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The present study examines the effect of storage conditions on the characteristics of cryogenic hydrogen jets released into the atmosphere, relevant to an accidental leakage scenario during storage or transportation. The compressible Reynolds-Averaged Navier–Stokes equations, coupled with the Peng–Robinson equation of state for hydrogen-air mixtures, are solved for a range of operating conditions (storage pressures from 3 – 7 bar and storage temperatures of 50 – 70 K). Flow structures in the near-orifice and self-similar regions are analysed, showing that the presence of shock waves creates conditions favourable for possible condensation of hydrogen and air. In the self-similar region, decay laws based on the shock exit conditions are proposed, demonstrating a slower decay of centreline temperature in comparison to hydrogen concentration and velocity. Additionally, a universal relationship between the centreline mole fraction of hydrogen and temperature is observed, explained using an adiabatic mixing model. [Display omitted] • Numerical simulations of cryogenic hydrogen jet dispersion are performed. • Shock waves in the near-orifice region create conditions conducive to condensation of air. • Scaling of far-field flow quantities using shock exit conditions is more appropriate than using orifice exit conditions. • A universal relationship between the centreline mole fraction of hydrogen and temperature is found. • The found universal relationship can be explained by considering adiabatic mixing between hydrogen and air. [ABSTRACT FROM AUTHOR]

We give an overview of some recent results on operator-valued (L p , L q) Fourier multipliers and stability theory for evolution equations. The aim is to provide a relatively nontechnical introduction to the underlying ideas, emphasizing the connection between the two areas. We also indicate how operator-valued (L p , L q) Fourier multipliers can be applied to functional calculus theory. [ABSTRACT FROM AUTHOR]

Deadwood decomposition modulates habitat structure and enhances resource availability within forest ecosystems. Deadwood decomposition is influenced by a combination of abiotic and biotic factors, wherein climatic variables, tree species, and wood characteristics play fundamental roles. However, the scarcity of studies conducted in dry and semiarid regions restricts our understanding of deadwood decomposition dynamics. Here, we studied the decomposition of logs in four plots across an elevation gradient spanning approximately 1000 m (from 1477 to 2317 m a.s.l.). The site was a burnt reforestation of different pine species in a Mediterranean mountain (Sierra Nevada, SE Spain). Logs of a range of diameters were cut to a similar length (75 cm), and their density loss was monitored over 15 years. We fitted three different types of functions (linear, negative exponential and negative sigmoidal) to evaluate the temporal trajectory of decomposition across the elevation gradient. Average wood density loss through the 15-year period ranged from 30.4 % to 63.3 % depending on the elevation plot, and it was highest at an intermediate elevation. The negative sigmoidal equation showed the best fit, but all functions rendered similar half-life values, which ranged between 12.8 and 29.4 years depending on the elevation plot. Contrary to most studies, larger-diameter logs experienced a quicker decomposition process, which could be linked to increased moisture retention and greater activity of large invertebrates in the larger-diameter logs. The variations observed across the elevation gradient are consistent with expectations on how the interaction between precipitation and temperature influences decomposition rates. The observed decomposition patterns in these mountain forests indicate a relatively rapid process, and underline the vital contribution of deadwood biological legacies to the preservation of soil fertility in the Mediterranean region. • We studied wood decomposition for 15 y in a Mediterranean mountain at 1477 – 2317 m elevation. • Trunks lost 30.4 % – 63.3 % of density, peaking at intermediate elevation. • A negative sigmoidal curve explained the process better than a linear or negative exponential. • Modelled half-life of wood ranged from 12.8 to 29.4 y across elevations. • Thicker logs decomposed faster, challenging findings from other regions. [ABSTRACT FROM AUTHOR]

The boundary stabilization problem of the Boussinesq KdV–KdV type system is investigated in this paper. An appropriate boundary feedback law consisting of a linear combination of a damping mechanism and a delay term is designed. Then, considering time-varying delay feedback together with a smallness restriction on the length of the spatial domain and the initial data, we show that the problem under consideration is well-posed. The proof combines Kato's approach and the fixed-point argument. Last but not least, we prove that the energy of the linearized KdV–KdV system decays exponentially by employing the Lyapunov method. [ABSTRACT FROM AUTHOR]

This brief considers the generalized exponential stability of impulsive stochastic functional differential equations (ISFDEs). Initially, An extension of Halanay inequality is derived. Subsequently, by employing this generalized Halanay inequality, we establish the generalized exponential stability result for the given systems. [ABSTRACT FROM AUTHOR]

The asymptotic stability and long time decay rates of solutions to linear Caputo time-fractional ordinary differential equations are known to be completely determined by the eigenvalues of the coefficient matrices. Very different from the exponential decay of solutions to classical ordinary differential equations, solutions of time-fractional ordinary differential equations decay only polynomially, leading to the so-called Mittag-Leffler stability, which were already extended to linear fractional delay differential equations (FDDEs) with real constants by Čermák et al. (2017) [17]. This paper is devoted to the asymptotical stability and long time decay rates of the solutions for a class of fractional delay abstract evolution equations with complex-valued coefficients. By applying the spectral decomposition method, we reformulate the fractional delay abstract evolution equations to an infinite-dimensional FDDEs. Through the root locus technique, we develop a necessary and sufficient stability condition in a coefficient criterion for FDDEs. At the same time, we are able to deal with the awful singularities caused by delay and fractional exponent by introducing a novel integral path, and hence to give an accurate estimation for the fractional resolvent operators. We show that the long time decay rates of the solutions for both linear FDDEs and fractional delay abstract evolution equations with complex-valued coefficients are O (t − α). Finally, several application models including both time and time-space fractional Schrödinger equations are presented to illustrate the effectiveness of our proposed criteria. • A stability criterion is established for complex-valued fractional delay abstract evolution equations. • A novel integral path is introduced to give an accurate estimation for the fractional resolvent operators. • The long-time decay rate is proved to be polynomial. • Our results provide stability criteria for various models such as time and time-space fractional Schrodinger equations. [ABSTRACT FROM AUTHOR]

