patterned materials for reverse offset printing was developed, with the aim of mitigating the step-coverage problem in multilayered devices. The proposed reflow process involves a single step of vapour annealing at moderate temperatures ranging from 60 to 70 °C. This step successfully changes the height profile of semi-dried ink patterns formed on a silicone blanket, from an initially rectangular shape to a rounded shape. A systematic investigation on the effects of various vapour species and vapour temperatures on the reflow process revealed that the miscibility between the vapour and the ink, and a low boiling point of the respective solvent (high vapour pressure) are the prerequisites for successful reflows of semi-dried ink layers patterned on a silicone blanket. The results suggested that the rewetting of previously semi-dried patterns is the main mechanism in the reflow process, which led to a change in the height profile. Furthermore, the reflowed patterns demonstrated almost identical peak-height thicknesses, irrespective of the width of the patterns. This is a unique property that is unattainable by other printing methods, including gravure offset printing and microcontact printing, wherein printed patterns have rounded shapes without a reflow process, but their thickness inevitably depends on the pattern sizes. (technical note)
Impact of Precipitation Patterns on Biomass and Species Richness of Annuals in a Dry Steppe
Yan, Hong; Liang, Cunzhu; Li, Zhiyong; Liu, Zhongling; Miao, Bailing; He, Chunguang; Sheng, Lianxi
2015-01-01
Annuals are an important component part of plant communities in arid and semiarid grassland ecosystems. Although it is well known that precipitation has a significant impact on productivity and species richness of community or perennials, nevertheless, due to lack of measurements, especially long-term experiment data, there is little information on how quantity and patterns of precipitation affect similar attributes of annuals. This study addresses this knowledge gap by analyzing how quantity and temporal patterns of precipitation affect aboveground biomass, interannual variation aboveground biomass, relative aboveground biomass, and species richness of annuals using a 29-year dataset from a dry steppe site at the Inner Mongolia Grassland Ecosystem Research Station. Results showed that aboveground biomass and relative aboveground biomass of annuals increased with increasing precipitation. The coefficient of variation in aboveground biomass of annuals decreased significantly with increasing annual and growing-season precipitation. Species richness of annuals increased significantly with increasing annual precipitation and growing-season precipitation. Overall, this study highlights the importance of precipitation for aboveground biomass and species richness of annuals. PMID:25906187
Arkle, Robert S.; Pilliod, David S.; Welty, Justin L.
2012-01-01
We examined the effects of three early season (spring) prescribed fires on burn severity patterns of summer wildfires that occurred 1–3 years post-treatment in a mixed conifer forest in central Idaho. Wildfire and prescribed fire burn severities were estimated as the difference in normalized burn ratio (dNBR) using Landsat imagery. We used GIS derived vegetation, topography, and treatment variables to generate models predicting the wildfire burn severity of 1286–5500 30-m pixels within and around treated areas. We found that wildfire severity was significantly lower in treated areas than in untreated areas and significantly lower than the potential wildfire severity of the treated areas had treatments not been implemented. At the pixel level, wildfire severity was best predicted by an interaction between prescribed fire severity, topographic moisture, heat load, and pre-fire vegetation volume. Prescribed fire severity and vegetation volume were the most influential predictors. Prescribed fire severity, and its influence on wildfire severity, was highest in relatively warm and dry locations, which were able to burn under spring conditions. In contrast, wildfire severity peaked in cooler, more mesic locations that dried later in the summer and supported greater vegetation volume. We found considerable evidence that prescribed fires have landscape-level influences within treatment boundaries; most notable was an interaction between distance from the prescribed fire perimeter and distance from treated patch edges, which explained up to 66% of the variation in wildfire severity. Early season prescribed fires may not directly target the locations most at risk of high severity wildfire, but proximity of these areas to treated patches and the discontinuity of fuels following treatment may influence wildfire severity and explain how even low severity treatments can be effective management tools in fire-prone landscapes.
Phytogeographical patterns of dry forests sensu stricto in northern Minas Gerais State, Brazil.
Arruda, Daniel M; Ferreira-Júnior, Walnir G; Duque-Brasil, Reinaldo; Schaefer, Carlos E R
2013-01-01
The Deciduous Complex that occurs in northern Minas Gerais State, Brazil, raises questions about the floristic affinities of these formations in relation to neighboring phytogeographical domains. Little is known about the identity of the seasonal forest formations that comprise this complex, or about its relationships to abiotic components, such as soils, topography and climate. This study aimed to recognize the patterns of floristic similarity of all studied fragments of dry forest of northern Minas Gerais with soil and climate attributes, based on the available database. Cluster analysis indicated the existence of two floristic groups that had clear associations with either the Koppen's BSh (semi-arid) or Aw (seasonal tropical) climates. Likewise, the subdivisions of these groups showed clear associations with the dominant soil classes in the region. The Red-Yellow Latosol is the dominant soil classes in the BSh climatic domain, seconded by alluvial areas associated with Fluvic Neosols. The Aw domain comprised a much varied set of soils: Nitosols, Argisols, Cambisols and Litholic Neosols, most derived from the Bambuí limestone/slate formation. The ecotonal nature of northern Minas Gerais State provides a complex interaction between the flora of neighboring phytogeographical domains. This, allied to pedogeomorphological factors, allowed a better understanding of the effects of late Quaternary climate changes for the Deciduous Complex evolution. We conclude that the Latosols under present-day semi-arid climates (BSh) are relicts of former wetter climates, during which humid forest (semideciduous) expansion took place. Later, these semideciduous forests were subjected to a much drier climate, when selection for deciduousness led to the present-days Deciduous Complex scenario.
Regina Gabriela Medina
2016-11-01
Full Text Available Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae, which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.
2002-01-01
The moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? This question has been pondered by scientists for over 200 years, and has consequences ranging from the history of the moon to the mixing of the oceans. Richard Ray at NASA's Goddard Space Flight Center, Greenbelt, Md. and Gary Egbert of the College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Ore. studied six years of altimeter data from the TOPEX/Poseidon satellite to address this question. According to their report in the June 15 issue of Nature, about 1 terawatt, or 25 to 30 percent of the total tidal energy dissipation, occurs in the deep ocean. The remainder occurs in shallow seas, such as on the Patagonian Shelf. 'By measuring sea level with the TOPEX/Poseidon satellite altimeter, our knowledge of the tides in the global ocean has been remarkably improved,' said Richard Ray, a geophysicist at Goddard. The accuracies are now so high that this data can be used to map empirically the tidal energy dissipation. (Red areas, above) The deep-water tidal dissipation occurs generally near rugged bottom topography (seamounts and mid-ocean ridges). 'The observed pattern of deep-ocean dissipation is consistent with topographic scattering of tidal energy into internal motions within the water column, resulting in localized turbulence and mixing', said Gary Egbert an associate professor at OSU. One important implication of this finding concerns the possible energy sources needed to maintain the ocean's large-scale 'conveyor-belt' circulation and to mix upper ocean heat into the abyssal depths. It is thought that 2 terawatts are required for this process. The winds supply about 1 terawatt, and there has been speculation that the tides, by pumping energy into vertical water motions, supply the remainder. However, all current general circulation models of the oceans ignore the tides. 'It is possible that properly
Diverse patterns of stored water use among saplings in seasonally dry tropical forests.
Wolfe, Brett T; Kursar, Thomas A
2015-12-01
Tree species in seasonally dry tropical forests likely vary in their drought-survival mechanisms. Drought-deciduousness, which reduces water loss, and low wood density, which may permit dependence on stored water, are considered key traits. For saplings of six species at two distinct sites, we studied these and two associated traits: the seasonal amount of water released per stem volume ("water released") and the hydraulic capacitance of the stem (C). Two deciduous species with low stem density, Cavanillesia platanifolia and Bursera simaruba, had high C and high dry-season stem water potential (Ψ(stem)), but differed in dry-season water released. C. platanifolia did not use stored water during the dry season whereas B. simaruba, in a drier forest, released stored water. In both, water released was highest while flushing leaves, suggesting that stored water supports leaf flushing. In contrast, two deciduous species with intermediate stem density, Annona hayesii and Genipa americana, had intermediate C, low dry-season Ψ(stem), and high seasonal change in water released. Meanwhile, two evergreen species with intermediate stem density, Cojoba rufescens and Astronium graveolens, had relatively low C, low dry-season Ψ(stem), and intermediate seasonal change in water released. Thus, at least three, distinct stored-water-use strategies were observed. Additionally, bark relative water content (RWC) decreased along with Ψ(stem) during the dry season while xylem RWC did not change, suggesting that bark-stored water buffers Ψ(stem) seasonally. Together these results suggest that seasonal use of stored water and change in Ψ(stem) are associated with functional groups that are characterized by combinations of deciduousness and stem density.
Plant diversity patterns in neotropical dry forests and their conservation implications.
Banda-R, Karina; Delgado-Salinas, Alfonso; Dexter, Kyle G; Linares-Palomino, Reynaldo; Oliveira-Filho, Ary; Prado, Darién; Pullan, Martin; Quintana, Catalina; Riina, Ricarda; Rodríguez M, Gina M; Weintritt, Julia; Acevedo-Rodríguez, Pedro; Adarve, Juan; Álvarez, Esteban; Aranguren B, Anairamiz; Arteaga, Julián Camilo; Aymard, Gerardo; Castaño, Alejandro; Ceballos-Mago, Natalia; Cogollo, Álvaro; Cuadros, Hermes; Delgado, Freddy; Devia, Wilson; Dueñas, Hilda; Fajardo, Laurie; Fernández, Ángel; Fernández, Miller Ángel; Franklin, Janet; Freid, Ethan H; Galetti, Luciano A; Gonto, Reina; González-M, Roy; Graveson, Roger; Helmer, Eileen H; Idárraga, Álvaro; López, René; Marcano-Vega, Humfredo; Martínez, Olga G; Maturo, Hernán M; McDonald, Morag; McLaren, Kurt; Melo, Omar; Mijares, Francisco; Mogni, Virginia; Molina, Diego; Moreno, Natalia Del Pilar; Nassar, Jafet M; Neves, Danilo M; Oakley, Luis J; Oatham, Michael; Olvera-Luna, Alma Rosa; Pezzini, Flávia F; Dominguez, Orlando Joel Reyes; Ríos, María Elvira; Rivera, Orlando; Rodríguez, Nelly; Rojas, Alicia; Särkinen, Tiina; Sánchez, Roberto; Smith, Melvin; Vargas, Carlos; Villanueva, Boris; Pennington, R Toby
2016-09-23
Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale. Copyright © 2016, American Association for the Advancement of Science.
Blink patterns and lid-contact times in dry-eye and normal subjects
Ousler GW 3rd
2014-05-01
Full Text Available George W Ousler 3rd,1 Mark B Abelson,1,2 Patrick R Johnston,1 John Rodriguez,1 Keith Lane,1 Lisa M Smith11Ora, Andover, MA, USA; 2Department of Ophthalmology, Harvard Medical School, Boston, MA, USAPurpose: To classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute.Materials and methods: This was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25%, 50%, 75%. Complete blinks were characterized as full (>0 seconds, extended (>0.1 seconds, or superextended (>0.5 seconds. The mean duration of each type of blink was determined and standardized per minute as total lid-contact time.Results: Total blinks observed were 4,990 (1,414 normal, 3,756 dry eye: 1,809 (50.59% partial and 1,767 (49.41% complete blinks among dry-eye subjects versus 741 (52.90% partial and 673 (47.60% complete blinks among normal subjects. Only superextended blinks of ≥0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3% versus 0.2%, respectively; P=0.023. Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P<0.001. Isolating only extended blinks (>0.1 second, the average contact time (seconds was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003. Isolating only superextended blinks (>0.5 seconds, average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P<0.001. The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P<0.001 than normal subjects.Conclusion: Dry-eye subjects spent 4.5% of a
Plant diversity patterns in neotropical dry forests and their conservation implications
K. Banda-R; A. Delgado-Salinas; K. G. Dexter; R. Linares-Palomino; A. Oliveira-Filho; D. Prado; M. Pullan; C. Quintana; R. Riina; G. M. Rodriguez M.; J. Weintritt; P. Acevedo-Rodriguez; J. Adarve; E. Alvarez; A. Aranguren B.; J. C. Arteaga; G. Aymard; A. Castano; N. Ceballos-Mago; A. Cogollo; H. Cuadros; F. Delgado; W. Devia; H. Duenas; L. Fajardo; A. Fernandez; M. A. Fernandez; J. Franklin; E. H. Freid; L. A. Galetti; R. Gonto; R. Gonzalez-M.; R. Graveson; E. H. Helmer; A. Idarraga; R. Lopez; H. Marcano-Vega; O. G. Martinez; H. M. Maturo; M. McDonald; K. McLaren; O. Melo; F. Mijares; V. Mogni; D. Molina; N. d. P. Moreno; J. M. Nassar; D. M. Neves; L. J. Oakley; M. Oatham; A. R. Olvera-Luna; F. F. Pezzini; O. J. R. Dominguez; M. E. Rios; O. Rivera; N. Rodriguez; A. Rojas; T. Sarkinen; R. Sanchez; M. Smith; C. Vargas; B. Villanueva; R. T. Pennington
2016-01-01
Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than...
Åshild Ø. Pedersen
2013-05-01
Full Text Available The western Palaearctic tundra is a breeding habitat for large populations of European geese. After their arrival in spring, pink-footed geese (Anser brachyrhynchus forage extensively on below-ground plant parts, using a feeding technique called grubbing that has substantial impact on the tundra vegetation. Previous studies have shown a high frequency of grubbing in lowland fen vegetation. In the present study, we examined the occurrence of grubbing in other habitat types on Spitsbergen, in the Arctic archipelago of Svalbard. Goose grubbing was surveyed along 19 altitudinal transects, going from the valley bottom to altitudes dominated by scree. Grubbing was more frequent in the wet habitat type at low altitudes compared to the drier habitat type at higher altitudes. For the dry habitat type, a higher frequency of grubbing was found in study plots with a south-east facing exposure where snowmelt is expected to be early. This suggests that pink-footed geese primarily use dry vegetation types for grubbing when they are snow-free in early spring and the availability of snow-free patches of the preferred wet vegetation types in the lowlands is limited. Dry vegetation types have poorer recovery rates from disturbance than wet ones. Sites with early snowmelt and dry vegetation types may therefore be at greater risk of long-term habitat degradation. We conclude that the high growth rate of the Svalbard-breeding pink-footed goose population suggests that increasing impacts of grubbing can be expected and argue that a responsible monitoring of the effects on the tundra ecosystem is crucial.
M. J. A. Werger
1983-11-01
Full Text Available Southern Africa is characterized by a highly diversified vegetational cover with extremes as contrasting as desert, tropical forest, alpine grassland, or mediterranean type scrub, and many other types in between. This vegetational pattern is strongly correlated to the climatological pattern. It is therefore likely that past changes in climate can still be partly traced in the vegetational pattern, particularly in geographical anomalies, and that study of these patterns provides complementary evidence to palynological research. The following anomalies in the vegetational pattern are briefly discussed: 1. island-wise occurrence of Afro-montane vegetation on mesic, sheltered sites in the southern Sudano- Zambezian Region, in particular in the Highveld grassland/False Karoo transition area; 2. similar westward occurrence of Sudano-Zambezian scrub patches in the Karoo-Namib Region near the Orange/Vaal confluence; 3. scattered occurrence of Sudano-Zambezian woody species in a matrix of Karoo-Namib vegetation in the marginal Karoo-Namib Region; 4. island-wise occurrence of frost-tolerant, dry, karroid dwarf shrub vegetation of predominantly C,-plants on isolated peaks in the winter rainfall area of Namaqualand; 5. peculiar patchy distribution of some succulents in wide areas of climatically rather homogeneous, succulent dwarf shrub vegetation of predominantly CAM-plants in the escarpment area of Namaqualand. a pattern reminiscent of that in many Cape fynbos species. Interpretation of these patterns logically leads to the conclusion that these result from a previously wetter, a previously cooler, or a previously wetter and cooler climate, respectively, over the parts of southern Africa under discussion. This conclusion is compared with published palynological views.
Choat, Brendan; Ball, Marilyn C; Luly, Jon G; Donnelly, Christine F; Holtum, Joseph A M
2006-05-01
Diurnal and seasonal patterns of leaf gas exchange and water relations were examined in tree species of contrasting leaf phenology growing in a seasonally dry tropical rain forest in north-eastern Australia. Two drought-deciduous species, Brachychiton australis (Schott and Endl.) A. Terracc. and Cochlospermum gillivraei Benth., and two evergreen species, Alphitonia excelsa (Fenzal) Benth. and Austromyrtus bidwillii (Benth.) Burret. were studied. The deciduous species had higher specific leaf areas and maximum photosynthetic rates per leaf dry mass in the wet season than the evergreens. During the transition from wet season to dry season, total canopy area was reduced by 70-90% in the deciduous species and stomatal conductance (g(s)) and assimilation rate (A) were markedly lower in the remaining leaves. Deciduous species maintained daytime leaf water potentials (Psi(L)) at close to or above wet season values by a combination of stomatal regulation and reduction in leaf area. Thus, the timing of leaf drop in deciduous species was not associated with large negative values of daytime Psi(L) (greater than -1.6 MPa) or predawn Psi(L) (greater than -1.0 MPa). The deciduous species appeared sensitive to small perturbations in soil and leaf water status that signalled the onset of drought. The evergreen species were less sensitive to the onset of drought and g(s) values were not significantly lower during the transitional period. In the dry season, the evergreen species maintained their canopies despite increasing water-stress; however, unlike Eucalyptus species from northern Australian savannas, A and g(s) were significantly lower than wet season values.
Chynoweth, Mark W; Lepczyk, Christopher A; Litton, Creighton M; Hess, Steven C; Kellner, James R; Cordell, Susan
2015-01-01
Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the conservation and restoration of some of the world's most critically endangered ecosystems. We hypothesized that feral goats would respond to resource pulses in vegetation by traveling to areas of recent green-up. To address this hypothesis, we fitted six male and seven female feral goats with Global Positioning System (GPS) collars equipped with an Argos satellite upload link to examine goat movements in relation to the plant phenology using the Normalized Difference Vegetation Index (NDVI). Movement patterns of 50% of males and 40% of females suggested conditional movement between non-overlapping home ranges throughout the year. A shift in NDVI values corresponded with movement between primary and secondary ranges of goats that exhibited long-distance movement, suggesting that vegetation phenology as captured by NDVI is a good indicator of the habitat and movement patterns of feral goats in tropical island dry landscapes. In the context of conservation and restoration of tropical island landscapes, the results of our study identify how non-native feral goats use resources across a broad landscape to sustain their populations and facilitate invasion of native plant communities.
Chynoweth, Mark W.; Lepczyk, Christopher A.; Litton, Creighton M.; Hess, Steve; Kellner, James; Cordell, Susan
2015-01-01
Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the conservation and restoration of some of the world’s most critically endangered ecosystems. We hypothesized that feral goats would respond to resource pulses in vegetation by traveling to areas of recent green-up. To address this hypothesis, we fitted six male and seven female feral goats with Global Positioning System (GPS) collars equipped with an Argos satellite upload link to examine goat movements in relation to the plant phenology using the Normalized Difference Vegetation Index (NDVI). Movement patterns of 50% of males and 40% of females suggested conditional movement between non-overlapping home ranges throughout the year. A shift in NDVI values corresponded with movement between primary and secondary ranges of goats that exhibited long-distance movement, suggesting that vegetation phenology as captured by NDVI is a good indicator of the habitat and movement patterns of feral goats in tropical island dry landscapes. In the context of conservation and restoration of tropical island landscapes, the results of our study identify how non-native feral goats use resources across a broad landscape to sustain their populations and facilitate invasion of native plant communities.
Differential Response Pattern of Oropharyngeal Pressure by Bolus and Dry Swallows.
Hasegawa, Mana; Kurose, Masayuki; Okamoto, Keiichiro; Yamada, Yoshiaki; Tsujimura, Takanori; Inoue, Makoto; Sato, Taisuke; Narumi, Takatsune; Fujii, Noritaka; Yamamura, Kensuke
2018-02-01
The aim of this study was to determine if bolus and dry swallow showed similar pressure changes in the oropharynx using our newly developed device. A unique character of it includes that baropressure can be measured with the sensor being placed in the balloon and can assess the swallowing mechanics in terms of pressure changes in the oropharynx with less influences of direct contacts of boluses and oropharyngeal structures during swallow indirectly. Fifteen healthy subjects swallowed saliva (dry), 15 ml of water, 45 ml of water, and 15 ml of two different types of food in terms of viscosity (potage soup-type and mayonnaise-type foods). Suprahyoid muscle activity was recorded simultaneously. Three parameters, area under the curve (AUC), peak amplitude, and duration of pressure, were analyzed from each swallow. Almost all of the bolus swallowing events had biphasic baropressure responses consisting of an early phase and late phase (99%), whereas 90% of the saliva swallowing events had a single phase. AUC, peak, and duration displayed greater effects during the late phase than during the early phase. Baropressure of the early phase, but not of the late phase, significantly increased with increasing volume; however, small but significant viscosity effects on pressure were seen during both phases. Peak pressure of the late phase was preceded by maximum muscle activity, whereas that of the early phase was seen when muscle activity displayed a peak response. These findings indicated that our device with the ability to measure baropressure has the potential to provide additional parameter to assess the swallow physiology, and biphasic baropressure responses in the early and late phases could reflect functional aspects of the swallowing reflexes.
Dissipative relativistic hydrodynamics
Imshennik, V.S.; Morozov, Yu.I.
1989-01-01
Using the comoving reference frame in the general non-inertial case, the relativistic hydrodynamics equations are derived with an account for dissipative effects in the matter. From the entropy production equation, the exact from for the dissipative tensor components is obtained. As a result, the closed system of equations of dissipative relativistic hydrodynamics is obtained in the comoving reference frame as a relativistic generalization of the known Navier-Stokes equations for Lagrange coordinates. Equations of relativistic hydrodynamics with account for dissipative effects in the matter are derived using the assocoated reference system in general non-inertial case. True form of the dissipative tensor components is obtained from entropy production equation. Closed system of equations for dissipative relativistic hydrodynamics is obtained as a result in the assocoated reference system (ARS) - relativistic generalization of well-known Navier-Stokes equations for Lagrange coordinates. Equation system, obtained in this paper for ARS, may be effectively used in numerical models of explosive processes with 10 51 erg energy releases which are characteristic for flashes of supernovae, if white dwarf type compact target suggested as presupernova
Cell lineage patterns in the shoot meristem of the sunflower embryo in the dry seed
Jegla, D.E.; Sussex, I.M.
1989-01-01
We mapped the fate of cells in the shoot meristem of the dry-seed embryo of sunflower, Helianthus annuus L. cv. Peredovic, using irradiation-induced somatic sectors. We analyzed 249 chlorophyll-deficient or glabrous (hairless) sectors generated in 236 plants. Most sectors observed in the inflorescence extended into vegetative nodes. Thus cell lineages that ultimately gave rise to reproductive structures also contributed to vegetative structures. No single sector extended the entire length of the shoot. Thus the shoot is not derived from one or a few apical initials. Rather, the position, vertical extent, and width of the sectors at different levels of the shoot suggest that the shoot is derived from three to four circumferential populations of cells in each of three cell layers of the embryo meristem. Sectors had no common boundaries even in plants with two or three independent sectors, but varied in extent and overlapped along the length of the shoot. Thus individual cells in a single circumferential population behaved independently to contribute lineages of different vertical extents to the growing shoot. The predicted number of circumferential populations of cells as well as the apparent cell number in each population was consistent with the actual number of cells in the embryo meristem observed in histological sections
Kal, Subhadeep; Mohanty, Nihar; Farrell, Richard A.; Franke, Elliott; Raley, Angelique; Thibaut, Sophie; Pereira, Cheryl; Pillai, Karthik; Ko, Akiteru; Mosden, Aelan; Biolsi, Peter
2017-04-01
Scaling beyond the 7nm technology node demands significant control over the variability down to a few angstroms, in order to achieve reasonable yield. For example, to meet the current scaling targets it is highly desirable to achieve sub 30nm pitch line/space features at back-end of the line (BEOL) or front end of line (FEOL); uniform and precise contact/hole patterning at middle of line (MOL). One of the quintessential requirements for such precise and possibly self-aligned patterning strategies is superior etch selectivity between the target films while other masks/films are exposed. The need to achieve high etch selectivity becomes more evident for unit process development at MOL and BEOL, as a result of low density films choices (compared to FEOL film choices) due to lower temperature budget. Low etch selectivity with conventional plasma and wet chemical etch techniques, causes significant gouging (un-intended etching of etch stop layer, as shown in Fig 1), high line edge roughness (LER)/line width roughness (LWR), non-uniformity, etc. In certain circumstances this may lead to added downstream process stochastics. Furthermore, conventional plasma etches may also have the added disadvantage of plasma VUV damage and corner rounding (Fig. 1). Finally, the above mentioned factors can potentially compromise edge placement error (EPE) and/or yield. Therefore a process flow enabled with extremely high selective etches inherent to film properties and/or etch chemistries is a significant advantage. To improve this etch selectivity for certain etch steps during a process flow, we have to implement alternate highly selective, plasma free techniques in conjunction with conventional plasma etches (Fig 2.). In this article, we will present our plasma free, chemical gas phase etch technique using chemistries that have high selectivity towards a spectrum of films owing to the reaction mechanism ( as shown Fig 1). Gas phase etches also help eliminate plasma damage to the
Elmqvist, Thomas; Pyykönen, Markku; Tengö, Maria; Rakotondrasoa, Fanambinantsoa; Rabakonandrianina, Elisabeth; Radimilahy, Chantal
2007-05-02
Loss of tropical forests and changes in land-use/land-cover are of growing concern worldwide. Although knowledge exists about the institutional context in which tropical forest loss is embedded, little is known about the role of social institutions in influencing regeneration of tropical forests. In the present study we used Landsat images from southern Madagascar from three different years (1984, 1993 and 2000) and covering 5500 km(2), and made a time-series analysis of three distinct large-scale patterns: 1) loss of forest cover, 2) increased forest cover, and 3) stable forest cover. Institutional characteristics underlying these three patterns were analyzed, testing the hypothesis that forest cover change is a function of strength and enforcement of local social institutions. The results showed a minor decrease of 7% total forest cover in the study area during the whole period 1984-2000, but an overall net increase of 4% during the period 1993-2000. The highest loss of forest cover occurred in a low human population density area with long distances to markets, while a stable forest cover occurred in the area with highest population density and good market access. Analyses of institutions revealed that loss of forest cover occurred mainly in areas characterized by insecure property rights, while areas with well-defined property rights showed either regenerating or stable forest cover. The results thus corroborate our hypothesis. The large-scale spontaneous regeneration dominated by native endemic species appears to be a result of a combination of changes in precipitation, migration and decreased human population and livestock grazing pressure, but under conditions of maintained and well-defined property rights. Our study emphasizes the large capacity of a semi-arid system to spontaneously regenerate, triggered by decreased pressures, but where existing social institutions mitigate other drivers of deforestation and alternative land-use.
Thomas Elmqvist
Full Text Available Loss of tropical forests and changes in land-use/land-cover are of growing concern worldwide. Although knowledge exists about the institutional context in which tropical forest loss is embedded, little is known about the role of social institutions in influencing regeneration of tropical forests. In the present study we used Landsat images from southern Madagascar from three different years (1984, 1993 and 2000 and covering 5500 km(2, and made a time-series analysis of three distinct large-scale patterns: 1 loss of forest cover, 2 increased forest cover, and 3 stable forest cover. Institutional characteristics underlying these three patterns were analyzed, testing the hypothesis that forest cover change is a function of strength and enforcement of local social institutions. The results showed a minor decrease of 7% total forest cover in the study area during the whole period 1984-2000, but an overall net increase of 4% during the period 1993-2000. The highest loss of forest cover occurred in a low human population density area with long distances to markets, while a stable forest cover occurred in the area with highest population density and good market access. Analyses of institutions revealed that loss of forest cover occurred mainly in areas characterized by insecure property rights, while areas with well-defined property rights showed either regenerating or stable forest cover. The results thus corroborate our hypothesis. The large-scale spontaneous regeneration dominated by native endemic species appears to be a result of a combination of changes in precipitation, migration and decreased human population and livestock grazing pressure, but under conditions of maintained and well-defined property rights. Our study emphasizes the large capacity of a semi-arid system to spontaneously regenerate, triggered by decreased pressures, but where existing social institutions mitigate other drivers of deforestation and alternative land-use.
Topological protection of multiparticle dissipative transport
Loehr, Johannes; Loenne, Michael; Ernst, Adrian; de Las Heras, Daniel; Fischer, Thomas M.
2016-06-01
Topological protection allows robust transport of localized phenomena such as quantum information, solitons and dislocations. The transport can be either dissipative or non-dissipative. Here, we experimentally demonstrate and theoretically explain the topologically protected dissipative motion of colloidal particles above a periodic hexagonal magnetic pattern. By driving the system with periodic modulation loops of an external and spatially homogeneous magnetic field, we achieve total control over the motion of diamagnetic and paramagnetic colloids. We can transport simultaneously and independently each type of colloid along any of the six crystallographic directions of the pattern via adiabatic or deterministic ratchet motion. Both types of motion are topologically protected. As an application, we implement an automatic topologically protected quality control of a chemical reaction between functionalized colloids. Our results are relevant to other systems with the same symmetry.
Graphene heat dissipating structure
Washburn, Cody M.; Lambert, Timothy N.; Wheeler, David R.; Rodenbeck, Christopher T.; Railkar, Tarak A.
2017-08-01
Various technologies presented herein relate to forming one or more heat dissipating structures (e.g., heat spreaders and/or heat sinks) on a substrate, wherein the substrate forms part of an electronic component. The heat dissipating structures are formed from graphene, with advantage being taken of the high thermal conductivity of graphene. The graphene (e.g., in flake form) is attached to a diazonium molecule, and further, the diazonium molecule is utilized to attach the graphene to material forming the substrate. A surface of the substrate is treated to comprise oxide-containing regions and also oxide-free regions having underlying silicon exposed. The diazonium molecule attaches to the oxide-free regions, wherein the diazonium molecule bonds (e.g., covalently) to the exposed silicon. Attachment of the diazonium plus graphene molecule is optionally repeated to enable formation of a heat dissipating structure of a required height.
Weiss, Ulrich
2008-01-01
Major advances in the quantum theory of macroscopic systems, in combination with stunning experimental achievements, have brightened the field and brought it to the attention of the general community in natural sciences. Today, working knowledge of dissipative quantum mechanics is an essential tool for many physicists. This book - originally published in 1990 and republished in 1999 as an enlarged second edition - delves much deeper than ever before into the fundamental concepts, methods, and applications of quantum dissipative systems, including the most recent developments. In this third edi
Chernousenko, V.M.; Kuklin, V.M.; Panachenko, I.P.; Vorob'yov, V.M.
1990-01-01
This paper reports on a wide spectrum of oscillations that is excited due to the evolution instabilities, being in a weak above-threshold state, in the inequilibrium media with decaying spectrum. In this case the pumping, whose part is played by an intensive wave or occupation inversion in the active medium, synchronized the phases of excited modes and, thus, forms the space dissipative structure of the field. In dissipative nonlinear media with nondecaying spectrum the space structures, formed due to the development of instability, experience small-scale hexagonal modulation
Collective variables and dissipation
Balian, R.
1984-09-01
This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory
Transient chaotic transport in dissipative drift motion
Oyarzabal, R.S. [Pós-Graduação em Ciências/Física, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Szezech, J.D. [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Batista, A.M., E-mail: antoniomarcosbatista@gmail.com [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, PR (Brazil); Souza, S.L.T. de [Departamento de Física e Matemática, Universidade Federal de São João del Rei, 36420-000, Ouro Branco, MG (Brazil); Caldas, I.L. [Instituto de Física, Universidade de São Paulo, 05315-970, São Paulo, SP (Brazil); Viana, R.L. [Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, PR (Brazil); Sanjuán, M.A.F. [Departamento de Física, Universidad Rey Juan Carlos, Tulipán s/n, 28933 Móstoles, Madrid (Spain)
2016-04-22
Highlights: • We consider a situation for which a chaotic transient is present in the dynamics of the two-wave model with damping. • The damping in plasma models can be a way for study a realistic behavior of confinement due the collisional effect. • The escape time as a function of the damping obey a power-law scaling. • We have made a qualitative transport analysis with a simple model that can be useful for more complete models. • We have shown that the pattern of the basin of attraction depends on the damping parameter. - Abstract: We investigate chaotic particle transport in magnetised plasmas with two electrostatic drift waves. Considering dissipation in the drift motion, we verify that the removed KAM surfaces originate periodic attractors with their corresponding basins of attraction. We show that the properties of the basins depend on the dissipation and the space-averaged escape time decays exponentially when the dissipation increases. We find positive finite time Lyapunov exponents in dissipative drift motion, consequently the trajectories exhibit transient chaotic transport. These features indicate how the transient plasma transport depends on the dissipation.
Lorenzen, Elke; Lee, Geoffrey
2013-12-01
A single-droplet acoustic levitator was used to determine the drying rate and the kinetics of inactivation of glutamate dehydrogenase in the presence of added trehalose or sorbitol. The solution was also spray dried under the same process condition of drying gas temperature on a bench-top machine. Both trehalose and sorbitol delay the point of onset of enzyme inactivation which lies after the critical point of drying. Both carbohydrates also reduce the apparent rate constant of inactivation calculated during the subsequent inactivation phase. The carbohydrates stabilise, therefore, the enzyme during droplet drying and particle formation mainly during the falling rate drying period. There is no difference between the stabilising effects of the two carbohydrates when examined as levitated single droplets. This suggests the importance of water replacement as a stabilising mechanism in the levitated droplets/particles. On spray drying, the trehalose stabilises the enzyme better than does the sorbitol at a drying gas (outlet) temperature of 60°C. This suggests glass formation with the trehalose but not the sorbitol during the very rapid drying process of small-atomised droplets in the spray dryer. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.
Theoretical Consolidation of Acoustic Dissipation
Casiano, M. J.; Zoladz, T. F.
2012-01-01
In many engineering problems, the effects of dissipation can be extremely important. Dissipation can be represented by several parameters depending on the context and the models that are used. Some examples of dissipation-related parameters are damping ratio, viscosity, resistance, absorption coefficients, pressure drop, or damping rate. This Technical Memorandum (TM) describes the theoretical consolidation of the classic absorption coefficients with several other dissipation parameters including linearized resistance. The primary goal of this TM is to theoretically consolidate the linearized resistance with the absorption coefficient. As a secondary goal, other dissipation relationships are presented.
Attractors of dissipative structure in three dissipative fluids
Kondoh, Yoshiomi
1993-10-01
A general theory with use of auto-correlations for distributions is presented to derive that realization of coherent structures in general dissipative dynamic systems is equivalent to that of self-organized states with the minimum dissipation rate for instantaneously contained energy. Attractors of dissipative structure are shown to be given by eigenfunctions for dissipative dynamic operators of the dynamic system and to constitute the self-organized and self-similar decay phase. Three typical examples applied to incompressible viscous fluids, to incompressible viscous and resistive magnetohydrodynamic (MHD) fluids and to compressible resistive MHD plasmas are presented to lead to attractors in the three dissipative fluids and to describe a common physical picture of self-organization and bifurcation of the dissipative structure. (author)
Liu, Wei; Nannarelli, Alberto
2008-01-01
A few classes of algorithms to implement division in hardware have been used over the years: division by digit-recurrence, by reciprocal approximation by iterative methods and by polynomial approximation. Due to the differences in the algorithms, a comparison among their implementation in terms o...... of performance and precision is sometimes hard to make. In this work, we use power dissipation and energy consumption as metrics to compare among those different classes of algorithms. There are no previous works in the literature presenting such a comparison....
Mode-locking via dissipative Faraday instability.
Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K
2016-08-09
Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.
Explicit dissipative structures
Roessler, O.E.
1987-01-01
Dissipative structures consisting of a few macrovariables arise out of a sea of reversible microvariables. Unexpected residual effects of the massive underlying reversibility, on the macrolevel, cannot therefore be excluded. In the age of molecular-dynamics simulations, explicit dissipative structures like excitable systems (explicit observers) can be generated in a computer from first reversible principles. A class of classical, 1-D Hamiltonian systems of chaotic type is considered which has the asset that the trajectorial behavior in phase space can be understood geometrically. If, as nuatural, the number of particle types is much smaller than that of particles, the Gibbs symmetry must be taken into account. The permutation invariance drastically changes the behavior in phase space (quasi-periodization). The explicity observer becomes effectively reversible on a short time scale. In consequence, his ability to measure microscopic motions is suspended in a characteristic fashion. Unlike quantum mechanics whose holistic nature cannot be transcended, the present holistic (internal-interface) effects - mimicking the former to some extent - can be understood fully in principle
Reddy, S Navakishore; Gupta, Suman; Gajbhiye, Vijay T
2013-09-01
The dissipation of pyraclostrobin, a strobilurin fungicide, in soil was found to be influenced by soil moisture, organic matter content and microbial population. Among the different moisture regimes, dissipation was faster under submerged condition (T1/2 10 days) followed by field capacity (T1/2 28.7 days) and in dry soil (T1/2 41.8 days). Use of sludge at 5 % level to Inceptisol favoured a faster dissipation of pyraclostrobin, whereas a slower rate of dissipation was observed in partial organic matter removed soil as compared to normal soil. Slower rate of dissipation was also observed in sterile soil (T1/2 47 days) compared to normal soil. Pyraclostrobin dissipated faster in Vertisol (T1/2 21.8 days) than in Inceptisol (T1/2 28.7 days). No significant difference in the dissipation rate was observed at 1 and 10 μg g(-1) fortification levels.
Magnetic intermittency of solar wind turbulence in the dissipation range
Pei, Zhongtian; He, Jiansen; Tu, Chuanyi; Marsch, Eckart; Wang, Linghua
2016-04-01
The feature, nature, and fate of intermittency in the dissipation range are an interesting topic in the solar wind turbulence. We calculate the distribution of flatness for the magnetic field fluctuations as a functionof angle and scale. The flatness distribution shows a "butterfly" pattern, with two wings located at angles parallel/anti-parallel to local mean magnetic field direction and main body located at angles perpendicular to local B0. This "butterfly" pattern illustrates that the flatness profile in (anti-) parallel direction approaches to the maximum value at larger scale and drops faster than that in perpendicular direction. The contours for probability distribution functions at different scales illustrate a "vase" pattern, more clear in parallel direction, which confirms the scale-variation of flatness and indicates the intermittency generation and dissipation. The angular distribution of structure function in the dissipation range shows an anisotropic pattern. The quasi-mono-fractal scaling of structure function in the dissipation range is also illustrated and investigated with the mathematical model for inhomogeneous cascading (extended p-model). Different from the inertial range, the extended p-model for the dissipation range results in approximate uniform fragmentation measure. However, more complete mathematicaland physical model involving both non-uniform cascading and dissipation is needed. The nature of intermittency may be strong structures or large amplitude fluctuations, which may be tested with magnetic helicity. In one case study, we find the heating effect in terms of entropy for large amplitude fluctuations seems to be more obvious than strong structures.
Conservation laws shape dissipation
Rao, Riccardo; Esposito, Massimiliano
2018-02-01
Starting from the most general formulation of stochastic thermodynamics—i.e. a thermodynamically consistent nonautonomous stochastic dynamics describing systems in contact with several reservoirs—we define a procedure to identify the conservative and the minimal set of nonconservative contributions in the entropy production. The former is expressed as the difference between changes caused by time-dependent drivings and a generalized potential difference. The latter is a sum over the minimal set of flux-force contributions controlling the dissipative flows across the system. When the system is initially prepared at equilibrium (e.g. by turning off drivings and forces), a finite-time detailed fluctuation theorem holds for the different contributions. Our approach relies on identifying the complete set of conserved quantities and can be viewed as the extension of the theory of generalized Gibbs ensembles to nonequilibrium situations.
Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.
1998-01-01
The binary character of the heavy ion collisions at intermediate energies in the exit channel has been observed under 30 MeV/n in medium and heavy systems. Measurements in light systems at energies approaching ∼ 100 MeV/nucleon as well as in very heavy systems have allowed to extend considerably the investigations of this binary process. Thus, the study of the Pb + Au system showed that the complete charge events indicated two distinct sources: the quasi-projectile and the quasi-target. The characteristics of these two sources are rather well reproduced by a trajectory computation which takes into account the Coulomb and nuclear forces and the friction appearing from the projectile-target interaction. The Wilczynski diagram is used to probe the correlation between the kinetic energy quenching and the deflecting angle. In case of the system Pb + Au at 29 MeV/nucleon the diagram indicate dissipative binary collisions typical for low energies. This binary aspect was also detected in the systems Xe + Ag at 44 MeV/nucleon, 36 Ar + 27 Al and 64 Zn + nat Ti. Thus, it was possible to reconstruct the quasi-projectile and to study its mass and excitation energy evolution as a function of the impact parameter. The dissipative binary collisions represent for the systems and energies under considerations the main contribution to the cross section. This does not implies that there are not other processes; particularly, the more or less complete fusion is also observed but with a low cross section which decreases with the increase of bombardment energy. More exclusive measurements with the INDRA detector on quasi-symmetric systems as Ar + KCl and Xe + Sn seem to confirm the importance of the binary collisions. The two source reconstruction of the Xe + Sn data at 50 MeV/nucleon reproduces the same behaviour as that observed in the system Pb + Au at 29 MeV/nucleon
Heterogeneous dissipative composite structures
Ryabov, Victor; Yartsev, Boris; Parshina, Ludmila
2018-05-01
The paper suggests mathematical models of decaying vibrations in layered anisotropic plates and orthotropic rods based on Hamilton variation principle, first-order shear deformation laminated plate theory (FSDT), as well as on the viscous-elastic correspondence principle of the linear viscoelasticity theory. In the description of the physical relationships between the materials of the layers forming stiff polymeric composites, the effect of vibration frequency and ambient temperature is assumed as negligible, whereas for the viscous-elastic polymer layer, temperature-frequency relationship of elastic dissipation and stiffness properties is considered by means of the experimentally determined generalized curves. Mitigation of Hamilton functional makes it possible to describe decaying vibration of anisotropic structures by an algebraic problem of complex eigenvalues. The system of algebraic equation is generated through Ritz method using Legendre polynomials as coordinate functions. First, real solutions are found. To find complex natural frequencies of the system, the obtained real natural frequencies are taken as input values, and then, by means of the 3rd order iteration method, complex natural frequencies are calculated. The paper provides convergence estimates for the numerical procedures. Reliability of the obtained results is confirmed by a good correlation between analytical and experimental values of natural frequencies and loss factors in the lower vibration tones for the two series of unsupported orthotropic rods formed by stiff GRP and CRP layers and a viscoelastic polymer layer. Analysis of the numerical test data has shown the dissipation & stiffness properties of heterogeneous composite plates and rods to considerably depend on relative thickness of the viscoelastic polymer layer, orientation of stiff composite layers, vibration frequency and ambient temperature.
Dissipative neutrino oscillations in randomly fluctuating matter
Benatti, F.; Floreanini, R.
2005-01-01
The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis
Dissipative neutrino oscillations in randomly fluctuating matter
Benatti, F.; Floreanini, R.
2005-01-01
The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: It takes into account matter-induced, decoherence phenomena that go beyond the standard Mikheyev-Smirnov-Wolfenstein (MSW) effect. A widely adopted density fluctuation pattern is found to be physically untenable: A more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.
Mark W. Chynoweth; Christopher A. Lepczyk; Creighton M. Litton; Steven C. Hess; James R. Kellner; Susan Cordell; Lalit Kumar
2015-01-01
Advances in wildlife telemetry and remote sensing technology facilitate studies of broad-scale movements of ungulates in relation to phenological shifts in vegetation. In tropical island dry landscapes, home range use and movements of non-native feral goats (Capra hircus) are largely unknown, yet this information is important to help guide the...
Tetetla-Rangel, Erika; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Hoekstra, Paul H.
2017-01-01
Determining which factors affect species richness is important for conservation theory and practice. However, richness of common and rare species may be affected by different factors. We use an extensive inventory of woody plants from a tropical dry forest landscape in Yucatan, Mexico to assess the
Notari, Alessio
2016-12-22
We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\\frac{\\phi}{f_\\gamma} F \\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density $\\rho_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_\\gamma$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_\\gamma$ is smaller than the field excursion $\\phi_0$ by about a factor of at least ${\\cal O} (20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of...
Dissipative structures in magnetorotational turbulence
Ross, Johnathan; Latter, Henrik N.
