We experimentally investigate the splashing mechanism of a millimeter-sized ethanol drop impinging on a structured solid surface, composed of micropillars, through side-view and top-view high-speed imaging. By increasing the impact velocity, we can tune the impact outcome from a gentle deposition to a violent splash, at which tiny droplets are ...

Nonlinear dynamics of encapsulated contrast microbubbles generates subharmonic response at stronger acoustic excitations. The response depends on environmental conditions such as ambient pressure. It has therefore been proposed that the subharmonic response could offer a novel means for non-invasive monitoring of organ-level blood pressure. For a free bubble, there exists ...

To estimate the incidence of hypertension in people with and without prehypertension and determine the factors that predict progression to hypertension. Data from a cohort of 25-74-year-old residents of Spanish Town, Jamaica, were analysed. All participants completed a structured questionnaire and had blood pressure (BP), anthropometric measurements and venous blood ...

Ultrasound enhances recombinant tissue plasminogen activator (rt-PA) thrombolysis via a cavitational mechanism. An ex vivo porcine carotid arterial model incorporating physiologic flow and pressure was developed and stable cavitation promoted for thrombolysis. Aged, retracted whole blood clots were exposed to plasma alone, plasma containing rt-PA (3.15 μg∕ml), or plasma with ...

Pressure-driven flow control systems are a critical component in many microfluidic devices. Compartmentalization of this functionality into a stand-alone module possessing a simple interface would allow reduction of the number of pneumatic interconnects required for fluidic control. Ideally, such a module would also be sufficiently compact for implementation in portable ...

It is well known from observations in the ocean, as well as limited experimental measurements and theoretical predictions for spherical bubbles, that the threshold acoustic pressure for generation of inertial cavitation increases with hydrostatic pressure. However, the precise nature of the relationship between hydrostatic and acoustic pressures at threshold has ...

Stable cavitation is correlated with thrombolytic efficacy for recombinant tissue plasminogen activator (rt-PA) mediated thrombolysis. An infusion of Definity(®) nucleated, promoted, and sustained stable cavitation in an ex vivo porcine carotid model exposed to 120-kHz continuous wave ultrasound. The optimal ultrasound pressure amplitude and the durations of active and quiescent ...

One of the primary purposes of the building enclosure is to separate occupants from the natural elements such as rain and snow. Water can penetrate this enclosure through four primary mechanisms: air pressure differences between interior and exterior, rain drop momentum, surface tension, and capillary action. The pressure equalized rainscreen ...

The static-pressure threshold for rupturing polymer-shelled ultrasound contrast agents (UCAs) manufactured by POINT Biomedical (mean diameter 3 μm, shell-thickness-to-radius ratio (STRR) 7.5 nm∕μm, count 961) and Philips Research (mean diameter 2 μm, STRR 40 nm∕μm, count 1048) was investigated. The UCAs were subjected to static overpressure in a glycerol-filled test ...

This paper investigated the effect of atomic force microscopy probe pressure on capacitance-voltage (C-V) and two-dimensional electron gas (2DEG) characteristics. Based on the experimental results, first principles and charge control model calculations were carried out to explore the origin of the changes in C-V and 2DEG characteristics. It is found ...

The in vivo cavitation response associated with blood-brain barrier (BBB) opening as induced by transcranial focused ultrasound (FUS) in conjunction with microbubbles was studied in order to better identify the underlying mechanism in its noninvasive application. A cylindrically focused hydrophone, confocal with the FUS transducer, was used as a passive ...

In this letter, we demonstrate a spherical nanocavities fabrication using an "air-molding" method, which is implemented by modulating the pressure difference across air-liquid interfaces in nanoholes on the mold. The cavities formation is theoretically considered and experimentally verified at macroscale first, and then a series of experiments are performed over ...

Dependence of monolithic column efficiency on column pressure was analyzed using modified Van Deemter relationship with incorporated inlet and outlet column pressures as independent variables. It was demonstrated that the highest column efficiency is observed at high pressures. Inlet and outlet pressure increase has to be controlled in such a ...

We describe the design and operation of an apparatus for loading gases into the sample volume of the Paris-Edinburgh press at room temperature and high pressure. The system can be used for studies of samples loaded as pure or mixed gases as well as for loading gases as pressure-transmitting media ...

This paper illustrates how varieties of cosmopolitanism are shaped through a mutually constitutive set of cultural dispositions and institutional practices that emerge at the interstices of global human right norms and local legal practices. Converging pressures of 'cosmopolitan imperatives' and the multiplicity of particularized manifestations are co-evolving in the context ...

Although an air-backed thin plate is an effective sound receiver structure, it is easily damaged via pressure unbalance caused by external hydrostatic pressure. To overcome this difficulty, a simple pressure-balancing module is proposed. Despite its small size and relative simplicity, with proper design and operation, micro-channel structure provides a solution ...