Comparison of Computational Fluid Dynamics (CFD) predictions with measurements is presented for cryo-compressed hydrogen vertical jets. The stagnation conditions of the experiments are characteristic of unintended leaks from pipe systems that connect cryogenic hydrogen storage tanks and could be encountered at a fuel cell refueling station. Jets with pressure up to 5 bar and temperatures just above the saturation liquid temperature were examined. Comparisons are made to the centerline mass fraction and temperature decay rates, the radial profiles of mass fraction and the contours of volume fraction. Two notional nozzle approaches are tested to model the under-expanded jet that was formed in the tests with pressures above 2 bar. In both approaches the mass and momentum balance from the throat to the notional nozzle are solved, while the temperature at the notional nozzle was assumed equal to the nozzle temperature in the first approach and was calculated by an energy balance in the second approach. The two approaches gave identical results. Satisfactory agreement with the measurements was found in terms of centerline mass fraction and temperature. However, for test with 3 and 4 bar release the concentration was overpredicted. Furthermore, a wider radial spread was observed in the predictions possibly revealing higher degree of diffusion using the k-ε turbulence model. An integral model for cryogenic jets was also developed and provided good results. Finally, a test simulation was performed with an ambient temperature jet and compared to the cold jet showing that warm jets decay faster than cold jets. [Display omitted] • Cryo-compressed hydrogen jets are simulated. • Good agreement with experiments is found, though more lateral spreading is predicted. • Integral model for cryogenic jets is developed providing satisfactory results. • Ambient temperature jets decay faster than cold jets. [ABSTRACT FROM AUTHOR]

We consider the stability of a system of two wave equations with only one boundary feedback and we show that the stability of the partially damped system depends on the transmission of energy between the two equations. The study confirms that the hidden regularity is an essential ingredient for the stability property. In particular, using a sharp regularity for Neumann problem of wave equation, we improve the usual results on the energy decay rate. This new approach can certainly be applied to other situations of partially damped systems. [ABSTRACT FROM AUTHOR]

• Decay rates of Salmonella , norovirus, and IAV were investigated in a lab-scale recirculating sewer system. • Predictive models based on wastewater data were established for these three pathogens. • By wastewater sequencing, we predicted the infection cases of different SARS-CoV-2 variants using a previous model. Wastewater-based epidemiology (WBE) is a promising tool for monitoring the spread of SARS-CoV-2 and other pathogens, providing a novel public health strategy to combat disease. In this study, we first analysed nationwide reports of infectious diseases and selected Salmonella , norovirus, and influenza A virus (IAV) as prioritized targets apart from SARS-CoV-2 for wastewater surveillance. Next, the decay rates of Salmonella , norovirus, and IAV in wastewater at various temperatures were established to obtain corrected pathogen concentrations in sewage. We then monitored the concentrations of these pathogens in wastewater treatment plant (WWTP) influents in three cities, establishing a prediction model to estimate the number of infected individuals based on the mass balance between total viral load in sewage and individual viral shedding. From October 2022 to March 2023, we conducted multipathogen wastewater surveillance (MPWS) in a WWTP serving one million people in Xi'an City, monitoring the concentration dynamics of SARS-CoV-2, Salmonella , norovirus, and IAV in sewage. The infection peaks of each pathogen were different, with Salmonella cases and sewage concentration declining from October to December 2022 and only occasionally detected thereafter. The SARS-CoV-2 concentration rapidly increased from December 5th, peaked on December 26th, and then quickly decreased until the end of the study. Norovirus and IAV were detected in wastewater from January to March 2023, peaking in February and March, respectively. We used the prediction models to estimate the rate of SARS-CoV-2 infection in Xi'an city, with nearly 90 % of the population infected in urban regions. There was no significant difference between the predicted and actual number of hospital admissions for IAV. We also accurately predicted the number of norovirus cases relative to the reported cases. Our findings highlight the importance of wastewater surveillance in addressing public health priorities, underscoring the need for a novel workflow that links the prediction results of populations with public health interventions and allocation of medical resources at the community level. This approach would prevent medical resource panic squeezes, reduce the severity and mortality of patients, and enhance overall public health outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigate the plasmon frequency and decay rate in a double bilayer graphene (DBLG) heterostructure made of two bilayer graphene (BLG) flakes separated by a spacer of thickness d. Calculations are carried out at zero temperature, within the random phase approximation, taking into account the inhomogeneity of the dielectric background of the system. Analytical expressions for plasmon frequencies are obtained by using the long wavelength expansions of the response and bare Coulomb interaction functions. We find that at long-wavelength limit, the acoustic (optical) plasmon mode shows the linear (square-root) energy dispersion and the inhomogeneity of dielectric background decreases the frequencies of both plasmon branches as in the case of DLG. The carrier density, spacer thickness and background dielectric constant affect remarkably on plasmon frequency and decay rate. • Dielectric inhomogeneity decreases energy of both branches. • Spacer and imbalance in densities affect notably plasmon modes. • γ of OP branch in DBLG is much larger than that in DLG. • γ of OP (AC) plasmon mode depends strongly (weakly) on κ 2 . [ABSTRACT FROM AUTHOR]

Highlights • Decay rates of above-ground CWD are given for nine New Zealand tree species. • Decay rates were also determined for below-ground CWD for two species. • The half-life of above-ground CWD averaged 25.7 years across species. • The decay rate varied between species and was influenced by diameter. • Below-ground CWD decay rates were similar or faster above-ground CWD decay rates. Abstract Decomposition rates of above-ground coarse woody debris (CWD) (>10 cm diameter) were determined for nine common New Zealand indigenous tree species, and of below-ground CWD for two species. CWD samples were obtained from fallen trees originating from known windfall events which had been decaying for 10–29 years on the forest floor. Species-specific decay rates were estimated from the density (dry mass divided by original volume) of CWD samples relative to the density of samples from live and freshly fallen trees. The estimated half-life (t 1/2) or time to lose 50% mass for above-ground CWD across all species was 25.7 years but varied between species and increased with increasing stem diameter. Adjusted to a common diameter at breast height of 60 cm and mean annual temperature of 10 °C, Prumnopitys taxifolia and Fuscospora cliffortioides were the slowest to decay with a t 1/2 of about 40 years, Fuscospora fusca , Weinmannia racemosa , Beilschmiedia tawa , Lophozonia menziesii and Prumnopitys ferruginea the next slowest with a t 1/2 of 27–34 years, while the remaining species (Dacrydium cupressinum and Dacrycarpus dacrydioides) decaying more rapidly with a t 1/2 of less than 20 years. A model was derived for predicting the exponential decay constant for the above-ground CWD of individual stems as a function of diameter at breast height and mean annual temperature adjusted for species. This model can be used to predict above-ground CWD carbon stock changes in New Zealand's natural forests following tree mortality. Below-ground CWD decay rates did not differ significantly from those of above-ground CWD for D. cupressinum , but were significantly faster for L. menziesii. [ABSTRACT FROM AUTHOR]