2018-03-01
Via the process of accretion, magnetorotational turbulence removes energy from a disk's orbital motion and transforms it into heat. Turbulent heating is far from uniform and is usually concentrated in small regions of intense dissipation, characterised by abrupt magnetic reconnection and higher temperatures. These regions are of interest because they might generate non-thermal emission, in the form of flares and energetic particles, or thermally process solids in protoplanetary disks. Moreover, the nature of the dissipation bears on the fundamental dynamics of the magnetorotational instability (MRI) itself: local simulations indicate that the large-scale properties of the turbulence (e.g. saturation levels, the stress-pressure relationship) depend on the short dissipative scales. In this paper we undertake a numerical study of how the MRI dissipates and the small-scale dissipative structures it employs to do so. We use the Godunov code RAMSES and unstratified compressible shearing boxes. Our simulations reveal that dissipation is concentrated in ribbons of strong magnetic reconnection that are significantly elongated in azimuth, up to a scale height. Dissipative structures are hence meso-scale objects, and potentially provide a route by which large scales and small scales interact. We go on to show how these ribbons evolve over time — forming, merging, breaking apart, and disappearing. Finally, we reveal important couplings between the large-scale density waves generated by the MRI and the small-scale structures, which may illuminate the stress-pressure relationship in MRI turbulence.
Tidal dissipation in the subsurface ocean of Enceladus
Matsuyama, I.; Hay, H.; Nimmo, F.; Kamata, S.
2017-12-01
Icy satellites of the outer solar system have emerged as potential habitable worlds due to the presence of subsurface oceans. As a long-term energy source, tidal heating in these oceans can influence the survivability of subsurface oceans, and the thermal, rotational, and orbital evolution of these satellites. Additionally, the spatial and temporal variation of tidal heating has implications for the interior structure and spacecraft observations. Previous models for dissipation in thin oceans are not generally applicable to icy satellites because either they ignore the presence of an overlying solid shell or use a thin shell membrane approximation. We present a new theoretical treatment for tidal dissipation in thin oceans with overlying shells of arbitrary thickness and apply it to Enceladus. The shell's resistance to ocean tides increases with shell thickness, reducing tidal dissipation as expected. Both the magnitude of energy dissipation and the resonant ocean thicknesses decrease as the overlying shell thickness increases, as previously shown using a membrane approximation. In contrast to previous work based on the traditional definition of the tidal quality factor, Q, our new definition is consistent with higher energy dissipation for smaller Q, and introduces a lower limit on Q. The dissipated power and tides are not in phase with the forcing tidal potential due to the delayed ocean response. The phase lag depends on the Rayleigh friction coefficient and ocean and shell thicknesses, which implies that phase lag observations can be used to constrain these parameters. Eccentricity heating produces higher dissipation near the poles, while obliquity heating produces higher dissipation near the equator, in contrast to the dissipation patterns in the shell. The time-averaged surface distribution of tidal heating can generate lateral shell thickness variations, providing an additional constraint on the Rayleigh friction coefficient. Explaining the endogenic power
Dissipative systems and Bateman's Hamiltonian
Pedrosa, I.A.; Baseia, B.
1983-01-01
It is shown, by using canonical transformations, that one can construct Bateman's Hamiltonian from a Hamiltonian for a conservative system and obtain a clear physical interpretation which explains the ambiguities emerging from its application to describe dissipative systems. (Author) [pt
Dissipative Effect and Tunneling Time
Samyadeb Bhattacharya
2011-01-01
Full Text Available The quantum Langevin equation has been studied for dissipative system using the approach of Ford et al. Here, we have considered the inverted harmonic oscillator potential and calculated the effect of dissipation on tunneling time, group delay, and the self-interference term. A critical value of the friction coefficient has been determined for which the self-interference term vanishes. This approach sheds new light on understanding the ion transport at nanoscale.
Notari, Alessio [Departament de Física Fondamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, Barcelona, 08028 Spain (Spain); Tywoniuk, Konrad, E-mail: notari@ffn.ub.es, E-mail: konrad.tywoniuk@cern.ch [Theoretical Physics Department, CERN, Geneva (Switzerland)
2016-12-01
We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term φ/ f {sub γ} F ∼ F , such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density ρ{sub R}, which can lead to inflation without the need of a flat potential. We analyze the system, for momenta k smaller than the cutoff f {sub γ}, including the backreaction numerically. We consider the evolution from a given static initial condition and explicitly show that, if f {sub γ} is smaller than the field excursion φ{sub 0} by about a factor of at least O (20), there is a friction effect which turns on before the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of perturbations, scalars and tensors. Such oscillations have a period of 4–5 efolds and an amplitude which is typically less than a few percent and decreases linearly with f {sub γ}. We also stress that the curvature perturbation on uniform density slices should be sensitive to slow-roll parameters related to ρ{sub R} rather than φ-dot {sup 2}/2 and we discuss the existence of friction terms acting on the perturbations, although we postpone a calculation of the power spectrum and of non-gaussianity to future work and we simply define and compute suitable slow roll parameters. Finally we stress that this scenario may be realized in the axion case, if the coupling 1/ f {sub γ} to U(1) (photons) is much larger than the coupling 1/ f {sub G} to non-abelian gauge fields (gluons), since the latter sets the range of the potential and therefore the maximal allowed φ{sub 0∼} f {sub G}.
Shew, A. M.; Ghosh, A.
2017-10-01
Remote sensing in the optical domain is widely used in agricultural monitoring; however, such initiatives pose a challenge for developing countries due to a lack of high quality in situ information. Our proposed methodology could help developing countries bridge this gap by demonstrating the potential to quantify patterns of dry season rice production in Bangladesh. To analyze approximately 90,000 km2 of cultivated land in Bangladesh at 30 m spatial resolution, we used two decades of remote sensing data from the Landsat archive and Google Earth Engine (GEE), a cloud-based geospatial data analysis platform built on Google infrastructure and capable of processing petabyte-scale remote sensing data. We reconstructed the seasonal patterns of vegetation indices (VIs) for each pixel using a harmonic time series (HTS) model, which minimizes the effects of missing observations and noise. Next, we combined the seasonality information of VIs with our knowledge of rice cultivation systems in Bangladesh to delineate rice areas in the dry season, which are predominantly hybrid and High Yielding Varieties (HYV). Based on historical Landsat imagery, the harmonic time series of vegetation indices (HTS-VIs) model estimated 4.605 million ha, 3.519 million ha, and 4.021 million ha of rice production for Bangladesh in 2005, 2010, and 2015 respectively. Fine spatial scale information on HYV rice over the last 20 years will greatly improve our understanding of double-cropped rice systems, current status of production, and potential for HYV rice adoption in Bangladesh during the dry season.
Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang
2006-01-01
Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.
Derroire, Géraldine; Powers, Jennifer S; Hulshof, Catherine M; Cárdenas Varela, Luis E; Healey, John R
2018-01-10
A coordinated response to environmental drivers amongst individual functional traits is central to the plant strategy concept. However, whether the trait co-ordination observed at the global scale occurs at other ecological scales (especially within species) remains an open question. Here, for sapling communities of two tropical dry forest types in Costa Rica, we show large differences amongst traits in the relative contribution of species turnover and intraspecific variation to their directional changes in response to environmental changes along a successional gradient. We studied the response of functional traits associated with the leaf economics spectrum and drought tolerance using intensive sampling to analyse inter- and intra-specific responses to environmental changes and ontogeny. Although the overall functional composition of the sapling communities changed during succession more through species turnover than through intraspecific trait variation, their relative contributions differed greatly amongst traits. For instance, community mean specific leaf area changed mostly due to intraspecific variation. Traits of the leaf economics spectrum showed decoupled responses to environmental drivers and ontogeny. These findings emphasise how divergent ecological mechanisms combine to cause great differences in changes of individual functional traits over environmental gradients and ecological scales.
Salas-Morales, Silvia H.; Meave, Jorge A.; Trejo, Irma
2015-12-01
Globally, climate is a fundamental driver of plant species' geographical distributions, yet we still lack a good understanding of climatic variation on tropical mountains and its consequences for elevational floristic patterns. In a seasonally dry region of southern Mexico, we analysed meteorological patterns along a large elevational gradient (0-3670 m a.s.l.) and examined their relationship with changes in floristic richness. Meteorological patterns were characterised using two data sources. First, climatic information was extracted from cartography and records from a few existing meteorological stations. Additionally, air temperature and humidity were recorded hourly during 1 year with data loggers, at sites representing 200-m elevation increments. Floristic information was extracted from a database containing 10,124 records of plant collections, and organized in 200-m elevational belts. Climatic charts distinguished three climate types along the gradient, all with marked rainfall seasonality, but these bore little correspondence with the information obtained with the data loggers. Mean annual air temperature decreased with increasing elevation (lapse rate of 0.542 °C 100 m-1). Thermal oscillation was minimum around 1400 m and increased towards both extremes of the gradient. Relative humidity opposed this pattern, with maxima between 800 and 1800 m, decreasing towards the highest elevations. An analysis of temperature frequency distributions revealed meteorological features undetectable from the annual or monthly means of this variable; despite an overall gradual transition of the proportions of time recorded at different temperatures, some changes did not conform to this pattern. The first discontinuity occurred between 1000-1200 m, where dominant temperatures shifted abruptly; also noticeable was an abrupt increase of the proportion of time elapsed at 0.1-10 °C between 2400 and 2600 m. Air temperature appears to be the most influential climatic factor
Dissipative structures and related methods
Langhorst, Benjamin R; Chu, Henry S
2013-11-05
Dissipative structures include at least one panel and a cell structure disposed adjacent to the at least one panel having interconnected cells. A deformable material, which may comprise at least one hydrogel, is disposed within at least one interconnected cell proximate to the at least one panel. Dissipative structures may also include a cell structure having interconnected cells formed by wall elements. The wall elements may include a mesh formed by overlapping fibers having apertures formed therebetween. The apertures may form passageways between the interconnected cells. Methods of dissipating a force include disposing at least one hydrogel in a cell structure proximate to at least one panel, applying a force to the at least one panel, and forcing at least a portion of the at least one hydrogel through apertures formed in the cell structure.
Microscopic nuclear dissipation. Pt. 2
Yannouleas, C.; Dworzecka, M.; Griffin, J.J.
1983-01-01
We have formulated a microscopic, nonperturbative, time reversible model which exhibits a dissipative decay of collective motion for times short compared to the system's Poincare time. The model assumes an RPA approximate description of the initial collective state within a restricted subspace, then traces its time evolution when an additional subspace is coupled to the restricted subspace by certain simplified matrix elements. It invokes no statistical assumptions. The damping of the collective motion occurs via real transitions from the collective state to other more complicated nuclear states of the same energy. It corresponds therefore to the so called 'one-body' long mean free path limit of nuclear dissipation when the collective state describes a surface vibration. When the simplest RPA approximation is used, this process associates the dissipation with the escape width for direct particle emission to the continuum. When the more detailed second RPA is used, it associates the dissipation with the spreading width for transitions to the 2p-2h components of the nuclear compound states as well. The energy loss rate for sharp n-phonon initial states is proportional to the total collective energy, unlike the dissipation of a classical damped oscillator, where it is proportional to the kinetic energy only. However, for coherent, multi-phonon wave packets, which explicitly describe the time-dependent oscillations of the mean field, dissipation proportional only to the kinetic energy is obtained. Canonical coordinates for the collective degree of freedom are explicitly introduced and a nonlinear frictional hamiltonian to describe such systems is specified by the requirement that it yield the same time dependence for the collective motion as the microscopic model. Thus, for the first time a descriptive nonlinear hamiltonian is derived explicitly from the underlying microscopic model of a nuclear system. (orig.)
Zero temperature dissipation and holography
Banerjee, Pinaki; Sathiapalan, B. [Institute of Mathematical Sciences,CIT Campus, Taramani, Chennai 600 113 (India)
2016-04-14
We use holographic techniques to study the zero-temperature limit of dissipation for a Brownian particle moving in a strongly coupled CFT at finite temperature in various space-time dimensions. The dissipative term in the boundary theory for ω→0, T→0 with ω/T held small and fixed, does not match the same at T=0, ω→0. Thus the T→0 limit is not smooth for ω
Dissipative heavy-ion collisions
Feldmeier, H.T.
1985-01-01
This report is a compilation of lecture notes of a series of lectures held at Argonne National Laboratory in October and November 1984. The lectures are a discussion of dissipative phenomena as observed in collisions of atomic nuclei. The model is based on a system which has initially zero temperature and the initial energy is kinetic and binding energy. Collisions excite the nuclei, and outgoing fragments or the compound system deexcite before they are detected. Brownian motion is used to introduce the concept of dissipation. The master equation and the Fokker-Planck equation are derived. 73 refs., 59 figs
van der Walt, Anita; Lopata, Andreas L; Nieuwenhuizen, Natalie E; Jeebhay, Mohamed F
2010-01-01
Three spice mill workers developed work-related allergy and asthma after prolonged exposure to high levels (>10 mg/m(3)) of inhalable spice dust. Patterns of sensitization to a variety of spices and putative allergens were identified. Work-related allergy and asthma were assessed on history, clinical evaluation, pulmonary function and fractional exhaled nitric oxide. Specific IgE reactivity to a range of common inhalant, food and spice allergens was evaluated using ImmunoCAP and allergen microarray. The presence of non-IgE-mediated reactions was determined by basophil stimulation (CAST-ELISA). Specific allergens were identified by immunoblotting to extracts of raw and dried processed garlic, onion and chili pepper. Asthma was confirmed in all 3 subjects, with work-related patterns prominent in worker 1 and 3. Sensitization to multiple spices and pollen was observed in both atopic workers 1 and 2, whereas garlic and chili pepper sensitization featured in all 3 workers. Microarray analysis demonstrated prominent profilin reactivity in atopic worker 2. Immunoblotting demonstrated a 50-kDa cross-reactive allergen in garlic and onion, and allergens of approximately 40 and 52 kDa in chili pepper. Dry powdered garlic and onion demonstrated greater IgE binding. This study demonstrated IgE reactivity to multiple spice allergens in workers exposed to high levels of inhalable spice dust. Processed garlic and onion powder demonstrated stronger IgE reactivity than the raw plant. Atopy and polysensitization to various plant profilins, suggesting pollen-food syndrome, represent additional risk factors for sensitizer-induced work-related asthma in spice mill workers. 2010 S. Karger AG, Basel.
Koster, N. B.; Molkenboer, F. T.; van Veldhoven, E.; Oostrom, S.
2011-04-01
We report on our findings on EUVL reticle contamination removal, inspection and repair. We show that carbon contamination can be removed without damage to the reticle by our plasma process. Also organic particles, simulated by PSL spheres, can be removed from both the surface of the absorber as well as from the bottom of the trenches. The particles shrink in size during the plasma treatment until they are vanished. The determination of the necessary cleaning time for PSL spheres was conducted on Ru coated samples and the final experiment was performed on our dummy reticle. Finally we show that the Helium Ion Microscope in combination with a Gas Injection System is capable of depositing additional lines and squares on the reticle with sufficient resolution for pattern repair.
ENERGY DISSIPATION PROCESSES IN SOLAR WIND TURBULENCE
Wang, Y.; Wei, F. S.; Feng, X. S.; Sun, T. R.; Zuo, P. B. [SIGMA Weather Group, State Key Laboratory for Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Xu, X. J. [Space Science Institute, Macau University of Science and Technology, Macao (China); Zhang, J., E-mail: yw@spaceweather.ac.cn [School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, MSN 3F3, Fairfax, Virginia 22030 (United States)
2015-12-15
Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation ultimately cannot be achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection (MR) are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind MR region. We find that the MR region shows unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for intermittent multifractal dissipation region scaling around a MR site, and they also have significant implications for the fundamental energy dissipation process.
Vera De Cauwer
2016-09-01
Full Text Available Background Tropical dry forests cover less than 13 % of the world’s tropical forests and their area and biodiversity are declining. In southern Africa, the major threat is increasing population pressure, while drought caused by climate change is a potential threat in the drier transition zones to shrub land. Monitoring climate change impacts in these transition zones is difficult as there is inadequate information on forest composition to allow disentanglement from other environmental drivers. Methods This study combined historical and modern forest inventories covering an area of 21,000 km2 in a transition zone in Namibia and Angola to distinguish late succession tree communities, to understand their dependence on site factors, and to detect trends in the forest composition over the last 40 years. Results The woodlands were dominated by six tree species that represented 84 % of the total basal area and can be referred to as Baikiaea - Pterocarpus woodlands. A boosted regression tree analysis revealed that late succession tree communities are primarily determined by climate and topography. The Schinziophyton rautanenii and Baikiaea plurijuga communities are common on slightly inclined dune or valley slopes and had the highest basal area (5.5 – 6.2 m2 ha−1. The Burkea africana - Guibourtia coleosperma and Pterocarpus angolensis – Dialium englerianum communities are typical for the sandy plateaux and have a higher proportion of smaller stems caused by a higher fire frequency. A decrease in overall basal area or a trend of increasing domination by the more drought and cold resilient B. africana community was not confirmed by the historical data, but there were significant decreases in basal area for Ochna pulchra and the valuable fruit tree D. englerianum. Conclusions The slope communities are more sheltered from fire, frost and drought but are more susceptible to human expansion. The community with the important timber tree P
Wei, Wei; Yu, Yun; Chen, Liding
2015-01-01
The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes.
... Eye » Facts About Dry Eye Listen Facts About Dry Eye Fact Sheet Blurb The National Eye Institute (NEI) ... and their families search for general information about dry eye. An eye care professional who has examined the ...
Erkus, Baris; Johnson, Erik A
2011-01-01
This paper investigates the dissipativity and performance characteristics of the semiactive control of the base isolated benchmark structure with magnetorheological (MR) fluid dampers. Previously, the authors introduced the concepts of dissipativity and dissipativity indices in the semiactive control of structures with smart dampers and studied the dissipativity characteristics of simple structures with idealized dampers. To investigate the effects of semiactive controller dissipativity characteristics on the overall performance of the base isolated benchmark building, a clipped optimal control strategy with a linear quadratic Gaussian (LQG) controller and a 20 ton MR fluid damper model is used. A cumulative index is proposed for quantifying the overall dissipativity of a control system with multiple control devices. Two control designs with different dissipativity and performance characteristics are considered as the primary controller in clipped optimal control. Numerical simulations reveal that the dissipativity indices can be classified into two groups that exhibit distinct patterns. It is shown that the dissipativity indices identify primary controllers that are more suitable for application with MR dampers and provide useful information in the semiactive design process that complements other performance indices. The computational efficiency of the proposed dissipativity indices is verified by comparing computation times
Dissipative effects in Multilevel Systems
Solomon, A I [Department of Physics and Astronomy, Open University, Milton Keynes MK7 6AA (United Kingdom); Schirmer, S G [Department of Applied Maths and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA (United Kingdom)
2007-11-15
Dissipation is sometimes regarded as an inevitable and regrettable presence in the real evolution of a quantum system. However, the effects may not always be malign, although often non-intuitive and may even be beneficial. In this note we we display some of these effects for N-level systems, where N = 2,3,4. We start with an elementary introduction to dissipative effects on the Bloch Sphere, and its interior, the Bloch Ball, for a two-level system. We describe explicitly the hamiltonian evolution as well as the purely dissipative dynamics, in the latter case giving the t {yields} {infinity} limits of the motion. This discussion enables us to provide an intuitive feeling for the measures of control-reachable states. For the three-level case we discuss the impossibility of isolating a two-level (qubit) subsystem; this is a Bohm-Aharonov type consequence of dissipation. We finally exemplify the four-level case by giving constraints on the decay of two-qubit entanglement.
Estimates of anelastic dissipation in the Earth's torsional modes
M. CAPUTO
1966-06-01
Full Text Available The decay of the amplitude of the free modes of the
Earth is a potential source of information on the mechanism of dissipation
of the elastic energy of the Earth.
However there are serious difficulties in the interpretation of the decay;
they are caused by several facts. One is the limited length of the significant
part of the record which prohibits to identify the splitting of all the modes
caused by the Earth rotation and also to follow the pattern in its rotation;
another reason is the coupling between modes, caused by the inhomogenities
and the flattening of the Earth, which can transfer energy from one mode
to another. The results available are therefore very few and of poor accuracy.
In order to seek new information on the mechanism of dissipation of
the elastic energy we solve a generalized form of the equation of elastodynamic
in which we have introduced some unspecified operators to represent
the dissipation of the elastic energy. By confronting these operators with
the observations we would hope to find informations on the mechanism
of dissipation. Unfortunately the laws of variation of Q with frequency,
found by various authors who were using different observations, are not in
agreement and are very uncertain. Therefore we can only estimate the
average values of the parameters of the supposed mechanisms of dissipation.
We analyze also the dissipation of energy due to viscous frictions at
the core mantle boundary. This dissipation would be negligible even for
viscosities of the core up to 1010 poise
Scalar dissipation rate and dissipative anomaly in isotropic turbulence
Donzis, D.A.; Sreenivasan, K.R.; Yeung, P.K.
2006-12-01
We examine available data from experiment and recent numerical simulations to explore the supposition that the scalar dissipation rate in turbulence becomes independent of the fluid viscosity when the viscosity is small and of scalar diffusivity when the diffusivity is small. The data are interpreted in the context of semi-empirical spectral theory of Obukhov and Corrsin when the Schmidt number, Sc, is below unity, and of Batchelor's theory when Sc is above unity. Practical limits in terms of the Taylor-microscale Reynolds number, R λ , as well as Sc, are deduced for scalar dissipation to become sensibly independent of molecular properties. In particular, we show that such an asymptotic state is reached if R λ Sc 1/2 >> 1 for Sc λ 1. (author)
Dissipation of Wave Energy by Cohesive Sediments
Kaihatu, James M; Sheremet, Alexandru
2004-01-01
Wave energy dissipation by bottom muds is studied. A dissipation mechanism which contains explicit expressions of wavenumber modification due to a viscous bottom fluid is incorporated into a nonlinear wave shoaling model...
Dissipation and nuclear collective motion
Hofmann, Helmut; Jensen, A.S.; Ngo, Christian; Siemens, P.J.; California Univ., Berkeley
1979-01-01
This contribution is intended to give a brief summary of a forthcoming paper which shall review extensively the linear response theory for dissipation and statistical fluctuations as well as its application to heavy-ion collisions. It shall contain new results on the following subjects: numerical computations of response functions and transport coefficients; dissipation in a self-consistent treatment of harmonic vibrations; introduction of collective variables within a quantum theory. The method used consists of an extended version of the Bohm and Pines treatment of the electron gas. It allows to deduce a quantum Hamiltonian for the collective and intrinsic motion including coupling terms; discussion and solution of a quantal Master equation for non-linear collective motion. Additionally, a somewhat elaborate discussion of the problems of irreversibility is given, especially in connection to a treatment within the moving basis
Kinetic approach to relativistic dissipation
Gabbana, A.; Mendoza, M.; Succi, S.; Tripiccione, R.
2017-08-01
Despite a long record of intense effort, the basic mechanisms by which dissipation emerges from the microscopic dynamics of a relativistic fluid still elude complete understanding. In particular, several details must still be finalized in the pathway from kinetic theory to hydrodynamics mainly in the derivation of the values of the transport coefficients. In this paper, we approach the problem by matching data from lattice-kinetic simulations with analytical predictions. Our numerical results provide neat evidence in favor of the Chapman-Enskog [The Mathematical Theory of Non-Uniform Gases, 3rd ed. (Cambridge University Press, Cambridge, U.K., 1970)] procedure as suggested by recent theoretical analyses along with qualitative hints at the basic reasons why the Chapman-Enskog expansion might be better suited than Grad's method [Commun. Pure Appl. Math. 2, 331 (1949), 10.1002/cpa.3160020403] to capture the emergence of dissipative effects in relativistic fluids.
Nuclear Dissipation from Fission Time
Gontchar, I.; Morjean, M.; Basnary, S.
2000-01-01
Fission times, pre-scission neutron multiplicities and GDR pre-scission γ-ray multiplicities measured for uranium or thorium nuclei formed with temperatures T ∼ 1.8 MeV have been compared with calculations performed with CDSM2, a two-dimensional dynamical model combined with a statistical one. Among the three experimental approaches considered, fission times give access to the most precise pieces of information on nuclear dissipation at high excitation energy. For the temperature range under consideration, an agreement between the model and data is achieved if one-body dissipation is used with a strength factor k red ∼ 0.45 ± 0.10 applied to the wall term for the mononuclear configuration. (authors)
Collisionless dissipation of Langmuir turbulence
Erofeev, V.I.
2002-01-01
An analysis of two experimental observations of Langmuir wave collapse is performed. The corresponding experimental data are shown to give evidence against the collapse. The physical reason for preventing the collapses is found to be the nonresonant electron diffusion in momentums. In this process, plasma thermal electrons are efficiently heated at the expense of wave energy, and intense collisionless wave dissipation takes place. The basic reason of underestimation of this phenomenon in traditional theory is shown to be the substitution of real plasma by a plasma probabilistic ensemble. A theory of nonresonant electron diffusion in a single collisionless plasma is developed. It is shown that corresponding collisionless wave dissipation may arrest spectral energy transfer towards small wave numbers
Anisotropy dissipation in quantum cosmology
Calzetta, E.; Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires, Argentina)
1991-01-01
We study the issue of decoherence and dissipation in the wave function of the Universe for a Bianchi type-I universe with classical and quantum matter. We obtain a coarse-grained description by tracing over the matter degrees of freedom. Provided that for small universes the wave function of the universe is concentrated on a neighborhood of the isotropic configuration, then the coarse-grained density matrix of the universe will show an even more marked peak around isotropy for large universes. In this sense we can say that, while decoherence makes the reduced density matrix of the universe diagonal, dissipation causes the universe to be isotropic with a high probability for large radii
Dissipative fluid mechanics of nuclei
Morgenstern, B.
1987-11-01
With the aim to describe nucleus-nucleus collisions at low energies in the present thesis for the first time dissipative fluid dynamics for large-amplitude nuclear motion have been formulated. Thereby the collective dynamics are described in a scaling approximation in which the wave function of the system is distorted by a vortex-free velocity field. For infintely extended nuclear matter this scaling of the wave functions leads to a deformation of the Fermi sphere. Two-body collisions destroy the collective deformation of the Fermi sphere and yield so the dissipative contribution of the motion. Equations of motion for a finite set of collective variables and a field equation for the collective velocity potential in the limit of infinitely many degrees of freedom were developed. In the elastic limit oscillations around the equilibrium position are described. For small collective amplitudes and vortex-free velocity fields the integrodifferential equation for the velocity potential in the elastic limit could be transformed to the divergence of the field equation of fluid dynamics. In the dissipative limit an equation results which is similar to the Navier-Stokes equation and transforms to the divergence of the Navier-Stokes equation for vortex-free fields. It was shown that generally the dynamics of the many-body system is described by non-Markovian equations. (orig./HSI) [de
Wei Wei
Full Text Available The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes.
Wei, Wei; Yu, Yun; Chen, Liding
2015-01-01
The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes. PMID:26207757
Markwalter, Christine F.; Gibson, Lauren E.; Mudenda, Lwiindi; Kimmel, Danielle W.; Mbambara, Saidon; Thuma, Philip E.; Wright, David W.
2018-01-01
Abstract. A rapid, on-bead enzyme-linked immunosorbent assay for Plasmodium lactate dehydrogenase (pLDH) and Plasmodium falciparum histidine-rich protein 2 (HRP2) was adapted for use with dried blood spot (DBS) samples. This assay detected both biomarkers from a single DBS sample with only 45 minutes of total incubation time and detection limits of 600 ± 500 pM (pLDH) and 69 ± 30 pM (HRP2), corresponding to 150 and 24 parasites/μL, respectively. This sensitive and reproducible on-bead detection method was used to quantify pLDH and HRP2 in patient DBS samples from rural Zambia collected at multiple time points after treatment. Biomarker clearance patterns relative to parasite clearance were determined; pLDH clearance followed closely with parasite clearance, whereas most patients maintained detectable levels of HRP2 for 35–52 days after treatment. Furthermore, weak-to-moderate correlations between biomarker concentration and parasite densities were found for both biomarkers. This work demonstrates the utility of the developed assay for epidemiological study and surveillance of malaria. PMID:29557342
Alveolar osteitis; Alveolitis; Septic socket ... You may be more at risk for dry socket if you: Have poor oral health Have a ... after having a tooth pulled Have had dry socket in the past Drink from a straw after ...
Dissipative hidden sector dark matter
Foot, R.; Vagnozzi, S.
2015-01-01
A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken U (1 )' gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength ε ˜10-9 appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on big bang nucleosynthesis and its contribution to the relativistic energy density at hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focusing on spiral and irregular galaxies. For these galaxies we modeled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.
Designing Biomimetic, Dissipative Material Systems
Balazs, Anna C. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Whitesides, George M. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology; Brinker, C. Jeffrey [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering. Dept. of Chemistry. Dept. of Molecular Genetics and Microbiology. Center for Micro-Engineered Materials; Aranson, Igor S. [UChicago, LLC., Argonne, IL (United States); Chaikin, Paul [New York Univ. (NYU), NY (United States). Dept. of Physics; Dogic, Zvonimir [Brandeis Univ., Waltham, MA (United States). Dept. of Physics; Glotzer, Sharon [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering. Dept. of Materials Science and Engineering. Dept. of Macromolecular Science and Engineering Physics; Hammer, Daniel [Univ. of Pennsylvania, Philadelphia, PA (United States). School of Engineering and Applied Science; Irvine, Darrell [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Materials Science and Engineering and Biological Engineering; Little, Steven R. [Univ. of Pittsburgh, PA (United States). Chemical Engineering Dept.; Olvera de la Cruz, Monica [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Parikh, Atul N. [Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering. Dept. of Chemical Engineering and Materials Science; Stupp, Samuel [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering. Dept. of Chemistry. Dept. of Medicine. Dept. of Biomedical Engineering; Szostak, Jack [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry and Chemical Biology
2016-01-21
Throughout human history, new materials have been the foundation of transformative technologies: from bronze, paper, and ceramics to steel, silicon, and polymers, each material has enabled far-reaching advances. Today, another new class of materials is emerging—one with both the potential to provide radically new functions and to challenge our notion of what constitutes a “material”. These materials would harvest, transduce, or dissipate energy to perform autonomous, dynamic functions that mimic the behaviors of living organisms. Herein, we discuss the challenges and benefits of creating “dissipative” materials that can potentially blur the boundaries between living and non-living matter.
Caspersen, Louise M; Christensen, Ib J; Kjær, Inger
2009-01-01
Objective. The purpose of this study was to analyze the correlation between direction of the infraorbital canal and maxillary width on frontal radiographs of dry human skulls. Material and methods. Forty-two symmetrical, dry human skulls (late adolescence and adult) with no dental or skeletal...... anomalies. Frontal radiographs were taken of each skull placed in the Frankfort horizontal plane, with a radiopaque marker in the infraorbital canal. The maxillary transversal growth pattern was expressed as the infraorbital transversal angle (IOt) formed between a line through the contour of the bilateral...
Natural approach to quantum dissipation
Taj, David; Öttinger, Hans Christian
2015-12-01
The dissipative dynamics of a quantum system weakly coupled to one or several reservoirs is usually described in terms of a Lindblad generator. The popularity of this approach is certainly due to the linear character of the latter. However, while such linearity finds justification from an underlying Hamiltonian evolution in some scaling limit, it does not rely on solid physical motivations at small but finite values of the coupling constants, where the generator is typically used for applications. The Markovian quantum master equations we propose are instead supported by very natural thermodynamic arguments. They themselves arise from Markovian master equations for the system and the environment which preserve factorized states and mean energy and generate entropy at a non-negative rate. The dissipative structure is driven by an entropic map, called modular, which introduces nonlinearity. The generated modular dynamical semigroup (MDS) guarantees for the positivity of the time evolved state the correct steady state properties, the positivity of the entropy production, and a positive Onsager matrix with symmetry relations arising from Green-Kubo formulas. We show that the celebrated Davies Lindblad generator, obtained through the Born and the secular approximations, generates a MDS. In doing so we also provide a nonlinear MDS which is supported by a weak coupling argument and is free from the limitations of the Davies generator.
Variational principles for dissipative waves
Dodin, I. Y.; Ruiz, D. E.
2016-10-01
Variational methods are a powerful tool in plasma theory. However, their applications are typically restricted to conservative systems or require doubling of variables, which often contradicts the purpose of the variational approach altogether. We show that these restrictions can be relaxed for some classes of dynamical systems that are of practical interest in plasma physics, particularly including dissipative plasma waves. Applications will be discussed to calculating dispersion relations and modulational dynamics of individual plasma waves and wave ensembles. The work was supported by the NNSA SSAA Program through DOE Research Grant No. DE-NA0002948, by the U.S. DOE through Contract No. DE-AC02-09CH11466, and by the U.S. DOD NDSEG Fellowship through Contract No. 32-CFR-168a.
Dissipation and leaching of 14C-monocrotophos in soil columns
Vig, K.; Singh, D.K.; Agarwal, H.C.
2001-01-01
Dissipation and leaching of 14 C-monocrotophos was studied in the field. Two sets of PVC cylinders were used - one set received only 14 C monocrotophos and the other received 14 C-monocrotophos along with dimethoate, deltamethrin, endosulfan, cypermethrin and 1.06 mg unlabelled monocrotophos. Both setups showed a similar pattern of dissipation with a half-life of 277.2 days. Leaching of monocrotophos was observed into the 30cm soil layer. (author)
Transport phenomena in dissipative heavy-ion collisions: the one-body dissipation approach
Feldmeier, H.
1987-01-01
The paper reviews dissipative collisions between two atomic nuclei, with the help of the classical description of Brownian movement and the Langevin equation. The 'one-body dissipation model' for dissipative heavy-ion collisions is discussed, and its predictions are compared with measured data. Special attention is paid to the non-equilibrium relation between friction and diffusion. (U.K.)
Scattering of traveling spots in dissipative systems
Nishiura, Yasumasa; Teramoto, Takashi; Ueda, Kei-Ichi
2005-12-01
One of the fundamental questions for self-organization in pattern formation is how spatial periodic structure is spontaneously formed starting from a localized fluctuation. It is known in dissipative systems that splitting dynamics is one of the driving forces to create many particle-like patterns from a single seed. On the way to final state there occur many collisions among them and its scattering manner is crucial to predict whether periodic structure is realized or not. We focus on the colliding dynamics of traveling spots arising in a three-component system and study how the transition of scattering dynamics is brought about. It has been clarified that hidden unstable patterns called "scattors" and their stable and unstable manifolds direct the traffic flow of orbits before and after collisions. The collision process in general can be decomposed into several steps and each step is controlled by such a scattor, in other words, a network among scattors forms the backbone for scattering dynamics. A variety of input-output relations comes from the complexity of the network as well as high Morse indices of the scattor. The change of transition manners is caused by the switching of the network from one structure to another, and such a change is caused by the singularities of scattors. We illustrate a typical example of the change of transition caused by the destabilization of the scattor. A new instability of the scattor brings a new destination for the orbit resulting in a new input-output relation, for instance, Hopf instability for the scattor of peanut type brings an annihilation.
Dissipative Solitons that Cannot be Trapped
Pardo, Rosa; Perez-Garcia, Victor M.
2006-01-01
We show that dissipative solitons in systems with high-order nonlinear dissipation cannot survive in the presence of trapping potentials of the rigid wall or asymptotically increasing type. Solitons in such systems can survive in the presence of a weak potential but only with energies out of the interval of existence of linear quantum mechanical stationary states
Quantum dissipation of a simple conservative system
Ibeh, G. J.; Mshelia, E. D.
2014-01-01
A model of quantum dissipative system is presented. Here dissipation of energy is demonstrated as based on the coupling of a free translational motion of a centre of mass to a harmonic oscillator. The two-dimensional arrangement of two coupled particles of different masses is considered.
Dissipative electromagnetism from a nonequilibrium thermodynamics perspective
Jelic, A.; Hütter, M.; Öttinger, H.C.
2006-01-01
Dissipative effects in electromagnetism on macroscopic scales are examined by coarse-graining the microscopic Maxwell equations with respect to time. We illustrate a procedure to derive the dissipative effects on the macroscopic scale by using a Green-Kubo type expression in terms of the microscopic
Dissipation in nucleus-nucleus collisions
Santanu Pal
1984-01-01
This paper deals with the mechanism of one- and two-body dissipations in nucleus-nucleus collisions. The average energy transferred to nuclear excitations is calculated using a time-dependent density matrix approach with lowest-order approximations. Considering the nuclei as Fermi gases, and using a gaussian-type NN interaction as the basic perturbation, simplified expressions are obtained for energy dissipations. These expressions are quite instructive to follow a number of interesting aspects of one- and two-body dissipations. It is theoretically observed that the memory time for the two-body dissipation is significantly smaller than that of one-body dissipation. A threshold-type dependence of the transferred energy on the relative velocity between the two nuclei is also observed. This threshold velocity is found to be related with the intrinsic nucleon kinetic energy for two-body dissipation and with the nuclear size for the one-body case. This observation further suggests that the total dissipated energy is shared between the two nuclei approximately in the ratio of their masses. The physical origin of these observations is also explained. Numerical calculations further illustrate some characteristic features of one- and two-body dissipations. (orig.)
On the stability of dissipative MHD equilibria
Teichmann, J.
1979-04-01
The global stability of stationary equilibria of dissipative MHD is studied uisng the direct Liapunov method. Sufficient and necessary conditions for stability of the linearized Euler-Lagrangian system with the full dissipative operators are given. The case of the two-fluid isentropic flow is discussed. (orig.)
Stamate, Eugen; Yeom, Geun Young
2016-01-01
generation) to 2,200 × 2,500 mm (eighth generation), and the substrate size is expected to increase further within a few years. This chapter aims to present relevant details on dry etching including the phenomenology, materials to be etched with the different recipes, plasma sources fulfilling the dry...
Analytical study of dissipative solitary waves
Dini, Fatemeh [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Emamzadeh, Mehdi Molaie [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Khorasani, Sina [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of); Bobin, Jean Louis [Universite Pierre et Marie Curie, Paris (France); Amrollahi, Reza [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Sodagar, Majid [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of); Khoshnegar, Milad [School of Electrical Engineering, Sharif University of Technology, PO Box 11365-363, Tehran (Iran, Islamic Republic of)
2008-02-15
In this paper, the analytical solution to a new class of nonlinear solitons is presented with cubic nonlinearity, subject to a dissipation term arising as a result of a first-order derivative with respect to time, in the weakly nonlinear regime. Exact solutions are found using the combination of the perturbation and Green's function methods up to the third order. We present an example and discuss the asymptotic behavior of the Green's function. The dissipative solitary equation is also studied in the phase space in the non-dissipative and dissipative forms. Bounded and unbounded solutions of this equation are characterized, yielding an energy conversation law for non-dissipative waves. Applications of the model include weakly nonlinear solutions of terahertz Josephson plasma waves in layered superconductors and ablative Rayleigh-Taylor instability.
A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields
Liu, J.-S. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Vojinovic, V. [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland); Patino, R. [Cinvestav-Merida, Departamento de Fisica Aplicada, Km. 6 carretera antigua a Progreso, AP 73 Cordemex, 97310 Merida, Yucatan (Mexico); Maskow, Th. [UFZ Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, D-04318 Leipzig (Germany); Stockar, U. von [Laboratory of Chemical and Biochemical Engineering, Swiss Federal Institute of Technology, EPFL, CH-1015 Lausanne (Switzerland)]. E-mail: urs.vonStockar@epfl.ch
2007-06-25
Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol{sup -1} of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure.
A comparison of various Gibbs energy dissipation correlations for predicting microbial growth yields
Liu, J.-S.; Vojinovic, V.; Patino, R.; Maskow, Th.; Stockar, U. von
2007-01-01
Thermodynamic analysis may be applied in order to predict microbial growth yields roughly, based on an empirical correlation of the Gibbs energy of the overall growth reaction or Gibbs energy dissipation. Due to the well-known trade-off between high biomass yield and high Gibbs energy dissipation necessary for fast growth, an optimal range of Gibbs energy dissipation exists and it can be correlated to physical characteristics of the growth substrates. A database previously available in the literature has been extended significantly in order to test such correlations. An analysis of the relationship between biomass yield and Gibbs energy dissipation reveals that one does not need a very precise estimation of the latter to predict the former roughly. Approximating the Gibbs energy dissipation with a constant universal value of -500 kJ C-mol -1 of dry biomass grown predicts many experimental growth yields nearly as well as a carefully designed, complex correlation available from the literature, even though a number of predictions are grossly out of range. A new correlation for Gibbs energy dissipation is proposed which is just as accurate as the complex literature correlation despite its dramatically simpler structure
Lagrangian descriptors in dissipative systems.
Junginger, Andrej; Hernandez, Rigoberto
2016-11-09
The reaction dynamics of time-dependent systems can be resolved through a recrossing-free dividing surface associated with the transition state trajectory-that is, the unique trajectory which is bound to the barrier region for all time in response to a given time-dependent potential. A general procedure based on the minimization of Lagrangian descriptors has recently been developed by Craven and Hernandez [Phys. Rev. Lett., 2015, 115, 148301] to construct this particular trajectory without requiring perturbative expansions relative to the naive transition state point at the top of the barrier. The extension of the method to account for dissipation in the equations of motion requires additional considerations established in this paper because the calculation of the Lagrangian descriptor involves the integration of trajectories in forward and backward time. The two contributions are in general very different because the friction term can act as a source (in backward time) or sink (in forward time) of energy, leading to the possibility that information about the phase space structure may be lost due to the dominance of only one of the terms. To compensate for this effect, we introduce a weighting scheme within the Lagrangian descriptor and demonstrate that for thermal Langevin dynamics it preserves the essential phase space structures, while they are lost in the nonweighted case.
Loretta Goldberg
2009-11-01
Full Text Available Helicteres guazumifolia Kunth and Helicteres baruensis Jacq. (Sterculiaceae are two sympatric species of shrubs common along the North Western tropical dry forest of Costa Rica. i recorded their nectar production within a 24 hour cycle. i also describe the morphology of extrafloral nectaries with scanning electron microscopy. in H. guazumifolia secretion was restricted to the first day of flower life span, shortly after anthesis (0600 hr - 1800 hr. Flowers secreted on average 15.63 ±8.45 µl (N=409. Nectar is composed of three main sugars: sucrose, fructose and glucose (mainly sucrose. A total of 17 free amino acids were identified: mainly proline, arginine, threonine and tyrosine, with a concentration above 70 Ng/µl. values were different for H. baruensis. Nectar secretion was confined to the second day after anthesis, starting at 1600 hr and ending at 0600 hr the following day. Flowers secreted on average 77.03 ±64.99 µl (N=163 of nectar. Nectar is also composed of three main sugars; however, it showed a tendency to be hexose-rich, having more fructose and glucose than sucrose. There were also 17 free amino acids, mainly proline, alanine, tyrosine, arginine and threonine. Patterns of nectar production are different between the two species for timing, and for amount and composition of nectar secretion. Rev. Biol. Trop. 57 (Suppl. 1: 161-177. Epub 2009 November 30.Helicteres guazumifolia Kunth y Helicteres baruensis Jacq. (Sterculiaceae son dos especies simpátricas de arbustos comunes en el bosque tropical seco de la zona noroeste de Costa Rica. Registré los patrones de producción de néctar de las dos especies según la hora del día o de la noche cuando hubo secreción de néctar. En H. guazumifolia se limitó al primer día del período de vida floral, desde el inicio de la antesis a las 0600 hr hasta las 1800 hr. Las flores secretaron en promedio 15.63 ±8.45 µl (N=409 de néctar. El néctar está compuesto por tres az
Dissipative structures and biological rhythms
Goldbeter, Albert
2017-10-01
Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.
Theoretical and practical aspects of aroma retention in spray drying and freeze drying
Coumans, W.J.; Kerkhof, P.J.A.M.; Bruin, S.
1994-01-01
A review with 75 refs. on aroma loss in slab drying, spray drying and freeze drying. For many food products the presence of volatile aroma components is a prime quality feature. Upon drying part of these components may be lost, leading to unbalanced flavor patterns in the reconstituted product. The
Low moduli elastomers with low viscous dissipation
Bejenariu, Anca Gabriela; Yu, Liyun; Skov, Anne Ladegaard
2012-01-01
A controlled reaction schema for addition curing silicones leads to both significantly lower elastic modulus and lower viscous dissipation than for the chemically identical network prepared by the traditional reaction schema....
Dissipation effects in mechanics and thermodynamics
Güémez, J.; Fiolhais, M.
2016-07-01
With the discussion of three examples, we aim at clarifying the concept of energy transfer associated with dissipation in mechanics and in thermodynamics. The dissipation effects due to dissipative forces, such as the friction force between solids or the drag force in motions in fluids, lead to an internal energy increase of the system and/or to heat transfer to the surroundings. This heat flow is consistent with the second law, which states that the entropy of the universe should increase when those forces are present because of the irreversibility always associated with their actions. As far as mechanics is concerned, the effects of the dissipative forces are included in Newton’s equations as impulses and pseudo-works.
Phenomenological approaches of dissipative heavy ion collisions
Ngo, C.
1983-09-01
These lectures describe the properties of dissipative heavy ion collisions observed in low bombarding energy heavy ion reactions. These dissipative collisions are of two different types: fusion and deep inelastic reactions. Their main experimental properties are described on selected examples. It is shown how it is possible to give a simple interpretation to the data. A large number of phenomenological models have been developped to understand dissipative heavy ion collisions. The most important are those describing the collision by classical mechanics and friction forces, the diffusion models, and transport theories which merge both preceding approaches. A special emphasis has been done on two phenomena observed in dissipative heavy ion collisions: charge equilibratium for which we can show the existence of quantum fluctuations, and fast fission which appears as an intermediate mechanism between deep inelastic reactions and compound nucleus formation [fr
Observed eddy dissipation in the Agulhas Current
Braby, L
2016-08-01
Full Text Available (negative) velocity anomalies propagate downstream in the Agulhas Current at 44 km/d (23 km/d). Many models are unable to represent these eddy dissipation processes, affecting our understanding of the Agulhas Current....
