In a previous study the Laplace transform has been introduced in order to solve the combined heat and mass transfer problem in absorbing laminar falling films with constant film velocity for an ...isothermal as well as an adiabatic wall boundary condition. It has been stated, that the Laplace transform basically allows to apply arbitrary wall boundary conditions in contrast to the Fourier method.
Therefore, in the present study a diabatic wall boundary condition is applied, which, as limiting cases, includes both the isothermal wall if the thermal resistance of the wall is zero as well as the adiabatic wall condition for an infinite thermal resistance of the wall.
Temperature and mass fraction profiles across the film as well as the evolution of the absorbed mass flux with increasing flow length are presented for two different thermal resistances of the wall and modified Stefan numbers. The results are compared to the limiting cases of the isothermal and the adiabatic wall boundary condition.
The present study offers an analytical solution with a more realistic boundary condition of a constant thermal resistance of the wall including the isothermal and the adiabatic wall boundary condition.
First, the potential role of Raman-based techniques in biomedicine is introduced. Second, an overview about the instrumentation for spontaneous and coherent Raman scattering microscopic imaging is ...given with a focus of recent developments. Third, imaging strategies are summarized including sequential registration with laser scanning microscopes, line imaging and global or wide-field imaging. Finally, examples of biomedical applications are presented in the context of single cells, laser tweezers, tissue sections, biopsies and whole animals.
Grigor'eva and Nakoryakov presented an analytical solution for combined heat and mass transfer in laminar falling films by means of the Fourier method. The obtained solutions exhibited mathematical ...instabilities for small flow length, such as oscillations in the mass fraction profile and a mismatch of the inlet temperature. Grigor'eva and Nakoryakov explained these instabilities with the inconsistency of the inlet and boundary conditions and therefore an additional short term solution was introduced.
In the present study the established tangent function, that is used to determine the eigenvalues within the Fourier method, is rearranged to a term without domain restrictions. Consequently, more eigenvalues are found, leading to a physical valid solution even for small flow lengths, matching the results of the short term solution perfectly.
•Mathematical instabilities of the established analytical solution using the Fourier method.•Necessity of two analytical solutions with no information of the range of validity so far.•The established tangent functions to find the eigenvalues are domain restricted.•Rearranging this functions results in more eigenvalues and the mathematical instabilities vanish.•Fourier method with complemented set of eigenvalues is physically valid for the whole range of flow length.
The actin cortex both facilitates and hinders the exocytosis of secretory granules. How cells consolidate these two opposing roles was not well understood. Here we show that antigen activation of ...mast cells induces oscillations in Ca(2+) and PtdIns(4,5)P(2) lipid levels that in turn drive cyclic recruitment of N-WASP and cortical actin level oscillations. Experimental and computational analysis argues that vesicle fusion correlates with the observed actin and Ca(2+) level oscillations. A vesicle secretion cycle starts with the capture of vesicles by actin when cortical F-actin levels are high, followed by vesicle passage through the cortex when F-actin levels are low, and vesicle fusion with the plasma membrane when Ca(2+) levels subsequently increase. Thus, cells employ oscillating levels of Ca(2+), PtdIns(4,5)P(2) and cortical F-actin to increase secretion efficiency, explaining how the actin cortex can function as a carrier as well as barrier for vesicle secretion.
Physical activity in patients with COPD Watz, H; Waschki, B; Meyer, T ...
The European respiratory journal,
02/2009, Letnik:
33, Številka:
2
Journal Article
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The present study aimed to measure physical activity in patients with chronic obstructive pulmonary disease (COPD) to: 1) identify the disease stage at which physical activity becomes limited; 2) ...investigate the relationship of clinical characteristics with physical activity; 3) evaluate the predictive power of clinical characteristics identifying very inactive patients; and 4) analyse the reliability of physical activity measurements. In total, 163 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I-IV; BODE (body mass index, airway obstruction, dyspnoea, exercise capacity) index score 0-10) and 29 patients with chronic bronchitis (normal spirometry; former GOLD stage 0) wore activity monitors that recorded steps per day, minutes of at least moderate activity, and physical activity levels for 5 days (3 weekdays plus Saturday and Sunday). Compared with patients with chronic bronchitis, steps per day, minutes of at least moderate activity and physical activity levels were reduced from GOLD stage II/BODE score 1, GOLD stage III/BODE score 3/4 and from GOLD stage III/BODE score 1, respectively. Reliability of physical activity measurements improved with the number of measured days and with higher GOLD stages. Moderate relationships were observed between clinical characteristics and physical activity. GOLD stages III and IV best predicted very inactive patients. Physical activity is reduced in patients with chronic obstructive pulmonary disease from Global Initiative for Chronic Obstructive Lung Disease stage II/ body mass index, airway obstruction, dyspnoea, exercise capacity score 1. Clinical characteristics of patients with chronic obstructive pulmonary disease only incompletely reflect their physical activity.