• Propose a new digital I-weighting algorithm for a sound level meter. • Prove that the decay rates of the existing F weighting and the S weighting do not meet the requirements of the I weighting. • Develop a new sound level meter with this digital I-weighting algorithm and test its performances. This paper presents a new digital impulse-weighting (I-weighting) method for sound level meter by using a peak detector with attenuator. Firstly, the decay rate of time-weighting algorithm is analyzed, and it is proved that the decay rates of the existing time-weighting models (i.e., the fast-time-weighting model and the slow-time-weighting model) cannot meet the requirements of the I-weighting algorithm of the sound level meter defined by the international standard IEC61672. A new digital I-weighting model is constructed by designing a peak detector with attenuator and amending the existing time-weighting model. Finally, the detailed digital I-weighting algorithm is given. The experimental results of this proposed I-weighting model show that the model's detection behaviors and decay rates all meet the requirements of class 1 sound level meters defined by IEC61672. [ABSTRACT FROM AUTHOR]

Abstract Indoor particles are affected by both indoor particle sources and outdoor particles penetrating into the indoor environment. Some human behaviors such as opening windows, cooking, and smoking influence indoor air quality strongly. Indoor particle sources increase the indoor particle concentrations by generating considerable amounts of particulate matters. Opening windows can increase the exchange efficiency of indoor and outdoor particles. In this study, the effects of indoor particle source emission and opening a window on indoor particle concentrations were estimated for the severe cold region of China using tests in a room-size chamber. Indoor and outdoor fine particulate matter (PM 2.5) mass concentrations and particle number concentrations from 0.3 to 10 μm were measured simultaneously in different test conditions. An indoor source was simulated using an aerosol generator to discharge dust, which was intercepted by indoor air conditioners. Indoor particle concentrations increased rapidly when the indoor source was active, and longer emission time led to greater growth. After ending indoor particle emission, indoor particle concentrations decreased due to infiltration and deposition, and opening the window can promote that decrease. Decay rates were greater for 2.5–10 μm particles because loss by gravitational settling is dominant for larger particles. When the window was opened, particle decay rates became extremely high; up to 19.09 h−1 for 2.5–10 μm particles and up to 9.73 h−1 for PM 2.5. Graphical abstract Image 1 Highlights • Particle generation rates for the source in this study were greater for smaller size particles. • I/O ratio increased more for particles in larger size intervals during the particle source emission. • Indoor particle removal efficiency by opening the window was affected by outdoor environment. • Decay rates increased largely after the window is opened and even up to 9.73 for PM 2.5. [ABSTRACT FROM AUTHOR]

• Faecal indicators should be based on the hydrodynamic properties of water systems. • FIB are appropriate in advection dominant waterbodies. • crAssphage and PMMoV are appropriate in dispersion/advection dominant waterbodies. The EU Bathing Water Directive (BWD) requires member states to assess bathing water quality according to the levels of faecal indicator bacteria (FIB) in designated bathing areas. However, this criterion has two significant limitations given that the BWD does not; (i) account for differences in hydrodynamic properties of bathing waters and, (ii) assumes that all faecal pathogens decay equally in aquatic environments. This study simulated sewage discharge events in three hypothetical aquatic environments characterised by different advection and dispersion parameters in the solute transport equation. Temporal changes in the downstream concentration of six faecal indicators were determined in simulations that utilised measured decay rates of each faecal indicator from a programme of controlled microcosm experiments in fresh and seawater environments. The results showed that the decay rates of faecal indicators are not a critical parameter in advection dominant water bodies, such as in fast-flowing rivers. Therefore, faecal indicator selection is less important in such systems and for these, FIB remains the most cost-effective faecal indicator to monitor the public health impacts of faecal contamination. In contrast, consideration of faecal indicator decay is important when assessing dispersion and advection/dispersion dominant systems, which would pertain to transitional (estuarine) and coastal waterbodies. Results suggest that the inclusion of viral indicators, such as crAssphage and PMMoV, could improve the reliability of water quality modelling and minimise the risk of waterborne illnesses from faecal contamination. [Display omitted] [ABSTRACT FROM AUTHOR]

Intertidal creeks form the primary hydrologic link between estuaries and land-based activities on barrier islands. Fecal indicators Enterococcus spp. ( Entero1 ), pathogens Shigella spp. ( ipaH ), Salmonella spp. ( invA ), E. coli of EHEC/EPEC groups ( eaeA ), E. coli of EAEC, EIEC, and UPEC groups ( set1B ), E. coli of STEC group ( stx1 ); and tetracycline resistance genes ( tet (B), tet (C), tet (D), tet (E), tet (K), tet (Q), tet (W), and tet (X); TRG) were detected in the headwater of Oakdale Creek (Sapelo Island, GA) receiving runoffs from Hog Hammock village. Excavation of drainage ditches around the village caused a high increase in the incidence of the above determinants. Water samples were collected from the headwater, transferred to diffusion chambers, submersed in the headwater, saltmarsh, and mouth of the creek; and the determinants were monitored for 3 winter months. With some exceptions, their persistence decreased in order headwater > saltmarsh > mouth. Genes associated with Enterococcus spp. were the most persistent at all the sites, following in the headwater with determinants for Salmonella spp. and E. coli of EAEC, EIEC, and UPEC groups. In the mouth, the most persistent gene was eae A indicating EHEC, EPEC, and STEC. Tet (B) and tet (C) persisted the longest in headwater and saltmarsh. No TRG persisted after 11 days in the mouth. Most determinants revealed correlations with temperature and pH, and inverse correlations with dissolved oxygen. Decay rates of the above determinants varied in the range of −0.02 to −0.81/day, and were up to 40 folds higher in the saltmarsh and mouth than in the headwater. Our data demonstrated that water parameters could to some extent predict a general trend in the fate of virulence and antibiotic resistance determinants in tidal creek tributaries but strongly suggested that their persistence in these tributaries cannot be predicted from that of enterococci, or extrapolated from one biological contaminant to another. [ABSTRACT FROM AUTHOR]

Autotrophic growth and decay rates of ammonium and nitrite oxidizing bacteria (AOB and NOB, respectively) have a significant impact on the design and on the process performance of wastewater treatment systems where nitrification occurs. Literature data on the separate decay rates of AOB and NOB is scarce and inconsistent. In this study, batch experiments based on respirometric techniques were conducted to determine the NOB decay rates under different oxidation-reduction potential conditions, in order to widen the understanding of nitrite dynamics. The decay rate measured under anoxic conditions was 85% lower than under aerobic conditions, whereas under anaerobic conditions the decay rate reduction was 92%. A design and simulation tool was used to assess the impact of applying these results in differentiated areas of an activated sludge system. Simulations show a greater impact for systems with a sludge retention time under 10 days, for which up to a 16-fold increase in NOB biomass concentration and up to 86% and 80% reductions in ammonium and nitrite concentrations in the effluent were calculated. Therefore, this work demonstrates that considering different decay rates for autotrophic biomass under different ORP conditions avoids underestimating system performance and over dimensioning new activated sludge schemes. [ABSTRACT FROM AUTHOR]