Minimum dissipative relaxed states in toroidal plasmas
organised equi- librium in RFP and tokamak by a deterministic approach to incompressible dissipative magnetohydrodynamics. In an earlier work Kondoh [8] formulated an energy principle including the edge plasma effects for a slightly resistive MHD ...
Energy dissipation in multifrequency atomic force microscopy
Valentina Pukhova
2014-04-01
Full Text Available The instantaneous displacement, velocity and acceleration of a cantilever tip impacting onto a graphite surface are reconstructed. The total dissipated energy and the dissipated energy per cycle of each excited flexural mode during the tip interaction is retrieved. The tip dynamics evolution is studied by wavelet analysis techniques that have general relevance for multi-mode atomic force microscopy, in a regime where few cantilever oscillation cycles characterize the tip–sample interaction.
Hamiltonian description and quantization of dissipative systems
Enz, Charles P.
1994-09-01
Dissipative systems are described by a Hamiltonian, combined with a “dynamical matrix” which generalizes the simplectic form of the equations of motion. Criteria for dissipation are given and the examples of a particle with friction and of the Lotka-Volterra model are presented. Quantization is first introduced by translating generalized Poisson brackets into commutators and anticommutators. Then a generalized Schrödinger equation expressed by a dynamical matrix is constructed and discussed.
Drift bifurcation detection for dissipative solitons
Liehr, A W; Boedeker, H U; Roettger, M C; Frank, T D; Friedrich, R; Purwins, H-G
2003-01-01
We report on the experimental detection of a drift bifurcation for dissipative solitons, which we observe in the form of current filaments in a planar semiconductor-gas-discharge system. By introducing a new stochastic data analysis technique we find that due to a change of system parameters the dissipative solitons undergo a transition from purely noise-driven objects with Brownian motion to particles with a dynamically stabilized finite velocity
Heat dissipation during hovering and forward flight in hummingbirds.
Powers, Donald R; Tobalske, Bret W; Wilson, J Keaton; Woods, H Arthur; Corder, Keely R
2015-12-01
Flying animals generate large amounts of heat, which must be dissipated to avoid overheating. In birds, heat dissipation is complicated by feathers, which cover most body surfaces and retard heat loss. To understand how birds manage heat budgets during flight, it is critical to know how heat moves from the skin to the external environment. Hummingbirds are instructive because they fly at speeds from 0 to more than 12 m s(-1), during which they transit from radiative to convective heat loss. We used infrared thermography and particle image velocimetry to test the effects of flight speed on heat loss from specific body regions in flying calliope hummingbirds (Selasphorus calliope). We measured heat flux in a carcass with and without plumage to test the effectiveness of the insulation layer. In flying hummingbirds, the highest thermal gradients occurred in key heat dissipation areas (HDAs) around the eyes, axial region and feet. Eye and axial surface temperatures were 8°C or more above air temperature, and remained relatively constant across speeds suggesting physiological regulation of skin surface temperature. During hovering, birds dangled their feet, which enhanced radiative heat loss. In addition, during hovering, near-body induced airflows from the wings were low except around the feet (approx. 2.5 m s(-1)), which probably enhanced convective heat loss. Axial HDA and maximum surface temperature exhibited a shallow U-shaped pattern across speeds, revealing a localized relationship with power production in flight in the HDA closest to the primary flight muscles. We conclude that hummingbirds actively alter routes of heat dissipation as a function of flight speed.
Batteries - dry cell ... Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries ...
Nasr, A; Iriemenam, N C; Troye-Blomberg, M
2011-01-01
The anti-malarial IgG immune response during the lengthy and dry season in areas of low malaria transmission as in Eastern Sudan is largely unknown. In this study, ELISA was used for the measurement of pre-existing total IgG and IgG subclasses to a panel of malaria antigens, MSP2-3D7, MSP2-FC27, ...
Arnott, Don.
1985-01-01
The environmental movement has consistently argued against disposal of nuclear waste. Reasons include its irretrievability in the event of leakage, the implication that reprocessing will continue and the legitimacy attached to an expanding nuclear programme. But there is an alternative. The author here sets out the background and a possible future direction of a campaign based on a call for dry storage. (author)
Energy dissipation mapping of cancer cells.
Dutta, Diganta; Palmer, Xavier-Lewis; Kim, Jinhyun; Qian, Shizhi; Stacey, Michael
2018-02-01
The purpose of this study is to map the energy dissipation of Jurkat cells using a single 60 nanosecond pulse electric field (NsPEF), primarily through atomic force microscopy (AFM). The phase shift is generated by the sample elements that do not have a heterogeneous surface. Monitoring and manipulating the phase shift is a powerful way for determining the dissipated energy and plotting the topography. The dissipated energy is a relative value, so the silica wafer and cover slip are given a set reference while the transmission of energy between the tip of the cantilever and cell surfaces is measured. The most important finding is that the magnitude and the number of variations in the dissipated energy change with the strength of NsPEF applied. Utilizing a single low field strength NsPEF (15kV/cm), minor changes in dissipated energy were found. The application of a single high field strength NsPEF (60kV/cm) to Jurkat cells resulted in a higher dissipated energy change versus that of in the low field strength condition. Thus, the dissipated energy from the Jurkat cells changes with the strength of NsPEF. By analyzing the forces via investigation in the tapping mode of the AFM, the stabilization of the cytoskeleton and membrane of the cell are related to the strength of NsPEF applied. Furthermore, the strength of NsPEF indicates a meaningful relationship to the survival of the Jurkat cells. Copyright © 2017 Elsevier Ltd. All rights reserved.
An estimate of energy dissipation due to soil-moisture hysteresis
McNamara, H.
2014-01-01
Processes of infiltration, transport, and outflow in unsaturated soil necessarily involve the dissipation of energy through various processes. Accounting for these energetic processes can contribute to modeling hydrological and ecological systems. The well-documented hysteretic relationship between matric potential and moisture content in soil suggests that one such mechanism of energy dissipation is associated with the cycling between wetting and drying processes, but it is challenging to estimate the magnitude of the effect in situ. The Preisach model, a generalization of the Independent Domain model, allows hysteresis effects to be incorporated into dynamical systems of differential equations. Building on earlier work using such systems with field data from the south-west of Ireland, this work estimates the average rate of hysteretic energy dissipation. Through some straightforward assumptions, the magnitude of this rate is found to be of O(10-5) W m-3. Key Points Hysteresis in soil-water dissipates energy The rate of dissipation can be estimated directly from saturation data The rate of heating caused is significant ©2013. American Geophysical Union. All Rights Reserved.
Decay of Kadomtsev-Petviashvili lumps in dissipative media
Clarke, S.; Gorshkov, K.; Grimshaw, R.; Stepanyants, Y.
2018-03-01
The decay of Kadomtsev-Petviashvili lumps is considered for a few typical dissipations-Rayleigh dissipation, Reynolds dissipation, Landau damping, Chezy bottom friction, viscous dissipation in the laminar boundary layer, and radiative losses caused by large-scale dispersion. It is shown that the straight-line motion of lumps is unstable under the influence of dissipation. The lump trajectories are calculated for two most typical models of dissipation-the Rayleigh and Reynolds dissipations. A comparison of analytical results obtained within the framework of asymptotic theory with the direct numerical calculations of the Kadomtsev-Petviashvili equation is presented. Good agreement between the theoretical and numerical results is obtained.
Van Ackeren, Caroline; Steingass, Herbert; Hartung, Karin; Funk, Rainer; Drochner, Winfried
2010-08-01
To study the effect of weaning age on average daily gain (ADG), dry matter intake (DMI) and ruminal fermentation, 10 rumen-cannulated male Holstein calves were randomly assigned to one of two treatments: (i) early weaned at 8 weeks of age (235 l milk); (ii) conventionally weaned at 12 weeks of age (347 l milk). Twice daily grass hay (9.0 MJ ME x kg(-1) DM) and a dry total mixed ration (TMR) (11.6 MJ ME x kg(-1) DM) containing 15% alfalfa hay and 85% concentrates were offered separately. Water was available ad libitum. Ruminal fluid was collected via cannulas at weeks 9, 11, 13 and 15, twice weekly just prior to as well as 1, 3, 5 and 7 h after morning feeding. Calves of both treatments achieved adequate ADG (947 vs. 959 g; p > 0.05). Just-weaned calves rapidly increased DMI (1.1-2.5 kg TMR and 2.4-3.6 kg TMR for early- and conventionally-weaned calves, respectively). From weeks 10-12 early-weaned calves consumed significantly more dry feed than conventionally-weaned calves (week 10: 2.5 vs. 1.6 kg/d; week 12: 3.4 vs. 2.4 kg/d). Early weaning stimulates DMI supporting ruminal fermentation intensity, indicated by lower ruminal pH. After weaning, only early-weaned calves achieved critical average ruminal pH (week 9: 5.7 vs. 6.0, p = 0.017; week 11: 5.9 vs. 6.2, p = 0.007). Experimental treatment did not affect the concentration of ruminal short-chain fatty acids (SCFA). For all calves, the effects of the concentrate-rich TMR were shown by a high SCFA level (daily average: 137-152 mmol x l(-1)) and an acetate to propionate to butyrate ratio between 51:36:9 and 54:33:10.
L. Galicia
2016-11-01
Full Text Available The tropical dry forest is an ecosystem that is undergoing rapid changes. Although global driving forces behind these changes have been addressed at a local scale, spatio-temporal dynamics are still largely unknown. The main objective of this study was to identify the causes governing the dynamics of changes in land use and land cover in the tropical dry forest in two municipalities in Southern México. Satellite imagery and air photographs were used in a GIS context to produce maps of land use and land cover for 1985, 1995 and 2006. A number of statistical methods (Markov chains, general lineal models and regression tree analysis were applied to identify the proximate and the underlying causes of deforestation, agriculture being the most important one. When agriculture is mainly for self consumption, topographic factors determine its location. Increasing job opportunities in the tourism sector has resulted in the abandonment of agricultural land; consequently, the forest has recovered. Different studies have examined the dynamics of local deforestation and its driving forces in México; however, this study considered both spatial and temporal elements in order to identify the most important underlying driving forces of deforestation and its dynamics at local scale, and also compared two neighboring municipalities.
Dynamics of quasi-stable dissipative systems
Chueshov, Igor
2015-01-01
This book is devoted to background material and recently developed mathematical methods in the study of infinite-dimensional dissipative systems. The theory of such systems is motivated by the long-term goal to establish rigorous mathematical models for turbulent and chaotic phenomena. The aim here is to offer general methods and abstract results pertaining to fundamental dynamical systems properties related to dissipative long-time behavior. The book systematically presents, develops and uses the quasi-stability method while substantially extending it by including for consideration new classes of models and PDE systems arising in Continuum Mechanics. The book can be used as a textbook in dissipative dynamics at the graduate level. Igor Chueshov is a Professor of Mathematics at Karazin Kharkov National University in Kharkov, Ukraine.
Sudden viscous dissipation in compressing plasma turbulence
Davidovits, Seth; Fisch, Nathaniel
2015-11-01
Compression of a turbulent plasma or fluid can cause amplification of the turbulent kinetic energy, if the compression is fast compared to the turnover and viscous dissipation times of the turbulent eddies. The consideration of compressing turbulent flows in inviscid fluids has been motivated by the suggestion that amplification of turbulent kinetic energy occurred on experiments at the Weizmann Institute of Science Z-Pinch. We demonstrate a sudden viscous dissipation mechanism whereby this amplified turbulent kinetic energy is rapidly converted into thermal energy, which further increases the temperature, feeding back to further enhance the dissipation. Application of this mechanism in compression experiments may be advantageous, if the plasma can be kept comparatively cold during much of the compression, reducing radiation and conduction losses, until the plasma suddenly becomes hot. This work was supported by DOE through contract 67350-9960 (Prime # DOE DE-NA0001836) and by the DTRA.
Effect of dissipation on dynamical fusion thresholds
Sierk, A.J.
1986-01-01
The existence of dynamical thresholds to fusion in heavy nuclei (A greater than or equal to 200) due to the nature of the potential-energy surface is shown. These thresholds exist even in the absence of dissipative forces, due to the coupling between the various collective deformation degrees of freedom. Using a macroscopic model of nuclear shape dynamics, It is shown how three different suggested dissipation mechanisms increase by varying amounts the excitation energy over the one-dimensional barrier required to cause compound-nucleus formation. The recently introduced surface-plus-window dissipation may give a reasonable representation of experimental data on fusion thresholds, in addition to properly describing fission-fragment kinetic energies and isoscalar giant multipole widths. Scaling of threshold results to asymmetric systems is discussed. 48 refs., 10 figs
Optimizing the microstructure of dissipative materials
Andreassen, Erik; Lazarov, Boyan Stefanov; Jensen, Jakob Søndergaard
the material’s loss factor, however, only for large wave lengths (small wave numbers) and constant material parameters (Andreasen et al., 2012). An alternative way to determine the material’s loss factor is to consider the material’s band diagram (Sigalas and Economou, 1992), from which the loss factor can......The aim of this work is to present a method to design material microstructures with high dissipation using topology optimization. In order to compute the macroscopic energy dissipation in periodic structures, we focus both on capturing the physical dissipation mechanism and to find the effective...... from experimental results in (Schaedler, 2011), where a highly energy absorbing material, constructed from structural elements with a small cross sectional area but large area moment of inertia, is presented. Furthermore, the applicability of multiscale finite element methods (Efendiev, 2009...
Induced waveform transitions of dissipative solitons
Kochetov, Bogdan A.; Tuz, Vladimir R.
2018-01-01
The effect of an externally applied force upon the dynamics of dissipative solitons is analyzed in the framework of the one-dimensional cubic-quintic complex Ginzburg-Landau equation supplemented by a potential term with an explicit coordinate dependence. The potential accounts for the external force manipulations and consists of three symmetrically arranged potential wells whose depth varies along the longitudinal coordinate. It is found out that under an influence of such potential a transition between different soliton waveforms coexisting under the same physical conditions can be achieved. A low-dimensional phase-space analysis is applied in order to demonstrate that by only changing the potential profile, transitions between different soliton waveforms can be performed in a controllable way. In particular, it is shown that by means of a selected potential, stationary dissipative soliton can be transformed into another stationary soliton as well as into periodic, quasi-periodic, and chaotic spatiotemporal dissipative structures.
Dissipative Continuous Spontaneous Localization (CSL) model.
Smirne, Andrea; Bassi, Angelo
2015-08-05
Collapse models explain the absence of quantum superpositions at the macroscopic scale, while giving practically the same predictions as quantum mechanics for microscopic systems. The Continuous Spontaneous Localization (CSL) model is the most refined and studied among collapse models. A well-known problem of this model, and of similar ones, is the steady and unlimited increase of the energy induced by the collapse noise. Here we present the dissipative version of the CSL model, which guarantees a finite energy during the entire system's evolution, thus making a crucial step toward a realistic energy-conserving collapse model. This is achieved by introducing a non-linear stochastic modification of the Schrödinger equation, which represents the action of a dissipative finite-temperature collapse noise. The possibility to introduce dissipation within collapse models in a consistent way will have relevant impact on the experimental investigations of the CSL model, and therefore also on the testability of the quantum superposition principle.
Microscopic theory of one-body dissipation
Koonin, S.E.; Randrup, J.; Hatch, R.; Kolomietz, V.
1977-01-01
A microscopic theory is developed for nuclear collective motion in the limit of a long nuclear mean-free path. Linear response techniques are applied to an independent particle model and expressions for the collective kinetic energy and rate of energy dissipation are obtained. For leptodermous systems, these quantities are characterized by mass and dissipation kernels coupling the velocities at different points on the nuclear surface. In a classical treatment, the kernels are given in terms of nucleon trajectories within the nuclear shape. In a quantal treatment, the dissipation kernel is related to the nuclear Green function. The spatial and thermal properties of the kernels are investigated. Corrections for the diffuseness of the potential and shell effects are also discussed. (Auth.)
Analysis of phononic bandgap structures with dissipation
Andreassen, Erik; Jensen, Jakob Søndergaard
2013-01-01
and longer wavelengths, we show that the two formulations produce nearly identical results in terms of propagation constant and wave decay. We use the k(ω)-formulation to compute loss factors with dissipative bandgap materials for steady-state wave propagation and create simplified diagrams that unify...... the spatial loss factor from dissipative and bandgap effects. Additionally, we demonstrate the applicability of the k(ω)-formulation for the computation of the band diagram for viscoelastic composites and compare the computed loss factors for low frequency wave propagation to existing results based on quasi...
New derivation of relativistic dissipative fluid dynamics
Jaiswal, Amaresh; Bhalerao, Rajeev S.; Pal, Subrata
2012-01-01
Relativistic dissipative hydrodynamics has been quite successful in explaining the spectra and azimuthal anisotropy of particles produced in heavy-ion collisions at the RHIC and recently at the LHC. The first-order dissipative fluid dynamics or the relativistic Navier-Stokes (NS) theory involves parabolic differential equations and suffers from a causality and instability. The second-order or Israel-Stewart (IS) theory with its hyperbolic equations restores causality but may not guarantee stability. The correct formulation of relativistic viscous fluid dynamics is far from settled and is under intense investigation
Quantum dissipation from power-law memory
Tarasov, Vasily E.
2012-01-01
A new quantum dissipation model based on memory mechanism is suggested. Dynamics of open and closed quantum systems with power-law memory is considered. The processes with power-law memory are described by using integration and differentiation of non-integer orders, by methods of fractional calculus. An example of quantum oscillator with linear friction and power-law memory is considered. - Highlights: ► A new quantum dissipation model based on memory mechanism is suggested. ► The generalization of Lindblad equation is considered. ► An exact solution of generalized Lindblad equation for quantum oscillator with linear friction and power-law memory is derived.
Mechanical energy dissipation in natural ceramic composites.
Mayer, George
2017-12-01
Ceramics and glasses, in their monolithic forms, typically exhibit low fracture toughness values, but rigid natural marine ceramic and glass composites have shown remarkable resistance to mechanical failure. This has been observed in load-extension behavior by recognizing that the total area under the curve, notably the part beyond the yield point, often conveys substantial capacity to carry mechanical load. The mechanisms underlying the latter observations are proposed as defining factors for toughness that provide resistance to failure, or capability to dissipate energy, rather than fracture toughness. Such behavior is exhibited in the spicules of glass sponges and in mollusk shells. There are a number of similarities in the manner in which energy dissipation takes place in both sponges and mollusks. It was observed that crack diversion, a new form of crack bridging, creation of new surface area, and other important energy-dissipating mechanisms occur and aid in "toughening". Crack tolerance, key to energy dissipation in these natural composite materials, is assisted by promoting energy distribution over large volumes of loaded specimens by minor components of organic constituents that also serve important roles as adhesives. Viscoelastic deformation was a notable characteristic of the organic component. Some of these energy-dissipating modes and characteristics were found to be quite different from the toughening mechanisms that are utilized for more conventional structural composites. Complementary to those mechanisms found in rigid natural ceramic/organic composites, layered architectures and very thin organic layers played major roles in energy dissipation in these structures. It has been demonstrated in rigid natural marine composites that not only architecture, but also the mechanical behavior of the individual constituents, the nature of the interfaces, and interfacial bonding play important roles in energy dissipation. Additionally, the controlling
Morphing of the Dissipative Reaction Mechanism
Schroeder, W.U.; Toke, J.; Gawlikowicz, W.; Houck, M.A.; Lu, J.; Pienkowski, L.
2003-01-01
Important trends in the evolution of heavy-ion reaction mechanisms with bombarding energy and impact parameter are reviewed. Essential features of dissipative reactions appear preserved at E/A = 50-62 MeV, such as dissipative orbiting and multi-nucleon exchange. The relaxation of the A/Z asymmetry with impact parameter is slow. Non-equilibrium emission of light particles and clusters is an important process accompanying the evolution of the mechanism. Evidence is presented for a new mechanism of statistical cluster emission from hot, metastable primary reaction products, driven by surface entropy. These results suggest a plausible reinterpretation of multi-fragmentation. (authors)
Complex Fluids in Energy Dissipating Systems
Francisco J. Galindo-Rosales
2016-07-01
Full Text Available The development of engineered systems for energy dissipation (or absorption during impacts or vibrations is an increasing need in our society, mainly for human protection applications, but also for ensuring the right performance of different sort of devices, facilities or installations. In the last decade, new energy dissipating composites based on the use of certain complex fluids have flourished, due to their non-linear relationship between stress and strain rate depending on the flow/field configuration. This manuscript intends to review the different approaches reported in the literature, analyses the fundamental physics behind them and assess their pros and cons from the perspective of their practical applications.
Dissipation in the superfluid helium film
Turkington, R.R.; Harris-Lowe, R.F.
1977-01-01
We have measured the rate of energy dissipation in superfluid helium film flow in an attempt to test a recent theory due to Harris-Lowe, which predicts that for superfluid stream velocities v/sub s/ that just exceed the critical velocity v/sub c0/, the rate of dissipation is given by an equation of the form Q=C(v/sub s/-v/sub c0/)/sup 3/2/. Our experiments at 1.33 K show that the exponent, predicted to be 3/2, is 1.491 +- 0.021
Dissipation and decoherence in quantum systems
Menskii, Mikhail B
2003-01-01
The theory of dissipative quantum systems and its relation to the quantum theory of continuous measurements are reviewed. Constructing a correct theory of a dissipative quantum system requires that the system's interaction with its environment (reservoir) be taken into account. Since information about the system is 'recorded' in the state of the reservoir, the quantum theory of continuous measurements can be used to account for the influence of the reservoir. If based on the use of restricted path integrals, this theory does not require an explicit reservoir model and is therefore much simpler technically. (reviews of topical problems)
Dissipative phenomena in condensed matter some applications
Dattagupta, Sushanta
2004-01-01
From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.
Morphing of the Dissipative Reaction Mechanism
Schroeder, W.U.; Toke, J.; Gawlikowicz, W.; Houck, M.A.; Lu, J.; Pienkowski, L. [Rochester Univ., Dept. of Chemistry, Rochester, NY (United States)
2003-07-01
Important trends in the evolution of heavy-ion reaction mechanisms with bombarding energy and impact parameter are reviewed. Essential features of dissipative reactions appear preserved at E/A = 50-62 MeV, such as dissipative orbiting and multi-nucleon exchange. The relaxation of the A/Z asymmetry with impact parameter is slow. Non-equilibrium emission of light particles and clusters is an important process accompanying the evolution of the mechanism. Evidence is presented for a new mechanism of statistical cluster emission from hot, metastable primary reaction products, driven by surface entropy. These results suggest a plausible reinterpretation of multi-fragmentation. (authors)
Effects of dissipation and fluctuation in preheating
Vartuli, Rodrigo; Ramos, Rudnei de O.
2006-01-01
In this paper, we study the effects of dissipation and fluctuation in preheating after inflation. The effective equation of motion for a scalar field χ interacting with lighter fields is derived using the field theoretical method of closed time path due to Schwinger, winch is suitable to study nonequilibrium and time dependent process. In this derivation the emergent equation is intrinsically dissipative and stochastic in nature. The resulting dynamics is then studied both analytically and numerically. The results obtained are then discussed for then relevance for the reheating epoch right after an inflationary phase(preheating) for the case of the evolution of the scalar field χ and its decay into fermion. (author)
Periodic solutions of dissipative systems revisited
Górniewicz Lech
2006-01-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
Periodic solutions of dissipative systems revisited
Lech Górniewicz
2006-05-01
Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.
Appendix to Power Dissipation in Division
Liu, Wei; Nannarelli, Alberto
This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation of the archite......This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation...
Fóti, S.; Nagy, Z.; Balogh, J.; Bartha, S.; Acosta, Manuel; Czóbel, S.; Péli, E.; Marek, Michal V.; Tuba, Z.
2009-01-01
Roč. 28, č. 4 (2009), s. 389-398 ISSN 1335-342X Institutional research plan: CEZ:AV0Z60870520 Institutional support: RVO:67179843 Keywords : chamber technique * coefficient of variation * semivariance * Soil respiration * spatial pattern Subject RIV: EH - Ecology, Behaviour
Townes, Lindsay R; Mwandama, Dyson; Mathanga, Don P; Wilson, Mark L
2013-11-11
Understanding the role of local environmental risk factors for malaria in holo-endemic, poverty-stricken settings will be critical to more effectively implement- interventions aimed at eventual elimination. Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children Authority (TA) regions dominated by small-scale agriculture. Ten villages were randomly selected from TA Sitola (n = 6) and Nsamala (n = 4). Within each village, during June to August 2011, a census was conducted of all households with children under-five and recorded their locations with a geographic position system (GPS) device. At each participating house, a nurse administered a malaria rapid diagnostic test (RDT) to children under five years of age, and a questionnaire to parents. Environmental data were collected for each house, including land cover within 50-m radius. Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models, including multivariate logistic regression (MLR) and multi-level multivariate logistic regression (MLLR). Spatial clustering of RDT status, environmental factors, and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi* statistic. Of 390 children enrolled from six villages in Sitola (n = 162) and four villages in Nsamala (n = 228), 45.6% tested positive (n = 178) for Plasmodium infection by RDT. The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture ( 2.58, p < 0.01) predominantly within TA Sitola, while residuals from MLLR showed no such clustering. This study provides evidence for significant, dry-season heterogeneity of malaria prevalence strongly linked to peridomestic land use, and particularly of elevated risk associated with nearby crop production.
Friction and dissipative phenomena in quantum mechanics
Kostin, M.D.
1975-01-01
Frictional and dissipative terms of the Schroedinger equation are studied. A proof is given showing that the frictional term of the Schroedinger--Langevin equation causes the quantum system to lose energy. General expressions are derived for the frictional term of the Schroedinger equation. (U.S.)
Entanglement from dissipation and holographic interpretation
Cantcheff, M.B. [IFLP-CONICET CC 67, La Plata, Buenos Aires (Argentina); Gadelha, Alexandre L. [Universidade Federal da Bahia, Instituto de Fisica, Salvador, BA (Brazil); Marchioro, Dafni F.Z.; Nedel, Daniel Luiz [Universidade Federal da Integracao Latino-Americana, Instituto Latino-Americano de Ciencias da Vida e da Natureza, Foz do Iguacu, PR (Brazil)
2018-02-15
In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacuum state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017). (orig.)
Entanglement from dissipation and holographic interpretation
Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dáfni F. Z.; Nedel, Daniel Luiz
2018-02-01
In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacumm state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017).
On multi-dissipative dynamic systems
Thygesen, Uffe Høgsbro
1999-01-01
We consider deterministic dynamic systems with state space representations which are dissipative in the sense of Willems (1972) with respect to several supply rates. This property is of interest in robustness analysis and in multi-objective control. We give conditions under which the convex cone...
Quantum phase transition with dissipative frustration
Maile, D.; Andergassen, S.; Belzig, W.; Rastelli, G.
2018-04-01
We study the quantum phase transition of the one-dimensional phase model in the presence of dissipative frustration, provided by an interaction of the system with the environment through two noncommuting operators. Such a model can be realized in Josephson junction chains with shunt resistances and resistances between the chain and the ground. Using a self-consistent harmonic approximation, we determine the phase diagram at zero temperature which exhibits a quantum phase transition between an ordered phase, corresponding to the superconducting state, and a disordered phase, corresponding to the insulating state with localized superconducting charge. Interestingly, we find that the critical line separating the two phases has a nonmonotonic behavior as a function of the dissipative coupling strength. This result is a consequence of the frustration between (i) one dissipative coupling that quenches the quantum phase fluctuations favoring the ordered phase and (ii) one that quenches the quantum momentum (charge) fluctuations leading to a vanishing phase coherence. Moreover, within the self-consistent harmonic approximation, we analyze the dissipation induced crossover between a first and second order phase transition, showing that quantum frustration increases the range in which the phase transition is second order. The nonmonotonic behavior is reflected also in the purity of the system that quantifies the degree of correlation between the system and the environment, and in the logarithmic negativity as an entanglement measure that encodes the internal quantum correlations in the chain.
Dissipative preparation of entanglement in optical cavities
Kastoryano, Michael James; Reiter, Florentin; Sørensen, Anders Søndberg
2011-01-01
We propose a novel scheme for the preparation of a maximally entangled state of two atoms in an optical cavity. Starting from an arbitrary initial state, a singlet state is prepared as the unique fixed point of a dissipative quantum dynamical process. In our scheme, cavity decay is no longer...
Characterizing pesticide dissipation in food crops
Fantke, Peter; Juraske, R.; Jolliet, O.
2013-01-01
Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure. Neverth......Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure....... Nevertheless, dissipation is a key mechanism in models assessing pesticide distribution in the cropenvironment and the magnitude of residues in harvest. We provide a consistent framework for characterizing pesticide dissipation in food crops for use in modeling approaches applied in health risk and impact...... degradation is dominating. We are currently testing the regression to predict degradation half-lives in crops. By providing mean degradation half-lives at 20°C for more than 300 pesticides, we reduce uncertainty and improve assumptions in current practice of health risk and impact assessments....
Viscosity measurement techniques in Dissipative Particle Dynamics
Boromand, Arman; Jamali, Safa; Maia, Joao M.
2015-11-01
In this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using Dissipative Particle Dynamics, DPD. In the first method, a microscopic definition of the pressure tensor is used in equilibrium and out of equilibrium to measure the zero-shear viscosity and shear viscosity, respectively. In the second method, a periodic Poiseuille flow and start-up transient shear flow is used and the shear viscosity is obtained from the velocity profiles by a numerical fitting procedure. Using the standard Lees-Edward boundary condition for DPD will result in incorrect velocity profiles at high values of the dissipative parameter. Although this issue was partially addressed in Chatterjee (2007), in this work we present further modifications (Lagrangian approach) to the original LE boundary condition (Eulerian approach) that will fix the deviation from the desired shear rate at high values of the dissipative parameter and decrease the noise to signal ratios in stress measurement while increases the accessible low shear rate window. Also, the thermostat effect of the dissipative and random forces is coupled to the dynamic response of the system and affects the transport properties like the viscosity and diffusion coefficient. We investigated thoroughly the dependency of viscosity measured by both Eulerian and Lagrangian methodologies, as well as numerical fitting procedures and found that all the methods are in quantitative agreement.
Magnetization dissipation in ferromagnets from scattering theory
Brataas, A.; Tserkovnyak, Y.; Bauer, G.E.W.
2011-01-01
The magnetization dynamics of ferromagnets is often formulated in terms of the Landau-Lifshitz-Gilbert (LLG) equation. The reactive part of this equation describes the response of the magnetization in terms of effective fields, whereas the dissipative part is parametrized by the Gilbert damping
Energy and dissipated work in snow avalanches
Bartelt, P.; Buser, O.
2004-12-01
Using the results of large scale avalanche experiments at the Swiss Vallée de la Sionne test site, the energy balance of several snow avalanches is determined. Avalanches convert approximately one-seventh of their potential energy into kinetic energy. The total potential energy depends strongly on the entrained snowcover, indicating that entrainment processes cannot be ignored when predicting terminal velocities and runout distances. We find energy dissipation rates on the order of 1 GW. Fluidization of the fracture slab can be identified in the experiments as an increase in dissipation rate, thereby explaining the initial and rapid acceleration of avalanches after release. Interestingly, the dissipation rates appear to be constant along the track, although large fluctuations in internal velocity exist. Thus, we can demonstrate within the context of non-equilibrium thermodynamics that -- in space -- granular snow avalanches are irreversible, dissipative systems that minimize entropy production because they appear to reach a steady-state non-equilibrium. A thermodynamic analysis reveals that fluctuations in velocity depend on the roughness of the flow surface and viscosity of the granular system. We speculate that this property explains the transition from flowing avalanches to powder avalanches.
Real-Time Observation of Internal Motion within Ultrafast Dissipative Optical Soliton Molecules
Krupa, Katarzyna; Nithyanandan, K.; Andral, Ugo; Tchofo-Dinda, Patrice; Grelu, Philippe
2017-06-01
Real-time access to the internal ultrafast dynamics of complex dissipative optical systems opens new explorations of pulse-pulse interactions and dynamic patterns. We present the first direct experimental evidence of the internal motion of a dissipative optical soliton molecule generated in a passively mode-locked erbium-doped fiber laser. We map the internal motion of a soliton pair molecule by using a dispersive Fourier-transform imaging technique, revealing different categories of internal pulsations, including vibrationlike and phase drifting dynamics. Our experiments agree well with numerical predictions and bring insights to the analogy between self-organized states of lights and states of the matter.
Malatesta, Luca; Tardella, Federico Maria; Piermarteri, Karina; Catorci, Andrea
2016-01-01
Facilitation processes constitute basic elements of vegetation dynamics in harsh systems. Recent studies in tropical alpine environments demonstrated how pioneer plant species defined as "ecosystem engineers" are capable of enhancing landscape-level richness by adding new species to the community through the modification of microhabitats, and also provided hints about the alternation of different ecosystem engineers over time. Nevertheless, most of the existing works analysed different ecosystem engineers separately, without considering the interaction of different ecosystem engineers. Focusing on the altitudinal limit of Peruvian Dry Puna vegetation, we hypothesized that positive interactions structure plant communities by facilitation cascades involving different ecosystem engineers, determining the evolution of the microhabitat patches in terms of abiotic resources and beneficiary species hosted. To analyze successional mechanisms, we used a "space-for-time" substitution to account for changes over time, and analyzed data on soil texture, composition, and temperature, facilitated species and their interaction with nurse species, and surface area of engineered patches by means of chemical analyses, indicator species analysis, and rarefaction curves. A successional process, resulting from the dynamic interaction of different ecosystem engineers, which determined a progressive amelioration of soil conditions (e.g. nitrogen and organic matter content, and temperature), was the main driver of species assemblage at the community scale, enhancing species richness. Cushion plants act as pioneers, by starting the successional processes that continue with shrubs and tussocks. Tussock grasses have sometimes been found to be capable of creating microhabitat patches independently. The dynamics of species assemblage seem to follow the nested assemblage mechanism, in which the first foundation species to colonize a habitat provides a novel substrate for colonization by other
Luca Malatesta
Full Text Available Facilitation processes constitute basic elements of vegetation dynamics in harsh systems. Recent studies in tropical alpine environments demonstrated how pioneer plant species defined as "ecosystem engineers" are capable of enhancing landscape-level richness by adding new species to the community through the modification of microhabitats, and also provided hints about the alternation of different ecosystem engineers over time. Nevertheless, most of the existing works analysed different ecosystem engineers separately, without considering the interaction of different ecosystem engineers. Focusing on the altitudinal limit of Peruvian Dry Puna vegetation, we hypothesized that positive interactions structure plant communities by facilitation cascades involving different ecosystem engineers, determining the evolution of the microhabitat patches in terms of abiotic resources and beneficiary species hosted. To analyze successional mechanisms, we used a "space-for-time" substitution to account for changes over time, and analyzed data on soil texture, composition, and temperature, facilitated species and their interaction with nurse species, and surface area of engineered patches by means of chemical analyses, indicator species analysis, and rarefaction curves. A successional process, resulting from the dynamic interaction of different ecosystem engineers, which determined a progressive amelioration of soil conditions (e.g. nitrogen and organic matter content, and temperature, was the main driver of species assemblage at the community scale, enhancing species richness. Cushion plants act as pioneers, by starting the successional processes that continue with shrubs and tussocks. Tussock grasses have sometimes been found to be capable of creating microhabitat patches independently. The dynamics of species assemblage seem to follow the nested assemblage mechanism, in which the first foundation species to colonize a habitat provides a novel substrate for
Full Text Available ... Stories Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué es el ojo seco? ...
Full Text Available ... Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué es el ojo seco? ...
Storage functions for dissipative linear systems are quadratic state functions
Trentelman, Harry L.; Willems, Jan C.
1997-01-01
This paper deals with dissipative dynamical systems. Dissipative dynamical systems can be used as models for physical phenomena in which energy exchange with their environment plays a role. In a dissipative dynamical system, the book-keeping of energy is done via the supply rate and a storage
Dissipation and the relaxation to equilibrium
Evans, Denis J; Williams, Stephen R; Searles, Debra J
2009-01-01
Using the recently derived dissipation theorem and a corollary of the transient fluctuation theorem (TFT), namely the second-law inequality, we derive the unique time independent, equilibrium phase space distribution function for an ergodic Hamiltonian system in contact with a remote heat bath. We prove under very general conditions that any deviation from this equilibrium distribution breaks the time independence of the distribution. Provided temporal correlations decay, we show that any nonequilibrium distribution that is an even function of the momenta eventually relaxes (not necessarily monotonically) to the equilibrium distribution. Finally we prove that the negative logarithm of the microscopic partition function is equal to the thermodynamic Helmholtz free energy divided by the thermodynamic temperature and Boltzmann's constant. Our results complement and extend the findings of modern ergodic theory and show the importance of dissipation in the process of relaxation towards equilibrium
Dynamical properties of dissipative XYZ Heisenberg lattices
Rota, R.; Minganti, F.; Biella, A.; Ciuti, C.
2018-04-01
We study dynamical properties of dissipative XYZ Heisenberg lattices where anisotropic spin-spin coupling competes with local incoherent spin flip processes. In particular, we explore a region of the parameter space where dissipative magnetic phase transitions for the steady state have been recently predicted by mean-field theories and exact numerical methods. We investigate the asymptotic decay rate towards the steady state both in 1D (up to the thermodynamical limit) and in finite-size 2D lattices, showing that critical dynamics does not occur in 1D, but it can emerge in 2D. We also analyze the behavior of individual homodyne quantum trajectories, which reveal the nature of the transition.
Energy balance for a dissipative quantum system
Kumar, Jishad
2014-01-01
The role of random force in maintaining equilibrium in a dissipative quantum system is studied here. We compute the instantaneous power supplied by the fluctuating (random) force, which provides information about the work done by the random force on the quantum subsystem of interest. The quantum Langevin equation formalism is used here to verify that, at equilibrium, the work done by the fluctuating force balances the energy lost by the quantum subsystem to the heat bath. The quantum subsystem we choose to couple to the heat bath is the charged oscillator in a magnetic field. We perform the calculations using the Drude regularized spectral density of bath oscillators instead of using a strict ohmic spectral density that gives memoryless damping. We also discuss the energy balance for our dissipative quantum system and in this regard it is to be understood that the physical system is the charged magneto-oscillator coupled to the heat bath, not the uncoupled charged magneto-oscillator. (paper)
Non-dissipative effects in nonequilibrium systems
Maes, Christian
2018-01-01
This book introduces and discusses both the fundamental aspects and the measurability of applications of time-symmetric kinetic quantities, outlining the features that constitute the non-dissipative branch of non-equilibrium physics. These specific features of non-equilibrium dynamics have largely been ignored in standard statistical mechanics texts. This introductory-level book offers novel material that does not take the traditional line of extending standard thermodynamics to the irreversible domain. It shows that although stationary dissipation is essentially equivalent with steady non-equilibrium and ubiquitous in complex phenomena, non-equilibrium is not determined solely by the time-antisymmetric sector of energy-entropy considerations. While this should not be very surprising, this book provides timely, simple reminders of the role of time-symmetric and kinetic aspects in the construction of non-equilibrium statistical mechanics.
On the Lagrangian description of dissipative systems
Martínez-Pérez, N. E.; Ramírez, C.
2018-03-01
We consider the Lagrangian formulation with duplicated variables of dissipative mechanical systems. The application of Noether theorem leads to physical observable quantities which are not conserved, like energy and angular momentum, and conserved quantities, like the Hamiltonian, that generate symmetry transformations and do not correspond to observables. We show that there are simple relations among the equations satisfied by these two types of quantities. In the case of the damped harmonic oscillator, from the quantities obtained by the Noether theorem follows the algebra of Feshbach and Tikochinsky. Furthermore, if we consider the whole dynamics, the degrees of freedom separate into a physical and an unphysical sector. We analyze several cases, with linear and nonlinear dissipative forces; the physical consistency of the solutions is ensured, observing that the unphysical sector has always the trivial solution.
Dissipative Boltzmann-Robertson-Walker cosmologies
Hiscock, W.A.; Salmonson, J.
1991-01-01
The equations governing a flat Robertson-Walker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and Israel-Stewart theories of dissipative relativistic fluids; the resulting cosmologies are compared and contrasted. The Eckart models are shown to always differ in a significant quantitative way from the Israel-Stewart models. It thus appears inappropriate to use the pathological (nonhyperbolic) Eckart theory for cosmological applications. For large bulk viscosities, both cosmological models approach asymptotic nonequilibrium states; in the Eckart model the total pressure is negative, while in the Israel-Stewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the Israel-Stewart models. These results suggest that ''bulk-viscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory
Astrophysical constraints on Planck scale dissipative phenomena.
Liberati, Stefano; Maccione, Luca
2014-04-18
The emergence of a classical spacetime from any quantum gravity model is still a subtle and only partially understood issue. If indeed spacetime is arising as some sort of large scale condensate of more fundamental objects, then it is natural to expect that matter, being a collective excitation of the spacetime constituents, will present modified kinematics at sufficiently high energies. We consider here the phenomenology of the dissipative effects necessarily arising in such a picture. Adopting dissipative hydrodynamics as a general framework for the description of the energy exchange between collective excitations and the spacetime fundamental degrees of freedom, we discuss how rates of energy loss for elementary particles can be derived from dispersion relations and used to provide strong constraints on the base of current astrophysical observations of high-energy particles.
Dissipation in graphene and nanotube resonators
Seoánez, C.; Guinea, F.; Castro Neto, A. H.
2007-09-01
Different damping mechanisms in graphene nanoresonators are studied: charges in the substrate, ohmic losses in the substrate and the graphene sheet, breaking and healing of surface bonds (Velcro effect), two level systems, attachment losses, and thermoelastic losses. We find that, for realistic structures and contrary to semiconductor resonators, dissipation is dominated by ohmic losses in the graphene layer and metallic gate. An extension of this study to carbon nanotube-based resonators is presented.
Dissipation in graphene and nanotube resonators
Seoanez, C.; Guinea, F.; Neto, A. H. Castro
2007-01-01
Different damping mechanisms in graphene nanoresonators are studied: charges in the substrate, ohmic losses in the substrate and the graphene sheet, breaking and healing of surface bonds (Velcro effect), two level systems, attachment losses, and thermoelastic losses. We find that, for realistic structures and contrary to semiconductor resonators, dissipation is dominated by ohmic losses in the graphene layer and metallic gate. An extension of this study to carbon nanotube-based resonators is ...
''Reduced'' magnetohydrodynamics and minimum dissipation rates
Montgomery, D.
1992-01-01
It is demonstrated that all solutions of the equations of ''reduced'' magnetohydrodynamics approach a uniform-current, zero-flow state for long times, given a constant wall electric field, uniform scalar viscosity and resistivity, and uniform mass density. This state is the state of minimum energy dissipation rate for these boundary conditions. No steady-state turbulence is possible. The result contrasts sharply with results for full three-dimensional magnetohydrodynamics before the reduction occurs
On local Hamiltonians and dissipative systems
Castagnino, M. [CONICET-Institutos de Fisica Rosario y de Astronomia y Fisica del Espacio Casilla de Correos 67, Sucursal 28, 1428, Buenos Aires (Argentina); Gadella, M. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura UNR, Rosario (Argentina) and Departamento de Fisica Teorica, Facultad de Ciencias c. Real de Burgos, s.n., 47011 Valladolid (Spain)]. E-mail: manuelgadella@yahoo.com.ar; Lara, L.P. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura UNR, Rosario (Argentina)
2006-11-15
We study a type of one-dimensional dynamical systems on the corresponding two-dimensional phase space. By using arguments related to the existence of integrating factors for Pfaff equations, we show that some one-dimensional non-Hamiltonian systems like dissipative systems, admit a Hamiltonian description by sectors on the phase plane. This picture is not uniquely defined and is coordinate dependent. A simple example is exhaustively discussed. The method, is not always applicable to systems with higher dimensions.
Dissipation and decoherence in Brownian motion
Bellomo, Bruno [Dipartimento di Scienze Fisiche ed Astronomiche dell' Universita di Palermo, Via Archirafi, 36, 90123 Palermo (Italy); Barnett, Stephen M [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Jeffers, John [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)
2007-05-15
We consider the evolution of a Brownian particle described by a measurement-based master equation. We derive the solution to this equation for general initial conditions and apply it to a Gaussian initial state. We analyse the effects of the diffusive terms, present in the master equation, and describe how these modify uncertainties and coherence length. This allows us to model dissipation and decoherence in quantum Brownian motion.
Offshore heat dissipation for nuclear energy centers
Bauman, H.F.