ABSTRACT
Our understanding of the unification of jetted AGN has evolved greatly as jet samples have increased in size. Here, based on the largest-ever sample of over 2000 well-sampled jet spectral ...energy distributions, we examine the synchrotron peak frequency – peak luminosity plane, and find little evidence for the anticorrelation known as the blazar sequence. Instead, we find strong evidence for a dichotomy in jets, between those associated with efficient or ‘quasar-mode’ accretion (strong/type II jets) and those associated with inefficient accretion (weak/type I jets). Type II jets include those hosted by high-excitation radio galaxies, flat-spectrum radio quasars (FSRQ), and most low-frequency-peaked BL Lac objects. Type I jets include those hosted by low-excitation radio galaxies and blazars with synchrotron peak frequency above 1015 Hz (nearly all BL Lac objects). We have derived estimates of the total jet power for over 1000 of our sources from low-frequency radio observations, and find that the jet dichotomy does not correspond to a division in jet power. Rather, type II jets are produced at all observed jet powers, down to the lowest levels in our sample, while type I jets range from very low to moderately high jet powers, with a clear upper bound at L 300MHz ∼1043 erg s−1. The range of jet power in each class matches exactly what is expected for efficient (i.e. a few to 100 % Eddington) or inefficient ( <0.5% Eddington) accretion on to black holes ranging in mass from $10^7{\, {\rm to}\,}10^{9.5}\, {\rm M}_\odot$.
In the present study the Laplace transform is applied to the partial differential equations obtained from the differential energy and absorbate balances for the combined heat and mass transfer ...problem in laminar falling films with uniform film velocity.
By means of the inverse Laplace transform an analytical solution is provided for the isothermal as well as for the adiabatic wall boundary condition. Temperature and mass fraction profiles across the film as well as the evolution of the absorbed mass flux as a function of the flow length are presented for the adiabatic wall condition as well as for the isothermal wall with different wall temperatures. Furthermore, the influence of the Lewis number on the absorbed mass flux is discussed.
In addition, the present method allows to apply other wall boundary conditions than the isothermal or the adiabatic wall boundary, which will be addressed in a subsequent study.
•Introduction of a more versatile analytical solving procedure using the Laplace transform.•Analytical solution to the combined heat and mass transfer for the isothermal and adiabatic wall.•Evaluation of the influence of the thermal wall boundary condition on the absorbed mass flux.•Discussion of the influence of the Lewis number on the absorbed mass flux.
We revisit the concept of a blazar sequence that relates the synchrotron peak frequency ( Delta *npeak) in blazars with synchrotron peak luminosity (L peak, in Delta *nL Delta *n) using a large ...sample of radio-loud active galactic nuclei. We present observational evidence that the blazar sequence is formed from two populations in the synchrotron Delta *npeak-L peak plane, each forming an upper edge to an envelope of progressively misaligned blazars, and connecting to an adjacent group of radio galaxies having jets viewed at much larger angles to the line of sight. When binned by jet kinetic power (L kin; as measured through a scaling relationship with extended radio power), we find that radio core dominance decreases with decreasing synchrotron L peak, revealing that sources in the envelope are generally more misaligned. We find population-based evidence of velocity gradients in jets at low kinetic powers (~1042-1044.5 erg s--1), corresponding to Fanaroff-Riley (FR) I radio galaxies and most BL Lac objects. These low jet power 'weak-jet' sources, thought to exhibit radiatively inefficient accretion, are distinguished from the population of non-decelerating, low synchrotron-peaking (LSP) blazars and FR II radio galaxies ('strong' jets) which are thought to exhibit radiatively efficient accretion. The two-population interpretation explains the apparent contradiction of the existence of highly core-dominated, low-power blazars at both low and high synchrotron peak frequencies, and further implies that most intermediate synchrotron peak sources are not intermediate in intrinsic jet power between LSP and high synchrotron-peaking (HSP) sources, but are more misaligned versions of HSP sources with similar jet powers.
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