Our main focus in the present paper is to study the global existence and asymptotic behavior of a nonlinear version of the Bresse system. As it has been already proved in Soufyane and Said-Houari (2014), the linear version of this system is of regularity-loss type. This regularity loss creates difficulties when dealing with the nonlinear problem since the dissipative property of the problem becomes very weak in the high frequency region and as a result the classical energy method fails. To overcome this difficulty, following Ide and Kawashima (2008) and Ikehata (2002), we use an energy method with negative weights to create an artificial damping which allows us to control the nonlinearity. [ABSTRACT FROM AUTHOR]

Tree bark represents a substantial component of coarse woody debris (CWD) in boreal forests. Estimating its decay rates improves our understanding of decomposition processes of woody debris and their effects on the forest carbon cycle. The atmospheric deposition of nitrogen (N) and phosphorus (P) from aerosols and gases has notably grown during the last century. We examined the effect of mineral N and P additions and temperature on the decay rate of aspen ( Populus tremula ) bark in a long-term incubation experiment at constant and sufficient moisture level. Fresh aspen bark with natural moisture was mixed with local soil ( Haplic Phaeozems ) in proportion of 2:1 by dry mass to prepare the soil-bark substrates (SBSs). Mineral elements (N and P) were added to the SBSs with a proportion of 1% of dry bark weight (for each element). The following treatments of SBS's were studied: (1) Bark + Soil, pure SBS ( control ); (2) Bark + Soil + N; (3) Bark + Soil + N + P and (4) pure soil, S . The SBSs were incubated in thermostats at 2, 12 and 22 °С for 12 months. The decay rate of SBSs (DecR, mg С kg − 1 h − 1 ) was measured by an infrared gas analyzer at least 1–2 times per week. Total carbon losses (TotL-C, g С kg − 1 of bark) were estimated using the accumulative curves of DecR throughout the experiment for each treatment. The decay constants (k) were calculated based on the single exponential model. The temperature sensitivity of the DecR was estimated using the temperature coefficient Q 10 . Mineral N and P additions decreased the C:N and increased the Lignin : Cellulose ratios during the long-term incubation of aspen bark and caused a considerable increase in the DecR, k values, TotL-C values, and consequently a decrease of the turnover time. The maximal values of TotL-C were attributed to the SBS-NP treatment at 22 °С and comprised 72% of the initial C content in bark. The turnover time of soil-bark substrates varied from 2 to 7.3 years depending on the treatment and temperature. The increase of the incubation temperature from 2 to 12 °C and from 12 to 22 °C caused a similar effect on the DecR over 12 months of the experiment, and the Q 10 in different treatments varied negligibly: from 1.21 to 1.37. The temperature effect was most significant only during the first 1–2 months of experiment, explaining ca. 83% of the mean DecR variance whereas the ‘Treatment’ factor was attributed for 76–83% of the mean DecR variance in later stages (3–12 months) of decay of aspen bark. A close relationship between the Lig:Cel ratio and DecR was observed during 1–2 months of incubation. We conclude that the effect of mineral additions on the decay rate of aspen bark is more important than the effect of temperature. The coupled effect of N and P additions was more pronounced than the effect of N addition alone. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of the physical–chemical characteristics of wastewater on PAA decay, in multi-component solutions of inorganic and organic compounds (11 compounds in total) representative of secondary effluents of wastewater treatment plants, disinfected at various PAA concentrations (2–5 mg/L). Batch experiments were defined using the statistical method of the Design of Experiments (DoE) in order to evaluate the effect of each compound and their interaction on PAA decay. Results showed that the organics consumed immediately a considerable amount of PAA, independently from the initial PAA concentration, and consumption dropped rapidly to almost nil after 5 min, whereas PAA consumption due to the inorganics was slow, dependent on the initial PAA concentration and persisted until the end of the experiments (60 min). In detail, inorganics (such as reduced iron and orthophosphate) have shown to be the main drivers of the exponential decay: iron, particularly, has proved to directly consume PAA due to its catalysing capacity, whereas orthophosphate has shown to mainly interact with iron, acting as a chelating compound towards iron and consequently reducing the iron effect in consuming PAA. As for organics, proteins such as, casein and peptone, have been highlighted as the main cause of the initial PAA demand, probably due to the homolytic fission of PAA to generate peroxyl and hydroxyl radicals, which are known to have a high reactivity towards proteins. Finally, a model for predicting the residual PAA concentration was obtained and validated; uncertainty analysis was also performed by a series of Monte Carlo simulations to propagate input uncertainties to the model output. [ABSTRACT FROM AUTHOR]

Electrospray ionization mass spectrometry with variable collision-induced dissociation (CID) was used to conduct a comprehensive study of cation-anion interaction strength in dicationic ionic liquids (ILs). This investigation reports the influence of anion structure (Cl − , Br − , NO 3 − , BF 4 − , and SCN − ) and spacer chain length (n = 4, 6, 8, and 10) on the interaction strength of dicationic ILs derived from 1, n -bis(3-methylimidazolim-1-yl)alkane. The anion-cation interaction strength was determined from the binary mixture of ILs and from the center-of-mass energy (E cm ). Moreover, two novel models were proposed, based on the extended first order and zero order equations, which allow determining the order of stability from the constant dissociation (K d ) and decay rate (k 0 ), respectively. Additionally, quantum chemical calculations of cation-anion energy were done in order to support experimental results. The order of energy of the anion-cation interaction determined by both E cm,1/2 and K d followed the same trend, while the order of the cation-anion interaction strength observed in the binary mixtures was in accordance with quantum chemical calculations. The model based on zero order process did not show good agreement with either the E cm,1/2 or K d , thus indicating that it is a very simplified model that does not result in an appropriate order for the cation-anion energy interaction. Orders were not comparable; however, it was the first time that binary mixture experiments and E cm were used with the same set of ILs. [ABSTRACT FROM AUTHOR]