1978-09-01
The technical, environmental, and economic aspects of utilizing the ocean or other large water bodies for the dissipation of reject heat from Nuclear Energy Centers (NECs) were investigated. An NEC in concept is an aggregate of nuclear power plants of 10 GW(e) capacity or greater on a common site. The use of once-through cooling for large power installations offers advantages including higher thermal efficiencies, especially under summer peak-load conditions, compared to closed-cycle cooling systems. A disadvantage of once-through cooling is the potential for greater adverse impacts on the aquatic environment. A concept is presented for minimizing the impacts of such systems by placing water intake and discharge locations relatively distant from shore in deeper water than has heretofore been the practice. This technique would avoid impacts on relatively biologically productive and ecologically sensitive shallow inshore areas. The NEC itself would be set back from the shoreline so that recreational use of the shore area would not be impaired. The characteristics of a heat-dissipation system of the size required for a NEC were predicted from the known characteristics of a smaller system by applying hydraulic scaling laws. The results showed that adequate heat dissipation can be obtained from NEC-sized systems located in water of appropriate depth. Offshore intake and discharge structures would be connected to the NEC pump house on shore via tunnels or buried pipelines. Tunnels have the advantage that shoreline and beach areas would not be disturbed. The cost of an offshore heat-dissipation system depends on the characteristics of the site, particularly the distance to suitably deep water and the type of soil or rock in which water conduits would be constructed. For a favorable site, the cost of an offshore system is estimated to be less than the cost of a closed-cycle system
Dissipation element analysis of turbulent scalar fields
Wang Lipo; Peters, Norbert
2008-01-01
Dissipation element analysis is a new approach for studying turbulent scalar fields. Gradient trajectories starting from each material point in a scalar field Φ'(x-vector,t) in ascending directions will inevitably reach a maximal and a minimal point. The ensemble of material points sharing the same pair ending points is named a dissipation element. Dissipation elements can be parameterized by the length scale l and the scalar difference Δφ ', which are defined as the straight line connecting the two extremal points and the scalar difference at these points, respectively. The decomposition of a turbulent field into dissipation elements is space-filling. This allows us to reconstruct certain statistical quantities of fine scale turbulence which cannot be obtained otherwise. The marginal probability density function (PDF) of the length scale distribution based on a Poisson random cutting-reconnection process shows satisfactory agreement with the direct numerical simulation (DNS) results. In order to obtain the further information that is needed for the modeling of scalar mixing in turbulence, such as the marginal PDF of the length of elements and all conditional moments as well as their scaling exponents, there is a need to model the joint PDF of l and Δφ ' as well. A compensation-defect model is put forward in this work to show the dependence of Δφ ' on l. The agreement between the model prediction and DNS results is satisfactory, which may provide another explanation of the Kolmogorov scaling and help to improve turbulent mixing models. Furthermore, intermittency and cliff structure can also be related to and explained from the joint PDF.
Driven-Dissipative Supersolid in a Ring Cavity
Mivehvar, Farokh; Ostermann, Stefan; Piazza, Francesco; Ritsch, Helmut
2018-03-01
Supersolids are characterized by the counterintuitive coexistence of superfluid and crystalline order. Here we study a supersolid phase emerging in the steady state of a driven-dissipative system. We consider a transversely pumped Bose-Einstein condensate trapped along the axis of a ring cavity and coherently coupled to a pair of degenerate counterpropagating cavity modes. Above a threshold pump strength the interference of photons scattered into the two cavity modes results in an emergent superradiant lattice, which spontaneously breaks the continuous translational symmetry towards a periodic atomic pattern. The crystalline steady state inherits the superfluidity of the Bose-Einstein condensate, thus exhibiting genuine properties of a supersolid. A gapless collective Goldstone mode correspondingly appears in the superradiant phase, which can be nondestructively monitored via the relative phase of the two cavity modes on the cavity output. Despite cavity-photon losses the Goldstone mode remains undamped, indicating the robustness of the supersolid phase.
Crises in a dissipative bouncing ball model
Livorati, André L.P., E-mail: livorati@usp.br [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Caldas, Iberê L. [Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil)
2015-11-06
Highlights: • We studied a dissipative bouncing ball dynamics. • A two-dimensional nonlinear mapping describes the dynamics. • Crises between attractors and its manifolds were characterized. • A new physical crisis between vibrating platform and an attractor was characterized. • The existence of a ‘robust’ chaotic attractor was set. - Abstract: The dynamics of a bouncing ball model under the influence of dissipation is investigated by using a two-dimensional nonlinear mapping. When high dissipation is considered, the dynamics evolves to different attractors. The evolution of the basins of the attracting fixed points is characterized, as we vary the control parameters. Crises between the attractors and their boundaries are observed. We found that the multiple attractors are intertwined, and when the boundary crisis between their stable and unstable manifolds occurs, it creates a successive mechanism of destruction for all attractors originated by the sinks. Also, a physical impact crisis is described, an important mechanism in the reduction of the number of attractors.
Dissipation range turbulent cascades in plasmas
Terry, P. W.; Almagri, A. F.; Forest, C. B.; Nornberg, M. D.; Rahbarnia, K.; Sarff, J. S.; Fiksel, G.; Hatch, D. R.; Jenko, F.; Prager, S. C.; Ren, Y.
2012-01-01
Dissipation range cascades in plasma turbulence are described and spectra are formulated from the scaled attenuation in wavenumber space of the spectral energy transfer rate. This yields spectra characterized by the product of a power law and exponential fall-off, applicable to all scales. Spectral indices of the power law and exponential fall-off depend on the scaling of the dissipation, the strength of the nonlinearity, and nonlocal effects when dissipation rates of multiple fluctuation fields are different. The theory is used to derive spectra for MHD turbulence with magnetic Prandtl number greater than unity, extending previous work. The theory is also applied to generic plasma turbulence by considering the spectrum from damping with arbitrary wavenumber scaling. The latter is relevant to ion temperature gradient turbulence modeled by gyrokinetics. The spectrum in this case has an exponential component that becomes weaker at small scale, giving a power law asymptotically. Results from the theory are compared to three very different types of turbulence. These include the magnetic plasma turbulence of the Madison Symmetric Torus, the MHD turbulence of liquid metal in the Madison Dynamo Experiment, and gyrokinetic simulation of ion temperature gradient turbulence.
Critical behavior in earthquake energy dissipation
Wanliss, James; Muñoz, Víctor; Pastén, Denisse; Toledo, Benjamín; Valdivia, Juan Alejandro
2017-09-01
We explore bursty multiscale energy dissipation from earthquakes flanked by latitudes 29° S and 35.5° S, and longitudes 69.501° W and 73.944° W (in the Chilean central zone). Our work compares the predictions of a theory of nonequilibrium phase transitions with nonstandard statistical signatures of earthquake complex scaling behaviors. For temporal scales less than 84 hours, time development of earthquake radiated energy activity follows an algebraic arrangement consistent with estimates from the theory of nonequilibrium phase transitions. There are no characteristic scales for probability distributions of sizes and lifetimes of the activity bursts in the scaling region. The power-law exponents describing the probability distributions suggest that the main energy dissipation takes place due to largest bursts of activity, such as major earthquakes, as opposed to smaller activations which contribute less significantly though they have greater relative occurrence. The results obtained provide statistical evidence that earthquake energy dissipation mechanisms are essentially "scale-free", displaying statistical and dynamical self-similarity. Our results provide some evidence that earthquake radiated energy and directed percolation belong to a similar universality class.
Relativistic electrodynamics of dissipative elastic media
Kranys, M.
1980-01-01
A phenomenological general relativistic electrodynamics is proposed for a dissipative elastic solid which is polarizable and magnetizable and whose governing equations form a hyperbolic system. Non-stationary transport equations are proposed for dissipative fluxes (and constitutive equations of electrodynamics) containing new cross-effect terms, as required for compatibility with an entropy principle expressed by a new balance equation (including a new Gibbs equation). The dynamic equations are deduced from the unified Minkowski-Abraham-Eckart energy-momentum tensor. The theory, formed by a set of 29 (reducible to 23) partial differential equations (in special relativity) governing the material behaviour of the system characterized by generalizing the constitutive equations of quasineutral media, together with Maxwell's equations, may be referred to as the electrodynamics of dissipative elastic media (or fluid). The proposed transport laws for polarization and magnetization generalize the well-known Debye law for relaxation and show the influence of shear and bulk viscosity on polarization and magentization. Besides the form of the entropy function, the free energy function in the non-stationary regime is also formulated. (auth)
Correlated Photon Dynamics in Dissipative Rydberg Media
Zeuthen, Emil; Gullans, Michael J.; Maghrebi, Mohammad F.; Gorshkov, Alexey V.
2017-07-01
Rydberg blockade physics in optically dense atomic media under the conditions of electromagnetically induced transparency (EIT) leads to strong dissipative interactions between single photons. We introduce a new approach to analyzing this challenging many-body problem in the limit of a large optical depth per blockade radius. In our approach, we separate the single-polariton EIT physics from Rydberg-Rydberg interactions in a serialized manner while using a hard-sphere model for the latter, thus capturing the dualistic particle-wave nature of light as it manifests itself in dissipative Rydberg-EIT media. Using this approach, we analyze the saturation behavior of the transmission through one-dimensional Rydberg-EIT media in the regime of nonperturbative dissipative interactions relevant to current experiments. Our model is able to capture the many-body dynamics of bright, coherent pulses through these strongly interacting media. We compare our model with available experimental data in this regime and find good agreement. We also analyze a scheme for generating regular trains of single photons from continuous-wave input and derive its scaling behavior in the presence of imperfect single-photon EIT.
Low Energy Dissipation Nano Device Research
Yu, Jenny
2015-03-01
The development of research on energy dissipation has been rapid in energy efficient area. Nano-material power FET is operated as an RF power amplifier, the transport is ballistic, noise is limited and power dissipation is minimized. The goal is Green-save energy by developing the Graphene and carbon nantube microwave and high performance devices. Higher performing RF amplifiers can have multiple impacts on broadly field, for example communication equipment, (such as mobile phone and RADAR); higher power density and lower power dissipation will improve spectral efficiency which translates into higher system level bandwidth and capacity for communications equipment. Thus, fundamental studies of power handling capabilities of new RF (nano)technologies can have broad, sweeping impact. Because it is critical to maximizing the power handling ability of grephene and carbon nanotube FET, the initial task focuses on measuring and understanding the mechanism of electrical breakdown. We aim specifically to determine how the breakdown voltage in graphene and nanotubes is related to the source-drain spacing, electrode material and thickness, and substrate, and thus develop reliable statistics on the breakdown mechanism and probability.
Belachsen, Idit; Marra, Francesco; Peleg, Nadav; Morin, Efrat
2017-04-01
Space-time patterns of rainfall are important climatic characteristics that influence runoff generation and flash flood magnitude. Their derivation requires high-resolution measurements to adequately represent the rainfall distribution, and is best provided by remote sensing tools. This need is further emphasized in dry climate regions, where rainfall is scarce and, often, local and highly variable. Our research is focused on understanding the nature of rainfall events in the dry Dead Sea region (Eastern Mediterranean) by identifying and characterizing the spatial structure and the dynamics of convective storm cores (known as rain cells). To do so, we take advantage of 25 years of corrected and gauge-adjusted weather radar data. A statistical analysis of convective rain-cells spatial and temporal characteristics was performed with respect to synoptic pattern, geographical location, and flash flood generation. Rain cells were extracted from radar data using a cell segmentation method and a tracking algorithm and were divided into rain events. A total of 10,500 rain cells, 2650 cell tracks and 424 rain events were elicited. Rain cell properties, such as mean areal and maximal rain intensity, area, life span, direction and speed, were derived. Rain events were clustered, according to several ERA-Interim atmospheric parameters, and associated with three main synoptic patterns: Cyprus Low, Low to the East of the study region and Active Red Sea Trough. The first two originate from the Mediterranean Sea, while the third is an extension of the African monsoon. On average, the convective rain cells in the region are 90 km2 in size, moving from West to East in 13 ms-1 and living 18 minutes. Several significant differences between rain cells of the various synoptic types were observed. In particular, Active Red Sea Trough rain cells are characterized by higher rain intensities and lower speeds, suggesting a higher flooding potential for small catchments. The north
Dissipative quantum dynamics and nonlinear sigma-model
Tarasov, V.E.
1992-01-01
Sedov variational principle which is the generalization of the least action principle for the dissipative and irreversible processes and the classical dissipative mechanics in the phase space is considered. Quantum dynamics for the dissipative and irreversible processes is constructed. As an example of the dissipative quantum theory the nonlinear two-dimensional sigma-model is considered. The conformal anomaly of the energy momentum tensor trace for closed bosonic string on the affine-metric manifold is investigated. The two-loop metric beta-function for nonlinear dissipative sigma-model was calculated. The results are compared with the ultraviolet two-loop conterterms for affine-metric sigma model. 71 refs
Spatial Inhomogeneity of Kinetic and Magnetic Dissipations in Thermal Convection
Hotta, H. [Department of Physics, Graduate School of Science, Chiba university, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522 (Japan)
2017-08-20
We investigate the inhomogeneity of kinetic and magnetic dissipations in thermal convection using high-resolution calculations. In statistically steady turbulence, the injected and dissipated energies are balanced. This means that a large amount of energy is continuously converted into internal energy via dissipation. As in thermal convection, downflows are colder than upflows and the inhomogeneity of the dissipation potentially changes the convection structure. Our investigation of the inhomogeneity of the dissipation shows the following. (1) More dissipation is seen around the bottom of the calculation domain, and this tendency is promoted with the magnetic field. (2) The dissipation in the downflow is much larger than that in the upflow. The dissipation in the downflow is more than 80% of the total at maximum. This tendency is also promoted with the magnetic field. (3) Although 2D probability density functions of the kinetic and magnetic dissipations versus the vertical velocity are similar, the kinetic and magnetic dissipations are not well correlated. Our result suggests that the spatial inhomogeneity of the dissipation is significant and should be considered when modeling a small-scale strong magnetic field generated with an efficient small-scale dynamo for low-resolution calculations.
Inferring energy dissipation from violation of the fluctuation-dissipation theorem
Wang, Shou-Wen
2018-05-01
The Harada-Sasa equality elegantly connects the energy dissipation rate of a moving object with its measurable violation of the Fluctuation-Dissipation Theorem (FDT). Although proven for Langevin processes, its validity remains unclear for discrete Markov systems whose forward and backward transition rates respond asymmetrically to external perturbation. A typical example is a motor protein called kinesin. Here we show generally that the FDT violation persists surprisingly in the high-frequency limit due to the asymmetry, resulting in a divergent FDT violation integral and thus a complete breakdown of the Harada-Sasa equality. A renormalized FDT violation integral still well predicts the dissipation rate when each discrete transition produces a small entropy in the environment. Our study also suggests a way to infer this perturbation asymmetry based on the measurable high-frequency-limit FDT violation.
Dynamics of dissipative systems and computational physics
Adam, Gh.; Scutaru, H.; Ixaru, L.; Adam, S.; Rizea, M.; Stefanescu, E.; Mihalache, D.; Mazilu, D.; Crasovan, L.
2002-01-01
During the first year of research activity in the frame of this project there have been investigated two main topics: I. Dynamics of systems of fermions in complex dissipative media; II. Solitons with topologic charge in dissipative systems. An essential problem of the quantum information systems is the controllability and observability of the quantum states, generally described by Lindblad's master equation with phenomenological coefficients. In its usual form, this equation describes a decay of the mean-values, but not necessarily the expected decaying transitions. The basic and very difficult problem of a dissipative quantum theory is to project the evolution of the total system (the system of interest + the environment) on the space of the system of interest. In this case, one obtains a quantum master equation where the system evolution is described by two terms: 1) a Hamiltonian term for the processes with energy conservation, and 2) a non-Hamiltonian term with coefficients depending on the dissipative coupling. That means that a master equation is based on some approximations enabling the replacement of the operators of the dissipative environment with average value coefficients. It is often assumed that the evolution operators of the dissipative system define a semigroup, not a group as in the case of an isolated system. In this framework, Lindblad obtained a quantum master equation in agreement with all the quantum-mechanical principles. However, the Lindblad master equation was unable to secure a correct description of the decaying states. To do that, one has to take into account the transition operators between the system eigenstates with appropriate coefficients. Within this investigation, we have obtained an equation obeying to this requirement, giving the ρ(t) time derivative in terms of creation-annihilation operators of the single-particle states |i>, and λ ij , representing the dissipative coefficients, the microscopic expressions of which are
Characteristics of a Dry Fog Ionizer
Murata, Y; Kudo, Y; Yonezawa, M
2008-01-01
The newly developed 'Dry Fog Ionizer' generates charged dry fog. The dry fog consists of very fine water droplets 8μm in mean diameter. This system consists of a dry fog nozzle (H.Ikeuchi and Co., LTD.), a ring electrode for induction charging (50mm outside diameter, and 10mm thick) in front of the nozzle, and a fan for dissipating charged dry fog. The ring electrode is DC or AC-biased and fine droplets ejected from the nozzle are electrified by induction charging. The particle size of the charged water droplets are reduced through evaporation during the transporting process by air flow, and completely evaporate approximately 2m from the nozzle under normal atmospheric conditions (25 deg. C, 60%R.H.) leaving high density ions. Using this system, high density ionic space charge can be realized in a remote spot from the ionizer. By this principle, the Dry Fog Ionizer shows strong charge-eliminating ability in the region away from the ionizer. When a dc bias of 5kV was applied to a ring electrode with the rate of water flow from the nozzle being 21/h, an ionic space-charge density of 1200nC /m 3 was able to be obtained at a distance 2m away from the ionizer, which was 10 2 times the value produced by an ordinary corona-type ionizer with an air blower.
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... Eye? Dry Eye Symptoms Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué ... Inside of Your Eyelid Nov 29, 2017 New Dry Eye Treatment is a Tear-Jerker Jul 21, 2017 Three ...
Dissipative motion perturbation theory and exact solutions
Lodder, J.J.
1976-06-01
Dissipative motion of classical and quantum systems is described. In particular, attention is paid to systems coupled to the radiation field. A dissipative equation of motion for a particle in an arbitrary potential coupled to the radiation field is derived by means of perturbation theory. The usual divrgencies associated with the radiation field are eliminated by the application of a theory of generalized functions. This theory is developed as a subject in its own right and is presented independently. The introduction of classical zero-point energy makes the classical equa tion of motion for the phase density formally the same as its quantum counterpart. In particular, it is shown that the classical zero-point energy prevents the collapse of a classical H-atom and gives rise to a classical ground state. For systems with a quadratic Hamiltoian, the equation of motion can be solved exactly, even in the continuum limit for the radiation field, by means of the new generalized functions. Classically, the Fokker-Planck equation is found without any approximations, and quantum mechanically, the only approximation is the neglect of the change in the ground state caused by the interaction. The derivation is valid even for strong damping and arbitrarily short times. There is no transient time. For harmonic oscillators complete equivalence is shown to exist between quantum mechanics and classical mechanics with zero-point energy. A discussion of the derivation of the Pauli equation is given and perturbation theory is compared with the exact derivation. The exactly solvable models are used to calculate the Langevin force of the radiation field. The result is that the classical Langevin force is exactly delta-correlated, while the quantum Langevin force is not delta-correlated at all. The fluctuation-dissipation theorem is shown to be an exact consequence of the solution to the equations of motion
Alfven wave absorption in dissipative plasma
Gavrikov, M B; Taiurskii, A A
2017-01-01
We consider nonlinear absorption of Alfven waves due to dissipative effects in plasma and relaxation of temperatures of electrons and ions. This study is based on an exact solution of the equations of two-fluid electromagnetic hydrodynamics (EMHD) of plasma. It is shown that in order to study the decay of Alfven waves, it suffices to examine the behavior of their amplitudes whose evolution is described by a system of ordinary differential equations (ODEs) obtained in this paper. On finite time intervals, the system of equations on the amplitudes is studied numerically, while asymptotic integration (the Hartman-Grobman theorem) is used to examine its large-time behavior. (paper)
Tunneling with dissipation in open quantum systems
Adamyan, G.G.; Antonenko, N.V.; Scheid, W.
1997-01-01
Based on the general form of the master equation for open quantum systems the tunneling is considered. Using the path integral technique a simple closed form expression for the tunneling rate through a parabolic barrier is obtained. The tunneling in the open quantum systems strongly depends on the coupling with environment. We found the cases when the dissipation prohibits tunneling through the barrier but decreases the crossing of the barrier for the energies above the barrier. As a particular application, the case of decay from the metastable state is considered
Dissipative Structures At Laser-Solid Interactions
Nanai, Laszlo
1989-05-01
The questions which are discussed in this lecture refer to one of sections of laser-solid interactions, namely: to formation of different dissipative structures on the surface of metals and semiconductors when they are irradiated by intensive laser light in chemically active media (f.e.air). Some particular examples of the development at different spatial and time instabilities, periodic and stochastic structures, auto-wave processes are present-ed using testing materials vanadium metal and semiconducting V205 single crystals and light sources: cw and pulsed CO2 and YAG lasers.
Dissipative charged fluid in a magnetic field
Abbasi, Navid; Davody, Ali, E-mail: davody.phy@gmail.com
2016-05-10
We study the collective excitations in a dissipative charged fluid at zero chemical potential when an external magnetic field is present. While in the absence of magnetic field, four collective excitations appear in the fluid, we find five hydrodynamic modes here. This implies that the magnetic field splits the degeneracy between the transverse shear modes. Using linear response theory, we then compute the retarded response functions. In particular, it turns out that the correlation between charge and the energy fluctuations will no longer vanish, even at zero chemical potential. By use of the response functions, we also derive the relevant Kubo formulas for the transport coefficients.
Full Text Available ... Ophthalmology/Strabismus Ocular Pathology/Oncology Oculoplastics/Orbit Refractive Management/Intervention Retina/Vitreous Uveitis Focus On ... Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms Causes of ...
Qin, Hua; Brookes, Philip C.; Xu, Jianming
2014-01-01
A number of Cucurbita species have the potential to extract polychlorinated biphenyls (PCBs) from soil, but their impact on the soil microbial communities responsible for PCB degradation remains unclear. A greenhouse experiment was conducted to investigate the effect of three Cucurbita and one Cucumis species on PCB dissipation and soil microbial community structure. Compared to the unplanted control, enhanced losses of PCBs (19.5%–42.7%) were observed in all planted soils. Cucurbita pepo and Cucurbita moschata treatments were more efficient in PCB dissipation, and have similar patterns of soil phospholipid fatty acids (PLFAs) and PCB congener profiles. Cucurbita treatments tend to have higher soil microbial biomass than Cucumis. Gram-negative (G − ) bacteria were significantly correlated with PCB degradation rates (R 2 = 0.719, p − bacteria were correlated with dissipation of the penta homologue group (R 2 = 0.590, p − bacteria contributed significantly to soil PCB dissipation. • Fungi have a great potential in the dissipation of high chlorinated biphenyls. -- Cucurbita associated fungi and G − bacteria have important influence on soil PCB dissipation rate and congener profile
Stochastic pump effect and geometric phases in dissipative and stochastic systems
Sinitsyn, Nikolai [Los Alamos National Laboratory
2008-01-01
The success of Berry phases in quantum mechanics stimulated the study of similar phenomena in other areas of physics, including the theory of living cell locomotion and motion of patterns in nonlinear media. More recently, geometric phases have been applied to systems operating in a strongly stochastic environment, such as molecular motors. We discuss such geometric effects in purely classical dissipative stochastic systems and their role in the theory of the stochastic pump effect (SPE).
Semiclassical evolution of dissipative Markovian systems
Ozorio de Almeida, A M; Rios, P de M; Brodier, O
2009-01-01
A semiclassical approximation for an evolving density operator, driven by a 'closed' Hamiltonian operator and 'open' Markovian Lindblad operators, is obtained. The theory is based on the chord function, i.e. the Fourier transform of the Wigner function. It reduces to an exact solution of the Lindblad master equation if the Hamiltonian operator is a quadratic function and the Lindblad operators are linear functions of positions and momenta. Initially, the semiclassical formulae for the case of Hermitian Lindblad operators are reinterpreted in terms of a (real) double phase space, generated by an appropriate classical double Hamiltonian. An extra 'open' term is added to the double Hamiltonian by the non-Hermitian part of the Lindblad operators in the general case of dissipative Markovian evolution. The particular case of generic Hamiltonian operators, but linear dissipative Lindblad operators, is studied in more detail. A Liouville-type equivariance still holds for the corresponding classical evolution in double phase space, but the centre subspace, which supports the Wigner function, is compressed, along with expansion of its conjugate subspace, which supports the chord function. Decoherence narrows the relevant region of double phase space to the neighbourhood of a caustic for both the Wigner function and the chord function. This difficulty is avoided by a propagator in a mixed representation, so that a further 'small-chord' approximation leads to a simple generalization of the quadratic theory for evolving Wigner functions
Dissipative time-dependent quantum transport theory.
Zhang, Yu; Yam, Chi Yung; Chen, GuanHua
2013-04-28
A dissipative time-dependent quantum transport theory is developed to treat the transient current through molecular or nanoscopic devices in presence of electron-phonon interaction. The dissipation via phonon is taken into account by introducing a self-energy for the electron-phonon coupling in addition to the self-energy caused by the electrodes. Based on this, a numerical method is proposed. For practical implementation, the lowest order expansion is employed for the weak electron-phonon coupling case and the wide-band limit approximation is adopted for device and electrodes coupling. The corresponding hierarchical equation of motion is derived, which leads to an efficient and accurate time-dependent treatment of inelastic effect on transport for the weak electron-phonon interaction. The resulting method is applied to a one-level model system and a gold wire described by tight-binding model to demonstrate its validity and the importance of electron-phonon interaction for the quantum transport. As it is based on the effective single-electron model, the method can be readily extended to time-dependent density functional theory.
Hydrodynamic relaxations in dissipative particle dynamics
Hansen, J. S.; Greenfield, Michael L.; Dyre, Jeppe C.
2018-01-01
This paper studies the dynamics of relaxation phenomena in the standard dissipative particle dynamics (DPD) model [R. D. Groot and P. B. Warren, J. Chem. Phys. 107, 4423 (1997)]. Using fluctuating hydrodynamics as the framework of the investigation, we focus on the collective transverse and longitudinal dynamics. It is shown that classical hydrodynamic theory predicts the transverse dynamics at relatively low temperatures very well when compared to simulation data; however, the theory predictions are, on the same length scale, less accurate for higher temperatures. The agreement with hydrodynamics depends on the definition of the viscosity, and here we find that the transverse dynamics are independent of the dissipative and random shear force contributions to the stress. For high temperatures, the spectrum for the longitudinal dynamics is dominated by the Brillouin peak for large length scales and the relaxation is therefore governed by sound wave propagation and is athermal. This contrasts the results at lower temperatures and small length scale, where the thermal process is clearly present in the spectra. The DPD model, at least qualitatively, re-captures the underlying hydrodynamical mechanisms, and quantitative agreement is excellent at intermediate temperatures for the transverse dynamics.
Hyperbolic theory of relativistic conformal dissipative fluids
Lehner, Luis; Reula, Oscar A.; Rubio, Marcelo E.
2018-01-01
We develop a complete description of the class of conformal relativistic dissipative fluids of divergence form, following the formalism described in [R. Geroch and L. Lindblom, Phys. Rev. D 41, 1855 (1990), 10.1103/PhysRevD.41.1855, S. Pennisi, Some considerations on a non linear approach to extended thermodynamics and in Proceedings of Symposium of Kinetic Theory and Extended Thermodynamics, Bologna, 1987.]. This type of theory is fully described in terms of evolution variables whose dynamics are governed by total divergence-type conservation laws. Specifically, we give a characterization of the whole family of conformal fluids in terms of a single master scalar function defined up to second-order corrections in dissipative effects, which we explicitly find in general form. This allows us to identify the equilibrium states of the theory and derive constitutive relations and a Fourier-like law for the corresponding first-order theory heat flux. Finally, we show that among this class of theories—and near equilibrium configurations—there exist symmetric hyperbolic ones, implying that for them one can define well-posed initial value problems.
Engineering dissipation with phononic spectral hole burning
Behunin, R. O.; Kharel, P.; Renninger, W. H.; Rakich, P. T.
2017-03-01
Optomechanics, nano-electromechanics, and integrated photonics have brought about a renaissance in phononic device physics and technology. Central to this advance are devices and materials supporting ultra-long-lived photonic and phononic excitations that enable novel regimes of classical and quantum dynamics based on tailorable photon-phonon coupling. Silica-based devices have been at the forefront of such innovations for their ability to support optical excitations persisting for nearly 1 billion cycles, and for their low optical nonlinearity. While acoustic phonon modes can persist for a similar number of cycles in crystalline solids at cryogenic temperatures, it has not been possible to achieve such performance in silica, as silica becomes acoustically opaque at low temperatures. We demonstrate that these intrinsic forms of phonon dissipation are greatly reduced (by >90%) by nonlinear saturation using continuous drive fields of disparate frequencies. The result is a form of steady-state phononic spectral hole burning that produces a wideband transparency window with optically generated phonon fields of modest (nW) powers. We developed a simple model that explains both dissipative and dispersive changes produced by phononic saturation. Our studies, conducted in a microscale device, represent an important step towards engineerable phonon dynamics on demand and the use of glasses as low-loss phononic media.
Analysing half-lives for pesticide dissipation in plants
Jacobsen, R.E.; Fantke, Peter; Trapp, Stefan
2015-01-01
Overall dissipation of pesticides from plants is frequently measured, but the contribution of individual loss processes is largely unknown. We use a pesticide fate model for the quantification of dissipation by processes other than degradation. The model was parameterised using field studies....... Scenarios were established for Copenhagen/Denmark and Shanghai/PR China, and calibrated with measured results. The simulated dissipation rates of 42 pesticides were then compared with measured overall dissipation from field studies using tomato and wheat. The difference between measured overall dissipation...... and scenario. Accordingly, degradation is the most relevant dissipation process for these 42 pesticides, followed by growth dilution. Volatilisation was less relevant, which can be explained by the design of plant protection agents. Uptake of active compound from soil into plants leads to a negative...
Dissipation of oxytetracycline in soils under different redox conditions
Yang Jigeng; Ying Guangguo; Zhou Lijun; Liu Shan; Zhao Jianliang
2009-01-01
This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.
Dissipation of oxytetracycline in soils under different redox conditions
Jigeng, Yang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Department of Chemistry and Chemical Engineering, Hunan University of Arts and Sciences, Changde 415000 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Lijun, Zhou; Shan, Liu; Jianliang, Zhao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China)
2009-10-15
This study investigated the dissipation kinetics of oxytetracycline in soils under aerobic and anoxic conditions. Laboratory experiments showed that the dissipation of oxytetracycline in soil followed first-order reaction kinetics and its dissipation rates decreased with increasing concentration. Oxytetracycline dissipated faster in soil under aerobic conditions than under anoxic conditions. The half-lives for oxytetracycline in soil under aerobic conditions ranged between 29 and 56 days for non-sterile treatments and 99-120 days for sterile treatments, while under anoxic conditions the half-lives of oxytetracycline ranged between 43 and 62 days in the non-sterile soil and between 69 and 104 days in the sterile soil. This suggests microbes can degrade oxytetracycline in agricultural soil. Abiotic factors such as strong sorption onto soil components also played a role in the dissipation of oxytetracycline in soil. - Oxytetracycline dissipation in soils is influenced by redox conditions and soil properties.
If there is dissipation the particle can gain energy
De Carvalho, R Egydio
2015-01-01
In this work, we summarize two different mechanisms to gain energy from the presence of dissipation in a time-dependent non-linear system. The particles can gain energy, in the average, from two different scenarios: i) for very week dissipation with the creation of an attractor with high velocity, and ii) in the opposite limit, for very strong dissipation, the particles can also gain energy from a boundary crisis. From the thermodynamic viewpoint both results are totally acceptable. (paper)
Effective mass approximation for tunneling states with dissipation
Chen Hong; Wu Xiang.
1987-08-01
The dissipative tunneling in an asymmetric double-well potential is studied at low temperature. With effective mass approximation, the dissipation can be replaced by a temperature-dependent effective mass. The effective mass increases with decreasing temperature and becomes infinite at T=0. The partition function of the system is derived, which has the same form as that of a non-dissipative tunneling system. Some possible applications in glasses and heavy fermion system are also discussed. (author). 21 refs, 1 fig
On Maximally Dissipative Shock Waves in Nonlinear Elasticity
Knowles, James K.
2010-01-01
Shock waves in nonlinearly elastic solids are, in general, dissipative. We study the following question: among all plane shock waves that can propagate with a given speed in a given one-dimensional nonlinearly elastic bar, which one—if any—maximizes the rate of dissipation? We find that the answer to this question depends strongly on the qualitative nature of the stress-strain relation characteristic of the given material. When maximally dissipative shocks do occur, they propagate according t...
The Fluctuation Theorem and Dissipation Theorem for Poiseuille Flow
Brookes, Sarah J; Reid, James C; Evans, Denis J; Searles, Debra J
2011-01-01
The fluctuation theorem and the dissipation theorem provide relationships to describe nonequilibrium systems arbitrarily far from, or close to equilibrium. They both rely on definition of a central property, the dissipation function. In this manuscript we apply these theorems to examine a boundary thermostatted system undergoing Poiseuille flow. The relationships are verified computationally and show that the dissipation theorem is potentially useful for study of boundary thermostatted systems consisting of complex molecules undergoing flow in the nonlinear regime.
Dissipation Assisted Quantum Memory with Coupled Spin Systems
Jiang, Liang; Verstraete, Frank; Cirac, Ignacio; Lukin, Mikhail
2009-05-01
Dissipative dynamics often destroys quantum coherences. However, one can use dissipation to suppress decoherence. A well-known example is the so-called quantum Zeno effect, in which one can freeze the evolution using dissipative processes (e.g., frequently projecting the system to its initial state). Similarly, the undesired decoherence of quantum bits can also be suppressed using controlled dissipation. We propose and analyze the use of this generalization of quantum Zeno effect for protecting the quantum information encoded in the coupled spin systems. This new approach may potentially enhance the performance of quantum memories, in systems such as nitrogen-vacancy color-centers in diamond.
Entropy model of dissipative structure on corporate social responsibility
Li, Zuozhi; Jiang, Jie
2017-06-01
Enterprise is prompted to fulfill the social responsibility requirement by the internal and external environment. In this complex system, some studies suggest that firms have an orderly or chaotic entropy exchange behavior. Based on the theory of dissipative structure, this paper constructs the entropy index system of corporate social responsibility(CSR) and explores the dissipative structure of CSR through Brusselator model criterion. Picking up listed companies of the equipment manufacturing, the research shows that CSR has positive incentive to negative entropy and promotes the stability of dissipative structure. In short, the dissipative structure of CSR has a positive impact on the interests of stakeholders and corporate social images.
Full Text Available ... Eye Symptoms Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué ... Your Eyelid Nov 29, 2017 New Dry Eye Treatment is a Tear-Jerker Jul 21, 2017 Three ...
Washimi, Hiroshi
1988-08-20
Dried lumber is classified into air dried and kiln-dried lumber. The water content of kiln-dried lumber is specified by the Japan Agricultural Standards. However, since building lumber varies in such factors as the location where it was growing, species and shape, the standards, though relaxed, are not being observed. In fact, lumbered products which are not ''Kiln-dried'' frequently bear ''kiln-dried lumber'' marks. In an attempt to correct the situation, the Forestry Agency has set up voluntary standards, but problems still remain. The conventional drying method consists of first subjecting the lumber to optimum drying, then letting bending and deformations to freely and fully appear, and follow this with corrective sawing to produce planks straight from end to end. Compared with air dried lumber in terms of moisture content, kiln-dried lumber remains much with same with minimal shrinkage and expansion. For oil-containing resin, such normal treatments as drying by heating, steaming and boiling seem to be quite effective. Kiln drying, which is becoming more and more important with changes in the circulation system, consists of the steaming-drying-heating method and the dehumidizing type drying method. The major factor which determines the drying cost is the number of days required for drying, which depends largely on the kind of lumber and moisture content. The Forestry Angency is promoting production of defoiled lumber. (2 figs, 2 tables)
Quantum thermodynamics for driven dissipative bosonic systems
Ochoa, Maicol A.; Zimbovskaya, Natalya; Nitzan, Abraham
2018-02-01
We investigate two prototypical dissipative bosonic systems under slow driving and arbitrary system-bath coupling strength, recovering their dynamic evolution as well as the heat and work rates, and we verify that thermodynamic laws are respected. Specifically, we look at the damped harmonic oscillator and the damped two-level system. For the former, we study independently the slow time-dependent perturbation in the oscillator frequency and in the coupling strength. For the latter, we concentrate on the slow modulation of the energy gap between the two levels. Importantly, we are able to find the entropy production rates for each case without explicitly defining nonequilibrium extensions for the entropy functional. This analysis also permits the definition of phenomenological friction coefficients in terms of structural properties of the system-bath composite.
An extended dissipative particle dynamics model
Cotter, C J
2003-01-01
The method of dissipative particle dynamics (DPD) was introduced by Hoogerbrugge & Koelman to study meso-scale material processes. The theoretical investigation of the DPD method was initiated by Espanol who used a Fokker-Planck formulation of the DPD method and applied the Mori-Zwanzig projection operator calculus to obtain the equations of hydrodynamics for DPD. A current limitation of DPD is that it requires a clear separation of scales between the resolved and unresolved processes. In this note, we suggest a simple extension of DPD that allows for inclusion of unresolved processes with exponentially decaying variance for any value of the decay rate. The main point of the extension is that it is as easy to implement as DPD in a numerical algorithm.
Dissipative dynamics of superconducting hybrid qubit systems
Montes, Enrique; Calero, Jesus M; Reina, John H
2009-01-01
We perform a theoretical study of composed superconducting qubit systems for the case of a coupled qubit configuration based on a hybrid qubit circuit made of both charge and phase qubits, which are coupled via a σ x x σ z interaction. We compute the system's eigen-energies in terms of the qubit transition frequencies and the strength of the inter-qubit coupling, and describe the sensitivity of the energy crossing/anti-crossing features to such coupling. We compute the hybrid system's dissipative dynamics for the cases of i) collective and ii) independent decoherence, whereby the system interacts with one common and two different baths of harmonic oscillators, respectively. The calculations have been performed within the Bloch-Redfield formalism and we report the solutions for the populations and the coherences of the system's reduced density matrix. The dephasing and relaxation rates are explicitly calculated as a function of the heat bath temperature.
Thermodynamique des moteurs thermiques aux structures dissipatives
Prigogine, Ilya
1999-01-01
Ce livre constitue à la fois une présentation complète de la thermodynamique et une introduction scientifique à l'œuvre de Prigogine. Les auteurs innovent en montrant comment la thermodynamique du non-équilibre est un prolongement naturel de la thermodynamique de l'équilibre. Elle constitue ainsi la science des processus irréversibles - " la flèche du temps " - dont les structures dissipatives sont les témoignages les plus éclatants. Les développements historiques en font, non seulement un texte de référence, mais aussi un livre de culture. Les nombreux exemples et exercices, comme les programmes informatiques et les références aux sites Internet en font un outil de travail irremplaçable.
Quantum Markov Chain Mixing and Dissipative Engineering
Kastoryano, Michael James
2012-01-01
This thesis is the fruit of investigations on the extension of ideas of Markov chain mixing to the quantum setting, and its application to problems of dissipative engineering. A Markov chain describes a statistical process where the probability of future events depends only on the state...... of the system at the present point in time, but not on the history of events. Very many important processes in nature are of this type, therefore a good understanding of their behaviour has turned out to be very fruitful for science. Markov chains always have a non-empty set of limiting distributions...... (stationary states). The aim of Markov chain mixing is to obtain (upper and/or lower) bounds on the number of steps it takes for the Markov chain to reach a stationary state. The natural quantum extensions of these notions are density matrices and quantum channels. We set out to develop a general mathematical...
Frank, T.D.
2010-01-01
We formulate Markov diffusion processes for canonical-dissipative systems exhibiting Nambu mechanics. Analytical expressions for stationary canonical-dissipative distributions are obtained. Nambu-Boltzmann distributions are derived as special cases for systems without energy pumping. The Markov short-time propagator is used to derive maximum likelihood estimators for parameters of a model that describes a particular dynamic motor pattern providing haptic cues.
Mukherjee, Santanu, E-mail: s.mukherjee@fz-juelich.de [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Tappe, Wolfgang; Weihermueller, Lutz; Hofmann, Diana; Köppchen, Stephan [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Laabs, Volker; Schroeder, Tom [BASF SE, Crop Protection, 67117, Limburgerhof (Germany); Vereecken, Harry [Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Burauel, Peter [Sustainable Campus, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany)
2016-02-15
Biopurification systems, such as biofilters, are biotechnological tools to prevent point sources of pesticide pollution stemming from on-farm operations. For the purification processes pesticide sorption and mineralization and/or dissipation are essential and both largely depend on the type of filling materials and the pesticide in use. In this paper the mineralization and dissipation of three contrasting {sup 14}C-labeled pesticides (bentazone, boscalid, and pyrimethanil) were investigated in laboratory incubation experiments using sandy soil, biochar produced from Pine woodchips, and/or digestate obtained from anaerobic digestion process using maize silage, chicken manure, beef and pig urine as feedstock. The results indicate that the addition of digestate increased pesticide mineralization, whereby the mineralization was not proportional to the digestate loads in the mixture, indicating a saturation effect in the turnover rate of pesticides. This effect was in correlation with the amount of water extractable DOC, obtained from the digestate based mixtures. Mixing biochar into the soil generally reduced total mineralization and led to larger sorption/sequestration of the pesticides, resulting in faster decrease of the extractable fraction. Also the addition of biochar to the soil/digestate mixtures reduced mineralization compared to the digestate alone mixture but mineralization rates were still higher as for the biochar/soil alone. In consequence, the addition of biochar to the soil generally decreased pesticide dissipation times and larger amounts of biochar led to high amounts of non-extractable residues of pesticide in the substrates. Among the mixtures tested, a mixture of digestate (5%) and biochar (5%) gave optimal results with respect to mineralization and simultaneous sorption for all three pesticides. - Highlights: • Biochar and digestate significantly affects the dissipation pattern of pesticides. • Addition of digestate enhanced mineralization of
Mukherjee, Santanu; Tappe, Wolfgang; Weihermueller, Lutz; Hofmann, Diana; Köppchen, Stephan; Laabs, Volker; Schroeder, Tom; Vereecken, Harry; Burauel, Peter
2016-01-01
Biopurification systems, such as biofilters, are biotechnological tools to prevent point sources of pesticide pollution stemming from on-farm operations. For the purification processes pesticide sorption and mineralization and/or dissipation are essential and both largely depend on the type of filling materials and the pesticide in use. In this paper the mineralization and dissipation of three contrasting "1"4C-labeled pesticides (bentazone, boscalid, and pyrimethanil) were investigated in laboratory incubation experiments using sandy soil, biochar produced from Pine woodchips, and/or digestate obtained from anaerobic digestion process using maize silage, chicken manure, beef and pig urine as feedstock. The results indicate that the addition of digestate increased pesticide mineralization, whereby the mineralization was not proportional to the digestate loads in the mixture, indicating a saturation effect in the turnover rate of pesticides. This effect was in correlation with the amount of water extractable DOC, obtained from the digestate based mixtures. Mixing biochar into the soil generally reduced total mineralization and led to larger sorption/sequestration of the pesticides, resulting in faster decrease of the extractable fraction. Also the addition of biochar to the soil/digestate mixtures reduced mineralization compared to the digestate alone mixture but mineralization rates were still higher as for the biochar/soil alone. In consequence, the addition of biochar to the soil generally decreased pesticide dissipation times and larger amounts of biochar led to high amounts of non-extractable residues of pesticide in the substrates. Among the mixtures tested, a mixture of digestate (5%) and biochar (5%) gave optimal results with respect to mineralization and simultaneous sorption for all three pesticides. - Highlights: • Biochar and digestate significantly affects the dissipation pattern of pesticides. • Addition of digestate enhanced mineralization of
Foucault Dissipation in a Rolling Cylinder: A Webcam Quantitative Study
Bonanno, A.; Bozzo, G.; Camarca, M.; Sapia, P.
2011-01-01
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault "eddy" currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis…
Dissipative differential systems and the state space H∞ control problem
Trentelman, H.L.; Willems, J.C.
2000-01-01
The purpose of this paper is to apply our very recent results on the synthesis of dissipative linear differential systems to the 'classical' state space H∞ control problem. We first review our general problem set-up, where the problem of rendering a given plant dissipative by general
Balance laws and centro velocity in dissipative systems
van Groesen, Embrecht W.C.; Mainardi, F.
1990-01-01
Starting with a density that is conserved for a dynamical system when dissipation is ignored, a local conservation law is derived for which the total flux (integrated over the spatial domain) is unique. When dissipation is incorporated, the conservation law becomes a balance law. The contribution
Observation of flow dissipation in 3He-B
Eisenstein, J.P.; Packard, R.E.
1982-01-01
Anomalous dissipation is observed in 3 He-B flowing in a U-tube device. The dissipation is of unknown origin and persists to the lowest measured velocity. The position of this result in the framework of other 3 He-B flow experiments is discussed
Dissipation and leaching of pyroxasulfone and s-metolachlor
Pyroxasulfone dissipation and mobility in the soil was evaluated and compared to S-metolachlor in 2009 and 2010 at two field sites in northern Colorado, on a Nunn fine clay loam, and Olney fine sandy loam soil. Pyroxasulfone dissipation half-life (DT50) values varied from 47 to 134 d, and those of S...
