Downhole seismic velocity logging techniques have been developed and applied in support of high-resolution reflection seismic surveys. For shallow high-resolution reflection surveying within unconsolidated overburden, velocity-depth control can sometimes be difficult to achieve; as well, unambiguous correlation of reflections with overburden stratigraphy is often problematic. Data obtained from downhole seismic logging can provide accurate velocity-depth functions and directly correlate seismic reflections to depth. The methodologies described in this paper are designed for slim-hole applications in plastic-cased boreholes (minimum ID of 50 mm) and with source and detector arrays that yield similar frequency ranges and vertical depth resolutions as the surface reflection surveys. Compressional- (P-) wave logging uses a multichannel hydrophone array with 0.5-m detector spacings in a fluid-filled borehole and a high-frequency, in-hole shotgun source at the surface. Overlapping array positions downhole results in redundant first-arrival data (picked using interactive computer techniques), which can be processed to provide accurate interval velocities. The data also can be displayed as a record suite, showing reflections and directly correlating reflection events with depths. Example applications include identification of gas zones, lithological boundaries within unconsolidated sediments, and the overburden-bedrock interface. Shear- (S-) wave logging uses a slimhole, well-locked, three-component (3-C) geophone pod and a horizontally polarized, hammer-and-loaded-plate source at ground surface. The pod is moved in successive 0.5- or l-m intervals downhole with no redundancy of overlapping data as in the P-wave method. First-arrival data can be obtained by picking the crossover onset of polarized energy or by closely examining particle-motion plots using all three components of motion. In unconsolidated sediments, shear-wave Velocity contrasts can be associated with changes in material density or dynamic shear modulus, which in turn can be related to consolidation. Example applications include identification of a lithological boundary for earthquake hazard applications and mapping massive ice within permafrost materials.

We consider the ejection dynamics of a flexible polymer chain out of confined environment. This situation arises in different physical contexts, including a flexible synthetic polymer partially confined in a nanopore and a viral genome partially ejected from its capsid. We describe the chain release from confinement both analytically and by means of dynamic Monte Carlo simulation. We find two distinct regimes of ejection dynamics depending on whether the chain is fully or partially confined. Partially confined chains are ejected from a pore of length L and diameter D after a typical time tau proportional to (LD5/3)-D-2, regardless of their contour length N. The process is driven by a constant force f approximate to 5k(B)T/D and follows a "capillary" law. The force value is model-independent as long as the pore diameter exceeds the persistence length of the polymer chain and for pore walls that do not attract the segments of the polymer. In contrast, the ejection of fully confined chains is largely diffusive, the residence time being a nonmonotonic function of N. The drift-dominated ejection of long chains is characterized by narrow distribution of exit times whereas for diffusive-dominated ejection the exit times are described by a broad distribution. One finds good agreement with recent nanofluidic experiments with DNA.

Background: Vascular load is an important determinant of ventricular function. Understanding the physiologic basis of vascular load is central to the development of new strategies and drugs to treat HF. Aim: to evaluate arterial stiffness, endothelial function, clinical status at baseline and in 6 months follow-up period of perindopril therapy in diastolic HF. Methods: 40 patients with exertional dyspnea, I-II NYHA, EF>45%, aged 62(8,4) years, F/M=27/13, history of CHF 29(16) months, BMI 29,4kg/m2. Arterial stiffness was assessed by measuring carotid-femoral PWV and central: mean BP(MAP), pulse pressure(CPP), AIX using applanation tonometry (Sphygmocor) at the baseline and in 6-months f-up. Endothelial dysfunction using FMD during reactive hyperemia (HDI 5000), clinical status with MQLHF were assessed at the baseline and in 6-months f-up period. All patients were on perindopril therapy, mean dose 8mg/day. Results: Baseline 6months f-up p PWV 10(8,6;11,9) 9(8,3;11,5) =0.06 CSBP 135(123;152) 132(124;140) ns CDBP 85(79;93) 82(80,5;90) ns SBP 145(134;154) 131(126;142) <0.05 DBP 85(80;91) 80(76;86) ns CPP 52(41,5;59) 44(42;52) ns MAP 105,5(97,5;115,5) 104(98;110) ns AIX 32,5(27,5;41.5) 38(30,38) ns FMD 5,6(3;6,5) 6,5(3,3;7,1) <0.05 NYHA FC 2(1;2) 1(1;2) <0.05 MQL 39,5(27;48) 33,5(25;41) ns Conclusions: The present study demonstrates that short-term perindopril therapy improved endothelial function, led to favourable trends with regard to the reduction of arterial stiffness and resulted in improvement of NYHA functional class in diastolic heart failure patients, that suggests that perindopril is therapeutically usefull in the therapy of diastolic HF.