Headwater streams are fully linked to surrounding riparian vegetation through coarse and fine organic matter inputs. However, forestry operations in or close to riparian corridors, particularly in mountainous forested microcatchments, can alter both the organic matter dynamics and the composition, structure and function of stream macroinvertebrate assemblages. Although it is an issue of great concern elsewhere, in Andean headwater streams scarce information exist about this respect. By using a paired-catchment approach (thinned vs . unthinned) in two sets of selected evergreen and deciduous small streams in southern Chile (39°S), we evaluated the effects of forest harvest on seasonal and annual litterfall dynamics and the structural and functional attributes of macroinvertebrates between January 2008 and January 2009. Metrics used to assess changes included riparian litterfall input, invertebrate colonization and leaf decomposition of dominant plant species (evergreen: Laureliopsis philippiana , Myrceugenia planipes ; deciduous: Nothofagus alpina ), taxa richness, functional feeding group (FFG) composition, and their densities and biomasses for each stream. In both experimental trials, microcatchments registered significant differences in the seasonal litterfall input. The total organic matter input was as follows: Unthinned evergreen (UE) = 3699, thinned evergreen (TE) = 3249, unthinned deciduous (UD) = 3151, and thinned deciduous (TD) = 2981 kg ha −1 y −1 . Leaf dry mass losses were significantly higher during summer and spring for L. philippiana and during summer and autumn for N. alpina . These results were concomitant to decomposition rates and macroinvertebrate abundance during colonization of the leaf bags. Macroinvertebrate density and biomass were also contrasted; shredders were the dominant FFG and showed significant seasonal differences between microcatchments in both in-stream and leaf bag studies. There were generally no major changes in FFG composition or taxa richness, but differences were detected comparatively in the abundance or density of collectors and shredders. Our results suggest that forestry activities carried out on riparian vegetation of Andean headwater streams can affect the structural and functional role of plants and benthic invertebrates and nutrient fluxes downstream. [ABSTRACT FROM AUTHOR]

Tree litter decomposition on disturbed post-mining sites has been mainly studied within successional gradients, whereas almost no results were shown from afforested spoil heaps. Litterfall and its decomposition rate are considered the most important ecological processes for soil restoration during stand development on such initial forest habitats. These processes allow development of a functional ecosystem and productive forest stands. Moreover, the pedogenesis process on such “soilless”’ habitats can be significantly improved and accelerated by tree species selection during afforestation. The main aim of the study was to determine litter decomposition rates of nine tree species used for afforestation of a lignite mine spoil heap. We assumed that leaf litter decomposition rates would differ among tree species studied and that the site conditions would significantly influence this process. Our study was conducted on the spoil heap of the lignite open cast mine in Bełchatów, central Poland. We studied leaf litter decomposition of Alnus glutinosa , Betula pendula , Pinus sylvestris , Quercus robur , Q. rubra and Robinia pseudoacacia in pure stands of these species (home stands), and litter decomposition of Acer pseudoplatanus , A. glutinosa , Fagus sylvatica , Prunus serotina , Q. rubra , and R. pseudoacacia in Scots pine stands. We used the litterbag method. The experiments lasted for three years and the samples were collected every three months. Leaf litter decomposition calculated for home stands after three years of decomposition was 94.4% of the initial leaf mass for A. glutinosa , 70.9% for R. pseudoacacia , 70.1% for P. sylvestris , 68.3% for B. pendula , 66.9% for Q. rubra and 61.5% for Q. robur . In Scots pine stands, after three years of the experiment, 92.3% of the initial leaf mass decomposed for P. serotina , 85.7% for A. glutinosa , 83.5% for A. pseudoplatanus , 65.2% for R. pseudoacacia , 50.9% for Q. rubra and 40.1% for F. sylvatica . A. glutinosa , R. pseudoacacia and Q. rubra leaves decomposed significantly faster in home stands than in Scots pine stands. Site aspect significantly influenced litter decomposition of the species studied, with higher rates mostly on the western slope. Our study revealed that the decision on tree species used for afforestation might shorten the period needed for soil restoration and achievement of sustainability of novel ecosystems. Proper selection of main and admixture tree species for afforestation of the post-mining sites might reduce the renewal period of the soilless and newly created habitats, which may provide noticeable ecological and economical effects during stand management. [ABSTRACT FROM AUTHOR]

We are concerned with the problem of boundary stabilization for wave equations with damping only on the nonlinear Wentzell boundary, and the damping is also nonlinear. We obtain boundary stabilization results (explicit energy decay rates), as well as the wellposedness, for the systems. Our method consists in establishing a new type of non-uniform integral inequality of energy, and exploiting it to derive the decay rates. The results are set up in all space dimensions. Even for the one dimensional linear system, the result is new, and we also indicate that the obtained decay rate is optimal in this case, that is, the obtained decay rate for linear strings is optimal. [ABSTRACT FROM AUTHOR]

Resuspended particles from flooring due to indoor human activities are believed to be one of the most important sources of particle matter (PM) compared to other indoor sources. In this work, particles resuspension due to human foot motion was studied in 50×25×25 cm environmentally controlled experimental chamber. Only the stepping down motion of the foot during the gait cycle is considered and modelled using an 8×22 cm rectangular plate which performs a rotation toward the floor. Temporal tracking of resuspended particles from representative samples of flooring materials is carried out with an Optical Particle Counters (Grimm 1.108). Resuspension source strengths estimated using the mass balance equation ranged from 0.05±0.005 s -1 to 0.5±0.05 s -1 and from 0.07±0.005 s -1 to 0.6±0.05 s -1 for smooth and rough linoleum, respectively. Results showed that resuspension source strengths increased with particle size. For all particle sizes, rough linoleum exhibited higher resuspension source strengths. [ABSTRACT FROM AUTHOR]

Decomposition transfers carbon (C) from detrital organic matter to soil and atmospheric pools. In forested ecosystems, deadwood accounts for a large proportion of the detrital C pool and is primarily decomposed by wood-inhabiting fungi (WIF). Deadwood reductions linked to forest harvesting may alter WIF richness and composition, thus indirectly influencing the persistence of deadwood and its contribution to C and nutrient cycling. Forest structure was enhanced via canopy gap creation and coarse woody debris (CWD) addition that mimic natural disturbance by windfall within a deciduous northern hardwood forest (Wisconsin, USA) to examine its effect on deadwood-associated biodiversity and function. Experimental sugar maple (Acer saccharum) logs were sampled, for DNA extraction, ten years after placement to determine the assembly of fungal community composition and its relationship to wood decay rates. Our findings suggest that the WIF community responded to gap disturbance by favoring species able to persist under more extreme microclimates caused by gaps. CWD addition under closed canopy tended to favor a different species assemblage from gap creation treatments and the control, where canopy was undisturbed and CWD was not added. This was presumably due to consistent microclimatic conditions and the abundance of CWD substrates for host specialists. Fungal OTU richness was significantly and inversely related to CWD decay rates, likely due to competition for resources. In contrast, fungal OTU composition was not significantly related to CWD decay rates, canopy openness or CWD addition amounts. Our study site represents a diverse fungal community in which complex interactions among wood-inhabiting organisms and abiotic factors are likely to slow CWD decomposition, which suggests that maintaining a biodiverse and microsite-rich ecosystem may enhance the capacity for C storage within temperate forests. [ABSTRACT FROM AUTHOR]