Braun-Le Chatelier principle in dissipative thermodynamics
Pavelka, Michal; Grmela, Miroslav
2016-01-01
Braun-Le Chatelier principle is a fundamental result of equilibrium thermodynamics, showing how stable equilibrium states shift when external conditions are varied. The principle follows from convexity of thermodynamic potential. Analogously, from convexity of dissipation potential it follows how steady non-equilibrium states shift when thermodynamic forces are varied, which is the extension of the principle to dissipative thermodynamics.
The thermodynamic basis of entransy and entransy dissipation
Xu, Mingtian
2011-01-01
In the present work, the entransy and entransy dissipation are defined from the thermodynamic point of view. It is shown that the entransy is a state variable and can be employed to describe the second law of thermodynamics. For heat conduction, a principle of minimum entransy dissipation is established based on the second law of thermodynamics in terms of entransy dissipation, which leads to the governing equation of the steady Fourier heat conduction without heat source. Furthermore, we derive the expressions of the entransy dissipation in duct flows and heat exchangers from the second law of thermodynamics, which paves the way for applications of the entransy dissipation theory in heat exchanger design. -- Highlights: → The concepts of entransy and entransy dissipation are defined from the thermodynamic point of view. → We find that the entransy is a new thermodynamic property. → The second law of thermodynamics can be described by the entransy and entransy dissipation. → The expressions of entransy dissipation in duct flows and heat exchangers are derived from the second law of thermodynamics.
Direct and indirect detection of dissipative dark matter
Fan, JiJi; Katz, Andrey; Shelton, Jessie, E-mail: jijifan1982@gmail.com, E-mail: katz.andrey@gmail.com, E-mail: jshelton137@gmail.com [Department of Physics, Harvard University, Cambridge, MA 02138 (United States)
2014-06-01
We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.
Dissipative quantum trajectories in complex space: Damped harmonic oscillator
Chou, Chia-Chun
2016-01-01
Dissipative quantum trajectories in complex space are investigated in the framework of the logarithmic nonlinear Schrödinger equation. The logarithmic nonlinear Schrödinger equation provides a phenomenological description for dissipative quantum systems. Substituting the wave function expressed in terms of the complex action into the complex-extended logarithmic nonlinear Schrödinger equation, we derive the complex quantum Hamilton–Jacobi equation including the dissipative potential. It is shown that dissipative quantum trajectories satisfy a quantum Newtonian equation of motion in complex space with a friction force. Exact dissipative complex quantum trajectories are analyzed for the wave and solitonlike solutions to the logarithmic nonlinear Schrödinger equation for the damped harmonic oscillator. These trajectories converge to the equilibrium position as time evolves. It is indicated that dissipative complex quantum trajectories for the wave and solitonlike solutions are identical to dissipative complex classical trajectories for the damped harmonic oscillator. This study develops a theoretical framework for dissipative quantum trajectories in complex space.
Dissipative nucleus-nucleus collisions: study of memory effects
Agarwal, K.C.; Yadav, H.L.
2002-01-01
Dissipative collisions between two heavy nuclei are described in terms of a macroscopic dynamical model within the framework of a multi-dimensional Fokker-Planck equation. The reaction 86 Kr(8.18 MeV/u) + 166 Er has been used as a prototype to study and demonstrate the memory effects for dissipation and diffusion processes
Dissipative quantum trajectories in complex space: Damped harmonic oscillator
Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw
2016-10-15
Dissipative quantum trajectories in complex space are investigated in the framework of the logarithmic nonlinear Schrödinger equation. The logarithmic nonlinear Schrödinger equation provides a phenomenological description for dissipative quantum systems. Substituting the wave function expressed in terms of the complex action into the complex-extended logarithmic nonlinear Schrödinger equation, we derive the complex quantum Hamilton–Jacobi equation including the dissipative potential. It is shown that dissipative quantum trajectories satisfy a quantum Newtonian equation of motion in complex space with a friction force. Exact dissipative complex quantum trajectories are analyzed for the wave and solitonlike solutions to the logarithmic nonlinear Schrödinger equation for the damped harmonic oscillator. These trajectories converge to the equilibrium position as time evolves. It is indicated that dissipative complex quantum trajectories for the wave and solitonlike solutions are identical to dissipative complex classical trajectories for the damped harmonic oscillator. This study develops a theoretical framework for dissipative quantum trajectories in complex space.
Two-dimensional dissipation in third sound resonance
Buck, A.L.; Mochel, J.M.; Illinois Univ., Urbana
1981-01-01
The first determination of non-linear superflow dissipation in a truly two-dimensional helium film is reported. Superfluid velocities were measured using third sound resonance on a closed superfluid film. The predicted power law dissipation function, with exponent of approximately eight, is observed at three temperatures in a film of 0.58 mobile superfluid layers. (orig.)
estimation of ionospheric energy dissipation for the year 2012 using
userpc
energy dissipation is the dominant channel of energy transfer in that year from the solar wind. This is consistent with many results found by other researchers. Keywords: Østgaard's Empirical Relation, Ionospheric Energy Dissipation, Electron. Precipitation, Joule Heating. INTRODUCTION. In the Earth's magnetosphere, the ...
Direct and indirect detection of dissipative dark matter
Fan, JiJi; Katz, Andrey; Shelton, Jessie
2014-01-01
We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints
Influence of viscous dissipation and radiation on MHD Couette flow ...
The overall analysis of the study of these parameters in various degrees show an increase in the velocity profile of the fluid, while radiation parameter decreases the temperature profile; viscous dissipation and Reynolds number increase the temperature profile of the fluid. Key word: Couette flow, viscous dissipation, ...
Effect of magnetic shear on dissipative drift instabilities
Guzdar, P.N.; Chen, L.; Kaw, P.K.; Oberman, C.
1978-03-01
In this letter we report the results of a linear radial eigenmode analysis of dissipative drift waves in a plasma with magnetic shear and spatially varying density gradient. The results of the analysis are shown to be consistent with a recent experiment on the study of dissipative drift instabilities in a toroidal stellarator
Energy dissipation of slot-type flip buckets
Wu, Jian-hua; Li, Shu-fang; Ma, Fei
2018-03-01
The energy dissipation is a key index in the evaluation of energy dissipation elements. In the present work, a flip bucket with a slot, called the slot-type flip bucket, is theoretically and experimentally investigated by the method of estimating the energy dissipation. The theoretical analysis shows that, in order to have the energy dissipation, it is necessary to determine the sequent flow depth h 1 and the flow speed V 1 at the corresponding position through the flow depth h 2 after the hydraulic jump. The relative flow depth h 2 / h 。 is a function of the approach flow Froude number Fr 。, the relative slot width b/B 。, and the relative slot angle θ/β. The expression for estimating the energy dissipation is developed, and the maximum error is not larger than 9.21%.
Dissipation of Alfven waves in compressible inhomogeneous media
Malara, F.; Primavera, L.; Veltri, P.
1997-01-01
In weakly dissipative media governed by the magnetohydrodynamics (MHD) equations, any efficient mechanism of energy dissipation requires the formation of small scales. Using numerical simulations, we study the properties of Alfven waves propagating in a compressible inhomogeneous medium, with an inhomogeneity transverse to the direction of wave propagation. Two dynamical effects, energy pinching and phase mixing, are responsible for the small-scales formation, similarly to the incompressible case. Moreover, compressive perturbations, slow waves and a static entropy wave are generated; the former are subject to steepening and form shock waves, which efficiently dissipate their energy, regardless of the Reynolds number. Rough estimates show that the dissipation times are consistent with those required to dissipate Alfven waves of photospheric origin inside the solar corona
Quantified Energy Dissipation Rates in the Terrestrial Bow Shock. 2; Waves and Dissipation
Wilson, L. B., III; Sibeck, D. G.; Breneman, A. W.; Le Contel, O.; Cully, C.; Turner, D. L.; Angelopoulos, V.; Malaspina, D. M.
2014-01-01
We present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collision-less bow shock using data from the Time History of Events and Macro-Scale Interactions during Sub-Storms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collision-less shocks. In every bow shock crossing examined, we observed both low-frequency (less than 10 hertz) and high-frequency (approximately or greater than10 hertz) electromagnetic waves throughout the entire transition region and into the magnetosheath. The low-frequency waves were consistent with magnetosonic-whistler waves. The high-frequency waves were combinations of ion-acoustic waves, electron cyclotron drift instability driven waves, electrostatic solitary waves, and whistler mode waves. The high-frequency waves had the following: (1) peak amplitudes exceeding delta B approximately equal to 10 nanoteslas and delta E approximately equal to 300 millivolts per meter, though more typical values were delta B approximately equal to 0.1-1.0 nanoteslas and delta E approximately equal to 10-50 millivolts per meter (2) Poynting fluxes in excess of 2000 microWm(sup -2) (micro-waves per square meter) (typical values were approximately 1-10 microWm(sup -2) (micro-waves per square meter); (3) resistivities greater than 9000 omega meters; and (4) associated energy dissipation rates greater than 10 microWm(sup -3) (micro-waves per cubic meter). The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for approximately 90 percent of the wave burst durations. For approximately 22 percent of these times, the wave-particle interactions needed to only be less than or equal to 0.1 percent efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave
Dissipation of Pendimethalin in Soybean Crop Under Field Conditions.
Tandon, Shishir
2016-05-01
Persistence of pendimethalin was studied in soil, soybean pods, straw and water under field conditions. Pendimethalin was applied at 1 and 2 kg a.i. ha(-1). Residues in soil were detected up to 60 and 90 days at the recommended and double dose, respectively. Dissipation followed first order kinetics and was accounted for by a biphasic pattern. The half-life for the initial phase and later phase was 12.73 and 26.60 days, respectively, for recommended and 7.25 and 37.91 days, respectively, for double dose. The limit of quantification was 0.005 µg g(-1) of sample. Percent recovery from soil, oil, defatted cake, straw and water samples fortified with 0.01-1.0 mg kg(-1) varied from 84.5 %-89.6 %, 84.6 %-88.7 %, 79.4 %-86.0 %, 78.2 %-85.6 % and 90.2 %-93.0 %, respectively. At harvest, pendimethalin residue in soybean pods, straw, and soil were below detectable limits. No residues of pendimethalin were detected in ground water. Current application of pendimethalin in the environment is not expected to cause adverse health effects form the consumption of soybeans.
Dissipation of 'dark energy' by cortex in knowledge retrieval.
Capolupo, Antonio; Freeman, Walter J; Vitiello, Giuseppe
2013-03-01
We have devised a thermodynamic model of cortical neurodynamics expressed at the classical level by neural networks and at the quantum level by dissipative quantum field theory. Our model is based on features in the spatial images of cortical activity newly revealed by high-density electrode arrays. We have incorporated the mechanism and necessity for so-called dark energy in knowledge retrieval. We have extended the model first using the Carnot cycle to define our measures for energy, entropy and temperature, and then using the Rankine cycle to incorporate criticality and phase transitions. We describe the dynamics of two interactive fields of neural activity that express knowledge, one at high and the other at low energy density, and the two operators that create and annihilate the fields. We postulate that the extremely high density of energy sequestered briefly in cortical activity patterns can account for the vividness, richness of associations, and emotional intensity of memories recalled by stimuli. Copyright © 2013 Elsevier B.V. All rights reserved.
Dry cooling tower operating experience in the LOFT reactor
Hunter, J.A.
1980-01-01
A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features
Templated Dry Printing of Conductive Metal Nanoparticles
Rolfe, David Alexander
Printed electronics can lower the cost and increase the ubiquity of electrical components such as batteries, sensors, and telemetry systems. Unfortunately, the advance of printed electronics has been held back by the limited minimum resolution, aspect ratio, and feature fidelity of present printing techniques such as gravure, screen printing and inkjet printing. Templated dry printing offers a solution to these problems by patterning nanoparticle inks into templates before drying. This dissertation shows advancements in two varieties of templated dry nanoprinting. The first, advective micromolding in vapor-permeable templates (AMPT) is a microfluidic approach that uses evaporation-driven mold filling to create submicron features with a 1:1 aspect ratio. We will discuss submicron surface acoustic wave (SAW) resonators made through this process, and the refinement process in the template manufacturing process necessary to make these devices. We also present modeling techniques that can be applied to future AMPT templates. We conclude with a modified templated dry printing that improves throughput and isolated feature patterning by transferring dry-templated features with laser ablation. This method utilizes surface energy-defined templates to pattern features via doctor blade coating. Patterned and dried features can be transferred to a polymer substrate with an Nd:YAG MOPA fiber laser, and printed features can be smaller than the laser beam width.
Xiong, Liping; Lan, Ganhui
2015-01-01
Sustained molecular oscillations are ubiquitous in biology. The obtained oscillatory patterns provide vital functions as timekeepers, pacemakers and spacemarkers. Models based on control theory have been introduced to explain how specific oscillatory behaviors stem from protein interaction feedbacks, whereas the energy dissipation through the oscillating processes and its role in the regulatory function remain unexplored. Here we developed a general framework to assess an oscillator’s regulation performance at different dissipation levels. Using the Escherichia coli MinCDE oscillator as a model system, we showed that a sufficient amount of energy dissipation is needed to switch on the oscillation, which is tightly coupled to the system’s regulatory performance. Once the dissipation level is beyond this threshold, unlike stationary regulators’ monotonic performance-to-cost relation, excess dissipation at certain steps in the oscillating process damages the oscillator’s regulatory performance. We further discovered that the chemical free energy from ATP hydrolysis has to be strategically assigned to the MinE-aided MinD release and the MinD immobilization steps for optimal performance, and a higher energy budget improves the robustness of the oscillator. These results unfold a novel mode by which living systems trade energy for regulatory function. PMID:26317492
Soap film vibration: origin of the dissipation.
Acharige, Sébastien Kosgodagan; Elias, Florence; Derec, Caroline
2014-11-07
We investigate the complex dispersion relationship of a transverse antisymmetric wave on a horizontal soap film. Experimentally, the complex wave number k at a fixed forcing frequency is determined by measuring the vibrating amplitude of the soap film: the wavelength (linked to the real part of k) is determined by the spatial variation of the amplitude; the decay length (linked to the imaginary part of k) is determined by analyzing the resonance curves of the vibrating wave as a function of frequency. Theoretically, we compute the complex dispersion relationship taking into account the physical properties of the bulk liquid and gas phase, and of the gas-liquid interfaces. The comparison between the computation (developed to the leading order under our experimental conditions) and the experimental results confirms that the phase velocity is fixed by the interplay between surface tension, and liquid and air inertia, as reported in previous studies. Moreover, we show that the attenuation of the transverse antisymmetric wave originates from the viscous dissipation in the gas phase surrounding the liquid film. This result is an important step in understanding the propagation of an acoustic wave in liquid foam, using a bottom-up approach.
Light energy dissipation under water stress conditions
Stuhlfauth, T.; Scheuermann, R.; Fock, H.P.
1990-01-01
Using 14 CO 2 gas exchange and metabolite analyses, stomatal as well as total internal CO 2 uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to -2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO 2 exchange was drastically reduced, whereas the total CO 2 uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO 2 . This CO 2 -recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO 2 recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations
Energy dissipation of rockfalls by coppice structures
G. Ciabocco
2009-06-01
Full Text Available The objective of this work is to develop elements to improve understanding of the behaviour of a coppice in relation to the phenomenon of falling boulders. The first section proposes an amendment to the equation for calculating the index which describes the probability of impact between a rock and plants in managed coppice forests. A study was carried out, using models to calculate the kinetic energy of a falling boulder along a slope considering the kinetic energy dissipated during the impact with the structure of forest plants managed by coppice. The output of the simulation models were then compared with the real dynamics of falling boulders in field tests using digital video.
It emerged from an analysis of the results of this comparison that a modification to the 1989 Gsteiger equation was required, in order to calculate the "Average Distance between Contacts" (ADC. To this purpose, the concept of "Structure of Interception", proposed in this paper, was developed, valid as a first approach for describing the differences in the spatial distribution of stems between coppice and forest. This study also aims to provide suggestions for forestry management, in order to maintain or increase the protective capacity of a coppice managed with conventional techniques for the area studied, modifying the dendrometric characteristics.
Light energy dissipation under water stress conditions
Stuhlfauth, T.; Scheuermann, R.; Fock, H.P. (Universitaet Kaiserslautern (West Germany))
1990-04-01
Using {sup 14}CO{sub 2} gas exchange and metabolite analyses, stomatal as well as total internal CO{sub 2} uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to {minus}2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO{sub 2} exchange was drastically reduced, whereas the total CO{sub 2} uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO{sub 2}. This CO{sub 2}-recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO{sub 2} recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations.
Dissipative dynamics of superconducting hybrid qubit systems
Montes, Enrique; Calero, Jesus M; Reina, John H, E-mail: enriquem@univalle.edu.c, E-mail: j.reina-estupinan@physics.ox.ac.u [Departamento de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)
2009-05-01
We perform a theoretical study of composed superconducting qubit systems for the case of a coupled qubit configuration based on a hybrid qubit circuit made of both charge and phase qubits, which are coupled via a sigma{sub x} x sigma{sub z} interaction. We compute the system's eigen-energies in terms of the qubit transition frequencies and the strength of the inter-qubit coupling, and describe the sensitivity of the energy crossing/anti-crossing features to such coupling. We compute the hybrid system's dissipative dynamics for the cases of i) collective and ii) independent decoherence, whereby the system interacts with one common and two different baths of harmonic oscillators, respectively. The calculations have been performed within the Bloch-Redfield formalism and we report the solutions for the populations and the coherences of the system's reduced density matrix. The dephasing and relaxation rates are explicitly calculated as a function of the heat bath temperature.
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Architected squirt-flow materials for energy dissipation
Cohen, Tal; Kurzeja, Patrick; Bertoldi, Katia
2017-12-01
In the present study we explore material architectures that lead to enhanced dissipation properties by taking advantage of squirt-flow - a local flow mechanism triggered by heterogeneities at the pore level. While squirt-flow is a known dominant source of dissipation and seismic attenuation in fluid saturated geological materials, we study its untapped potential to be incorporated in highly deformable elastic materials with embedded fluid-filled cavities for future engineering applications. An analytical investigation, that isolates the squirt-flow mechanism from other potential dissipation mechanisms and considers an idealized setting, predicts high theoretical levels of dissipation achievable by squirt-flow and establishes a set of guidelines for optimal dissipation design. Particular architectures are then investigated via numerical simulations showing that a careful design of the internal voids can lead to an increase of dissipation levels by an order of magnitude, compared with equivalent homogeneous void distributions. Therefore, we suggest squirt-flow as a promising mechanism to be incorporated in future architected materials to effectively and reversibly dissipate energy.
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Nonlinear dynamics of drift structures in a magnetized dissipative plasma
Aburjania, G. D.; Rogava, D. L.; Kharshiladze, O. A.
2011-01-01
and localized, while the cyclone is less intense and has a larger size. In the course of further evolution, the cyclone persists for a relatively longer time, while the anticyclone breaks into small-scale vortices and dissipation hastens this process. It is found that the relaxation of the vortex by viscous dissipation differs in character from that by the frictional force. The time scale on which the vortex is damped depends strongly on its typical size: larger scale vortices are longer lived structures. It is shown that, as the instability develops, the initial vortex is amplified and the lifetime of the dipole pair components-cyclone and anticyclone-becomes longer. As time elapses, small-scale noise is generated in the system, and the spatial structure of the perturbation potential becomes irregular. The pattern of interaction of solitary vortex structures among themselves and with the medium shows that they can take part in strong drift turbulence and anomalous transport of heat and matter in an inhomogeneous magnetized plasma.
Identification of energy dissipation mechanisms in CNT-reinforced nanocomposites
Gardea, Frank; Lagoudas, Dimitris C; Naraghi, Mohammad; Glaz, Bryan; Riddick, Jaret
2016-01-01
In this paper we present our recent findings on the mechanisms of energy dissipation in polymer-based nanocomposites obtained through experimental investigations. The matrix of the nanocomposite was polystyrene (PS) which was reinforced with carbon nanotubes (CNTs). To study the mechanical strain energy dissipation of nanocomposites, we measured the ratio of loss to storage modulus for different CNT concentrations and alignments. CNT alignment was achieved via hot-drawing of PS-CNT. In addition, CNT agglomeration was studied via a combination of SEM imaging and Raman scanning. We found that at sufficiently low strains, energy dissipation in composites with high CNT alignment is not a function of applied strain, as no interfacial slip occurs between the CNTs and PS. However, below the interfacial slip strain threshold, damping scales monotonically with CNT content, which indicates the prevalence of CNT-CNT friction dissipation mechanisms within agglomerates. At higher strains, interfacial slip also contributes to energy dissipation. However, the increase in damping with strain, especially when CNT agglomerates are present, does not scale linearly with the effective interface area between CNTs and PS, suggesting a significant contribution of friction between CNTs within agglomerates to energy dissipation at large strains. In addition, for the first time, a comparison between the energy dissipation in randomly oriented and aligned CNT composites was made. It is inferred that matrix plasticity and tearing caused by misorientation of CNTs with the loading direction is a major cause of energy dissipation. The results of our research can be used to design composites with high energy dissipation capability, especially for applications where dynamic loading may compromise structural stability and functionality, such as rotary wing structures and antennas. (paper)
Global dissipativity of continuous-time recurrent neural networks with time delay
Liao Xiaoxin; Wang Jun
2003-01-01
This paper addresses the global dissipativity of a general class of continuous-time recurrent neural networks. First, the concepts of global dissipation and global exponential dissipation are defined and elaborated. Next, the sets of global dissipativity and global exponentially dissipativity are characterized using the parameters of recurrent neural network models. In particular, it is shown that the Hopfield network and cellular neural networks with or without time delays are dissipative systems
Magnetic energy dissipation in force-free jets
Choudhuri, Arnab Rai; Konigl, Arieh
1986-01-01
It is shown that a magnetic pressure-dominated, supersonic jet which expands or contracts in response to variations in the confining external pressure can dissipate magnetic energy through field-line reconnection as it relaxes to a minimum-energy configuration. In order for a continuous dissipation to occur, the effective reconnection time must be a fraction of the expansion time. The dissipation rate for the axisymmetric minimum-energy field configuration is analytically derived. The results indicate that the field relaxation process could be a viable mechanism for powering the synchrotron emission in extragalactic jets if the reconnection time is substantially shorter than the nominal resistive tearing time in the jet.
Energy dissipation through wind-generated breaking waves
ZHANG Shuwen; CAO Ruixue; XIE Lingling
2012-01-01
Wave breaking is an important process that controls turbulence properties and fluxes of heat and mass in the upper oceanic layer.A model is described for energy dissipation per unit area at the ocean surface attributed to wind-generated breaking waves,in terms of ratio of energy dissipation to energy input,windgenerated wave spectrum,and wave growth rate.Also advanced is a vertical distribution model of turbulent kinetic energy,based on an exponential distribution method.The result shows that energy dissipation rate depends heavily on wind speed and sea state.Our results agree well with predictions of previous works.
Relative Entropy, Interaction Energy and the Nature of Dissipation
Bernard Gaveau
2014-06-01
Full Text Available Many thermodynamic relations involve inequalities, with equality if a process does not involve dissipation. In this article we provide equalities in which the dissipative contribution is shown to involve the relative entropy (a.k.a. Kullback-Leibler divergence. The processes considered are general time evolutions both in classical and quantum mechanics, and the initial state is sometimes thermal, sometimes partially so. By calculating a transport coefficient we show that indeed—at least in this case—the source of dissipation in that coefficient is the relative entropy.
Dissipation of magnetic energy during disruptive current termination
Yamazaki, K.; Schmidt, G.L.
1983-09-01
The magnetic coupling during a disruption between the plasma and the various coil systems on the PDX tokamak has been modeled. Using measured coil currents, the model indicates that dissipation of magnetic energy in the plasma equal to 75 % of the energy stored in the poloidal field of the plasma current does occur and that coupling between the plasma and the coil systems can reduce such dissipation. In the case of PDX ohmic discharges, bolometric measurements of radiation and charge exchange, integrated over a disruption, account for 90 % of the calculated energy dissipation. (author)
Skyrmionic spin Seebeck effect via dissipative thermomagnonic torques
Kovalev, Alexey A.
2014-06-01
We derive thermomagnonic torque and its "β-type" dissipative correction from the stochastic Landau-Lifshitz-Gilbert equation. The β-type dissipative correction describes viscous coupling between magnetic dynamics and magnonic current and it stems from spin mistracking of the magnetic order. We show that thermomagnonic torque is important for describing temperature gradient induced motion of skyrmions in helical magnets while dissipative correction plays an essential role in generating transverse Magnus force. We propose to detect such skyrmionic motion by employing the transverse spin Seebeck effect geometry.
Influence of queue propagation and dissipation on route travel times
Raovic, Nevena
into account (Bliemer, 2008). Yperman (2007) indicates that there is a significant difference in queue-propagation and queue-dissipation between the LTM and DQM. This results in different route travel times, and can further affect route choice. In this paper, different approaches to represent queue propagation...... and dissipation through the CTM, LTM and DQM are studied. A simple network allows to show how these approaches influence route travel time. Furthermore, the possibility of changing the existing DQM is considered in order to more realistically represent queue propagation and dissipation, which would lead to more...... accurate route travel times....
Engineering high-order nonlinear dissipation for quantum superconducting circuits
Mundhada, S. O.; Grimm, A.; Touzard, S.; Shankar, S.; Minev, Z. K.; Vool, U.; Mirrahimi, M.; Devoret, M. H.
Engineering nonlinear driven-dissipative processes is essential for quantum control. In the case of a harmonic oscillator, nonlinear dissipation can stabilize a decoherence-free manifold, leading to protected quantum information encoding. One possible approach to implement such nonlinear interactions is to combine the nonlinearities provided by Josephson circuits with parametric pump drives. However, it is usually hard to achieve strong nonlinearities while avoiding undesired couplings. Here we propose a scheme to engineer a four-photon drive and dissipation in a harmonic oscillator by cascading experimentally demonstrated two-photon processes. We also report experimental progress towards realization of such a scheme. Work supported by: ARO, ONR, AFOSR and YINQE.
Dry and Semi-Dry Tropical Cyclones
Cronin, T.; Chavas, D. R.
2017-12-01
Our understanding of dynamics in our real moist atmosphere is strongly informed by idealized dry models. It is widely believed that tropical cyclones (TCs) are an intrinsically moist phenomenon - relying fundamentally on evaporation and latent heat release - yet recent numerical modeling work has found formation of dry axisymmetric tropical cyclones from a state of dry radiative-convective equilibrium. What can such "dry hurricanes" teach us about intensity, structure, and size of real moist tropical cyclones in nature? Are dry TCs even stable in 3D? What about surfaces that are nearly dry but have some latent heat flux - can they also support TCs? To address these questions, we use the SAM cloud-system resolving model to simulate radiative-convective equilibrium on a rapidly rotating f-plane, subject to constant tropospheric radiative cooling. We use a homogeneous surface with fixed temperature and with surface saturation vapor pressure scaled by a factor 0-1 relative to that over pure water - allowing for continuous variation between moist and dry limits. We also explore cases with surface enthalpy fluxes that are uniform in space and time, where partitioning between latent and sensible heat fluxes is specified directly. We find that a completely moist surface yields a TC-world where multiple vortices form spontaneously and persist for tens of days. A completely dry surface can also yield a parallel dry TC-world with many vortices that are even more stable and persistent. Spontaneous cyclogenesis, however, is impeded for a range of low to intermediate surface wetness values, and by the combination of large rotation rates and a dry surface. We discuss whether these constraints on spontaneous cyclogenesis might arise from: 1) rain evaporation in the subcloud layer limiting the range of viable surface wetness values, and 2) a natural convective Rossby number limiting the range of viable rotation rates. Finally, we discuss simulations with uniform surface enthalpy
Particle Acceleration in Dissipative Pulsar Magnetospheres
Kazanas, Z.; Kalapotharakos, C.; Harding, A.; Contopoulos, I.
2012-01-01
Pulsar magnetospheres represent unipolar inductor-type electrical circuits at which an EM potential across the polar cap (due to the rotation of their magnetic field) drives currents that run in and out of the polar cap and close at infinity. An estimate ofthe magnitude of this current can be obtained by dividing the potential induced across the polar cap V approx = B(sub O) R(sub O)(Omega R(sub O)/c)(exp 2) by the impedance of free space Z approx eq 4 pi/c; the resulting polar cap current density is close to $n {GJ} c$ where $n_{GJ}$ is the Goldreich-Julian (GJ) charge density. This argument suggests that even at current densities close to the GJ one, pulsar magnetospheres have a significant component of electric field $E_{parallel}$, parallel to the magnetic field, a condition necessary for particle acceleration and the production of radiation. We present the magnetic and electric field structures as well as the currents, charge densities, spin down rates and potential drops along the magnetic field lines of pulsar magnetospheres which do not obey the ideal MHD condition $E cdot B = 0$. By relating the current density along the poloidal field lines to the parallel electric field via a kind of Ohm's law $J = sigma E_{parallel}$ we study the structure of these magnetospheres as a function of the conductivity $sigma$. We find that for $sigma gg OmegaS the solution tends to the (ideal) Force-Free one and to the Vacuum one for $sigma 11 OmegaS. Finally, we present dissipative magnetospheric solutions with spatially variable $sigma$ that supports various microphysical properties and are compatible with the observations.
A dissipative model of solar system
Vladimir, V. G.
2009-04-01
rotation of planets, and the small tidal deformations arising under influence of gradients of gravitational forces. The method of division of movements receives the equations describing movements of the centers of weights of planets and their own rotations. In the offered model takes place a dissipation of the energy which source are internally viscous forces of each planet. The system supposes the first integral - the law of preservation of the kinetic moment concerning the centre of weights of system. As a result of deformations of planets in the law of the universal gravitation which has been written down for material points, there are small conservative amendments. The equations of movement describe movement of the centers of weights of planets and their rotation around of the centers of weights in view of the tidal phenomena and the dissipative forces. The connected system of the equations consists of 3N the vector equations of the second order representing the theorems of movement of the centers of weights of planets, and N the vector equations of the first order determining changes of the own kinetic moments of each planet. Stationary values of full mechanical energy on the variety set in integral of the kinetic moment, correspond to stationary movements - to rotations of system as firm body with constant angular speed around of the centre of weights of all system. Angular speed of stationary rotation is directed along a constant vector of the kinetic moment, and the axis of rotation is the main central axis of inertia of system. We shall notice, that deformations of planets in stationary movement are constant, as in system of coordinates rotating with constant angular speed centrifugal forces and forces of gravitational interaction of planets are constant. Stationary configurations of system are determined according to Routh`s technique as stationary points of the changed potential energy submitted by the sum potential energies of centrifugal and gravitational
Sibuet, R
2008-01-01
For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R and D/industries, merits over conventional pumps and future growth scope will be discussed
The effects of dissipation on topological mechanical systems
Xiong, Ye; Wang, Tianxiang; Tong, Peiqing
2016-09-01
We theoretically study the effects of isotropic dissipation in a topological mechanical system which is an analogue of Chern insulator in mechanical vibrational lattice. The global gauge invariance is still conserved in this system albeit it is destroyed by the dissipation in the quantum counterpart. The chiral edge states in this system are therefore robust against strong dissipation. The dissipation also causes a dispersion of damping for the eigenstates. It will modify the equation of motion of a wave packet by an extra effective force. After taking into account the Berry curvature in the wave vector space, the trace of a free wave packet in the real space should be curved, feinting to break the Newton’s first law.
Energy-dissipation-model for metallurgical multi-phase-systems
Mavrommatis, K.T. [Rheinisch-Westfaelische Technische Hochschule Aachen, Aachen (Germany)
1996-12-31
Entropy production in real processes is directly associated with the dissipation of energy. Both are potential measures for the proceed of irreversible processes taking place in metallurgical systems. Many of these processes in multi-phase-systems could then be modelled on the basis of the energy-dissipation associated with. As this entity can often be estimated using very simple assumptions from first principles, the evolution of an overall measure of systems behaviour can be studied constructing an energy-dissipation -based model of the system. In this work a formulation of this concept, the Energy-Dissipation-Model (EDM), for metallurgical multi-phase-systems is given. Special examples are studied to illustrate the concept, and benefits as well as the range of validity are shown. This concept might be understood as complement to usual CFD-modelling of complex systems on a more abstract level but reproducing essential attributes of complex metallurgical systems. (author)
Nonoscillatory shock capturing scheme using flux limited dissipation
Jameson, A.
1985-01-01
A method for modifying the third order dissipative terms by the introduction of flux limiters is proposed. The first order dissipative terms can then be eliminated entirely, and in the case of a scalar conservation law the scheme is converted into a total variation diminishing scheme provided that an appropriate value is chosen for the dissipative coefficient. Particular attention is given to: (1) the treatment of the scalar conservation law; (2) the treatment of the Euler equations for inviscid compressible flow; (3) the boundary conditions; and (4) multistage time stepping and multigrid schemes. Numerical results for transonic flows suggest that a central difference scheme augmented by flux limited dissipative terms can lead to an effective nonoscillatory shock capturing method. 20 references
On the quantization of sectorially Hamiltonian dissipative systems
Castagnino, M. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Instituto de Astronomia y Fisica del Espacio, Casilla de Correos 67, Sucursal 28, 1428 Buenos Aires (Argentina); Gadella, M. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Departamento de Fisica Teorica, Atomica y Optica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain)], E-mail: manuelgadella@yahoo.com.ar; Lara, L.P. [Instituto de Fisica de Rosario, 2000 Rosario (Argentina); Facultad Regional Rosario, UTN, 2000 Rosario (Argentina)
2009-10-15
We present a theoretical discussion showing that, although some dissipative systems may have a sectorial Hamiltonian description, this description does not allow for canonical quantization. However, a quantum Liouville counterpart of these systems is possible, although it is not unique.
On the quantization of sectorially Hamiltonian dissipative systems
Castagnino, M.; Gadella, M.; Lara, L.P.
2009-01-01
We present a theoretical discussion showing that, although some dissipative systems may have a sectorial Hamiltonian description, this description does not allow for canonical quantization. However, a quantum Liouville counterpart of these systems is possible, although it is not unique.
Energy-dissipation-model for metallurgical multi-phase-systems
Mavrommatis, K T [Rheinisch-Westfaelische Technische Hochschule Aachen, Aachen (Germany)
1997-12-31
Entropy production in real processes is directly associated with the dissipation of energy. Both are potential measures for the proceed of irreversible processes taking place in metallurgical systems. Many of these processes in multi-phase-systems could then be modelled on the basis of the energy-dissipation associated with. As this entity can often be estimated using very simple assumptions from first principles, the evolution of an overall measure of systems behaviour can be studied constructing an energy-dissipation -based model of the system. In this work a formulation of this concept, the Energy-Dissipation-Model (EDM), for metallurgical multi-phase-systems is given. Special examples are studied to illustrate the concept, and benefits as well as the range of validity are shown. This concept might be understood as complement to usual CFD-modelling of complex systems on a more abstract level but reproducing essential attributes of complex metallurgical systems. (author)
Dissipation in a Quantum Wire: Fact and Fantasy
Das, Mukunda P.; Green, Frederick
2008-01-01
Where, and how, does energy dissipation of electrical energy take place in a ballistic wire? Fully two decades after the advent of the transmissive phenomenology of electrical conductance, this deceptively simple query remains unanswered. We revisit the quantum kinetic basis of dissipation and show its power to give a definitive answer to our query. Dissipation leaves a clear, quantitative trace in the non-equilibrium current noise of a quantum point contact; this signature has already been observed in the laboratory. We then highlight the current state of accepted understandings in the light of well-known yet seemingly contradictory measurements. The physics of mesoscopic transport rests not in coherent carrier transmission through a perfect and dissipationless metallic channel, but explicitly in their dissipative inelastic scattering at the wire's interfaces and adjacent macroscopic leads.
Quantum dynamics in nanoscale magnets in dissipative environments
Miyashita, S; Saito, K; Kobayashi, H.; de Raedt, H.A.
2000-01-01
In discrete energy structure of nanoscale magnets, nonadiabatic transitions at avoided level crossings lead to fundamental processes of dynamics of magnetizations. The thermal environment causes dissipative effects on these processes. In this paper we review the features of the nonadiabatic
Dissipative Structures of the Kuramoto–Sivashinsky Equation
N. A. Kudryashov
2015-01-01
Full Text Available In the present work, we study the features of dissipative structures formation described by the periodic boundary value problem for the Kuramoto-Sivashinsky equation. The numerical algorithm which is based on the pseudospectral method is presented. We prove the efficiency and accuracy of the proposed numerical method on the exact solution of the equation considered. Using this approach, we performed the numerical simulation of dissipative structure formations described by the Kuramoto–Sivashinsky equation. The influence of the problem parameters on these processes are studied. The quantitative and qualitative characteristics of dissipative structure formations are described. We have shown that there is a value of the control parameter at which the processes of dissipative structure formation are observed. In particular, using the cyclic convolution we define the average value of this parameter. Also, we find the dependence of the amplitude of the structures on the value of control parameter.
Reversible dissipative processes, conformal motions and Landau damping
Herrera, L.; Di Prisco, A.; Ibáñez, J.
2012-01-01
The existence of a dissipative flux vector is known to be compatible with reversible processes, provided a timelike conformal Killing vector (CKV) χ α =(V α )/T (where V α and T denote the four-velocity and temperature respectively) is admitted by the spacetime. Here we show that if a constitutive transport equation, either within the context of standard irreversible thermodynamics or the causal Israel–Stewart theory, is adopted, then such a compatibility also requires vanishing dissipative fluxes. Therefore, in this later case the vanishing of entropy production generated by the existence of such CKV is not actually associated to an imperfect fluid, but to a non-dissipative one. We discuss also about Landau damping. -- Highlights: ► We review the problem of compatibility of dissipation with reversibility. ► We show that the additional assumption of a transport equation renders such a compatibility trivial. ► We discuss about Landau damping.
Beam-to-Column Connections with Demountable Energy Dissipative Plates
Vasile-Mircea Venghiac
2018-03-01
Full Text Available The behavior of steel structures subjected to seismic actions depends directly on the connections behavior. There are two current tendencies for ensuring the structural ductility: allowing the formation of plastic hinges in the beams by using reduced beam sections or reduced web sections or by ensuring the plastic hinge formation in the connection by using dissipative elements. This paper presents a new perspective regarding the energy dissipation mechanism formation within the beam-to-column connection. The design of connections capable of dissipating large amounts of energy, with an acceptable strength and ductile behavior is a real challenge for engineers. Sustainability is a big advantage for these connections. Another big advantage is the possibility of restoring the functionality of the damaged construction in a short time interval and with reduced costs. The introduction of connections with demountable energy dissipative plates can be a step forward in designing new beam-to-column connections for steel structures.
Effect of viscous dissipation and radiation in an annular cone
Ahmed, N. J. Salman; Kamangar, Sarfaraz; Khan, T. M. Yunus; Azeem
2016-01-01
The viscous dissipation is an effect due to which heat is generated inside the medium. The presence of radiation further complicates the heat transfer behavior inside porous medium. The present paper discusses the combined effect of viscous dissipation and radiation inside a porous medium confined in an annular cone with inner radius r_i. The viscous dissipation and radiation terms are included in the energy equation thereby solving the coupled momentum and energy equations with the help of finite element method. The results are presented in terms of isothermal and streamline indicating the thermal and fluid flow behavior of porous medium. It is found that the combination of viscous dissipation and radiation parameter and the cone angle has significant effect on the heat transfer and fluid flow behavior inside the porous medium. The fluid velocity is found to increase with the increase in Raleigh number
Effect of viscous dissipation and radiation in an annular cone
Ahmed, N. J. Salman; Kamangar, Sarfaraz [Centre for Energy Sciences, Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 Malaysia (Malaysia); Khan, T. M. Yunus, E-mail: yunus.tatagar@gmail.com [Centre for Energy Sciences, Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 Malaysia (Malaysia); Dept. of Mechanical Engineering, BVB College of Engineering & Technology, Hubli (India); Azeem [Dept. of Computer System & Technology, University of Malaya, Kuala Lumpur (Malaysia)
2016-06-21
The viscous dissipation is an effect due to which heat is generated inside the medium. The presence of radiation further complicates the heat transfer behavior inside porous medium. The present paper discusses the combined effect of viscous dissipation and radiation inside a porous medium confined in an annular cone with inner radius r{sub i}. The viscous dissipation and radiation terms are included in the energy equation thereby solving the coupled momentum and energy equations with the help of finite element method. The results are presented in terms of isothermal and streamline indicating the thermal and fluid flow behavior of porous medium. It is found that the combination of viscous dissipation and radiation parameter and the cone angle has significant effect on the heat transfer and fluid flow behavior inside the porous medium. The fluid velocity is found to increase with the increase in Raleigh number.
Dissipation-driven quantum phase transitions in collective spin systems
Morrison, S; Parkins, A S
2008-01-01
We consider two different collective spin systems subjected to strong dissipation-on the same scale as interaction strengths and external fields-and show that either continuous or discontinuous dissipative quantum phase transitions can occur as the dissipation strength is varied. First, we consider a well-known model of cooperative resonance fluorescence that can exhibit a second-order quantum phase transition, and analyse the entanglement properties near the critical point. Next, we examine a dissipative version of the Lipkin-Meshkov-Glick interacting collective spin model, where we find that either first- or second-order quantum phase transitions can occur, depending only on the ratio of the interaction and external field parameters. We give detailed results and interpretation for the steady-state entanglement in the vicinity of the critical point, where it reaches a maximum. For the first-order transition we find that the semiclassical steady states exhibit a region of bistability. (fast track communication)
Dissipative phenomena in deep inelastic heavy ion collisions
Gross, D.H.E.; Krappe, H.J.; Lindenberger, K.H.; Lipperheide, R.; Moehring, K.
1978-01-01
During this meeting the following theoretical concepts for deep-inelastic heavy ion reactions were discussed: the energy transfer and friction, direct or statistical mechanisms, dissipation and fluctuation. (WL) [de
Domen Zupančič
2012-01-01
Full Text Available Despite the modesty of hiska, they show a simple understanding of corbelling technique. One could say they are all examples of human landscape cultivation. Although there is no evident common line when comparing all types of hiska, the cunning eye may observe one shared feature: the positioning of the entrance. More or less all the documented shelters have south or south-western facing entrances. The burja is a cold northerly wind; from the south (Adriatic Sea the winds are warmer. When resting, the setting sun is taken as a sign of the ending of the working day and a reward for the whole day’s efforts. Entrances are the only openings to these structures, and they should serve as well as possible - to watch over the crops, to wait when hunting, to enjoy the calm of evening light, to breathe the sea wind.The syntax of the architectural language of layering stone and shaping the pattern of the landscape remain an inventive realisation of spatial ideas from the past until today. Not only ideas of shaping space - these ideas are basic interventions in the natural habitat which contribute to survival. Culture and an awareness of its values are the origins of local development and reasonable heritage preservation. The next step are tutorial days with workshops on how to build dry stone structures, walls and other stone architecture, as the DSWA organisation in the UK is doing.
Dissipative light-bullets in the filamentation of femtosecond pulses
Porras, M.A.; Gonzalo, I.
2010-01-01
Complete text of publication follows. With the growing interest in filamentation in solid and liquid media, the regime of filamentation with anomalous dispersion is receiving more attention. In this work we show that basics aspects of the filament dynamics in this regime can be explained in terms of a novel type of light-bullet, which is not of solitary or of conical types, but a wave-packet that maximizes the energy dissipation into the medium while remaining localized and stationary in propagation. We first show that a nonlinear optical medium at a given carrier wave length at which dispersion is anomalous, supports 'dissipative' light-bullets, i.e., waves localized in space and time and that propagate without change as a result of a balance between nonlinear compression and nonlinear absorption. Among them, the particular dissipative light-bullet with the highest possible dissipation is unique in a given medium, in the sense that all its properties are fixed by the properties of the medium at the carrier wave length. In this light-bullet, self-focusing continuously transports energy towards the pulse center by an amount that just compensates for the nonlinear losses. Figure 1(a) shows the radial profiles of the dissipative light-bullets that maximizes energy dissipation for several orders of multi-photon absorption responsible for the nonlinear losses. We have also found that this dissipative light-bullet tends to be spontaneously formed in the filamentary dynamics in media with anomalous dispersion. Figure 1(b) shows the peak intensity, the total energy and losses of a pulse that undergoes self-focusing and filamentation in an ideal medium with only Kerr nonlinearity and multi-photon absorption. This simple model reproduces the particularly long filament 'segments' and the 'burst' observed in experiments and in more accurate simulations. The peak intensity in the filament is identical to that of the dissipative light-bullet with maximum dissipation, and the
Transitions in the Communication Capacity of Dissipative Qubit Channels
Daems, D.
2009-05-01
The information transmission is studied for quantum channels in which the noise includes dissipative effects, more specifically, nonunitality. Noise is usually a nuisance but can sometimes be helpful. For these channels, the communication capacity is shown to increase with the dissipative component of the noise and may exhibit transitions beyond which it increases faster. The optimal states are constructed analytically as well as the pertaining “phase” diagram.
Transport theory of dissipative heavy-ion collisions
Norenberg, W.