Increased arterial stiffness abnormal ventricular-vascular coupling have increasingly been recognized as playing an important pathophysiologic role in HF, both systolic and with normal ejection fraction. Aim: to assess and compare arterial stiffness, central blood pressure parameters in systolic heart failure patients with ischemic and non-ischemic aetiology. Methods: 2 groups of patients with systolic (EF<40%) congestive heart failure (CHF) I-IV functional classes NYHA were enrolled in the study: 1) ischemic aetiology group was respresented by 60 patients with ischemic heart disease: Age, years 59(10), BMI (kg/m2) 28,41, CHF 36(10,4) months, FC NYHA 8(12%)/33(55%)/11(27%)/3(6%); EF 33,3%; 100%sinus rhythm; SBP 124(17,3)mmHg, DBP 77,3(9,5)mmHg; therapy: diuretics 42(76%), BB/ACEi 100%. 2) non-ischemic aetiology group - 15 patients with dilated cardiomyopathy: Age, years 42,2 (9,4), BMI (kg/m2) 28,5, CHF 38(7,2) months, FC NYHA 4(26%)/6(42%)/4(26%)/1(6%); EF 28,2%; 100%sinus rhythm; SBP 119(9,24)mmHg, DBP 77,5(8,1)mmHg, therapy: diuretic 12(80%), BB/ACEi 100%. Carotid-femoral pulse wave velocity (c-f PWV) was measured as index of arterial stiffness, central blood pressure parameters: mean arterial pressure, pulse pressure, aortic augmentation index, using applanation tonometry (Sphygmocor). Results:C-f PWV was lower in non-ischemic group compared with ischemic group (6,8(6,4;7,8) vs. 9,0(7,5;10,0) m/sec;p<0.005). Central BP parameters (MAP,CPP,AIX) didn’t differ between 2 selected groups (p>0.05). Conclusions: Arterial stiffness is increased in patients with ischemic systolic CHF comparing with non-ischemic systolic CHF, that may suggest that arterial stiffness is implicated in the complex of pathophysiology of CHF. The behavior of central blood pressure gemodynamics is common both in ischemic and non-ischemic aetiology groups.

It remains challenging to predict and estimate potential damage from tsunamis using computer models. One of the approaches to validate models is to compare their results with site observations. We carried out numerical modeling for both the underwater landslide and the associated tsunami that occurred near Kitimat, British Columbia, Canada on 27 April 1975. A few observations of high water marks along the coastline indicated 8.2 m tsunami waves. Previous survey results of the seafloor showed that a landslide traveled about 5 km down the axis of the fjord from its source areas on the sidewall of the fjord, near the head of the inlet, and on the lower Kitimat River delta. We modeled the subaqueous slope failure as a Bingham visco‐plastic fluid (debris flow) based on previous geotechnical investigations at the site, and numerically solved the landslide‐generated tsunami wave and debris flow equations using a finite‐volume Godunov‐type scheme. This method resolves abrupt wave and landslide front interactions and remains oscillation‐free. The computed motion of the debris flow is generally consistent with observations; simulations indicate that the failure propagated approximately 4.5 km down the fjord axis from its inception point. We have found that computed amplitudes for the tsunami wave crest at the coast of Kitimat Arm were between 6 and 11 m; these values are somewhat higher than previous simplistic solitary wave theory estimates of 6.3 m and observations of 8.2 m.

The chromatographic behavior of low-molecular-mass poly(ethylene glycol) (PEG), and of its mono- and dimethyl ethers (PEG-MME and PEG-DME, respectively) has been studied in the isocratic mode of reversed-phase liquid adsorption chromatography (RP-LAC) on C-18-modified silica (ODS2) column packings with pore diameters of 8 nm and 30 nm, using methanol-water of different compositions as mobile phase. For all three types of oligomers completely resolved chromatograms were obtained, in which all peaks could be identified. Precise and detailed data on the molar mass dependence of distribution coefficients resulted from these experiments. The experimental data were interpreted according to simple molecular statistical theory based on the model of a rigid-rod molecule, which is capable of being adsorbed inside the homogeneous layers near the pore walls. This approach allowed us to determine the free energies of transfer of the repeating unit (oxyethylene group) and of the two types of the end groups (methoxy and hydroxy groups) from a solution (in mixed eluents of different composition) into a bonded C-18 phase. In addition, the effective thickness of the bonded layer was estimated as well as the critical point of adsorption for polyoxyethylene, which is of importance for separation of macromolecules by using the critical-condition mode of liquid chromatography.

Liquid adsorption chromatography retention modes of poly(ethylene glycol) (PEG), its mono- and dimethyl ethers (MMEs and DMEs) and also of fatty alcohol ethoxylates (FAEs) are studied both experimentally and theoretically. The experimental system under investigation was a Spherisorb S5W 80 Å column and isopropanol–water as the mobile phase. At various compositions of the mobile phase (in the range of 75 to 87% of isopropanol) chromatograms exhibiting good peak resolution were obtained and the dependencies of the elution volume on the number of repeating EO units for both PEG and FAE samples evaluated on the basis of a closer inspection of the chromatographic data. The experiments did not reveal any differences between the chromatographic behavior of PEGs, MMEs and DMEs, while the FAEs gave substantially smaller values of elution volume at all mobile phase compositions. These data were interpreted by using a molecular-statistic theory of homopolymers (to describe both PEG, MME and DME) and two-block copolymers (for FAEs) based on a continuum Gaussian chain model of macromolecules and a slit-like model of pores of stationary phase, wide pore approximation and the adsorption chromatography mode for PEG molecules were assumed in the development of this theory. This theory described very well the experimental data obtained, and two thermodynamic parameters characterizing interactions of EO units of PEG and both EO and (CH2)n chains of FAE molecules with the adsorbent pore walls have been determined from the comparison of the theory and the experiments. Although the mean thickness of adsorbed oxyethylene chain, H, was estimated as being equal to about 3.5–4.5 Å, H proved to be slightly decreasing with increasing isopropanol content in mobile phase. Chromatograms visualizing the adsorption of PEG and FAE molecules are presented, and the correspondence between the theoretical approach and the experimental situation under investigation is discussed.