The initial value problem and global properties of solutions are studied for the vector equation: ( ‖ u ′ ‖ l u ′ ) ′ + ‖ A 1 2 u ‖ β A u + g ( u ′ ) = 0 in a finite dimensional Hilbert space under suitable assumptions on g . [ABSTRACT FROM AUTHOR]

In this study, the aging of culturable FIB and DNA representing genetic markers for Enterococcus spp. (ENT1A), general Bacteroides (GB3), and human-associated Bacteroides (HF183) in freshwater sediments was evaluated. Freshwater sediment was collected from four different sites within the upper and lower reach of the Topanga Creek Watershed and two additional comparator sites within the Santa Monica Bay, for a total of six sites. Untreated (ambient) and oven-dried (reduced microbiota) sediment was inoculated with 5% sewage and artificial freshwater. Microcosms were held for a 21-day period and sampled on day 0, 1, 3, 5, 7, 12, and 21. There were substantial differences in decay among the sediments tested, and decay rates were related to sediment characteristics. In the ambient sediments, smaller particle size and higher levels of organic matter and nutrients (nitrogen and phosphorus) were associated with increased persistence of the GB3 marker and culturable Escherichia coli (cEC) and enterococci (cENT). The HF183 marker exhibited decay rates of −0.50 to −0.96 day −1 , which was 2–5 times faster in certain ambient sediments than decay of culturable FIB and the ENT1A and GB3 markers. The ENT1A and GB3 markers decayed at rates of between −0.07 and −0.28 and −0.10 to −0.44 day −1 , and cEC and cENT decayed at rates of between −0.22 and −0.81 and −0.03 and −0.40 day −1 , respectively. In the oven-dried sediments, increased persistence of all indicators and potential for limited growth of culturable FIB and the GB3 and ENT1A markers was observed. A simplified two-box model using the HF183 marker and cENT decay rates generated from the microcosm experiments was applied to two reaches within the Topanga Canyon watershed in order to provide context for the variability in decay rates observed. The model predicted lower ambient concentrations of enterococci in sediment in the upper (90 MPN g −1 ) versus lower Topanga watershed (530 MPN g −1 ) and low ambient levels of the HF183 marker (below the LLOQ) in sediments in both lower and upper watersheds. It is important to consider the variability in the persistence of genetic markers and FIB when evaluating indicators of fecal contamination in sediments, even within one watershed. [ABSTRACT FROM AUTHOR]

Blowup solutions for the multidimensional isotropic inhomogeneous Landau-Lifshitz (ILL) equation on a hyperbolic n -space H 2 are obtained. If the inhomogeneous terms are carefully selected, the ILL will guarantee three types of singularity solutions. Type I and type II blowup solutions of any dimensional ILL on H 2 can develop a finite time singularity from smooth initial data with finite L 2 energy. We prove the decay rate of energy density of the type III implicit blowup solution. If ε and C are non-zero constants, this solution develops a singularity in finite time with a local ( r ∈ [ ε , C ] ) finite initial energy. [ABSTRACT FROM AUTHOR]

A finite element (FE) model and a boundary element (BE) model have been developed to predict the decay rate, vibration and noise responses of an embedded rail track. These models are validated using measured results. The optimisation of the embedded rail track is conducted using these calculated models. The results indicate that the optimised cross-section of the gutter for the embedding rail can significantly reduce the radiated noise of the embedded rail track. The embedded rail track using the I-shaped cross-section gutter reduces the radiated noise of the track by at least by 3 dB(A). Furthermore, combining the material parameter optimisation with the gutter cross-section optimisation can further reduce the radiated noise of the embedded rail track. Increasing the Young’s modulus of the rail pad in the embedded rail track with the I-shaped cross-section gutter can result in a radiated noise reduction of 4 dB(A). [ABSTRACT FROM AUTHOR]

Although decaying wood plays an important role in global carbon (C) cycling, how changes in microbial community are related to wood C quality and then affect wood organic C loss during wood decomposition remains unclear. In this study, a chronosequence method was used to examine the relationships between wood C loss rates and microbial community compositions during Chinese fir ( Cunninghamia lanceolata ) stump decomposition. Our results showed that microbial community shifted from fungi-dominated at early stages (0–15 years) to relatively more bacteria-dominated at later stages (15–35 years) of wood decomposition. Fungal phospholipid fatty acid (PLFA) content primarily explained wood C loss rates at early stages of wood decomposition. Fungal biomass was positively correlated with proportions of relatively high-quality C (e.g., O-alkyl C), but bacterial biomass was positively correlated with low-quality C. In addition, fungi appeared to be the dominated community under low wood moisture (<20%) at early stages, but fungal biomass tended to decrease and bacterial biomass increased with increasing wood moisture at later stages. Our findings suggest that the fungal community is the dominant decomposer of wood at early stages and may be positively influenced by relatively high-quality wood C and low wood moisture. Bacterial community may benefited from low-quality wood C and high wood moisture at later stages. Enhanced understanding of microbial responses to wood quality and environment is important to improve predictions in wood decomposition models. [ABSTRACT FROM AUTHOR]

This paper focuses on the stability and dissipativity of stochastic functional differential equations. Firstly, we proposed some generalized Halanay inequalities which improve and extend some existing works. Secondly, based on the generalized Halanay inequalities, the stability and dissipativity criteria of stochastic functional differential equations are derived. Finally, some numerical examples are given to illustrate the effectiveness of the main results. [ABSTRACT FROM AUTHOR]

To safeguard human health, legislative measures require the monitoring of faecal indicator bacteria (FIB) concentrations in recreational and shellfish waters. Consequently, numerous studies have focussed on FIB survival in the water column and more recently in estuarine sediments. However, there is a paucity of information regarding the influence of contrasting suspended particulate matter (SPM) concentrations on the survival of FIB in the water column of estuaries. Here, microcosms containing freshwater or brackish water with low, high and extreme SPM concentrations were inoculated with sewage and ovine faeces and the decay rate of Escherichia coli , coliforms and enterococci were determined by enumeration over five consecutive days. E. coli derived from ovine faeces proliferated and persisted at high levels in both freshwater and brackish microcosms (no decay), whereas ovine enterococci demonstrated a net decay over the duration of the experiment. Furthermore, SPM concentration had a significant effect on the decay rates of both E. coli and enterococci from ovine faeces in brackish microcosms, but decay rate was greater at low SPM concentrations for E. coli , whereas the opposite was observed for enterococci, whose decay rates increased as SPM concentration increased. E. coli , enterococci and coliforms derived from wastewater demonstrated a net decay in both freshwater and brackish microcosms, with contrasting effects of SPM concentration on decay rate. In addition, some FIB groups demonstrated contrasting responses (decay or proliferation) in the first 24 h following inoculation into freshwater versus brackish microcosms. Overall, SPM concentrations influenced the proliferation and decay rates of FIB in brackish waters, but had minimal influence in freshwater. These results demonstrate that the survival rates of FIB in aquatic environments are system specific, species and source dependent, and influenced by SPM concentration. This study has important implications for catchment-based risk assessments and source apportionment of FIB pollution in aquatic environments. [ABSTRACT FROM AUTHOR]