1979-01-01
The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavy-ion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental information (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (author)
Research on Characteristics of New Energy Dissipation With Symmetrical Structure
Ming, Wen; Huang, Chun-mei; Huang, Hao-wen; Wang, Xin-fang
2018-03-01
Utilizing good energy consumption capacity of arc steel bar, a new energy dissipation with symmetrical structure was proposed in this article. On the base of collection experimental data of damper specimen Under low cyclic reversed loading, finite element models were built by using ANSYS software, and influences of parameter change (Conduction rod diameter, Actuation plate thickness, Diameter of arc steel rod, Curved bars initial bending) on energy dissipation performance were analyzed. Some useful conclusions which can lay foundations for practical application were drawn.
Quench dynamics of a disordered array of dissipative coupled cavities.
Creatore, C; Fazio, R; Keeling, J; Türeci, H E
2014-09-08
We investigate the mean-field dynamics of a system of interacting photons in an array of coupled cavities in the presence of dissipation and disorder. We follow the evolution of an initially prepared Fock state, and show how the interplay between dissipation and disorder affects the coherence properties of the cavity emission, and show that these properties can be used as signatures of the many-body phase of the whole array.
New results from dissipative diabatic dynamics and nuclear elastoplasticity
Noerenberg, W.; Technische Hochschule Darmstadt
1986-10-01
I present new results about dissipative diabatic dynamics and nuclear elastoplasticity, in particular on a self-consistent diabatic formulation, on first numerical calculations of dissipative diabatic dynamics in two collective degrees of freedom, on quasi-elastic recoil in central nucleus-nucleus collisions, on the diabatic hindrance of fusion reactions and on the diabatic emission of nucleons in central nucleus-nucleus collisions. (orig./HSI)
Energy dissipation in a finite volume of magnetic fluid
Bashtovoi, V.; Motsar, A.; Reks, A., E-mail: alexfx20@yandex.ru
2017-06-01
This study is devoted to investigation of energy dissipation processes which happen in a magnetic fluid drop with compound magnet during its motion in cylindrical non magnetic container. The possibility of energy dissipation control by means of electromagnetic field is examined. It's found that a change of magnetic field of compound magnet can lead to both increase and decrease of oscillation decay time and relative damping factor can be varied in a range of ±35%.
Transport theory of dissipative heavy-ion collisions
Noerenberg, W.
1979-03-01
The lectures present the formulation of a transport theory, the derivation of a practicable transport equation (Fokker-Planck equation) and the evaluation of transport coefficients for dissipative (or deeply inelastic) heavyion collisions. The applicability of the theoretical concept is tested with remarkable success in the analyses of various experimental informations (mass transfer, angular-momentum dissipation and energy loss). Some critical remarks on the present situation of transport theories are added. Future developments are outlined. (orig.) [de
Kinetic energy dissipation in heavy-ion collisions
Fedotov, S.I.; Jolos, R.V.; Kartavenko, V.G.
1979-01-01
Kinetic energy dissipation mechanism is considered in deep inelastic heavy-ion collisions. It is shown that the significant part of the kinetic energy loss can be explained by the excitation of the nuclear matter multipole vibrations. The main contribution of the energy dissipation is given by the time dependent heavy-ion interaction potential renormalized due to the nuclear excitations, rather than by the velocity proportional frictional forces
Dissipation and spontaneous symmetry breaking in brain dynamics
Freeman, Walter J; Vitiello, Giuseppe
2008-01-01
We compare the predictions of the dissipative quantum model of the brain with neurophysiological data collected from electroencephalograms resulting from high-density arrays fixed on the surfaces of primary sensory and limbic areas of trained rabbits and cats. Functional brain imaging in relation to behavior reveals the formation of coherent domains of synchronized neuronal oscillatory activity and phase transitions predicted by the dissipative model
Sound propagation in dry granular materials : discrete element simulations, theory, and experiments
Mouraille, O.J.P.
2009-01-01
In this study sound wave propagation through different types of dry confined granular systems is studied. With three-dimensional discrete element simulations, theory and experiments, the influence of several micro-scale properties: friction, dissipation, particle rotation, and contact disorder, on
Plate Tectonics as a Far-From-Equilibrium Self-Organized Dissipative System
Anderson, D. L.
2001-12-01
A fluid above the critical Rayleigh number is far from equilibrium and spontaneously organizes itself into patterns involving the collective motion of large numbers of molecules which are resisted by the viscosity of the fluid. No external template is involved in forming the pattern. In 1928 Pearson showed that Bénard's experiments were driven by variations in surface tension at the top of the fluid and the surface motions drove convection in the fluid. In this case, the surface organized itself AND the underlying fluid. Both internal buoyancy driven flow and flow driven by surface forces can be far-from-equilibrium self-organized open systems that receive energy and matter from the environment. In the Earth, the cold thermal boundary layer at the surface drives plate tectonics and introduces temperature, shear and pressure gradients into the mantle that drive mantle convection. The mantle provides energy and material but may not provide the template. Plate tectonics is therefore a candidate for a far-from-equilibrium dissipative self-organizing system. Alternatively, one could view mantle convection as the self-organized system and the plates as simply the surface manifestation. Lithospheric architecture also imposes lateral temperature gradients onto the mantle which can drive and organize flow. Far-from-equilibrium self-organization requires; an open system, interacting parts, nonlinearities or feedbacks, an outside steady source of energy or matter, multiple possible states and a source of dissipation. In uniform fluids viscosity is the source of dissipation. Sources of dissipation in the plate system include bending, breaking, folding, shearing, tearing, collision and basal drag. These can change rapidly, in contrast to plate driving forces, and introduce the sort of fluctuations that can reorganize far-from-equilibrium systems. Global plate reorganizations can alternatively be thought of as convective overturns of the mantle, or thermal weakening of plates
The TKE dissipation rate in the northern South China Sea
Lozovatsky, Iossif; Liu, Zhiyu; Fernando, Harindra Joseph S.; Hu, Jianyu; Wei, Hao
2013-12-01
The microstructure measurements taken during the summer seasons of 2009 and 2010 in the northern South China Sea (between 18°N and 22.5°N, and from the Luzon Strait to the eastern shelf of China) were used to estimate the averaged dissipation rate in the upper pycnocline of the deep basin and on the shelf. Linear correlation between and the estimates of available potential energy of internal waves, which was found for this data set, indicates an impact of energetic internal waves on spatial structure and temporal variability of . On the shelf stations, the bottom boundary layer depth-integrated dissipation reaches 17-19 mW/m2, dominating the dissipation in the water column below the surface layer. In the pycnocline, the integrated dissipation was mostly ˜10-30 % of . A weak dependence of bin-averaged dissipation on the Richardson number was noted, according to , where ɛ 0 + ɛ m is the background value of for weak stratification and Ri cr = 0.25, pointing to the combined effects of shear instability of small-scale motions and the influence of larger-scale low frequency internal waves. The latter broadly agrees with the MacKinnon-Gregg scaling for internal-wave-induced turbulence dissipation.
Jdpd: an open java simulation kernel for molecular fragment dissipative particle dynamics.
van den Broek, Karina; Kuhn, Hubert; Zielesny, Achim
2018-05-21
Jdpd is an open Java simulation kernel for Molecular Fragment Dissipative Particle Dynamics with parallelizable force calculation, efficient caching options and fast property calculations. It is characterized by an interface and factory-pattern driven design for simple code changes and may help to avoid problems of polyglot programming. Detailed input/output communication, parallelization and process control as well as internal logging capabilities for debugging purposes are supported. The new kernel may be utilized in different simulation environments ranging from flexible scripting solutions up to fully integrated "all-in-one" simulation systems.
Cold collisions in dissipative optical lattices
Piilo, J; Suominen, K-A
2005-01-01
The invention of laser cooling methods for neutral atoms allows optical and magnetic trapping of cold atomic clouds in the temperature regime below 1 mK. In the past, light-assisted cold collisions between laser cooled atoms have been widely studied in magneto-optical atom traps (MOTs). We describe here theoretical studies of dynamical interactions, specifically cold collisions, between atoms trapped in near-resonant, dissipative optical lattices. The extension of collision studies to the regime of optical lattices introduces several complicating factors. For the lattice studies, one has to account for the internal substates of atoms, position-dependent matter-light coupling, and position-dependent couplings between the atoms, in addition to the spontaneous decay of electronically excited atomic states. The developed one-dimensional quantum-mechanical model combines atomic cooling and collision dynamics in a single framework. The model is based on Monte Carlo wavefunction simulations and is applied when the lattice-creating lasers have frequencies both below (red-detuned lattice) and above (blue-detuned lattice) the atomic resonance frequency. It turns out that the radiative heating mechanism affects the dynamics of atomic cloud in a red-detuned lattice in a way that is not directly expected from the MOT studies. The optical lattice and position-dependent light-matter coupling introduces selectivity of collision partners. The atoms which are most mobile and energetic are strongly favoured to participate in collisions, and are more often ejected from the lattice, than the slow ones in the laser parameter region selected for study. Consequently, the atoms remaining in the lattice have a smaller average kinetic energy per atom than in the case of non-interacting atoms. For blue-detuned lattices, we study how optical shielding emerges as a natural part of the lattice and look for ways to optimize the effect. We find that the cooling and shielding dynamics do not mix
Bioindicator demonstrates high persistence of sulfentrazone in dry soil
Renato Coradello Lourenço
2015-09-01
Full Text Available In sugarcane crop areas, the application of preemergence herbicides with long residual effect in the soil has been frequently necessary. The herbicide persistence in the soil must be high especially because of applications during the dry season of the year, after sugarcane harvest. This study aimed at estimating the sulfentrazone persistence and dissipation in dry soil using bioindicator. Five experiments were carried out, divided into two phases. In the first phase, three dose-response curves were adjusted to select the best bioindicator to be adopted in the second phase. Niger was adopted due to its lower sensibility to sulfentrazone. In the second phase, a new dose-response curve was carried out, with six doses of sulfentrazone, in order to standardize the bioindicator sensibility to sulfentrazone. At the end, another experiment with six periods of sulfentrazone persistence in dry clay soil was developed. Persistence periods were: 182, 154, 125, 98 and 30 days. The bioindicator was seeded at the application day in treated plots and control. In this experiment, the sulfentrazone dose applied was 800 g ha-1. Niger was considered a good species to estimate the sulfentrazone persistence in dry soil. The sulfentrazone phytotoxic activity was identified up to 182 days after application, and its average dissipation rate was 2.15 g ha-1 day-1, with half-life higher than 182 days.
Spatial variability of atrazine dissipation in an allophanic soil.
Müller, Karin; Smith, Roger E; James, Trevor K; Holland, Patrick T; Rahman, Anis
2003-08-01
The small-scale variability (0.5 m) of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) concentrations and soil water contents in a volcanic silt loam soil (Haplic Andosol, FAO system) was studied in an area of 0.1 ha. Descriptive and spatial statistics were used to analyse the data. On average we recovered 102% of the applied atrazine 2 h after the herbicide application (CV = 35%). An increase in the CV of the concentrations with depth could be ascribed to a combination of extrinsic and intrinsic factors. Both variables, atrazine concentrations and soil water content, showed a high horizontal variability. The semivariograms of the atrazine concentrations exhibited the pure nugget effect, no pattern could be determined along the 15.5-m long transects on any of the seven sampling days over a 55-day period. Soil water content had a weak spatial autocorrelation with a range of 6-10 m. The dissipation of atrazine analysed using a high vertical sampling resolution of 0.02 m to 0.2 m showed that 70% of the applied atrazine persisted in the upper 0.02-m layer of the soil for 12 days. After 55 days and 410 mm of rainfall the centre of the pesticide mass was still at a soil depth of 0.021 m. The special characteristics of the soil (high organic carbon content, allophanic clay) had a strong influence on atrazine sorption and mobility. The mass recovery after 55 days was low. The laboratory degradation rate for atrazine, determined in a complementary incubation study and corrected for the actual field temperature using the Arrhenius equation, only accounted for about 35% of the losses that occurred in the field. Results suggest field degradation rates to be more changeable in time and much faster than under controlled conditions. Preferential flow is discussed as a component of the field transport process.
Drying and energy technologies
Lima, A
2016-01-01
This book provides a comprehensive overview of essential topics related to conventional and advanced drying and energy technologies, especially motivated by increased industry and academic interest. The main topics discussed are: theory and applications of drying, emerging topics in drying technology, innovations and trends in drying, thermo-hydro-chemical-mechanical behaviors of porous materials in drying, and drying equipment and energy. Since the topics covered are inter- and multi-disciplinary, the book offers an excellent source of information for engineers, energy specialists, scientists, researchers, graduate students, and leaders of industrial companies. This book is divided into several chapters focusing on the engineering, science and technology applied in essential industrial processes used for raw materials and products.
Jones, Steven M.; Paik, Jong-Ah
2013-01-01
A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.
Dry etching for microelectronics
Powell, RA
1984-01-01
This volume collects together for the first time a series of in-depth, critical reviews of important topics in dry etching, such as dry processing of III-V compound semiconductors, dry etching of refractory metal silicides and dry etching aluminium and aluminium alloys. This topical format provides the reader with more specialised information and references than found in a general review article. In addition, it presents a broad perspective which would otherwise have to be gained by reading a large number of individual research papers. An additional important and unique feature of this book
Stern, Michael E; Pflugfelder, Stephen C
2004-04-01
Dry eye is a condition of altered tear composition that results from a diseased or dysfunctional lacrimal functional unit. Evidence suggests that inflammation causes structural alterations and/or functional paralysis of the tear-secreting glands. Changes in tear composition resulting from lacrimal dysfunction, increased evaporation and/or poor clearance have pro-inflammatory effects on the ocular surface. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. Anti-inflammatory therapies for dry eye target one or more of the inflammatory mediators/pathways that have been identified in dry eye.
Chow, A T
1988-11-14
Dried lumber is a high-value-added product, especially when it is of high quality. Lumber damaged during the drying operation can represent substantial lost revenue. It has been demonstrated that dehumidification kilns can improve lumber quality, and reduce energy consumption over conventional drying methods. A summary of the literature on drying hardwood lumber, particularly using heat pump dehumidification, has been prepared to allow the information to be readily accessible to Ontario Hydro personnel who work with customers in the lumber industry. For that purpose, this summary has been prepared from the perspective of the customer, a dry kiln operator. Included are brief descriptions of drying schedules, precautions needed to minimize drying defects in the lumber, and rules-of-thumb for selecting and estimating the capital cost of the drying equipment. A selection of drying schedules and moisture contents of green lumber, a glossary of lumber defects and brief descriptions of the possible preventive measures are also included. 10 refs., 8 figs., 4 tabs.
EFFECTS OF LOCAL DISSIPATION PROFILES ON MAGNETIZED ACCRETION DISK SPECTRA
Tao, Ted; Blaes, Omer
2013-01-01
We present spectral calculations of non-LTE accretion disk models appropriate for high-luminosity stellar mass black hole X-ray binary systems. We first use a dissipation profile based on scaling the results of shearing box simulations of Hirose et al. to a range of annuli parameters. We simultaneously scale the effective temperature, orbital frequency, and surface density with luminosity and radius according to the standard α-model. This naturally brings increased dissipation to the disk surface layers (around the photospheres) at small radii and high luminosities. We find that the local spectrum transitions directly from a modified blackbody to a saturated Compton scattering spectrum as we increase the effective temperature and orbital frequency while decreasing midplane surface density. Next, we construct annuli models based on the parameters of a L/L Edd = 0.8 disk orbiting a 6.62 solar mass black hole using two modified dissipation profiles that explicitly put more dissipation per unit mass near the disk surface. The new dissipation profiles are qualitatively similar to the one found by Hirose et al., but produce strong near power-law spectral tails. Our models also include physically motivated magnetic acceleration support based once again on scaling the Hirose et al. results. We present three full-disk spectra, each based on one of the dissipation prescriptions. Our most aggressive dissipation profile results in a disk spectrum that is in approximate quantitative agreement with certain observations of the steep power-law spectral states from some black hole X-ray binaries.
Chen, Yanyi; Wu, Hongyu; Wen, Zhe
2017-05-01
Inland waterway transportation is an important part of the comprehensive transportation system of sustainable development, and it is also a way of transportation which is restricted by natural conditions greatly. In recent years, the problems of insufficient traffic capacity of The Three Gorges become prominent due to the increasing in the number of ships. And the ship's detention caused by gale, frog, accident and one-way traffic in dry season has occurred, which not only increased the pressure of the navigable waterway but also seriously affected the safety of shipping. Based on the different types of ships, the Arena software was used to simulate the ship traffic flow. The paper analyzed the traffic congestion propagation and dissipation rule of the ship under different navigation control methods, and provided decision reference for the navigation management department to formulate the relevant navigation control strategy.
Energy dissipation during an explosion in a porous elasto-plastic medium
Lovetskii, E.E.; Maslennikov, A.M.; Fetisov, V.S.
1979-01-01
A study is made of the redistribution of energy from camouflage blasting in a saturated porous medium. The study is undertaken with the aid of a numerical solution to a system of hydrodynamic equations, that account for shear strength of the substance under investigation. A study is made of the energy characteristics of explosion, their dynamic development, the influence of strength parameters of the medium, and porosity on these characteristics. A mechanism that is associated with the impact compression of matter is identified as the basic mechanism of energy dissipation for dry porous media. Water saturation of pores brings the energy characteristics of the explosion close to the explosion in a monolith. 12 references, 5 figures, 1 table.
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Observation-based input and dissipation version of WAVEWATCH III
Zieger, Stefan; Babanin, Alexander; Rogers, Erick; Young, Ian
2013-04-01
Measurements collected at Lake George, Australia, resulted in new insights on the processes of wind wave interaction and white-capping dissipation and consequently new parameterisations of these source terms. The new nonlinear wind input source term accounts for dependence of the growth increment on wave steepness, for airflow separation which leads to a relative reduction of the growth under extreme wind conditions, and for negative growth rate under adverse winds. The new wave breaking and whitecapping dissipation source function features two separate terms: the inherent breaking term and a cumulative dissipation term due to influences of longer waves on wave breaking of shorter waves. Another novel feature of this dissipation is the threshold in terms of spectral density: below this threshold breaking stops and whitecapping becomes zero. In such conditions dissipation due to wave interaction with water turbulence takes over, which regime is particularly relevant for decaying seas and for swell. This paper describes these source terms implemented in WAVEWATCH III and evaluates the performance against existing source terms in duration-limited simulations and against buoy measurements for windsea-dominated conditions. Results show agreement by means of growth curves and integral parameters in the simulations and hindcast. The paper also introduces wave breaking probability as model output, along with standard wind-wave metrics.
Power injected in dissipative systems and the fluctuation theorem
Aumaître, S.; Fauve, S.; McNamara, S.; Poggi, P.
We consider three examples of dissipative dynamical systems involving many degrees of freedom, driven far from equilibrium by a constant or time dependent forcing. We study the statistical properties of the injected and dissipated power as well as the fluctuations of the total energy of these systems. The three systems under consideration are: a shell model of turbulence, a gas of hard spheres colliding inelastically and excited by a vibrating piston, and a Burridge-Knopoff spring-block model. Although they involve different types of forcing and dissipation, we show that the statistics of the injected power obey the ``fluctuation theorem" demonstrated in the case of time reversible dissipative systems maintained at constant total energy, or in the case of some stochastic processes. Although this may be only a consequence of the theory of large deviations, this allows a possible definition of ``temperature" for a dissipative system out of equilibrium. We consider how this ``temperature" scales with the energy and the number of degrees of freedom in the different systems under consideration.
Coronal heating by Alfven waves dissipation in compressible nonuniform media
Malara, Francesco; Primavera, Leonardo; Veltri, Pierluigi
1996-01-01
The possibility to produce small scales and then to efficiently dissipate energy has been studied by Malara et al. [1992b] in the case of MHD disturbances propagating in an weakly dissipative incompressible and inhomogeneous medium, for a strictly 2D geometry. We extend this work to include both compressibility and the third component for vector quantities. Numerical simulations show that, when an Alfven wave propagates in a compressible nonuniform medium, the two dynamical effects responsible for the small scales formation in the incompressible case are still at work: energy pinching and phase-mixing. These effects give rise to the formation of compressible perturbations (fast and slow waves or a static entropy wave). Some of these compressive fluctuations are subject to the steepening of the wave front and become shock waves, which are extremely efficient in dissipating their energy, their dissipation being independent of the Reynolds number. Rough estimates of the typical times the various dynamical processes take to produce small scales show that these times are consistent with those required to dissipate inside the solar corona the energy of Alfven waves of photospheric origin
Strong tidal dissipation in Io and Jupiter from astrometric observations.
Lainey, Valéry; Arlot, Jean-Eudes; Karatekin, Ozgür; Van Hoolst, Tim
2009-06-18
Io is the volcanically most active body in the Solar System and has a large surface heat flux. The geological activity is thought to be the result of tides raised by Jupiter, but it is not known whether the current tidal heat production is sufficiently high to generate the observed surface heat flow. Io's tidal heat comes from the orbital energy of the Io-Jupiter system (resulting in orbital acceleration), whereas dissipation of energy in Jupiter causes Io's orbital motion to decelerate. Here we report a determination of the tidal dissipation in Io and Jupiter through its effect on the orbital motions of the Galilean moons. Our results show that the rate of internal energy dissipation in Io (k(2)/Q = 0.015 +/- 0.003, where k(2) is the Love number and Q is the quality factor) is in good agreement with the observed surface heat flow, and suggest that Io is close to thermal equilibrium. Dissipation in Jupiter (k(2)/Q = (1.102 +/- 0.203) x 10(-5)) is close to the upper bound of its average value expected from the long-term evolution of the system, and dissipation in extrasolar planets may be higher than presently assumed. The measured secular accelerations indicate that Io is evolving inwards, towards Jupiter, and that the three innermost Galilean moons (Io, Europa and Ganymede) are evolving out of the exact Laplace resonance.
Dissipative dark matter halos: The steady state solution
Foot, R.
2018-02-01
Dissipative dark matter, where dark matter particle properties closely resemble familiar baryonic matter, is considered. Mirror dark matter, which arises from an isomorphic hidden sector, is a specific and theoretically constrained scenario. Other possibilities include models with more generic hidden sectors that contain massless dark photons [unbroken U (1 ) gauge interactions]. Such dark matter not only features dissipative cooling processes but also is assumed to have nontrivial heating sourced by ordinary supernovae (facilitated by the kinetic mixing interaction). The dynamics of dissipative dark matter halos around rotationally supported galaxies, influenced by heating as well as cooling processes, can be modeled by fluid equations. For a sufficiently isolated galaxy with a stable star formation rate, the dissipative dark matter halos are expected to evolve to a steady state configuration which is in hydrostatic equilibrium and where heating and cooling rates locally balance. Here, we take into account the major cooling and heating processes, and numerically solve for the steady state solution under the assumptions of spherical symmetry, negligible dark magnetic fields, and that supernova sourced energy is transported to the halo via dark radiation. For the parameters considered, and assumptions made, we were unable to find a physically realistic solution for the constrained case of mirror dark matter halos. Halo cooling generally exceeds heating at realistic halo mass densities. This problem can be rectified in more generic dissipative dark matter models, and we discuss a specific example in some detail.
Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar
M. D. Shupe
2012-06-01
Full Text Available Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4–6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tethered-balloon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2–3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds.
Compaction shock dissipation in low density granular explosive
Rao, Pratap T.; Gonthier, Keith A., E-mail: gonthier@me.lsu.edu; Chakravarthy, Sunada [Mechanical and Industrial Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
2016-06-14
The microstructure of granular explosives can affect dissipative heating within compaction shocks that can trigger combustion and initiate detonation. Because initiation occurs over distances that are much larger than the mean particle size, homogenized (macroscale) theories are often used to describe local thermodynamic states within and behind shocks that are regarded as the average manifestation of thermodynamic fields at the particle scale. In this paper, mesoscale modeling and simulation are used to examine how the initial packing density of granular HMX (C{sub 4}H{sub 8}N{sub 8}O{sub 8}) C{sub 4}H{sub 8}N{sub 8}O{sub 8} having a narrow particle size distribution influences dissipation within resolved, planar compaction shocks. The model tracks the evolution of thermomechanical fields within large ensembles of particles due to pore collapse. Effective shock profiles, obtained by averaging mesoscale fields over space and time, are compared with those given by an independent macroscale compaction theory that predicts the variation in effective thermomechanical fields within shocks due to an imbalance between the solid pressure and a configurational stress. Reducing packing density is shown to reduce the dissipation rate within shocks but increase the integrated dissipated work over shock rise times, which is indicative of enhanced sensitivity. In all cases, dissipated work is related to shock pressure by a density-dependent power law, and shock rise time is related to pressure by a power law having an exponent of negative one.
Signatures of a dissipative phase transition in photon correlation measurements
Fink, Thomas; Schade, Anne; Höfling, Sven; Schneider, Christian; Imamoglu, Ataç
2018-04-01
Understanding and characterizing phase transitions in driven-dissipative systems constitutes a new frontier for many-body physics1-8. A generic feature of dissipative phase transitions is a vanishing gap in the Liouvillian spectrum9, which leads to long-lived deviations from the steady state as the system is driven towards the transition. Here, we show that photon correlation measurements can be used to characterize the corresponding critical slowing down of non-equilibrium dynamics. We focus on the extensively studied phenomenon of optical bistability in GaAs cavity polaritons10,11, which can be described as a first-order dissipative phase transition12-14. Increasing the excitation strength towards the bistable range results in an increasing photon-bunching signal along with a decay time that is prolonged by more than nine orders of magnitude as compared with that of single polaritons. In the limit of strong polariton interactions leading to pronounced quantum fluctuations, the mean-field bistability threshold is washed out. Nevertheless, the functional form with which the Liouvillian gap closes as the thermodynamic limit is approached provides a signature of the emerging dissipative phase transition. Our results establish photon correlation measurements as an invaluable tool for studying dynamical properties of dissipative phase transitions without requiring phase-sensitive interferometric measurements.
Ryutova, M.P.; Habbal, S.R.
1995-01-01
The influence of parallel plasma flows on the propagation of shear Alfvacute en waves along magnetic structures is considered. It is shown that even in a simple case of regular mass flows directed along the magnetic field, their presence considerably modifies the dissipation of shear Alfvacute en waves, affecting both the magnitude and the height of maximum dissipation. The strongest effect occurs in the case of downflows when the flow velocity at a certain height becomes equal to the Alfvacute en velocity. Near that point, the wave comes to extinction and gives off its energy completely. The axial extent of the absorption region is evaluated. This effect can be directly associated with observed high-velocity downflows in the transition region, and, in particular, can serve as a qualitative explanation for the high variability of the emission observed near 10 5 K. In the presence of upward mass flows and moderate downflows, the dissipation of phase-mixed Alfvacute en waves is accompanied by the radial redistribution of the energy input across the magnetic structure, thus creating a mosaic pattern in the emitting regions. The flow velocities are assumed to be below the thresholds which correspond to the onset of hydrodynamic and dissipative instabilities. copyright 1995 The American Astronomical Society
Numerical Simulation of the Thermal Performance of a Dry Storage Cask for Spent Nuclear Fuel
Heui-Yung Chang
2018-01-01
Full Text Available In this study, the heat flow characteristics and thermal performance of a dry storage cask were investigated via thermal flow experiments and a computational fluid dynamics (CFD simulation. The results indicate that there are many inner circulations in the flow channel of the cask (the channel width is 10 cm. These circulations affect the channel airflow efficiency, which in turn affects the heat dissipation of the dry storage cask. The daily operating temperatures at the top concrete lid and the upper locations of the concrete cask are higher than those permitted by the design specification. The installation of the salt particle collection device has a limited negative effect on the thermal dissipation performance of the dry storage cask.
Wang Ping; Wang Haizhen; Wu Laosheng; Di Hongjie; He Yan; Xu Jianming
2012-01-01
Biodegradation processes and changes in microbial community structure were investigated in black carbon (BC) amended soils in a laboratory experiment using two soils (black soil and red soil). We applied different percentages of charcoal as BC (0%, 0.5% and 1% by weight) with 100 mg kg −1 of phenanthrene. Soil samples were collected at different incubation times (0, 7, 15, 30, 60, 120 d). The amendment with BC caused a marked decrease in the dissipation (ascribed to mainly degradation and/or sequestration) of phenanthrene residues from soil. Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil, 0.5% BC amendments were higher. There were significant changes in the PLFA pattern in phenanthrene-spiked soils with time but BC had little effect on the microbial community structure of phenanthrene-spiked soils, as indicated by principal component analysis (PCA) of the PLFA signatures. - Highlights: ► Extracted phenanthrene increased substantially as the BC amount increased. ► Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil. ► BC caused a marked decrease in the dissipation of phenanthrene from soil. ► PLFA pattern in phenanthrene-spiked soils with time had significant changes. - BC amendments on phenanthrene extraction were different for two soils and time was a more effective factor in microbial community changes.
Estimating Half-Lives for Pesticide Dissipation from Plants
Fantke, Peter; Gillespie, Brenda W.; Juraske, Ronnie
2014-01-01
Pesticide risk and impact assessment models critically rely on and are sensitive to information describing dissipation from plants. Despite recent progress, experimental data are not available for all relevant pesticide−plant combinations, and currently no model predicting plant dissipation...... accounts for the influence of substance properties, plant characteristics, temperature, and study conditions. In this study, we propose models to estimate half-lives for pesticide dissipation from plants and provide recommendations for how to use our results. On the basis of fitting experimental...... under field conditions. Half-lives range from 0.2 days for pyrethrins to 31 days for dalapon. Parameter estimates are provided to correct for specific plant species, temperatures, and study conditions. Finally, we propose a predictive regression model for pesticides without available measured...
Memory effects in dissipative nucleus-nucleus collision
Yadav, H.L.; Agarwal, K.C.
2002-01-01
A macroscopic dynamical model within the framework of a multidimensional Fokker-Planck equation is employed for a theoretical description of low-energy dissipative collisions between two heavy nuclei. The effect of two-body collisions leading to intrinsic equilibrium has been treated phenomenologically using the basic concepts of dissipative diabatic dynamics. The heavy-ion reaction 86 Kr(8.18 MeV/u) + 166 Er has been as a prototype to study and demonstrate the memory effects for dissipation and diffusion processes. Our calculated results for the deflection angle, angular distributions dσ/dθ cm , energy distributions dσ/dΔΕ, and element distributions dσ/dΖ illustrate a remarkable dependence on the memory effects and are consistent with the experimental data
Memory effects in dissipative nucleus-nucleus collision
Yadav, H L
2002-01-01
A macroscopic dynamical model within the framework of a multidimensional Fokker-Planck equation is employed for a theoretical description of low-energy dissipative collisions between two heavy nuclei. The effect of two-body collisions leading to intrinsic equilibrium has been treated phenomenologically using the basic concepts of dissipative diabatic dynamics. The heavy-ion reaction sup 8 sup 6 Kr(8.18 MeV/u) + sup 1 sup 6 sup 6 Er has been as a prototype to study and demonstrate the memory effects for dissipation and diffusion processes. Our calculated results for the deflection angle, angular distributions d sigma/d theta sub c sub m , energy distributions d sigma/d DELTA EPSILON, and element distributions d sigma/d ZETA illustrate a remarkable dependence on the memory effects and are consistent with the experimental data
Log-Normal Turbulence Dissipation in Global Ocean Models
Pearson, Brodie; Fox-Kemper, Baylor
2018-03-01
Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly log-normal distribution even at large horizontal scales O (10 km ) . As the horizontal scales of resolved turbulence are larger than the ocean is deep, the Kolmogorov-Yaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply; instead, the down-scale potential enstrophy cascade of quasigeostrophic turbulence should. Yet, energy dissipation obeys approximate log-normality—robustly across depths, seasons, regions, and subgrid schemes. The distribution parameters, skewness and kurtosis, show small systematic departures from log-normality with depth and subgrid friction schemes. Log-normality suggests that a few high-dissipation locations dominate the integrated energy and enstrophy budgets, which should be taken into account when making inferences from simplified models and inferring global energy budgets from sparse observations.
Dissipative elastic metamaterial with a low-frequency passband
Yongquan Liu
2017-06-01
Full Text Available We design and experimentally demonstrate a dissipative elastic metamaterial structure that functions as a bandpass filter with a low-frequency passband. The mechanism of dissipation in this structure is well described by a mass-spring-damper model that reveals that the imaginary part of the wavenumber is non-zero, even in the passband of dissipative metamaterials. This indicates that transmittance in this range can be low. A prototype for this viscoelastic metamaterial model is fabricated by 3D printing techniques using soft and hard acrylics as constituent materials. The transmittance of the printed metamaterial is measured and shows good agreement with theoretical predictions, demonstrating its potential in the design of compact waveguides, filters and other advanced devices for controlling mechanical waves.
Logarithmic scaling in the near-dissipation range of turbulence
Sreenivasan, K.R.; Bershadskii, A.
2006-12-01
A logarithmic scaling for structure functions, in the form S p ∼ [ln(r/η)] ζp , where η is the Kolmogorov dissipation scale and ζ p are the scaling exponents, is suggested for the statistical description of the near-dissipation range for which classical power-law scaling does not apply. From experimental data at moderate Reynolds numbers, it is shown that the logarithmic scaling, deduced from general considerations for the near-dissipation range, covers almost the entire range of scales (about two decades) of structure functions, for both velocity and passive scalar fields. This new scaling requires two empirical constants, just as the classical scaling does, and can be considered the basis for extended self-similarity. (author)
Transport behavior in superconductors at extreme dissipation levels
Kunchur, M.N.
1996-09-01
A number of fundamental physical phenomena unfold in the mixed state of superconductor, when subjected to enormous current and power-dissipation levels. A sufficiently large current can destroy the superconducting state itself--the so-called pair-breaking effect. At intermediate current densities, below the onset of pair-breaking, one expects to see the free viscous flow of flux vortices. In the present work a pulsed-current technique was used to explore this dissipative regime of high-T c superconductors, verifying both free flux flow and the pair-breaking effect, as predicted by traditional theories. This paper concentrates on the dissipation and Hall behavior in the free flux flow state
Dissipative optomechanics in a Michelson-Sagnac interferometer.
Xuereb, André; Schnabel, Roman; Hammerer, Klemens
2011-11-18
Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.
Nanomechanical dissipation at a tip-induced Kondo onset
Baruselli, Pier Paolo; Fabrizio, Michele; Tosatti, Erio
2017-08-01
The onset or demise of Kondo effect in a magnetic impurity on a metal surface can be triggered, as sometimes observed, by the simple mechanical nudging of a tip. Such a mechanically driven quantum phase transition must reflect in a corresponding mechanical dissipation peak; yet, this kind of signature has not been focused upon so far. Aiming at the simplest theoretical modeling, we treat the impurity as an Anderson impurity model, the tip action as a hybridization switching, and solve the problem by numerical renormalization group. Studying this model as function of temperature and magnetic field we are able to isolate the Kondo contribution to dissipation. While that is, reasonably, of the order of the Kondo energy, its temperature evolution shows a surprisingly large tail even above the Kondo temperature. The detectability of Kondo mechanical dissipation in atomic force microscopy is also discussed.
Modeling compaction-induced energy dissipation of granular HMX
Gonthier, K.A. [Lamar Univ., Beaumont, TX (US). Dept. of Mechanical Engineering; Menikoff, R.; Son, S.F.; Asay, B.W. [Los Alamos National Lab., NM (US)
1998-12-31
A thermodynamically consistent model is developed for the compaction of granular solids. The model is an extension of the single phase limit of two-phase continuum models used to describe Deflagration-to-Detonation Transition (DDT) experiments. The focus is on the energetics and dissipation of the compaction process. Changes in volume fraction are partitioned into reversible and irreversible components. Unlike conventional DDT models, the model is applicable from the quasi-static to dynamic compaction regimes for elastic, plastic, or brittle materials. When applied to the compaction of granular HMX (a brittle material), the model predicts results commensurate with experiments including stress relaxation, hysteresis, and energy dissipation. The model provides a suitable starting point for the development of thermal energy localization sub-scale models based on compaction-induced dissipation.
Dissipation, intermittency, and singularities in incompressible turbulent flows
Debue, P.; Shukla, V.; Kuzzay, D.; Faranda, D.; Saw, E.-W.; Daviaud, F.; Dubrulle, B.
2018-05-01
We examine the connection between the singularities or quasisingularities in the solutions of the incompressible Navier-Stokes equation (INSE) and the local energy transfer and dissipation, in order to explore in detail how the former contributes to the phenomenon of intermittency. We do so by analyzing the velocity fields (a) measured in the experiments on the turbulent von Kármán swirling flow at high Reynolds numbers and (b) obtained from the direct numerical simulations of the INSE at a moderate resolution. To compute the local interscale energy transfer and viscous dissipation in experimental and supporting numerical data, we use the weak solution formulation generalization of the Kármán-Howarth-Monin equation. In the presence of a singularity in the velocity field, this formulation yields a nonzero dissipation (inertial dissipation) in the limit of an infinite resolution. Moreover, at finite resolutions, it provides an expression for local interscale energy transfers down to the scale where the energy is dissipated by viscosity. In the presence of a quasisingularity that is regularized by viscosity, the formulation provides the contribution to the viscous dissipation due to the presence of the quasisingularity. Therefore, our formulation provides a concrete support to the general multifractal description of the intermittency. We present the maps and statistics of the interscale energy transfer and show that the extreme events of this transfer govern the intermittency corrections and are compatible with a refined similarity hypothesis based on this transfer. We characterize the probability distribution functions of these extreme events via generalized Pareto distribution analysis and find that the widths of the tails are compatible with a similarity of the second kind. Finally, we make a connection between the topological and the statistical properties of the extreme events of the interscale energy transfer field and its multifractal properties.
Dissipation of Turbulence in the Wake of a Wind Turbine
Lundquist, J. K.; Bariteau, L.
2015-02-01
The wake of a wind turbine is characterized by increased turbulence and decreased wind speed. Turbines are generally deployed in large groups in wind farms, and so the behaviour of an individual wake as it merges with other wakes and propagates downwind is critical in assessing wind-farm power production. This evolution depends on the rate of turbulence dissipation in the wind-turbine wake, which has not been previously quantified in field-scale measurements. In situ measurements of winds and turbulence dissipation from the wake region of a multi-MW turbine were collected using a tethered lifting system (TLS) carrying a payload of high-rate turbulence probes. Ambient flow measurements were provided from sonic anemometers on a meteorological tower located near the turbine. Good agreement between the tower measurements and the TLS measurements was established for a case without a wind-turbine wake. When an operating wind turbine is located between the tower and the TLS so that the wake propagates to the TLS, the TLS measures dissipation rates one to two orders of magnitude higher in the wake than outside of the wake. These data, collected between two and three rotor diameters downwind of the turbine, document the significant enhancement of turbulent kinetic energy dissipation rate within the wind-turbine wake. These wake measurements suggest that it may be useful to pursue modelling approaches that account for enhanced dissipation. Comparisons of wake and non-wake dissipation rates to mean wind speed, wind-speed variance, and turbulence intensity are presented to facilitate the inclusion of these measurements in wake modelling schemes.
Suzuki, Hiroyuki.
1997-01-01
A plurality of blowing ports with introduction units are disposed to a plurality of ducts in a dry well, and a cooling unit comprising a cooler, a blower and an isolating valve is disposed outside of the dry well. Cooling air and the atmosphere in the dry well are mixed to form a cooling gas and blown into the dry well to control the temperature. Since the cooling unit is disposed outside of the dry well, the maintenance of the cooling unit can be performed even during the plant operation. In addition, since dampers opened/closed depending on the temperature of the atmosphere are disposed to the introduction units for controlling the temperature of the cooling gas, the temperature of the atmosphere in the dry well can be set to a predetermined level rapidly. Since an axial flow blower is used as the blower of the cooling unit, it can be contained in a ventilation cylinder. Then, the atmosphere in the dry well flowing in the ventilation cylinder can be prevented from leaking to the outside. (N.H.)
A mesoscopic simulation of static and dynamic wetting using many-body dissipative particle dynamics
Ghorbani, Najmeh; Pishevar, Ahmadreza
2018-01-01
A many-body dissipative particle dynamics simulation is applied here to pave the way for investigating the behavior of mesoscale droplets after impact on horizontal solid substrates. First, hydrophobic and hydrophilic substrates are simulated through tuning the solid-liquid interfacial interaction parameters of an innovative conservative force model. The static contact angles are calculated on homogeneous and several patterned surfaces and compared with the predicted values by the Cassie's law in order to verify the model. The results properly evaluate the amount of increase in surface superhydrophobicity as a result of surface patterning. Then drop impact phenomenon is studied by calculating the spreading factor and dimensionless height versus dimensionless time and the comparisons made between the results and the experimental values for three different static contact angles. The results show the capability of the procedure in calculating the amount of maximum spreading factor, which is a significant concept in ink-jet printing and coating process.
Glyphosate Dissipation in Different Soils Under No-Till and Conventional Till
Okada, Elena; Costa, Jose Luis; Francisco, Bedmar
2017-04-01
Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides in the market. It is used as a weed controller in chemical fallow under no-till systems, and it is also applied in various genetically modified crops (e.g. soybean, corn, cotton). Though it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The description of glyphosate biodegradation in soils with a long term history under agricultural practices is of interest. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from Argentina. The studied soils belong to areas of high agronomic land use and different edaphoclimatic conditions, situated in Manfredi (MAN), Pergamino (PER) and Paraná (PAR). Soil samples were taken from long-term field trials with a history of more than 16 years under no-till and conventional tillage management. To study glyphosate dissipation in soil under controlled laboratory conditions, 400 g of dry soil sample were placed in 1.5 L flasks. A dose corresponding to 6 L ha-1 of commercial glyphosate ATANOR II® (35.6 % a.i.) was applied on day 0. The dose applied was equivalent to a final concentration in soil of 4000 μg Kg-1 of active ingredient. The moisture of the soil samples was kept at 60 % of the field capacity. Samples were incubated in the dark at a constant temperature of 22°C ± 1°C. A sub-sample of 5 g was taken from each flask at day 0 (after application), 1, 3, 7, 15, 20, 28, 44 and 62. Glyphosate and AMPA in soil samples was extracted with a strong basic solution (100 mM Na2B4O7•10H2O/ 100 mM K3PO4, pH=9) and then derivitazed with FMOC-Cl. Detection and quantification of the compounds was performed by ultra-performance liquid chromatography coupled with a mass spectrometer (UPLC MS/MS). The results showed that forty percent of the applied glyphosate was degraded
Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems
Rabidin Zairul Amin; Seng Gan Kee; Wahab Mohd Jamil Abdul
2017-01-01
Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be ac...
Energy Dissipation in Sandwich Structures During Axial Compression
Urban, Jesper
2002-01-01
The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full-scale structu......The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full...
Entanglement generation through local field and quantum dissipation
Stockburger, Jürgen T; Schmidt, Rebecca; Ankerhold, Joachim
2015-01-01
Entanglement in a Gaussian two-mode system can be generated by local driving if additional non-local features are introduced to the dynamics. We demonstrate that weak to moderate ohmic friction arising from a dissipative environment can enable entanglement generation in a driven system. This synergy of driving and dissipation is highly sensitive to the pulse shape; several simple pulse shapes fail to produce this effect at all or deposit large amounts of energy in the system as a side effect. Complex pulse shapes, determined by optimal control techniques, however, are effective without detrimental side effects. (paper)
ΛCDM model with dissipative nonextensive viscous dark matter
Gimenes, H. S.; Viswanathan, G. M.; Silva, R.
2018-03-01
Many models in cosmology typically assume the standard bulk viscosity. We study an alternative interpretation for the origin of the bulk viscosity. Using nonadditive statistics proposed by Tsallis, we propose a bulk viscosity component that can only exist by a nonextensive effect through the nonextensive/dissipative correspondence (NexDC). In this paper, we consider a ΛCDM model for a flat universe with a dissipative nonextensive viscous dark matter component, following the Eckart theory of bulk viscosity, without any perturbative approach. In order to analyze cosmological constraints, we use one of the most recent observations of Type Ia Supernova, baryon acoustic oscillations and cosmic microwave background data.
Radiation and viscous dissipation effect on square porous annulus
Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Quadir, G. A. [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia)
2016-06-08
The present study is carried out to investigate the effect of radiation and viscous dissipation in a square porous annulus subjected to outside hot T{sub h} and inside cold T{sub c} temperature. The square annulus has a hollow section of dimension D×D at the interior of annulus. The flow is assumed to obey Darcy law. The governing equations are non-dimensionalised and solved with the help of finite element method. Results are discussed with respect to viscous dissipation parameter, radiation parameter and size of the hollow section of annulus.
New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Kuznetsova, Masha
2011-01-01
A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron's rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.
New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
Zenitani, Seiji; Hesse, Michael; Klimas, Alex; Kuznetsova, Masha
2012-01-01
A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron s rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.
An exact solution for quantum tunneling in a dissipative system
Yu, L.H.
1996-01-01
Applying a technique developed recently for a harmonic oscillator coupled to a bath of harmonic oscillators, we present an exact solution for the tunneling problem in an Ohmic dissipative system with inverted harmonic potential. The result shows that while the dissipation tends to suppress the tunneling, the Brownian motion tends to enhance the tunneling. Whether the tunneling rate increases or not would then depend on the initial conditions. We give a specific formula to calculate the tunneling probability determined by various parameters and the initial conditions
Energy Dissipation Rate in an Agitated Crucible Containing Molten Metal
Li, Tao; Shimasaki, Shin-ichi; Narita, Shunsuke; Taniguchi, Shoji
2017-10-01
The energy dissipation rate (EDR) is an important parameter for characterizing the behavior of inclusion coagulation in agitated molten metal. To clarify the inclusion coagulation mechanism, we review previous water model studies by particularly focusing on the relation between the impeller torque and the EDR of the fluid, which indicates the ratio of energy dissipated in the viscous medium to the energy inputted by the rotating impeller. In the present study, simulations coupled with experiments were performed to determine the relation between the torque and the effective EDR for water and liquid Al in crucibles with and without baffles.
Spectral signatures for swash on reflective, intermediate and dissipative beaches
Hughes, Michael G; Aagaard, Troels; Baldock, Tom E
2014-01-01
(reflective, intermediate and dissipative), with beach gradients ranging from approximately 1:6 to 1:60 exposed to offshore significant wave heights of 0.5–3.0 m. The ratio of swash energy in the short-wave (f > 0.05 Hz) to long-wave (f ... the three beach types. Swash energy at short-wave frequencies is dominant on reflective and intermediate beaches and swash at long-wave frequencies is dominant on dissipative beaches; consistent with previously reported spectral signatures for the surf zone on these beach types. The available swash spectra...
Construction of Lyapunov Function for Dissipative Gyroscopic System
Xu Wei; Ao Ping; Yuan Bo
2011-01-01
We introduce a force decomposition to construct a potential function in deterministic dynamics described by ordinary differential equations in the context of dissipative gyroscopic systems. Such a potential function serves as the corresponding Lyapunov function for the dynamics, hence it gives both quantitative and qualitative descriptions for stability of motion. As an example we apply our force decomposition to a four-dimensional dissipative gyroscopic system. We explicitly obtain the potential function for all parameter regimes in the linear limit, including those regimes where the Lyapunov function was previously believed not to exist. (general)
Dissipation and fluctuation of quantum fields in expanding universes
Morikawa, M.
1990-01-01
A stochastic dynamics of a long-wavelength part of a scalar field in an expanding universe is derived by using the influence functional method. Dissipation as well as fluctuation are derived for general parameters: a mass, a coupling to the scalar curvature, and a cutoff scale parameter. A dissipation-fluctuation relation is found with a temperature which is proportional to the Hawking temperature, but system dependent. The method is further applied to an expanding universe with a power law and yields the dispersion which agrees with that obtained by the regularization method. The back reaction to the background de Sitter space itself is also obtained
Evolution of wave function in a dissipative system
Yu, Li-Hua; Sun, Chang-Pu
1994-01-01
For a dissipative system with Ohmic friction, we obtain a simple and exact solution for the wave function of the system plus the bath. It is described by the direct product in two independent Hilbert space. One of them is described by an effective Hamiltonian, the other represents the effect of the bath, i.e., the Brownian motion, thus clarifying the structure of the wave function of the system whose energy is dissipated by its interaction with the bath. No path integral technology is needed in this treatment. The derivation of the Weisskopf-Wigner line width theory follows easily.
Radiation and viscous dissipation effect on square porous annulus
Badruddin, Irfan Anjum; Quadir, G. A.
2016-01-01
The present study is carried out to investigate the effect of radiation and viscous dissipation in a square porous annulus subjected to outside hot T h and inside cold T c temperature. The square annulus has a hollow section of dimension D×D at the interior of annulus. The flow is assumed to obey Darcy law. The governing equations are non-dimensionalised and solved with the help of finite element method. Results are discussed with respect to viscous dissipation parameter, radiation parameter and size of the hollow section of annulus.
Ko, Dong Guk; Cong Ge, Jun; Im, Ik Tae; Choi, Nag Jung; Kim, Min Soo
2018-01-01
In this study, we analyzed the heat dissipation performance of UCD lamp ballast fin with various aspect ratios. The minimum grid size was 0.02 mm and the number of grid was approximately 11,000. In order to determine the influence of the aspect ratio on the heat dissipation performance of UCD lamp ballast fin, the heat transfer area of the fin was kept constant at 4 mm2. The aspect ratios of the fin were 2 mm: 2 mm (basic model), 1.5 mm: 2.7 mm and 2.7 mm: 1.5 mm, respectively. The heat flux and heat flux time at fin were kept constant at 1×105 W/m2 and 10 seconds, respectively. The heat dissipation performance by the fin was the best at an aspect ratio of 1.5 mm: 2.7 mm.
Effects of Different Temperatures for Drying Cervical Mucus Smear ...
The effects of different room temperatures for drying cervical mucus on crystallisation of fern-tree patterns was determined using cervical mucus smears from 60 women undergoing investigation for infertility at the University of Benin Teaching Hospital. Cervical mucus smears were dried in the oven at 15, 20, 25, 30 and 35C ...
Partial drying accelerates bacterial growth recovery to rewetting
Meisner, Annelein; Leizeaga, Ainara; Rousk, Johannes
2017-01-01
, bacterial growth rates increase immediately in a linear fashion. In the Type 2 pattern, bacterial growth rates increase exponentially after a lag period. However, soils are often only partially dried. Partial drying (higher remaining moisture content before rewetting) may be considered a less harsh...
Full Text Available ... seasonal allergens and dry eye Apr 27, 2015 Choosing Wisely When It Comes to Eye Care, Part ... Name: Member ID: * Phone Number: * Email: * Enter code: * Message: Thank you Your feedback has been sent.
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... on a budget Skin care products Skin care secrets Skin lighteners Skin of color Summer skin problems ... condition, such as eczema. Additional related information Dermatologists' top tips for relieving dry skin FIND A DERMATOLOGIST ...
Faugeras, P.
1997-01-01
Various dry processes have been studied and more or less developed in order particularly to reduce the waste quantities but none of them had replaced the PUREX process, for reasons departing to policy errors, un-appropriate demonstration examples or too late development, although realistic and efficient dry processes such as a fluoride selective volatility based processes have been demonstrated in France (CLOVIS, ATILA) and would be ten times cheaper than the PUREX process. Dry processes could regain interest in case of a nuclear revival (following global warming fears) or thermal wastes over-production. In the near future, dry processes could be introduced in complement to the PUREX process, especially at the end of the process cycle, for a more efficient recycling and safer storage (inactivation)
Coppa, N.V.; Stewart, P.; Renzi, E.
1999-01-01
The present invention provides methods and apparatus for freeze drying in which a solution, which can be a radioactive salt dissolved within an acid, is frozen into a solid on vertical plates provided within a freeze drying chamber. The solid is sublimated into vapor and condensed in a cold condenser positioned above the freeze drying chamber and connected thereto by a conduit. The vertical positioning of the cold condenser relative to the freeze dryer helps to help prevent substances such as radioactive materials separated from the solution from contaminating the cold condenser. Additionally, the system can be charged with an inert gas to produce a down rush of gas into the freeze drying chamber to also help prevent such substances from contaminating the cold condenser
Full Text Available ... removed or pushed down the tear duct to insert a permanent punctal plug? Sep 12, 2017 Why ... Eye from Jennifer Aniston Sep 02, 2016 The link between seasonal allergens and dry eye Apr 27, ...
Federal Laboratory Consortium — Located near the K-Basins (see K-Basins link) in Hanford's 100 Area is a facility called the Cold Vacuum Drying Facility (CVDF).Between 2000 and 2004, workers at the...
Reversible dissipative processes, conformal motions and Landau damping
Herrera, L., E-mail: laherrera@cantv.net.ve [Departamento de Física Teórica e Historia de la Ciencia, Universidad del País Vasco, Bilbao (Spain); Di Prisco, A., E-mail: adiprisc@fisica.ciens.ucv.ve [Departamento de Física Teórica e Historia de la Ciencia, Universidad del País Vasco, Bilbao (Spain); Ibáñez, J., E-mail: j.ibanez@ehu.es [Departamento de Física Teórica e Historia de la Ciencia, Universidad del País Vasco, Bilbao (Spain)
2012-02-06
The existence of a dissipative flux vector is known to be compatible with reversible processes, provided a timelike conformal Killing vector (CKV) χ{sup α}=(V{sup α})/T (where V{sup α} and T denote the four-velocity and temperature respectively) is admitted by the spacetime. Here we show that if a constitutive transport equation, either within the context of standard irreversible thermodynamics or the causal Israel–Stewart theory, is adopted, then such a compatibility also requires vanishing dissipative fluxes. Therefore, in this later case the vanishing of entropy production generated by the existence of such CKV is not actually associated to an imperfect fluid, but to a non-dissipative one. We discuss also about Landau damping. -- Highlights: ► We review the problem of compatibility of dissipation with reversibility. ► We show that the additional assumption of a transport equation renders such a compatibility trivial. ► We discuss about Landau damping.
Nonlinear von Neumann equations for quantum dissipative systems
Messer, J.; Baumgartner, B.
1978-01-01
For pure states nonlinear Schroedinger equations, the so-called Schroedinger-Langevin equations are well-known to model quantum dissipative systems of the Langevin type. For mixtures it is shown that these wave equations do not extend to master equations, but to corresponding nonlinear von Neumann equations. Solutions for the damped harmonic oscillator are discussed. (Auth.)
Nonlinear von Neumann equations for quantum dissipative systems
Messer, J.; Baumgartner, B.
For pure states nonlinear Schroedinger equations, the so-called Schroedinger-Langevin equations are well-known to model quantum dissipative systems of the Langevin type. For mixtures it is shown that these wave equations do not extend to master equations, but to corresponding nonlinear von Neumann equations. Solutions for the damped harmonic oscillator are discussed. (Author)
Mathematical Modeling for Energy Dissipation Behavior of Velocity ...
The developed oil-pressure damper is installed with an additional Relief Valve parallel to the Throttle Valve. This is intended to obtain an adaptive control by changing the damping coefficient of this damper using changeable orifice size. In order to simulate its actual energy-dissipating behavior, a serial friction model and a ...
Towards better integrators for dissipative particle dynamics simulations
Besold, Gerhard; Vattulainen, Ilpo Tapio; Karttunen, Mikko
2000-01-01
Coarse-grained models that preserve hydrodynamics provide a natural approach to study collective properties of soft-matter systems. Here, we demonstrate that commonly used integration schemes in dissipative particle dynamics give rise to pronounced artifacts in physical quantities such as the com...
The Benjamin-Bona-Mahony equation with dissipative memory
Dell'Oro, Filippo; Mammeri, Y.; Pata, V.
2015-01-01
Roč. 22, č. 4 (2015), s. 899-910 ISSN 1021-9722 Institutional support: RVO:67985840 Keywords : Benjamin-Bona-Mahony equation * dissipative memory * exponential stability * nonlinear contraction semigroup Subject RIV: BA - General Mathematics Impact factor: 0.797, year: 2015 http://link.springer.com/article/10.1007%2Fs00030-014-0308-8
Tracking the attenuation and nonbreaking dissipation of swells using altimeters
Jiang, Haoyu; Stopa, Justin E.; Wang, He; Husson, Romain; Mouche, Alexis; Chapron, Bertrand; Chen, Ge
2016-02-01
A method for systematically tracking swells across oceanic basins is developed by taking advantage of high-quality data from space-borne altimeters and wave model output. The evolution of swells is observed over large distances based on 202 swell events with periods ranging from 12 to 18 s. An empirical attenuation rate of swell energy of about 4 × 10-7 m-1 is estimated using these observations, and the nonbreaking energy dissipation rates of swells far away from their generating areas are also estimated using a point source model. The resulting acceptance range of nonbreaking dissipation rates is -2.5 to 5.0 × 10-7 m-1, which corresponds to a dissipation e-folding scales of at least 2000 km for steep swells, to almost infinite for small-amplitude swells. These resulting rates are consistent with previous studies using in-situ and synthetic aperture radar (SAR) observations. The frequency dispersion and angular spreading effects during swell propagation are discussed by comparing the results with other studies, demonstrating that they are the two dominant processes for swell height attenuation, especially in the near field. The resulting dissipation rates from these observations can be used as a reference for ocean engineering and wave modeling, and for related studies such as air-sea and wind-wave-turbulence interactions.
Modeling the Thermosphere as a Driven-Dissipative Thermodynamic System
2013-03-01
8 Figure 2: Illustration of the geocentric solar magnetospheric coordinate system............15 Figure 3: Diagram of the...to test new methods of modeling the thermospheric environment. Thermosphere as a Driven-Dissipative Thermodynamic System One approach for modeling... approach uses empirical coupling and relaxation constants to model the 4 input of energy to the thermosphere from the solar wind during
On the dissipative Lax-Phillips scattering theory
Neidhardt, H.
1987-01-01
The paper is devoted to the characterization of all possible scattering matrices occurring in a dissipative Lax-Phillips scattering theory. The characterization is obtained in terms of an analytically unitary synthesis of a strongly measurable contraction-valued function which generalizes the notion of Darlingtom synthesis
Chaotic neoclassical separatrix dissipation in parametric drift-wave decay.
Kabantsev, A A; Tsidulko, Yu A; Driscoll, C F
2014-02-07
Experiments and theory characterize a parametric decay instability between plasma drift waves when the nonlinear coupling is modified by an electrostatic barrier. Novel mode coupling terms representing enhanced dissipation and mode phase shifts are caused by chaotic separatrix crossings on the wave-ruffled separatrix. Experimental determination of these coupling terms is in broad agreement with new chaotic neoclassical transport analyses.
The dissipative flow of superfluid helium-3 through capillaries
Kopnin, N.B.
1986-01-01
The equations are obtained which describe the behaviour of the chemical potential (pressure) of the superfluid helium-3 flowing through a narrow capillary, diffusively scattering boundaries being taken into consideration. The possibility is discussed whether the dissipation experimentally observed by Manninen and Pekola can be understood in terms of the phase-slip process
Fluctuation and dissipation in nonequilibrium quantum field theory
Ramos, Rudnei O.
1994-01-01
The nonequilibrium dynamics of a scalar field is studied using perturbation theory and a real time finite temperature formulation. The evolution equation for the scalar field is explicitly obtained, and terms responsible for noise (fluctuations) and dissipation are identified and studied in the high temperature limit. (author)
Dissipation of the fungicide hexaconazole in oil palm plantation.
Maznah, Zainol; Halimah, Muhamad; Ismail, Sahid; Idris, Abu Seman
2015-12-01
Hexaconazole is a potential fungicide to be used in the oil palm plantation for controlling the basal stem root (BSR) disease caused by Ganoderma boninense. Therefore, the dissipation rate of hexaconazole in an oil palm agroecosystem under field conditions was studied. Two experimental plots were treated with hexaconazole at the recommended dosage of 4.5 g a.i. palm(-1) (active ingredient) and at double the recommended dosage (9.0 g a.i. palm(-1)), whilst one plot was untreated as control. The residue of hexaconazole was detected in soil samples in the range of 2.74 to 0.78 and 7.13 to 1.66 mg kg(-1) at the recommended and double recommended dosage plots, respectively. An initial relatively rapid dissipation rate of hexaconazole residues occurred but reduced with time. The dissipation of hexaconazole in soil was described using first-order kinetics with the value of coefficient regression (r (2) > 0.8). The results indicated that hexaconazole has moderate persistence in the soil and the half-life was found to be 69.3 and 86.6 days in the recommended and double recommended dosage plot, respectively. The results obtained highlight that downward movement of hexaconazole was led by preferential flow as shown in image analysis. It can be concluded that varying soil conditions, environmental factors, and pesticide chemical properties of hexaconazole has a significant impact on dissipation of hexaconazole in soil under humid conditions.
Minimum Energy Dissipation under Cocurrent Flow in Packed Beds
Akramov, T.A.; Stavárek, Petr; Jiřičný, Vladimír; Staněk, Vladimír
2011-01-01
Roč. 50, č. 18 (2011), s. 10824-10832 ISSN 0888-5885 R&D Projects: GA ČR GA104/09/0880 Institutional research plan: CEZ:AV0Z40720504 Keywords : energy dissipation * current flow * packed bed Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.237, year: 2011
High-Density Quantum Sensing with Dissipative First Order Transitions.
Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik
2018-04-13
The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to sqrt[N]. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T_{2} coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.
Nondestructive evaluation of dissipative behavior of reinforced concrete structure
Luong, M.P. [Ecole Polytechnique, LMS, CNRS, 91 - Palaiseau (France)
2001-07-01
Current technological developments tend toward increased exploitation of materials strengths and toward tackling extreme loads and environmental actions such as offshore structures subject to wind and wave loading, or buildings in seismic area. Concrete is widely used as a construction material because of its high strength-cost ratio in many applications. Experience of earthquakes and laboratory tests has shown that well designed and detailed reinforced concrete is suitable for earthquake resistant structures. The most severe likely earthquake can be survived if the members are sufficiently ductile to absorb and dissipate seismic energy by inelastic deformation. This requires a designer to assess realistically the acceptable levels of strength and to ensure adequate dissipation. This paper proposes the use of infrared thermography as a nondestructive, noncontact and real-time technique to examine diverse mechanisms of dissipation and to illustrate the onset of damage process, stress concentration and heat dissipation localization in loaded zone. In addition, this technique can be used as a nondestructive method for evaluating the fatigue limit of concrete structure subject to repeated loading.
Information-theoretic outlook of the quantum dissipation problem
Kowalski, A.M.; Plastino, A.; Proto, A.N.
1992-08-01
The interaction between two harmonic oscillators, a classical and a quantum one, coupled through a linear term, is analyzed by recourse to the generalized Ehrenfest theorem. The model is able to mimic dissipating behaviour for the quantum oscillator without violation of any quantum rule. (author). 13 refs, 5 figs
One-dimensional autonomous systems and dissipative systems
Lopez, G.
1996-01-01
The Lagrangian and the Generalized Linear Momentum are given in terms of a constant of motion for a one-dimensional autonomous system. The possibility of having an explicit Hamiltonian expression is also analyzed. The approach is applied to some dissipative systems. Copyright copyright 1996 Academic Press, Inc
Power Dissipation Challenges in Multicore Floating-Point Units
Liu, Wei; Nannarelli, Alberto
2010-01-01
, we analyze the impact of power dissipation in floating-point (FP) units and we consider different alternatives in the implementation of FP-division that lead to substantial energy savings. We compare the implementation of division in a Fused Multiply-Add (FMA) unit based on the Newton-Raphson...
On the gravitational instability of a dissipative medium
Colin, L S Garcia; Sandoval-Villalbazo, Alfredo
2002-01-01
This paper shows that the ordinary Jeans wave number can be obtained as a limiting case of a more general approach that includes dissipative effects. Corrections to the Jeans critical mass associated with viscosity are established. Some possible implications of the results are finally discussed
High-Density Quantum Sensing with Dissipative First Order Transitions
Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik
2018-04-01
The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to √{N }. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T2 coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.
A model for turbulent dissipation rate in a constant pressure ...
J Dey
the logarithmic region. However, measurement of the. Taylor microscale remains a difficult task, as it involves correlation function [1]. Consequently, an appreciation of the Taylor microscale, dissipation rate, etc., is lacking in practice due to complexity involved in estimating these quantities. Segalini et al [2] have proposed a ...
Conservation-dissipation structure of chemical reaction systems.
Yong, Wen-An
2012-12-01
In this Brief Report, we show that balanced chemical reaction systems governed by the law of mass action have an elegant conservation-dissipation structure. From this structure a number of important conclusions can be easily deduced. In particular, with the help of this structure we can rigorously justify the classical partial equilibrium approximation in chemical kinetics.
ENERGY DISSIPATION IN MAGNETIC NULL POINTS AT KINETIC SCALES
Olshevsky, Vyacheslav; Lapenta, Giovanni; Divin, Andrey; Eriksson, Elin; Markidis, Stefano
2015-01-01
We use kinetic particle-in-cell and MHD simulations supported by an observational data set to investigate magnetic reconnection in clusters of null points in space plasma. The magnetic configuration under investigation is driven by fast adiabatic flux rope compression that dissipates almost half of the initial magnetic field energy. In this phase powerful currents are excited producing secondary instabilities, and the system is brought into a state of “intermittent turbulence” within a few ion gyro-periods. Reconnection events are distributed all over the simulation domain and energy dissipation is rather volume-filling. Numerous spiral null points interconnected via their spines form null lines embedded into magnetic flux ropes; null point pairs demonstrate the signatures of torsional spine reconnection. However, energy dissipation mainly happens in the shear layers formed by adjacent flux ropes with oppositely directed currents. In these regions radial null pairs are spontaneously emerging and vanishing, associated with electron streams and small-scale current sheets. The number of spiral nulls in the simulation outweighs the number of radial nulls by a factor of 5–10, in accordance with Cluster observations in the Earth's magnetosheath. Twisted magnetic fields with embedded spiral null points might indicate the regions of major energy dissipation for future space missions such as the Magnetospheric Multiscale Mission
A field theory description of constrained energy-dissipation processes
Mandzhavidze, I.D.; Sisakyan, A.N.
2002-01-01
A field theory description of dissipation processes constrained by a high-symmetry group is given. The formalism is presented in the example of the multiple-hadron production processes, where the transition to the thermodynamic equilibrium results from the kinetic energy of colliding particles dissipating into hadron masses. The dynamics of these processes is restricted because the constraints responsible for the colour charge confinement must be taken into account. We develop a more general S-matrix formulation of the thermodynamics of nonequilibrium dissipative processes and find a necessary and sufficient condition for the validity of this description; this condition is similar to the correlation relaxation condition, which, according to Bogolyubov, must apply as the system approaches equilibrium. This situation must physically occur in processes with an extremely high multiplicity, at least if the hadron mass is nonzero. We also describe a new strong-coupling perturbation scheme, which is useful for taking symmetry restrictions on the dynamics of dissipation processes into account. We review the literature devoted to this problem
Scattering for wave equations with dissipative terms in layered media
Mitsuteru Kadowaki
2011-05-01
Full Text Available In this article, we show the existence of scattering solutions to wave equations with dissipative terms in layered media. To analyze the wave propagation in layered media, it is necessary to handle singular points called thresholds in the spectrum. Our main tools are Kato's smooth perturbation theory and some approximate operators.
Nondestructive evaluation of dissipative behavior of reinforced concrete structure
Luong, M.P.
2001-01-01
Current technological developments tend toward increased exploitation of materials strengths and toward tackling extreme loads and environmental actions such as offshore structures subject to wind and wave loading, or buildings in seismic area. Concrete is widely used as a construction material because of its high strength-cost ratio in many applications. Experience of earthquakes and laboratory tests has shown that well designed and detailed reinforced concrete is suitable for earthquake resistant structures. The most severe likely earthquake can be survived if the members are sufficiently ductile to absorb and dissipate seismic energy by inelastic deformation. This requires a designer to assess realistically the acceptable levels of strength and to ensure adequate dissipation. This paper proposes the use of infrared thermography as a nondestructive, noncontact and real-time technique to examine diverse mechanisms of dissipation and to illustrate the onset of damage process, stress concentration and heat dissipation localization in loaded zone. In addition, this technique can be used as a nondestructive method for evaluating the fatigue limit of concrete structure subject to repeated loading
Dissipative N-point-vortex Models in the Plane
Shashikanth, Banavara N.
2010-02-01
A method is presented for constructing point vortex models in the plane that dissipate the Hamiltonian function at any prescribed rate and yet conserve the level sets of the invariants of the Hamiltonian model arising from the SE (2) symmetries. The method is purely geometric in that it uses the level sets of the Hamiltonian and the invariants to construct the dissipative field and is based on elementary classical geometry in ℝ3. Extension to higher-dimensional spaces, such as the point vortex phase space, is done using exterior algebra. The method is in fact general enough to apply to any smooth finite-dimensional system with conserved quantities, and, for certain special cases, the dissipative vector field constructed can be associated with an appropriately defined double Nambu-Poisson bracket. The most interesting feature of this method is that it allows for an infinite sequence of such dissipative vector fields to be constructed by repeated application of a symmetric linear operator (matrix) at each point of the intersection of the level sets.
Evaluation of carbon dioxide dissipation within a euthanasia chamber.
Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P-
2014-07-01
CO₂ euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO₂ to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO₂ levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO₂ dropped to below 10% COv within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO₂ dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO₂ dissipation. We recommend that users allow 2 min for CO₂ to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate.
Surfaces for high heat dissipation with no Leidenfrost limit
Sajadi, Seyed Mohammad; Irajizad, Peyman; Kashyap, Varun; Farokhnia, Nazanin; Ghasemi, Hadi
2017-07-01
Heat dissipation from hot surfaces through cooling droplets is limited by the Leidenfrost point (LFP), in which an insulating vapor film prevents direct contact between the cooling droplet and the hot surface. A range of approaches have been developed to raise this limit to higher temperatures, but the limit still exists. Recently, a surface architecture, decoupled hierarchical structure, was developed that allows the suppression of LFP completely. However, heat dissipation by the structure in the low superheat region was inferior to other surfaces and the structure required an extensive micro/nano fabrication procedure. Here, we present a metallic surface structure with no LFP and high heat dissipation capacity in all temperature ranges. The surface features the nucleate boiling phenomenon independent of the temperature with an approximate heat transfer coefficient of 20 kW m-2 K-1. This surface is developed in a one-step process with no micro/nano fabrication. We envision that this metallic surface provides a unique platform for high heat dissipation in power generation, photonics/electronics, and aviation systems.
Simulation of coupled electromagnetic and heat dissipation problems
Janssen, H.H.J.M.; Maten, ter E.J.W.; Houwelingen, van D.
1994-01-01
A description is given of an integrated simulation environment for the solution of coupled electromagnetic and heat dissipation problems in two dimensions, in particular for the field of induction heating, dielectric heating, and hysteresis heating. The equations are coupled because the most
Absolute dissipative drift-wave instabilities in tokamaks
Chen, L.; Chance, M.S.; Cheng, C.Z.
1979-07-01
Contrary to previous theoretical predictions, it is shown that the dissipative drift-wave instabilities are absolute in tokamak plasmas. The existence of unstable eigenmodes is shown to be associated with a new eigenmode branch induced by the finite toroidal couplings
Dissipation Mechanisms and Particle Acceleration at the Earth's Bow Shock
Desai, M. I.; Burch, J. L.; Broll, J. M.; Genestreti, K.; Torbert, R. B.; Ergun, R.; Wei, H.; Giles, B. L.; Russell, C. T.; Phan, T.; Chen, L. J.; Lai, H.; Wang, S.; Schwartz, S. J.; Allen, R. C.; Mauk, B.; Gingell, I.
2017-12-01
NASA's Magnetospheric Multiscale (MMS) mission has four spacecraft equipped with identical state-of-the-art instruments that acquire magnetic and electric field, plasma wave, and particle data at unprecedented temporal resolution to study the fundamental physics of magnetic reconnection in the Earth's magnetosphere. During Phase 1a, MMS also encountered and crossed the Earth's bow shock more than 300 times. We use burst data during 2 bow shock crossings to shed new light on key open questions regarding the formation, evolution, and dissipation mechanisms at collisionless shocks. Specifically, we focus on two events that exhibit clear differences in the ion and electron properties, the associated wave activity, and, therefore in the nature of the dissipation. In the case of a quasi-perpendicular, low beta shock crossing, we find that the dissipation processes are most likely associated with field-aligned electron beams that are coincident with high frequency electrostatic waves. On the other hand, the dissipation processes at an oblique, high beta shock crossing are largely governed by the quasi-static electric field and generation of magnetosonic whistler waves that result in perpendicular temperature anisotropy for the electrons. We also discuss the implications of these results for ion heating, reflection, and particle acceleration.
Luminaries-level structure improvement of LEDs for heat dissipation ...
the natural convection heat transfer process of LED luminaries is simulated by compu- ... Heat dissipation has become one of the key problems limiting the large ... micro channel heat radiator, are able to reject heat efficiently, they may make LED ... convection heat transfer coefficient, for example, adopting finned surface to ...
A non-linear dissipative model of magnetism
Durand, P.; Paidarová, Ivana
2010-01-01
Roč. 89, č. 6 (2010), s. 67004 ISSN 1286-4854 R&D Projects: GA AV ČR IAA100400501 Institutional research plan: CEZ:AV0Z40400503 Keywords : non-linear dissipative model of magnetism * thermodynamics * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry http://epljournal.edpsciences.org/
Constructal entransy dissipation minimization for 'volume-point' heat conduction
Chen Lingen; Wei Shuhuan; Sun Fengrui
2008-01-01
The 'volume to point' heat conduction problem, which can be described as to how to determine the optimal distribution of high conductivity material through the given volume such that the heat generated at every point is transferred most effectively to its boundary, has became the focus of attention in the current constructal theory literature. In general, the minimization of the maximum temperature difference in the volume is taken as the optimization objective. A new physical quantity, entransy, has been identified as a basis for optimizing heat transfer processes in terms of the analogy between heat and electrical conduction recently. Heat transfer analyses show that the entransy of an object describes its heat transfer ability, just as the electrical energy in a capacitor describes its charge transfer ability. Entransy dissipation occurs during heat transfer processes, as a measure of the heat transfer irreversibility with the dissipation related thermal resistance. By taking equivalent thermal resistance (it corresponds to the mean temperature difference), which reflects the average heat conduction effect and is defined based on entransy dissipation, as an optimization objective, the 'volume to point' constructal problem is re-analysed and re-optimized in this paper. The constructal shape of the control volume with the best average heat conduction effect is deduced. For the elemental area and the first order construct assembly, when the thermal current density in the high conductive link is linear with the length, the optimized shapes of assembly based on the minimization of entransy dissipation are the same as those based on minimization of the maximum temperature difference, and the mean temperature difference is 2/3 of the maximum temperature difference. For the second and higher order construct assemblies, the thermal current densities in the high conductive link are not linear with the length, and the optimized shapes of the assembly based on the
Intrinsic Energy Dissipation Limits in Nano and Micromechanical Resonators
Iyer, Srikanth Subramanian
Resonant microelectromechanical Systems (MEMS) have enabled miniaturization of high-performance inertial sensors, radio-frequency filters, timing references and mass-based chemical sensors. Despite the increasing prevalence of MEMS resonators for these applications, the energy dissipation in these structures is not well-understood. Accurate prediction of the energy loss and the resulting quality factor (Q) has significant design implications because it is directly related to device performance metrics including sensitivity for resonant sensors, bandwidth for radio-frequency filters and phase-noise for timing references. In order to assess the future potential for MEMS resonators it is critically important to evaluate the energy dissipation limits, which will dictate the ultimate performance resonant MEMS devices can achieve. This work focuses on the derivation and evaluation of the intrinsic mechanical energy dissipation limit for single-crystal nano and micromechanical resonators due to anharmonic phonon-phonon scattering in the Akhiezer regime. The energy loss is derived using perturbation theory and the linearized Boltzmann transport equation for phonons, and includes the direction and polarization dependent mode-Gruneisen parameters in order to capture the strain-induced anharmonicity among phonon branches. Evaluation of the quality factor limit reveals that Akhiezer damping, previously thought to depend only on material properties, has a strong dependence on crystal orientation and resonant mode shape. The robust model provides a dissipation limit for all resonant modes including shear-mode vibrations, which have significantly reduced energy loss because dissipative phonon-phonon scattering is restricted to volume-preserving phonon branches, indicating that Lame or wine-glass mode resonators will have the highest upper limit on mechanical efficiency. Finally, the analytical dissipation model is integrated with commercial finite element software in order to
Mars’ Low Dissipation Factor at 11-h - Interpretation from Anelasticity-Based Dissipation Model
Castillo-Rogez, Julie; Choukroun, M.
2010-10-01
We explore the information contained in the ratio of the tidal Love number k2 to the dissipation factor Q characterizing the response of Mars to the tides exerted by its satellite Phobos (11-h period). Assuming that Mars can be approximated as a Maxwell body, Bills et al. [1] have inferred an average viscosity of the Martian mantle 8.7x1014 Pa s. Such a low viscosity appears inconsistent with Mars’ thermal evolution and current heat budget models. Alternative explanations include the presence of partial melt in the mantle [2], or the presence of an aquifer in the crust [3]. We revisit the interpretation of Mars’ k2/Q using a laboratory-based attenuation model that accounts for material viscoelasticity and anelasticity. As a first step, we have computed Mars’ k2/Q for an interior model that includes a solid inner core, a liquid core layer, a mantle, and crust (consistent with the observed moment of inertia, and k2 measured at the orbital period), and searched for the range of mantle viscosities that can explain the observed k2/Q. Successful models are characterized by an average mantle viscosity between 1018 and 1022 Pa s, which rules out the presence of partial melt in the mantle. We can narrow down that range by performing a more detailed calculation of the mineralogy and temperature profiles. Preliminary results will be presented at the meeting. References: [1] Bills et al. (2005) JGR 110, E00704; [2] Ruedas et al. (2009 White paper to the NRC Planetary Science decadal survey; [3] Bills et al. (2009) LPS 40, 1712. MC is supported by a NASA Postdoctoral Program Fellowship, administered by Oak Ridge Associated Universities. This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under a contract to NASA. Government sponsorship acknowledged.
Dissipation enhanced vibrational sensing in an olfactory molecular switch
Chęcińska, Agata; Heaney, Libby; Pollock, Felix A.; Nazir, Ahsan
2015-01-01
Motivated by a proposed olfactory mechanism based on a vibrationally activated molecular switch, we study electron transport within a donor-acceptor pair that is coupled to a vibrational mode and embedded in a surrounding environment. We derive a polaron master equation with which we study the dynamics of both the electronic and vibrational degrees of freedom beyond previously employed semiclassical (Marcus-Jortner) rate analyses. We show (i) that in the absence of explicit dissipation of the vibrational mode, the semiclassical approach is generally unable to capture the dynamics predicted by our master equation due to both its assumption of one-way (exponential) electron transfer from donor to acceptor and its neglect of the spectral details of the environment; (ii) that by additionally allowing strong dissipation to act on the odorant vibrational mode, we can recover exponential electron transfer, though typically at a rate that differs from that given by the Marcus-Jortner expression; (iii) that the ability of the molecular switch to discriminate between the presence and absence of the odorant, and its sensitivity to the odorant vibrational frequency, is enhanced significantly in this strong dissipation regime, when compared to the case without mode dissipation; and (iv) that details of the environment absent from previous Marcus-Jortner analyses can also dramatically alter the sensitivity of the molecular switch, in particular, allowing its frequency resolution to be improved. Our results thus demonstrate the constructive role dissipation can play in facilitating sensitive and selective operation in molecular switch devices, as well as the inadequacy of semiclassical rate equations in analysing such behaviour over a wide range of parameters
Qin, Hua; Brookes, Philip C; Xu, Jianming
2014-01-01
A number of Cucurbita species have the potential to extract polychlorinated biphenyls (PCBs) from soil, but their impact on the soil microbial communities responsible for PCB degradation remains unclear. A greenhouse experiment was conducted to investigate the effect of three Cucurbita and one Cucumis species on PCB dissipation and soil microbial community structure. Compared to the unplanted control, enhanced losses of PCBs (19.5%-42.7%) were observed in all planted soils. Cucurbita pepo and Cucurbita moschata treatments were more efficient in PCB dissipation, and have similar patterns of soil phospholipid fatty acids (PLFAs) and PCB congener profiles. Cucurbita treatments tend to have higher soil microbial biomass than Cucumis. Gram-negative (G(-)) bacteria were significantly correlated with PCB degradation rates (R(2) = 0.719, p Cucurbita related soil microorganisms could play an important role in remediation of PCB contaminated soils. Copyright © 2013 Elsevier Ltd. All rights reserved.
Skin histology and its role in heat dissipation in three pinniped species
Khamas Wael A
2012-08-01
Full Text Available Abstract Background Pinnipeds have a thick blubber layer and may have difficulty maintaining their body temperature during hot weather when on land. The skin is the main thermoregulatory conduit which emits excessive body heat. Methods Thorough evaluation of the skin histology in three pinniped species; the California sea lion-Zalophus californianus, the Pacific harbor seal-Phoca vitulina richardsi, and the Northern elephant seal-Mirounga angustirostris, was conducted to identify the presence, location and distribution of skin structures which contribute to thermoregulation. These structures included hair, adipose tissue, sweat glands, vasculature, and arteriovenous anastomoses (AVA. Thermal imaging was performed on live animals of the same species to correlate histological findings with thermal emission of the skin. Results The presence and distribution of skin structures directly relates to emissivity of the skin in all three species. Emissivity of skin in phocids (Pacific harbor and Northern elephant seals follows a different pattern than skin in otariids (California sea lions. The flipper skin in phocids tends to be the most emissive region during hot weather and least emissive during cold weather. On the contrary in otariids, skin of the entire body has a tendency to be emissive during both hot and cold weather. Conclusion Heat dissipation of the skin directly relates to the presence and distribution of skin structures in all three species. Different skin thermal dissipation patterns were observed in phocid versus otariid seals. Observed thermal patterns can be used for proper understanding of optimum thermal needs of seals housed in research facilities, rescue centers and zoo exhibits.
Bayala, Jules; Heng, Lee Kheng; van Noordwijk, Meine; Ouedraogo, Sibiri Jean
2008-11-01
Hydraulic redistribution (HR) in karité ( Vitellaria paradoxa) and néré ( Parkia biglobosa) tree species was studied by monitoring the soil water potential ( ψs) using thermocouple psychrometers at four compass directions, various distances from trees and at different soil depths (max depth 80 cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount of water redistribued based on ψs values. Tree transpiration rate was also estimated from sap velocity using thermal dissipative probes (TDP) and sapwood area, and the contribution of hydraulically redistributed water in tree transpiration was determined. The results revealed on average that 46% of the psychrometer readings under karité and 33% under néré showed the occurrence of HR for the two years. Soil under néré displayed significantly lower fluctuations of ψs (0.16 MPa) compared to soil under karité (0.21 MPa). The results of this study indicated that the existence of HR leads to a higher ψs in the plant rhizosphere and hence is important for soil water dynamics and plant nutrition by making more accessible the soluble elements. The simulation showed that the amount of water redistributed would be approximately 73.0 L and 247.1 L per tree per day in 2005 for karité and néré, and would represent respectively 60% and 53% of the amount transpired a day. Even though the model has certainly overestimated the volume of water hydraulically redistributed by the two species, this water may play a key role in maintaining fine root viability and ensuring the well adaptation of these species to the dry areas. Therefore, knowledge of the extent of such transfers and of the seasonal patterns is required and is of paramount importance in parkland systems both for trees and associated crops.
Dissipation of Flonicamid in Honeysuckle and Its Transfer during Brewing Process.
Wang, Yujie; Xue, Jian; Jin, Hongyu; Ma, Shuangcheng
2017-05-01
The dissipation of flonicamid in Honeysuckle and transfer pattern from Honeysuckle to its tea infusion were investigated. Flonicamid was applied on Honeysuckle crop at two dosages, 60 g of active gradient per hectare (g a.i. hm -2 ) and 180 g a.i. hm -2 (recommended and triple the recommended) in Fenqiu, Henan Province in 2015 and 2016. Gas Chromatography-Electron Capture Detector (GC-ECD) detection methods were developed for the analysis of flonicamid residues in honeysuckles and its infusion. The recoveries in both honeysuckles and its infusion ranged from 81.5 to 101.7% with relative standard deviations (RSDs) of 3.2-9.1%. The dissipations of flonicamid in Honeysuckle were found to follow the first order kinetics with half-life ranging between 2.8 and 3.2 d. After recommended dose pesticide application, contents of flonicamid residues were lower than theoretical maximum residue limit (tMRL). Flonicamid residues can easily transfer from Honeysuckle to its tea infusion and transfer rates of flonicamid decrease with the brewing temperature reduction or the brewing times increase. These results are helpful to establish maximum residue limit and develop guidance on the appropriate and secure use of flonicamid in Honeysuckle.
Dry etching technology for semiconductors
Nojiri, Kazuo
2015-01-01
This book is a must-have reference to dry etching technology for semiconductors, which will enable engineers to develop new etching processes for further miniaturization and integration of semiconductor integrated circuits. The author describes the device manufacturing flow, and explains in which part of the flow dry etching is actually used. The content is designed as a practical guide for engineers working at chip makers, equipment suppliers and materials suppliers, and university students studying plasma, focusing on the topics they need most, such as detailed etching processes for each material (Si, SiO2, Metal etc) used in semiconductor devices, etching equipment used in manufacturing fabs, explanation of why a particular plasma source and gas chemistry are used for the etching of each material, and how to develop etching processes. The latest, key technologies are also described, such as 3D IC Etching, Dual Damascene Etching, Low-k Etching, Hi-k/Metal Gate Etching, FinFET Etching, Double Patterning ...
Tarasov, V.E.
1994-07-01
Sedov variational principle, which is the generalization of the least actional principle for the dissipative processes is used to generalize the canonical quantization and von Neumann equation for dissipative systems (particles and strings). (author). 66 refs, 1 fig
Hansen, Kurt Kielsgaard; Geiker, Mette Rica; Nygaard, Peter Vagn
2002-01-01
Estimated and measured relative humidity (RH) change during drying are compared for two concretes, 1: w/c=0.46 and 2: w/(c+0.5fa+2sf)=0.50. The estimations were undertaken by means of the Swedish program TorkaS 1.0. Measurements were performed by RH-sensors type Humi-Guard. Drying of 150 mm thick...... samples from sides at 60% RH and 22 °C took place from 4 to 56 days after casting. At the end of the drying period the measured RH was about 4% lower than the estimated RH at 1/5th depth from the exposed surface for both concretes. In the middle of the samples, the measured RH of concretes 1 and 2 were 2...
K. Loewe
2017-06-01
Full Text Available The Arctic climate is changing; temperature changes in the Arctic are greater than at midlatitudes, and changing atmospheric conditions influence Arctic mixed-phase clouds, which are important for the Arctic surface energy budget. These low-level clouds are frequently observed across the Arctic. They impact the turbulent and radiative heating of the open water, snow, and sea-ice-covered surfaces and influence the boundary layer structure. Therefore the processes that affect mixed-phase cloud life cycles are extremely important, yet relatively poorly understood. In this study, we present sensitivity studies using semi-idealized large eddy simulations (LESs to identify processes contributing to the dissipation of Arctic mixed-phase clouds. We found that one potential main contributor to the dissipation of an observed Arctic mixed-phase cloud, during the Arctic Summer Cloud Ocean Study (ASCOS field campaign, was a low cloud droplet number concentration (CDNC of about 2 cm−3. Introducing a high ice crystal concentration of 10 L−1 also resulted in cloud dissipation, but such high ice crystal concentrations were deemed unlikely for the present case. Sensitivity studies simulating the advection of dry air above the boundary layer inversion, as well as a modest increase in ice crystal concentration of 1 L−1, did not lead to cloud dissipation. As a requirement for small droplet numbers, pristine aerosol conditions in the Arctic environment are therefore considered an important factor determining the lifetime of Arctic mixed-phase clouds.
Ghate, S.R.; Chhinnan, M.S.
1983-07-01
High moisture in-shell pecans were dried by keeping them in direct and indirect contact with silica gel to investigate their drying characteristics. In-shell pecans were also dried with ambient air from a controlled environment chamber and with air dehumidified by silica gel. Direct contact and dehumidified air drying seemed feasible approaches.
Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems
Rabidin Zairul Amin
2017-01-01
Full Text Available Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be achieved in artificial drying kilns such as conventional kiln, dehumidification kiln, solar kiln, radio frequency-vacuum, etc. The objective of this study was to evaluate the characteristics of 30 mm and 50 mm thick kekatong (Cynometra spp. timber dried using kiln drying (KD and radio frequency-vacuum drying (RFV system. The investigation involved drying time, moisture content (MC variations between and within boards, drying defects, shrinkage, and drying stress. Drying defects include checks (surface, end, and internal checks and warping (bowing, cuping, spring, and twisting. The results showed that RFV drying time was reduced to 50% compared to the KD. RFV dried boards demonstrated a more uniform MC between and within boards. Shrinkage in width and thickness, as well as tangential/radial and volumetric shrinkages were substantially less in RFV boards. The amount of cupping, bowing and spring were very low and negligible in all drying runs. There was no twisting observed in all drying methods. The number of stress-free RFV board was higher than KD. With proper procedure, the RFV technology could be used for drying heavy hardwoods which are difficult to dry in conventional kilns due to excessive drying times and degradation.
Energy dissipation dataset for reversible logic gates in quantum dot-cellular automata.
Bahar, Ali Newaz; Rahman, Mohammad Maksudur; Nahid, Nur Mohammad; Hassan, Md Kamrul
2017-02-01
This paper presents an energy dissipation dataset of different reversible logic gates in quantum-dot cellular automata. The proposed circuits have been designed and verified using QCADesigner simulator. Besides, the energy dissipation has been calculated under three different tunneling energy level at temperature T =2 K. For estimating the energy dissipation of proposed gates; QCAPro tool has been employed.
FREEZE DRYING PROCESS: A REVIEW
Soham Shukla
2011-01-01
Among the various methods of drying, this article has mentioned only one most important method, “Freeze drying”. This method is mainly used for the drying of thermo labile materials. This method works on the principle of sublimation. This method is divided into 3 steps for its better understanding; these are Freezing, Primary drying, and secondary drying. There are many advantages and disadvantages of this method, but still this is the most useful drying method nowadays.