European beech is one of the most important European trees, not only because of its expected role in the face of climate change, but also as a frequent species in forest reserves, national parks and the NATURA 2000 network. For such areas, naturalness and biodiversity conservation are significant issues, in which the presence of deadwood plays an important role. To manage deadwood in forests, one needs to know how the residence time of coarse woody debris is influenced by the environment. In this study, we analysed a dataset of 4260 logs from beech-dominated primeval and natural forest reserves in three climatically different regions (cold-dry, warm-dry and warm-humid region), working with a time series of more than 40 years (1972–2015). With the help of Bayesian Survival Trajectory Analysis, we examined differences between residence times in the three regions and in three DBH classes. In addition, we analysed qualitative characteristics of fallen logs – the mortality mode and the position of logs during decomposition – and calculated their total decomposition time and time to reach an advanced decay stage. The analyses confirmed the significant impact of macroclimate on residence time. In the cold-dry region the diameter classes 10–24 cm (small-sized logs) and 25–54 cm (medium-sized logs) had the longest residence time (38 and 48 years, respectively). In the warm-dry region with a favourable composition of fungal communities, the diameter class 55+ cm (large-sized logs) logs had the shortest residence time (43 years). The rates of decomposition of beech logs in contact with the ground or suspended logs were significantly different in all three regions, with logs lying on the ground decomposing 9–15 years sooner. These results can be used in retention forestry. If the continuity of the deadwood environment is to be preserved, it is necessary to ensure a “supply” of dead stems (offering differing habitats) at least once every 24–35 years. During this period, 50% of logs decay completely and the other 50% of logs progress to an advanced decay stage. [ABSTRACT FROM AUTHOR]

In Central Brazil, over one million square kilometers of native savanna vegetation known as Cerrado have been cleared and converted to farmland over the past forty years. A factorial experiment was designed to assess the effects of land use, litter type, soil organisms and season on litter decay in the prevailing natural and agricultural systems ( i.e. Cerrado remnants, grasslands and soybean croplands) in Mato Grosso. Decay rates were estimated by using the litterbag method. Two different mesh sizes were used to evaluate the effects of soil macro- and mesofauna (coarse mesh; 5 mm) and of soil microorganisms (fine; 20 μm). The original litter found in each land use area (Cerrado leaf-litter, Brachiaria -grass or soybean residues) was used to estimate the decay of in situ litter; a standard substrate (maize litter) was employed to evaluate the effect of the environment. Finally, the experiment was carried out during a dry and a rainy season to differentiate the effect of the other factors from the seasonal effect. We found that: (1) the effects of land use and management practice were only significant in the dry season; (2) decomposability of litter was not predicted by the initial C:N ratio of the litter types; (3) soil fauna contributed to the litter breakdown with 13–57%; (4) decay rates were overall higher in the rainy season; (5) all evaluated factors (in following order: season > soil organisms > litter type > land use) and their interactions explained about 70% of the variance in the decay rates in the study area. Change in land use affected litter decay mainly through a shift in the litter quality; the introduced plant species produced highly decomposable litters. [ABSTRACT FROM AUTHOR]

In this paper, we first prove the regularity in H m ( R 3 ) of weak solutions to the Navier–Stokes–Voigt equations with initial data in H K ( R 3 ) for all m ≤ K . Then we compute the upper bound of decay rate for these solutions, specifically, we prove that ‖ ∇ m u ( t ) ‖ 2 + ‖ ∇ m + 1 u ( t ) ‖ 2 ≤ c ( 1 + t ) − 3 / 2 − m , for large t , when u 0 ∈ H σ m + 1 ( R 3 ) ∩ L 1 ( R 3 ) , m ∈ N . [ABSTRACT FROM AUTHOR]

This paper is concerned with energy decay rates for a nonlinear von Kármán equation with infinite memory and rotational inertia. We obtain decay rate 1 / t only under a monotonicity condition on the memory kernel g , besides basic conditions for the wellposedness of the equation. The advantage of this lies in the fact that without assuming any of the various estimates of the derivative of g or other additional conditions required in the previously related results on von Kármán systems, we obtain an explicit decay rate, which is optimal in some sense. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the decay properties of axially symmetric solutions to the steady incompressible magnetohydrodynamic equations in R 3 with finite Dirichlet integral. We first derive the decay rates of general D-solutions to the axisymmetric MHD equations. In the special case where the magnetic field only has the swirl component h (r , z) = h θ (r , z) e θ , we obtain better decay rates. The last result examines the decay rates along the axis O z also within the special class of D-solutions with only swirl magnetic field. The main tool in this paper is the combination of the scaling argument, the Brezis–Gallouet inequality and the weighted energy estimate. [ABSTRACT FROM AUTHOR]

In this paper, we consider the stability and decay rate of viscous contact wave for the Cauchy problem of one-dimensional compressible Navier–Stokes equations with radiation under the zero mass condition. we consider the case that the constitutive relations for the pressure p , the specific internal energy e , the specific volume v and the absolute temperature θ are given by p = R θ / v + a θ 4 / 3 , e = C v θ + a v θ 4 , with R > 0 , C v > 0 , and a > 0 being the perfect gas constant, the specific heat and the radiation constant, respectively. Our main idea is to use the smallness of the strength of the contact wave to control the possible growth of its solutions induced by the nonlinearity of the system and interactions between the solutions and the contact wave. The key point in our analysis is to obtain the uniform convergence rate of a contact wave pattern (1 + t) − 5 8 ln 1 2 (2 + t) by using a new inequality (see Lemma 2.3) and a weighted characteristic energy estimate. [ABSTRACT FROM AUTHOR]