Rastogi, Bharat; Williams, A. Park; Fischer, Douglas T.; Iacobellis, Sam F.; McEachern, A. Kathryn; Carvalho, Leila; Jones, Charles Leslie; Baguskas, Sara A.; Still, Christopher J.
2016-01-01
The presence of low-lying stratocumulus clouds and fog has been known to modify biophysical and ecological properties in coastal California where forests are frequently shaded by low-lying clouds or immersed in fog during otherwise warm and dry summer months. Summer fog and stratus can ameliorate summer drought stress and enhance soil water budgets, and often have different spatial and temporal patterns. Here we use remote sensing datasets to characterize the spatial and temporal patterns of cloud cover over California’s northern Channel Islands. We found marine stratus to be persistent from May through September across the years 2001-2012. Stratus clouds were both most frequent and had the greatest spatial extent in July. Clouds typically formed in the evening, and dissipated by the following early afternoon. We present a novel method to downscale satellite imagery using atmospheric observations and discriminate patterns of fog from those of stratus and help explain patterns of fog deposition previously studied on the islands. The outcomes of this study contribute significantly to our ability to quantify the occurrence of coastal fog at biologically meaningful spatial and temporal scales that can improve our understanding of cloud-ecosystem interactions, species distributions and coastal ecohydrology.
A Dissipative Connector for CLT Buildings: Concept, Design and Testing
Scotta, Roberto; Marchi, Luca; Trutalli, Davide; Pozza, Luca
2016-01-01
This paper deals with the conception and characterization of an innovative connection for cross-laminated timber (CLT) panels. The connection is designed to provide an adequate level of dissipative capacity to CLT structures also when realized with large horizontal panels and therefore prone to fragile shear sliding failure. The connector, named X-bracket, has been theorized and designed by means of numerical parametric analyses. Furthermore, its cyclic behavior has been verified with experimental tests and compared to that of traditional connectors. Numerical simulations of cyclic tests of different CLT walls anchored to the foundation with X-brackets were also performed to assess their improved seismic performances. Finally, the analysis of the response of a 6 m × 3 m squat wall demonstrates that the developed connection provides good ductility and dissipation capacities also to shear walls realized with a single CLT panel. PMID:28773265
Non-dissipative energy capture of confined liquid in nanopores
Xu, Baoxing; Chen, Xi [Columbia Nanomechanics Research Center, Department of Earth and Environmental Engineering, Columbia University, New York, New York 10027 (United States); Lu, Weiyi; Zhao, Cang [Department of Structural Engineering, University of California–San Diego, La Jolla, California 92093-0085 (United States); Qiao, Yu, E-mail: yqiao@ucsd.edu [Department of Structural Engineering, University of California–San Diego, La Jolla, California 92093-0085 (United States); Program of Materials Science and Engineering, University of California–San Diego, La Jolla, CA 92093 (United States)
2014-05-19
In the past, energy absorption of protection/damping materials is mainly based on energy dissipation, which causes a fundamental conflict between the requirements of safety/comfort and efficiency. In the current study, a nanofluidic “energy capture” system is reported, which is based on nanoporous materials and nonwetting liquid. Both molecular dynamics simulations and experiments show that as the liquid overcomes the capillary effect and infiltrates into the nanopores, the mechanical energy of a stress wave could be temporarily stored by the confined liquid phase and isolated from the wave energy transmission path. Such a system can work under a relatively low pressure for mitigating high-pressure stress waves, not necessarily involved in any energy dissipation processes.
Non-dissipative energy capture of confined liquid in nanopores
Xu, Baoxing; Chen, Xi; Lu, Weiyi; Zhao, Cang; Qiao, Yu
2014-01-01
In the past, energy absorption of protection/damping materials is mainly based on energy dissipation, which causes a fundamental conflict between the requirements of safety/comfort and efficiency. In the current study, a nanofluidic “energy capture” system is reported, which is based on nanoporous materials and nonwetting liquid. Both molecular dynamics simulations and experiments show that as the liquid overcomes the capillary effect and infiltrates into the nanopores, the mechanical energy of a stress wave could be temporarily stored by the confined liquid phase and isolated from the wave energy transmission path. Such a system can work under a relatively low pressure for mitigating high-pressure stress waves, not necessarily involved in any energy dissipation processes.
Dynamic response function and large-amplitude dissipative collective motion
Wu Xizhen; Zhuo Yizhong; Li Zhuxia; Sakata, Fumihiko.
1993-05-01
Aiming at exploring microscopic dynamics responsible for the dissipative large-amplitude collective motion, the dynamic response and correlation functions are introduced within the general theory of nuclear coupled-master equations. The theory is based on the microscopic theory of nuclear collective dynamics which has been developed within the time-dependent Hartree-Fock (TDHF) theory for disclosing complex structure of the TDHF-manifold. A systematic numerical method for calculating the dynamic response and correlation functions is proposed. By performing numerical calculation for a simple model Hamiltonian, it is pointed out that the dynamic response function gives an important information in understanding the large-amplitude dissipative collective motion which is described by an ensemble of trajectories within the TDHF-manifold. (author)
Solvable Family of Driven-Dissipative Many-Body Systems
Foss-Feig, Michael; Young, Jeremy T.; Albert, Victor V.; Gorshkov, Alexey V.; Maghrebi, Mohammad F.
2017-11-01
Exactly solvable models have played an important role in establishing the sophisticated modern understanding of equilibrium many-body physics. Conversely, the relative scarcity of solutions for nonequilibrium models greatly limits our understanding of systems away from thermal equilibrium. We study a family of nonequilibrium models, some of which can be viewed as dissipative analogues of the transverse-field Ising model, in that an effectively classical Hamiltonian is frustrated by dissipative processes that drive the system toward states that do not commute with the Hamiltonian. Surprisingly, a broad and experimentally relevant subset of these models can be solved efficiently. We leverage these solutions to compute the effects of decoherence on a canonical trapped-ion-based quantum computation architecture, and to prove a no-go theorem on steady-state phase transitions in a many-body model that can be realized naturally with Rydberg atoms or trapped ions.
Causal dissipation for the relativistic dynamics of ideal gases.
Freistühler, Heinrich; Temple, Blake
2017-05-01
We derive a general class of relativistic dissipation tensors by requiring that, combined with the relativistic Euler equations, they form a second-order system of partial differential equations which is symmetric hyperbolic in a second-order sense when written in the natural Godunov variables that make the Euler equations symmetric hyperbolic in the first-order sense. We show that this class contains a unique element representing a causal formulation of relativistic dissipative fluid dynamics which (i) is equivalent to the classical descriptions by Eckart and Landau to first order in the coefficients of viscosity and heat conduction and (ii) has its signal speeds bounded sharply by the speed of light. Based on these properties, we propose this system as a natural candidate for the relativistic counterpart of the classical Navier-Stokes equations.
Electrostatic shock structures in dissipative multi-ion dusty plasmas
Elkamash, I. S.; Kourakis, I.
2018-06-01
A comprehensive analytical model is introduced for shock excitations in dusty bi-ion plasma mixtures, taking into account collisionality and kinematic (fluid) viscosity. A multicomponent plasma configuration is considered, consisting of positive ions, negative ions, electrons, and a massive charged component in the background (dust). The ionic dynamical scale is focused upon; thus, electrons are assumed to be thermalized, while the dust is stationary. A dissipative hybrid Korteweg-de Vries/Burgers equation is derived. An analytical solution is obtained, in the form of a shock structure (a step-shaped function for the electrostatic potential, or an electric field pulse) whose maximum amplitude in the far downstream region decays in time. The effect of relevant plasma configuration parameters, in addition to dissipation, is investigated. Our work extends earlier studies of ion-acoustic type shock waves in pure (two-component) bi-ion plasma mixtures.
Irreversibility and dissipation in finite-state automata
Ganesh, Natesh; Anderson, Neal G.
2013-01-01
Irreversibility and dissipation in finite-state automata (FSA) are considered from a physical-information-theoretic perspective. A quantitative measure for the computational irreversibility of finite automata is introduced, and a fundamental lower bound on the average energy dissipated per state transition is obtained and expressed in terms of FSA irreversibility. The irreversibility measure and energy bound are germane to any realization of a deterministic automaton that faithfully registers abstract FSA states in distinguishable states of a physical system coupled to a thermal environment, and that evolves via a sequence of interactions with an external system holding a physical instantiation of a random input string. The central result, which is shown to follow from quantum dynamics and entropic inequalities alone, can be regarded as a generalization of Landauer's Principle applicable to FSAs and tailorable to specified automata. Application to a simple FSA is illustrated.
Stable schemes for dissipative particle dynamics with conserved energy
Stoltz, Gabriel, E-mail: stoltz@cermics.enpc.fr
2017-07-01
This article presents a new numerical scheme for the discretization of dissipative particle dynamics with conserved energy. The key idea is to reduce elementary pairwise stochastic dynamics (either fluctuation/dissipation or thermal conduction) to effective single-variable dynamics, and to approximate the solution of these dynamics with one step of a Metropolis–Hastings algorithm. This ensures by construction that no negative internal energies are encountered during the simulation, and hence allows to increase the admissible timesteps to integrate the dynamics, even for systems with small heat capacities. Stability is only limited by the Hamiltonian part of the dynamics, which suggests resorting to multiple timestep strategies where the stochastic part is integrated less frequently than the Hamiltonian one.
Observation of a Dissipation-Induced Classical to Quantum Transition
J. Raftery
2014-09-01
Full Text Available Here, we report the experimental observation of a dynamical quantum phase transition in a strongly interacting open photonic system. The system studied, comprising a Jaynes-Cummings dimer realized on a superconducting circuit platform, exhibits a dissipation-driven localization transition. Signatures of the transition in the homodyne signal and photon number reveal this transition to be from a regime of classical oscillations into a macroscopically self-trapped state manifesting revivals, a fundamentally quantum phenomenon. This experiment also demonstrates a small-scale realization of a new class of quantum simulator, whose well-controlled coherent and dissipative dynamics is suited to the study of quantum many-body phenomena out of equilibrium.
A Dissipative Connector for CLT Buildings: Concept, Design and Testing.
Scotta, Roberto; Marchi, Luca; Trutalli, Davide; Pozza, Luca
2016-02-26
This paper deals with the conception and characterization of an innovative connection for cross-laminated timber (CLT) panels. The connection is designed to provide an adequate level of dissipative capacity to CLT structures also when realized with large horizontal panels and therefore prone to fragile shear sliding failure. The connector, named X-bracket, has been theorized and designed by means of numerical parametric analyses. Furthermore, its cyclic behavior has been verified with experimental tests and compared to that of traditional connectors. Numerical simulations of cyclic tests of different CLT walls anchored to the foundation with X-brackets were also performed to assess their improved seismic performances. Finally, the analysis of the response of a 6 m × 3 m squat wall demonstrates that the developed connection provides good ductility and dissipation capacities also to shear walls realized with a single CLT panel.
Hathaway, Thomas J.; Bell, Jr., Harold S.
1979-01-01
This invention provides a solids feeder for feeding dry coal to a pressurized gasifier at elevated temperatures substantially without losing gas from the gasifier by providing a lock having a double-acting piston that feeds the coals into the gasifier, traps the gas from escaping, and expels the trapped gas back into the gasifier.
... a combination of heredity and environmental factors, including smoking and diet. The condition develops as the eye ages. Dry ... nonsmokers. Ask your doctor for help to stop smoking. Maintain a ... controlling your diet. Choose a diet rich in fruits and vegetables. ...
G.G. Chandrakant (Gujar)
2011-01-01
textabstractDue to several reasons, currently the global supply chains are getting stretched further away into the hinterlands from the gateway seaports. This single fact enhances the importance of dry ports. It would not be against logic, to state that in coming times, as a result of ever-growing
Full Text Available ... bloodshot when I wake up? Jun 26, 2016 Why are my eyes dry after LASIK? Jun 19, 2016 Can I be tested whether I close my eyes when I sleep? Feb 10, 2016 Can light sensitivity from Parkinson’s ...
Dissipative Control Systems and Disturbance Attenuation for Nonlinear H∞ Problems
Frankowska, H.; Quincampoix, M.
1999-01-01
We characterize functions satisfying a dissipative inequality associated with a control problem. Such a characterization is provided in terms of an epicontingent solution, or a viscosity supersolution to a partial differential equation called Isaacs' equation. Links between supersolutions and epicontingent solutions to Isaacs' equation are studied. Finally, we derive (possibly discontinuous) disturbance attenuation feedback of the H ∞ problem from contingent formulation of Isaacs' equation
Robust Performance And Dissipation of Stochastic Control Systems
Thygesen, Uffe Høgsbro
and topology on the space of supply rates. For instance, we give conditions under which the available storage is a continuous convex function of the supply rate. Dissipation theory in the existing literature applies only to deterministic systems. This is unfortunate since robust control applications typically...... is a prototype of robust adaptive control problems. We show that the optimal (minimax) controller for this problem is finite dimensional but not based on certainty equivalence, and we discuss the heuristic certainty equivalence controller....
Entanglement replication in driven dissipative many-body systems.
Zippilli, S; Paternostro, M; Adesso, G; Illuminati, F
2013-01-25
We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.
Measurement fidelity in the presence of coherent dynamics or dissipation
You, Jian-Qiang; Ashhab, S.; Nori, Franco
2011-03-01
We analyze the problem of a charge qubit probed by a quantum point contact when the measurement is concurrent with Hamiltonian-induced coherent dynamics or dissipation. This additional dynamics changes the state of the qubit before the measurement is completed. As a result, the measurement fidelity is reduced. We calculate the reduction in measurement fidelity in these cases. References: S. Ashhab, J. Q. You, and F. Nori, New J. Phys. 11, 083017 (2009); Phys. Scr. T137, 014005 (2009).
A simulation for energy dissipation in nuclear reactions
Mshelia, E.D.; Ngadda, Y.H.
1989-01-01
A model for energy dissipation is presented which demonstrates energy transfer from a collective degree of freedom, represented by free motion, into intrinsic modes, represented by four coupled oscillators. The quantum mechanical probability amplitude for internal excitation is expressed as a multiple integral of a product of translational and intrinsic wavefunctions and exactly solved analytically. Its numerical values as a function of quantities of physical interest have been calculated, represented graphically and discussed. The results show that the probability distributions are peaked. (author)
A fat fractal crisis in a quasi-dissipative system
Shen, Ying; Dai, Jun; Jiang, Yumei; He, Yue; He, Da-Ren
2006-01-01
A crisis, induced by a sudden change of a fat strange set to a transit, is observed in a system, which is a two-dimensional discontinuous and noninvertible map and displays a dissipation sowing linear time dependence. It is shown analytically and numerically that, in this crisis, the characteristic scaling exponent takes a large value of 1.72; this is in agreement with the observed superlong transients
Wave Dissipation on Low- to Super-Energy Coral Reefs
Harris, D. L.
2016-02-01
Coral reefs are valuable, complex and bio-diverse ecosystems and are also known to be one of the most effective barriers to swell events in coastal environments. Previous research has found coral reefs to be remarkably efficient in removing most of the wave energy during the initial breaking and transformation on the reef flats. The rate of dissipation is so rapid that coral reefs have been referred to as rougher than any known coastal barrier. The dissipation of wave energy across reef flats is crucial in maintaining the relatively low-energy conditions in the back reef and lagoonal environments providing vital protection to adjacent beach or coastal regions from cyclone and storm events. A shift in the regulation of wave energy by reef flats could have catastrophic consequences ecologically, socially, and economically. This study examined the dissipation of wave energy during two swell events in Tahiti and Moorea, French Polyesia. Field sites were chosen in varying degrees of exposure and geomorphology from low-energy protected sites (Tiahura, Moorea) to super-energy sites (Teahupo'o, Tahiti). Waves were measured during two moderate to large swell events in cross reef transects using short-term high-resolution pressure transducers. Wave conditions were found to be similar in all back reef locations despite the very different wave exposure at each reef site. However, wave conditions on the reef flats were different and mirrored the variation in wave exposure with depth over the reef flat the primary regulator of reef flat wave height. These results indicate that coral reef flats evolve morphodynamically with the wave climate, which creates coral reef geomorphologies capable of dissipating wave energy that results in similar back reef wave conditions regardless of the offshore wave climate.
Quantum tight-binding chains with dissipative coupling
Mogilevtsev, D; Slepyan, G Ya; Garusov, E; Kilin, S Ya; Korolkova, N
2015-01-01
We present a one-dimensional tight-binding chain of two-level systems coupled only through common dissipative Markovian reservoirs. This quantum chain can demonstrate anomalous thermodynamic behavior contradicting Fourier law. Population dynamics of individual systems of the chain is polynomial with the order determined by the initial state of the chain. The chain can simulate classically hard problems, such as multi-dimensional random walks. (paper)
Dynamics of the conservative and dissipative spin-orbit problem
Celletti, A; Lega, E
2006-01-01
We investigate the dynamics of the spin--orbit coupling under different settings. First we consider the conservative problem, and then we add a dissipative torque as provided by MacDonald's or Darwin's models. By means of frequency analysis and of the computation of the maximum Lyapunov indicator we explore the different dynamical behaviors associated to the main resonances. In particular we focus on the 1:1 and 3:2 resonances in which the Moon and Mercury are actually trapped.
Nonlinear saturation of dissipative trapped ion instability and anomalous transport
Sugihara, Masayoshi; Ogasawara, Masatada.
1977-04-01
An expression for the turbulent collision frequency is derived by summing up the most dominant terms from each order in the perturbation expansion in order to obtain the nonlinear saturation level of the dissipative trapped ion instability. Numerical calculation shows that the anomalous diffusion coefficient at the saturated state is in good agreement with the result of Kadomtsev and Pogutse when the effect of the magnetic shear is taken into account. (auth.)
Robustness of Linear Systems towards Multi-Dissipative Pertubations
Thygesen, Uffe Høgsbro; Poulsen, Niels Kjølstad
1997-01-01
We consider the question of robust stability of a linear time invariant plant subject to dynamic perturbations, which are dissipative in the sense of Willems with respect to several quadratic supply rates. For instance, parasitic dynamics are often both small gain and passive. We reduce several...... robustness analysis questions to linear matrix inequalities: robust stability, robust H2 performance and robust performance in presence of disturbances with finite signal-to-noise ratios...
Dissipative Effects in the Effective Field Theory of Inflation
Lopez Nacir, Diana; /Buenos Aires, CONICET /Buenos Aires U.; Porto, Rafael A.; /Princeton, Inst. Advanced Study /ISCAP, New York /Columbia U.; Senatore, Leonardo; /Stanford U., ITP /SLAC /KIPAC, Menlo Park; Zaldarriaga, Matias; /Princeton, Inst. Advanced Study
2012-09-14
We generalize the effective field theory of single clock inflation to include dissipative effects. Working in unitary gauge we couple a set of composite operators, {Omicron}{sub {mu}{nu}}..., in the effective action which is constrained solely by invariance under time-dependent spatial diffeomorphisms. We restrict ourselves to situations where the degrees of freedom responsible for dissipation do not contribute to the density perturbations at late time. The dynamics of the perturbations is then modified by the appearance of 'friction' and noise terms, and assuming certain locality properties for the Green's functions of these composite operators, we show that there is a regime characterized by a large friction term {gamma} >> H in which the {zeta}-correlators are dominated by the noise and the power spectrum can be significantly enhanced. We also compute the three point function <{zeta}{zeta}{zeta}> for a wide class of models and discuss under which circumstances large friction leads to an increased level of non-Gaussianities. In particular, under our assumptions, we show that strong dissipation together with the required non-linear realization of the symmetries implies |f{sub NL}| {approx} {gamma}/c{sub s}{sup 2} H >> 1. As a paradigmatic example we work out a variation of the 'trapped inflation' scenario with local response functions and perform the matching with our effective theory. A detection of the generic type of signatures that result from incorporating dissipative effects during inflation, as we describe here, would teach us about the dynamics of the early universe and also extend the parameter space of inflationary models.
Critical review of hydraulic modeling on atmospheric heat dissipation
Onishi, Y.; Brown, S.M.
1977-01-01
Objectives of this study were: to define the useful roles of hydraulic modeling in understanding the predicting atmospheric effects of heat dissipation systems; to assess the state-of-the-art of hydraulic modeling of atmospheric phenomena; to inventory potentially useful existing hydraulic modeling facilities both in the United States and abroad; and to scope hydraulic model studies to assist the assessment of atmospheric effects of nuclear energy centers
Infrared Drying Parameter Optimization
Jackson, Matthew R.
In recent years, much research has been done to explore direct printing methods, such as screen and inkjet printing, as alternatives to the traditional lithographic process. The primary motivation is reduction of the material costs associated with producing common electronic devices. Much of this research has focused on developing inkjet or screen paste formulations that can be printed on a variety of substrates, and which have similar conductivity performance to the materials currently used in the manufacturing of circuit boards and other electronic devices. Very little research has been done to develop a process that would use direct printing methods to manufacture electronic devices in high volumes. This study focuses on developing and optimizing a drying process for conductive copper ink in a high volume manufacturing setting. Using an infrared (IR) dryer, it was determined that conductive copper prints could be dried in seconds or minutes as opposed to tens of minutes or hours that it would take with other drying devices, such as a vacuum oven. In addition, this study also identifies significant parameters that can affect the conductivity of IR dried prints. Using designed experiments and statistical analysis; the dryer parameters were optimized to produce the best conductivity performance for a specific ink formulation and substrate combination. It was determined that for an ethylene glycol, butanol, 1-methoxy 2- propanol ink formulation printed on Kapton, the optimal drying parameters consisted of a dryer height of 4 inches, a temperature setting between 190 - 200°C, and a dry time of 50-65 seconds depending on the printed film thickness as determined by the number of print passes. It is important to note that these parameters are optimized specifically for the ink formulation and substrate used in this study. There is still much research that needs to be done into optimizing the IR dryer for different ink substrate combinations, as well as developing a
Study of dissipation in superconductors at high frequency regime
Vallet, Christophe
1994-01-01
This thesis is devoted to the study of the Joule effect dissipation occurring in superconducting accelerating cavities. Two mechanisms of dissipation are presented: the first concerns the magnetic flux present around the cryostat and trapped by the (Niobium) superconducting cavity during a temperature descent; a theoretical and experimental study allow the evaluation of the percentage of flux which rests trapped and its contribution to the dissipation. Improving the magnetic shielding leads to a remnant field of the order of several milli-Gauss and the surface resistance drops from 25 nΩ to 4.2 nΩ (with a few other modifications). The second mechanism is related to the polycrystalline structure of the superconductor. A theoretical study evaluates this contribution to about 3 nΩ. A complex process of recrystallization is needed in order to overcome this effect. Using an electron beam at low energy might help in reaching this goal and thus observing surface resistance values smaller than ever obtained. (author) [fr
Foucault dissipation in a rolling cylinder: a webcam quantitative study
Bonanno, A; Bozzo, G; Camarca, M; Sapia, P
2011-01-01
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault 'eddy' currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis done by means of software tools freely available within Windows operating system (Paint and Movie Maker). The proposed method allows us to experimentally discern the contribution to dissipation due to the velocity-independent rolling friction from that owed to the viscous-like friction emerging from complex electrodynamic interactions among eddy currents and the external magnetic field. In this way a microdissipation of some tens of μW is measured. The easily reproducible experimental setup, the simple implementation of data analysis and the discussion on various experimental approaches and strategies make the proposed activity highly significant for university undergraduates, since involved crucial skills can be efficiently strengthened.
Foucault dissipation in a rolling cylinder: a webcam quantitative study
Bonanno, A; Bozzo, G; Camarca, M; Sapia, P, E-mail: sapia@fis.unical.it [Physics Department, University of Calabria, I-87036 Rende, CS (Italy)
2011-03-15
In this paper we present an experimental strategy to measure the micro power dissipation due to Foucault 'eddy' currents in a copper cylinder rolling on two parallel conductive rails in the presence of a magnetic field. Foucault power dissipation is obtained from kinematical measurements carried out by using a common PC webcam and video analysis done by means of software tools freely available within Windows operating system (Paint and Movie Maker). The proposed method allows us to experimentally discern the contribution to dissipation due to the velocity-independent rolling friction from that owed to the viscous-like friction emerging from complex electrodynamic interactions among eddy currents and the external magnetic field. In this way a microdissipation of some tens of {mu}W is measured. The easily reproducible experimental setup, the simple implementation of data analysis and the discussion on various experimental approaches and strategies make the proposed activity highly significant for university undergraduates, since involved crucial skills can be efficiently strengthened.
Fractional Stochastic Differential Equations Satisfying Fluctuation-Dissipation Theorem
Li, Lei; Liu, Jian-Guo; Lu, Jianfeng
2017-10-01
We propose in this work a fractional stochastic differential equation (FSDE) model consistent with the over-damped limit of the generalized Langevin equation model. As a result of the `fluctuation-dissipation theorem', the differential equations driven by fractional Brownian noise to model memory effects should be paired with Caputo derivatives, and this FSDE model should be understood in an integral form. We establish the existence of strong solutions for such equations and discuss the ergodicity and convergence to Gibbs measure. In the linear forcing regime, we show rigorously the algebraic convergence to Gibbs measure when the `fluctuation-dissipation theorem' is satisfied, and this verifies that satisfying `fluctuation-dissipation theorem' indeed leads to the correct physical behavior. We further discuss possible approaches to analyze the ergodicity and convergence to Gibbs measure in the nonlinear forcing regime, while leave the rigorous analysis for future works. The FSDE model proposed is suitable for systems in contact with heat bath with power-law kernel and subdiffusion behaviors.
Statistical and dynamical properties of a dissipative kicked rotator
Oliveira, Diego F. M.; Leonel, Edson D.
2014-11-01
Some dynamical and statistical properties for a conservative as well as the dissipative problem of relativistic particles in a waveguide are considered. For the first time, two different types of dissipation namely: (i) due to viscosity and; (ii) due to inelastic collision (upon the kick) are considered individually and acting together. For the first case, and contrary to what is expected for the original Zaslavsky’s relativistic model, we show there is a critical parameter where a transition from local to global chaos occurs. On the other hand, after considering the introduction of dissipation also on the kick, the structure of the phase space changes in the sense that chaotic and periodic attractors appear. We study also the chaotic sea by using scaling arguments and we proposed an analytical argument to reinforce the validity of the scaling exponents obtained numerically. In principle such an approach can be extended to any two-dimensional map. Finally, based on the Lyapunov exponent, we show that the parameter space exhibits infinite families of self-similar shrimp-shape structures, corresponding to periodic attractors, embedded in a large region corresponding to chaotic attractors.
Constraining planetary migration and tidal dissipation with coeval hot Jupiters
O'Connor, Christopher E.; Hansen, Bradley M. S.
2018-06-01
We investigate the constraints on the formation of, and tidal dissipation processes in, hot Jupiters (HJs) that can be inferred based on reliable knowledge of the age of a system or population. Particular attention is paid to the role of young systems (such as those in open clusters or star-forming regions) in such studies. For an ensemble of coeval HJ (or proto-HJ) systems, we quantify the effect of age on the distribution of orbital eccentricities with respect to orbital periods as well as the location of the observed `pile-up' feature. We expect the effects of pre-main-sequence stellar evolution to be important only if a substantial fraction of HJs approach their current orbits early in protostellar contraction (ages ≲ 10 Myr). Application to the HJs presently known in the cluster M 67 yields constraints on the dissipation roughly consistent with those gleaned from planets in the field; for those in the Hyades and Praesepe, our results suggest a higher degree of dissipation at early times than that inferred from other populations.
Traits of estuarine marsh plants affect wave dissipation
Schulte Ostermann, Tilla; Heuner, Maike; Bouma, Tjeerd
2017-04-01
Estuarine vegetation can attenuate hydrodynamic forces such as waves or flow velocities and therefore has an important role in natural tidal bank protection. This function depends on the degree of hydrodynamic forces, bank morphology and on plant traits of the dominant species. The traits vary between the species but also between different marsh sites. Biomass, stem density and biomechanical properties are crucial factors that influence the rate of wave dissipation. These properties illustrate the trade-offs a species is facing in such a dynamic habitat and highlight the ability of dominant species such as Bolboschoenus maritimus and Schoenoplectus tabernaemontani to protect the tidal bank. Along the Elbe estuary, traits of dominant marsh plant species were measured on different sites. The sites vary e.g. in their elevation, salt levels and inundation periods. To analyse the role that plant traits can play in wave dissipation, the structure of the vegetation as well as the composition was recorded. Biomechanical tests helped to understand the species traits regarding stem flexibility and to determine the effects of plant traits on wave dynamics and vice versa. On the conference, we will present how plant traits affect the wave dissipation on tidal marshes and why they vary.
Energy spectrum, dissipation, and spatial structures in reduced Hall magnetohydrodynamic
Martin, L. N.; Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Gomez, D. O. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio, CONICET, Buenos Aires (Argentina)
2012-05-15
We analyze the effect of the Hall term in the magnetohydrodynamic turbulence under a strong externally supported magnetic field, seeing how this changes the energy cascade, the characteristic scales of the flow, and the dynamics of global magnitudes, with particular interest in the dissipation. Numerical simulations of freely evolving three-dimensional reduced magnetohydrodynamics are performed, for different values of the Hall parameter (the ratio of the ion skin depth to the macroscopic scale of the turbulence) controlling the impact of the Hall term. The Hall effect modifies the transfer of energy across scales, slowing down the transfer of energy from the large scales up to the Hall scale (ion skin depth) and carrying faster the energy from the Hall scale to smaller scales. The final outcome is an effective shift of the dissipation scale to larger scales but also a development of smaller scales. Current sheets (fundamental structures for energy dissipation) are affected in two ways by increasing the Hall effect, with a widening but at the same time generating an internal structure within them. In the case where the Hall term is sufficiently intense, the current sheet is fully delocalized. The effect appears to reduce impulsive effects in the flow, making it less intermittent.
Heat Dissipation for Microprocessor Using Multiwalled Carbon Nanotubes Based Liquid
Trinh, Pham Van; Chuc, Nguyen Van; Khoi, Phan Hong; Minh, Phan Ngoc
2013-01-01
Carbon nanotubes (CNTs) are one of the most valuable materials with high thermal conductivity (2000 W/m · K compared with thermal conductivity of Ag 419 W/m · K). This suggested an approach in applying the CNTs in thermal dissipation system for high power electronic devices, such as computer processor and high brightness light emitting diode (HB-LED). In this work, multiwalled carbon nanotubes (MWCNTs) based liquid was made by COOH functionalized MWCNTs dispersed in distilled water with concentration in the range between 0.2 and 1.2 gram/liter. MWCNT based liquid was used in liquid cooling system to enhance thermal dissipation for computer processor. By using distilled water in liquid cooling system, CPU's temperature decreases by about 10°C compared with using fan cooling system. By using MWCNT liquid with concentration of 1 gram/liter MWCNTs, the CPU's temperature decreases by 7°C compared with using distilled water in cooling system. Theoretically, we also showed that the presence of MWCNTs reduced thermal resistance and increased the thermal conductivity of liquid cooling system. The results have confirmed the advantages of the MWCNTs for thermal dissipation systems for the μ-processor and other high power electronic devices. PMID:24453829
Dissipation and energy balance in electronic dynamics of Na clusters
Vincendon, Marc; Suraud, Eric; Reinhard, Paul-Gerhard
2017-06-01
We investigate the impact of dissipation on the energy balance in the electron dynamics of metal clusters excited by strong electro-magnetic pulses. The dynamics is described theoretically by Time-Dependent Density-Functional Theory (TDDFT) at the level of Local Density Approximation (LDA) augmented by a self interaction correction term and a quantum collision term in Relaxation-Time Approximation (RTA). We evaluate the separate contributions to the total excitation energy, namely energy exported by electron emission, potential energy due to changing charge state, intrinsic kinetic and potential energy, and collective flow energy. The balance of these energies is studied as function of the laser parameters (frequency, intensity, pulse length) and as function of system size and charge. We also look at collisions with a highly charged ion and here at the dependence on the impact parameter (close versus distant collisions). Dissipation turns out to be small where direct electron emission prevails namely for laser frequencies above any ionization threshold and for slow electron extraction in distant collisions. Dissipation is large for fast collisions and at low laser frequencies, particularly at resonances. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.
Dissipation of fragrance materials in sludge-amended soils.
DiFrancesco, Angela M; Chiu, Pei C; Standley, Laurel J; Allen, Herbert E; Salvito, Daniel T
2004-01-01
A possible removal mechanism for fragrance materials (FMs) in wastewater is adsorption to sludge, and sludge application to land may be a route through which FMs are released to the soil environment. However, little is known about the concentrations and fate of FMs in soil receiving sludge application. This study was conducted to better understand the dissipation of FMs in sludge-amended soils. We first determined the spiking and extraction efficiencies for 22 FMs in soil and leachate samples. Nine FMs were detected in digested sludges from two wastewater treatment plants in Delaware using these methods. We conducted a 1-year die-away experiment which involved four different soils amended with sludge, with and without spiking of the 22 FMs. The initial dissipation of FMs in all spiked trays was rapid, and only seven FMs remained at concentrations above the quantification limits after 3 months: AHTN, HHCB, musk ketone, musk xylene, acetyl cedrene, OTNE, and DPMI. After 1 year, the only FMs remaining in all spiked trays were musk ketone and AHTN. DPMI was the only FM that leached significantly from the spiked trays, and no FMs were detected in leachate from any unspiked tray. While soil organic matter content affected the dissipation rate in general, different mechanisms (volatilization, transformation, leaching) appeared to be important for different FMs.
Anelastic tidal dissipation in multi-layer planets
Remus, F.; Mathis, S.; Zahn, J.-P.; Lainey, V.
2012-09-01
Earth-like planets have anelastic mantles, whereas giant planets may have anelastic cores. As for the fluid parts of a body, the tidal dissipation of such solid regions, gravitationally perturbed by a companion body, highly depends on its internal friction, and thus on its internal structure. Therefore, modelling this kind of interaction presents a high interest to provide constraints on planets interiors, whose properties are still quite uncertain. Here, we examine the equilibrium tide in the solid part of a planet, taking into account the presence of a fluid envelope. We derive the different Love numbers that describe its deformation and discuss the dependence of the quality factor Q on the chosen anelastic model and the size of the core. Taking plausible values for the anelastic parameters, and discussing the frequency-dependence of the solid dissipation, we show how this mechanism may compete with the dissipation in fluid layers, when applied to Jupiter- and Saturn-like planets. We also discuss the case of the icy giants Uranus and Neptune. Finally, we present the way to implement the results in the equations that describe the dynamical evolution of planetary systems.
Relativistic dissipative hydrodynamics and the nuclear equation of state
Olson, T.S.; Hiscock, W.A.
1989-01-01
The theory of dissipative, relativistic fluids due to Israel and Stewart is used to constrain the form of the nuclear equation of state. In the Israel-Stewart theory, there are conditions on the equation of state and other thermodynamic properties (the ''second-order'' coefficients) of a fluid which, if satisfied, guarantee that equilibria are stable and that fluid perturbations propagate causally and obey hyperbolic equations. The second-order coefficients in the Israel-Stewart theory, which are relaxation times for the dissipative degrees of freedom and coupling constants between different forms of dissipation, are derived for a free, degenerate Fermi gas. It is shown rigorously that the free, degenerate Fermi gas is stable (and hence causal) at all temperatures in this theory. These values for the second-order coefficients are then used in the stability conditions to constrain various proposed expressions for the nuclear ground-state energy. The stability conditions are found to provide significantly more stringent constraints on the proposed equations of state than the usual simple restriction that the adiabatic sound speed be less than the speed of light
Dissipation and nonlocality in a general expanding braneworld universe
Remazeilles, Mathieu
2009-01-01
We study the evolution of both scalar and tensor cosmological perturbations in a Randall-Sundrum braneworld having an arbitrary expansion history. We adopt a four dimensional point of view where the degrees of freedom on the brane constitute an open quantum system coupled to an environment composed of the bulk gravitons. Because of the expansion of the universe, the brane degrees of freedom and the bulk degrees of freedom interact as they propagate forward in time. Brane excitations may decay through the emission of bulk gravitons which may escape to future infinity, leading to a sort of dissipation from the four dimensional point of view of an observer on the brane. Bulk gravitons may also be reflected off of the curved bulk and reabsorbed by the brane, thereby transformed into quanta on the brane, leading to a sort of nonlocality from the four dimensional point of view. The dissipation and the nonlocality are encoded into the retarded bulk propagator. We estimate the dissipation rates of the bound state as well as of the matter degrees of freedom at different cosmological epochs and for different sources of matter on the brane. We use a near-brane limit of the bulk geometry for the study when purely nonlocal bulk effects are encountered.
Optimal coherent control of dissipative N-level systems
Jirari, H.; Poetz, W.
2005-01-01
General optimal coherent control of dissipative N-level systems in the Markovian time regime is formulated within Pointryagin's principle and the Lindblad equation. In the present paper, we study feasibility and limitations of steering of dissipative two-, three-, and four-level systems from a given initial pure or mixed state into a desired final state under the influence of an external electric field. The time evolution of the system is computed within the Lindblad equation and a conjugate gradient method is used to identify optimal control fields. The influence of both field-independent population and polarization decay on achieving the objective is investigated in systematic fashion. It is shown that, for realistic dephasing times, optimum control fields can be identified which drive the system into the target state with very high success rate and in economical fashion, even when starting from a poor initial guess. Furthermore, the optimal fields obtained give insight into the system dynamics. However, if decay rates of the system cannot be subjected to electromagnetic control, the dissipative system cannot be maintained in a specific pure or mixed state, in general
Blood drop patterns: Formation and applications.
Chen, Ruoyang; Zhang, Liyuan; Zang, Duyang; Shen, Wei
2016-05-01
The drying of a drop of blood or plasma on a solid substrate leads to the formation of interesting and complex patterns. Inter- and intra-cellular and macromolecular interactions in the drying plasma or blood drop are responsible for the final morphologies of the dried patterns. Changes in these cellular and macromolecular components in blood caused by diseases have been suspected to cause changes in the dried drop patterns of plasma and whole blood, which could be used as simple diagnostic tools to identify the health of humans and livestock. However, complex physicochemical driving forces involved in the pattern formation are not fully understood. This review focuses on the scientific development in microscopic observations and pattern interpretation of dried plasma and whole blood samples, as well as the diagnostic applications of pattern analysis. Dried drop patterns of plasma consist of intricate visible cracks in the outer region and fine structures in the central region, which are mainly influenced by the presence and concentration of inorganic salts and proteins during drying. The shrinkage of macromolecular gel and its adhesion to the substrate surface have been thought to be responsible for the formation of the cracks. Dried drop patterns of whole blood have three characteristic zones; their formation as functions of drying time has been reported in the literature. Some research works have applied engineering treatment to the evaporation process of whole blood samples. The sensitivities of the resultant patterns to the relative humidity of the environment, the wettability of the substrates, and the size of the drop have been reported. These research works shed light on the mechanisms of spreading, evaporation, gelation, and crack formation of the blood drops on solid substrates, as well as on the potential applications of dried drop patterns of plasma and whole blood in diagnosis. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.
Filipovic, N; Haber, S; Kojic, M; Tsuda, A
2008-01-01
Traditional DPD methods address dissipative and random forces exerted along the line connecting neighbouring particles. Espanol (1998 Phys. Rev. E 57 2930-48) suggested adding dissipative and random force components in a direction perpendicular to this line. This paper focuses on the advantages and disadvantages of such an addition as compared with the traditional DPD method. Our benchmark system comprises fluid initially at rest occupying the space between two concentric cylinders rotating with various angular velocities. The effect of the lateral force components on the time evolution of the simulated velocity profile was also compared with that of the known analytical solution. The results show that (i) the solution accuracy at steady state has improved and the error has been reduced by at least 30% (in one case by 75%), (ii) the DPD time to reach steady state has been halved, (iii) the CPU time has increased by only 30%, and (iv) no significant differences exist in density and temperature distributions
Spray Drying Processing: granules production and drying kinetics of droplets
Mondragon, R.; Julia, J. E.; Barba, A.; Jarque, J. C.
2013-01-01
Spray drying is a unit operation very common in many industrial processes. For each particular application, the resulting granulated material must possess determined properties that depend on the conditions in which the spray drying processing has been carried out, and whose dependence must be known in order to optimize the quality of the material obtained. The large number of variables that influence on the processes of matter and energy transfer and on the formation of granular material has required a detailed analysis of the drying process. Over the years there have been many studies on the spray drying processing of all kind of materials and the influence of process variables on the drying kinetics of the granulated material properties obtained. This article lists the most important works published for both the spray drying processing and the drying of individual droplets, as well as studies aimed at modeling the drying kinetics of drops. (Author)
Cassava Sun Drying Performance on Various Surfaces and Drying ...
Traditional processing methods that include ... The traditional sun drying method is very inefficient as the product can take 2-. 3 days to dry. .... using a digital balance (Ohaus Corporation type). The same applied .... preservation and marketing.
Xingtuan Yang
2015-01-01
Full Text Available This study investigates the anisotropic characteristics of turbulent energy dissipation rate in a rotating jet flow via direct numerical simulation. The turbulent energy dissipation tensor, including its eigenvalues in the swirling flows with different rotating velocities, is analyzed to investigate the anisotropic characteristics of turbulence and dissipation. In addition, the probability density function of the eigenvalues of turbulence dissipation tensor is presented. The isotropic subrange of PDF always exists in swirling flows relevant to small-scale vortex structure. Thus, with remarkable large-scale vortex breakdown, the isotropic subrange of PDF is reduced in strongly swirling flows, and anisotropic energy dissipation is proven to exist in the core region of the vortex breakdown. More specifically, strong anisotropic turbulence dissipation occurs concentratively in the vortex breakdown region, whereas nearly isotropic turbulence dissipation occurs dispersively in the peripheral region of the strong swirling flows.
Energy Dissipation-Based Method for Fatigue Life Prediction of Rock Salt
He, Mingming; Huang, Bingqian; Zhu, Caihui; Chen, Yunsheng; Li, Ning
2018-05-01
The fatigue test for rock salt is conducted under different stress amplitudes, loading frequencies, confining pressures and loading rates, from which the evaluation rule of the dissipated energy is revealed and analysed. The evolution of energy dissipation under fatigue loading is divided into three stages: the initial stage, the second stage and the acceleration stage. In the second stage, the energy dissipation per cycle remains stable and shows an exponential relation with the stress amplitude; the failure dissipated energy only depends on the mechanical behaviour of the rock salt and confining pressure, but it is immune to the loading conditions. The energy dissipation of fatigued rock salt is discussed, and a novel model for fatigue life prediction is proposed on the basis of energy dissipation. A simple model for evolution of the accumulative dissipated energy is established. Its prediction results are compared with the test results, and the proposed model is validated.
Stanković Mirjana S.
2003-01-01
Full Text Available The IGPC Engineering Department designed basic projects for dry alcohol production plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects a production plant with a capacity of 40 m3/y was manufactured, at "Zorka Pharma", Šabac in 1995-1996. The product meets all quality demands, as well as environmental regulations. The dry alcohol production process is fully automatized. There is no waste in the process, neither gaseous, nor liquid. The chosen process provides safe operation according to temperature regime and resistance in the pipes, air purification columns and filters. Working at increased pressure is suitable for evaporation and condensation at increased temperatures. The production process can be controlled manually, which is necessary during start-up, and repairs.
Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.
Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu
2016-05-01
The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.
Global Warming and 21st Century Drying
Cook, Benjamin I.; Smerdun, Jason E.; Seager, Richard; Coats, Sloan
2014-01-01
Global warming is expected to increase the frequency and intensity of droughts in the twenty-first century, but the relative contributions from changes in moisture supply (precipitation) versus evaporative demand (potential evapotranspiration; PET) have not been comprehensively assessed. Using output from a suite of general circulation model (GCM) simulations from phase 5 of the Coupled Model Intercomparison Project, projected twentyfirst century drying and wetting trends are investigated using two offline indices of surface moisture balance: the Palmer Drought Severity Index (PDSI) and the Standardized Precipitation Evapotranspiration Index (SPEI). PDSI and SPEI projections using precipitation and Penman- Monteith based PET changes from the GCMs generally agree, showing robust cross-model drying in western North America, Central America, the Mediterranean, southern Africa, and the Amazon and robust wetting occurring in the Northern Hemisphere high latitudes and east Africa (PDSI only). The SPEI is more sensitive to PET changes than the PDSI, especially in arid regions such as the Sahara and Middle East. Regional drying and wetting patterns largely mirror the spatially heterogeneous response of precipitation in the models, although drying in the PDSI and SPEI calculations extends beyond the regions of reduced precipitation. This expansion of drying areas is attributed to globally widespread increases in PET, caused by increases in surface net radiation and the vapor pressure deficit. Increased PET not only intensifies drying in areas where precipitation is already reduced, it also drives areas into drought that would otherwise experience little drying or even wetting from precipitation trends alone. This PET amplification effect is largest in the Northern Hemisphere mid-latitudes, and is especially pronounced in western North America, Europe, and southeast China. Compared to PDSI projections using precipitation changes only, the projections incorporating both