This work studies the aging processes of commercial LiCoO 2 /mesocarbon microbeads (MCMB) cells which are cycled at 25 °C, 35 °C, 45 °C respectively at the 0.6 C charge/discharge rate and 30% depth of discharge. The capacity degradation of the cells is fast at elevated temperature, and the cycle life tested at 45 °C is about a quarter of the cycling time at 25 °C. The fresh and the aged cells are disassembled to characterize the morphology and the composition of electrode surface, as well as the bulk structure and the electrochemical performance of single electrode. It is found that the formation of SEI film and the polarization of the full cell lead to state of charge (SOC) shift in the cathode. The cathode SOC shift and the decay in the reversible capacity of LiCoO 2 cathode dominate the aging of the full cell. The former is the prevailing aging factor at 25 °C, while the latter factor becomes the leading cause of cell aging at 45 °C. The unstable and thick SEI film on the cathode under elevated temperature influences the lithium ion diffusion, resulting in the increased polarization and the decreased intrinsic performance of LiCoO 2 cathode. The proper range of test temperature ensuring no changes in aging mechanism and the decay rate of capacity caused by each aging factor are proposed by analyzing the performance of the full cells and the electrodes. After comparing the test results, it is concluded that the aging process at 45 °C is not the same as that at room temperature. [ABSTRACT FROM AUTHOR]

Changing the properties of photoprotein aequorin such as the wavelength emission and decay half-life by using bioluminescence resonance energy transfer (BRET) phenomenon is the main aim in this paper. BRET system was set up with CdSe/ZnS quantum dot nanoparticles as an acceptor molecule and photoprotein as an energy donor molecule. Quantum dots are semiconductor nanoparticles with very interesting optical properties, including broad excitation spectra, narrow and the symmetric band width emission spectra, tunable by their sizes, compositions, negligible photo-bleaching and good chemical and photo-stability. In this QD-BRET system, aequorin is conjugated to the carboxyl groups on quantum dot surface by EDC/NHS chemistry as cross linker. Bioluminescence energy generates by aequorin upon adding Ca 2 + and transfers to the quantum dots in a radiationless manner and emits at a longer wavelength. The determined bioluminescent parameters for this method included aequorin activity, emission spectra and decay half-life time. In fact, this spectrum tuning strategy resulted in a change in bioluminescent properties of photoprotein, therefore, the maximum emission wavelength shifted from 455 to 540 nm and the decay time increased from 3.76 to 12.11 s. Nowadays, photoproteins with different characteristics are capable of being employed as a reporter in multi-analyte detections and in vivo imaging. [ABSTRACT FROM AUTHOR]

Jahn-Teller (JT) and pseudo-Jahn-Teller (PJT) effects in the ground, first and second excited electronic states of the trifluoromethane radical cation are theoretically examined here. Extensive ab initio computation of electronic potential energy surfaces and their coupling surfaces are performed. Full quantum dynamics are obtained by both time-independent and time-dependent quantum mechanical methods. This system belongs to ( E + A )⊗ e JT-PJT family. Our results compare well with the experimental data. JT interactions are fairly strong in the second excited B ˜ 2 E electronic state and the PJT interaction between A ˜ 2 A 2 - B ˜ 2 E electronic states is stronger which cause an increase of the spectral line density of the vibronic spectrum. [ABSTRACT FROM AUTHOR]

Measurement data of long-lived radionuclides, for example, 85 Kr, 90 Sr, 108m Ag, 133 Ba, 152 Eu, 154 Eu and 226 Ra, and particularly the relative residuals of fitted raw data from current measurements of ionization chambers for half-life determination show small periodic seasonal variations with amplitudes of about 0.15%. The interpretation of these fluctuations is a matter of controversy whether the observed effect is produced by some interaction with the radionuclides themselves or is an artifact of the measuring chain. At the origin of such a discussion there is the exponential decay law of radioactive substances used for data fitting, one of the fundamentals of nuclear physics. Some groups of physicists use statistical methods and analyze correlations with various parameters of the measurement data and, for example, the Earth-Sun distance, as a basis of interpretation. In this article, data measured at the Physikalisch-Technische Bundesanstalt and published earlier are the subject of a correlation analysis using the corresponding time series of data with varying measurement conditions. An overview of these measurement conditions producing instrument instabilities is given and causality relations are discussed. The resulting correlation coefficients for various series of the same radionuclide using similar measurement conditions are in the order of 0.7, which indicates a high correlation, and for series of the same radionuclide using different measurement conditions and changes of the measuring chain of the order of −0.2 or even lower, which indicates an anti-correlation. These results provide strong arguments that the observed seasonal variations are caused by the measuring chain and, in particular, by the type of measuring electronics used. [ABSTRACT FROM AUTHOR]

The static and dynamic aspects of Jahn-Teller(JT) and pseudo-Jahn-Teller(PJT) interactions between ground ( X ˜ 2 A 2 ′ ) and first three excited electronic states ( A ˜ 2 E ′ , B ˜ 2 E ″ and C ˜ 2 A ′ 1 ) of bicyclo- [2,2,2]-octa-2,5,7-triene (barrelene) radical cation (Bl + ) are theoretically investigated here. This belongs to the ( E + E ) ⊗ e and ( E + A ) ⊗ e JT-PJT class of compounds as described by the symmetry of the electronic states and the molecular point group. The complex vibronic dynamics on the coupled electronic states of the cation is simulated by both time-independent and time-dependent wave packet propagation method using multi configuration time-dependent Hartree scheme. The JT effects in the A ˜ and B ˜ electronic states and the PJT coupling between the B ˜ and C ˜ electronic states of Bl + are found very strong. The final theoretical results are compared with the experimental results. [ABSTRACT FROM AUTHOR]

In the present paper we examine the Saint-Venant end effect in the nano tubes via a continuum mechanics with consideration of surface elasticity. The Saint-Venant end effect is quantitatively described by the decay rate. By analytically solving an axial-symmetric torsion in a circular cross-section tube configuration, we demonstrate that the decay rate decreases as the radius of the nano wire/tube decreases with consideration of the surface effect. [ABSTRACT FROM AUTHOR]

We analytically study the scalar perturbation of non-asymptotically flat (NAF) rotating linear dilaton black holes (RLDBHs) in 4-dimensions. We show that both radial and angular wave equations can be solved in terms of the hypergeometric functions. The exact greybody factor (GF), the absorption cross-section (ACS), and the decay rate (DR) for the massless scalar waves are computed for these black holes (BHs). The results obtained for ACS and DR are discussed through graphs. [ABSTRACT FROM AUTHOR]

A Weisskopf–Wigner theory has been used to investigate the spontaneous emission of a two-level atom placed in a photon superfluid. It is found that the atom decays exponentially. However, the atomic decay rate changes periodically with the position of the atom and it is minimal when the atom is located at the wave nodes. The largest decay rate of the atom in photon superfluid has the same order of magnitude as it is in vacuum of free space. Moreover, the analytical result shows that the decay of an atom in photon superfluid, compared with that in planar cavity without photon superfluid, will be inhibited. The physical origin of atomic decay inhibition is also discussed. [ABSTRACT FROM AUTHOR]