The mechanism of loss of "reworkability" or tabletability of dry granulated microcrystalline cellulose (MCC) was investigated in relation to both granule size enlargement and granule hardness. Slugs of MCC were prepared under three pressures (12.5, 37.5, and 93.8 MPa) and tabletability (tensile strength vs. pressure) of respective granules (three different ...

Predation pressure and resource availability often interact in structuring herbivore communities, with their relative influence varying in space and time. The operation of multiple ecological pressures and guild-specific herbivore responses may combine to override simple predictions of how the roles of plant quality and predation pressure vary in space. For ...

Ion rejection properties of cylindrical nanopores with bipolar fixed charge distributions have been investigated theoretically by means of an approximate model based on the Poisson-Nernst-Planck (PNP) theory and accounting for the electroosmosis phenomenon. The approximate model has been shown to give results that are in good agreement with the full ...

Five different pre-treatments were investigated to enhance the solubilisation and anaerobic biodegradability of kitchen waste (KW) in thermophilic batch and continuous tests. In the batch solubilisation tests, the highest and the lowest solubilisation efficiency were achieved with the thermo-acid and the pressure-depressure pre-treatments, respectively. However, in the batch biodegradability tests, ...

Resonant ultrasound spectroscopy provides for an experimental determination of the elastic moduli of a solid sample. The moduli are extracted by matching a theoretically computed resonant spectrum to the experimental vibrational spectrum. To determine the pressure dependence of the moduli, the vibrational spectrum can be taken with the sample in ...

In case of a terrorist bomb attack the influence and efficiency of venting areas in tubular structures like train carriages is of interest. The pressure-time function of an air blast wave resulting from a solid charge is first compared to that of a gas or dust explosion and the capability ...

Subharmonic scattering of phospholipid-shell microbubbles excited at relatively low acoustic pressure amplitudes (<30 kPa) has been associated with echo responses from compression-only bubbles having initial surface tension values close to zero. In this work, the relation between sbharmonics and compression-only behavior of phospholipid-shell microbubbles was investigated, experimentally and by simulation, ...

Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. ...

The urodynamic effects of intravesical PGE2 instillation on bladder function and detrusor overactivity (DO) during the filling phase were investigated in rats by measuring intraabdominal and intravesical pressures simultaneously. Continuous cystometry was performed inconscious, female and male Sprague- Dawley rats. We investigated pressure-, volume-, and DO-related parameters. Intravesical instillation of ...

The aim of this work is to study the effect of compaction on the specific surface area of tablets composed of various pharmaceutical materials (microcrystalline cellulose, lactose, and anhydrous calcium phosphate) compacted under seven degrees of compaction pressure. In a first part, the influence of the deformation behavior of the ...

Medical ultrasound has shown great potential as a minimally invasive therapy technique. It can be used in areas such as histotripsy, thermal ablation, and administering medication. The success of these therapies is improved by the cavitation of small microbubbles, and often it is useful to know which bubbles might provide ...

Short-term changes in the hydraulic head of surface water bodies are known to influence the shallow response of hydraulically connected groundwaters. Associated with these fluctuations is the physical increase in stream water creating a mechanical load on the ground surface. This load is supported by the geologic materials (sediment or ...

The mean blood pressure did not depend on the sex of animals and was characterized by the same ontogenetic changes in males and females. The mean blood pressure in infantile and, particularly, in old rats was higher than in adult animals. The increase in blood pressure in old rats was ...

Gravity-driven flow of concentrated suspensions (solid volume fraction ϕ>0.50) of non-brownian spherical particles through a channel contraction at low Reynolds number is studied experimentally. The abrupt change in the flow area at the contraction forms distinct shear-rate regions having different fluid pressures, which are related to the concept of particle ...

This paper numerically investigates the effect of mass transfer processes on spherical single bubble dynamics using the Hertz-Langmuir-Knudsen approximation for the mass flux across the interface. Bubble behavior, with and without mass transfer, is studied for different values of pressure wave amplitude and frequency, as well as initial bubble radius. ...

There is no community based study of prevalence of hypertension from Himachal Pradesh, so we undertook this study. Population based survey was done in three villages of Himachal Pradesh of different Districts. Total 1092 adults of > or =18 years of age were examined. 507 (46.42%) were males and 573 ...

Removal rate, air shock, and ablative recoil pressure parameters were measured as a function of laser intensity I(peak) during nanosecond laser ablation of graphite. Surface vaporization of molten graphite at low intensities I(peak)<0.15 GW/cm(2) was observed to transform into its near-critical phase explosion (intense homogeneous boiling) at the threshold intensity ...

To study bacterial behavior under varying hydration conditions similar to surface soil, we have developed a system called the Pressurized Porous Surface Model (PPSM). Thin liquid films created by imposing a matric potential of -0.4 MPa impact gene expression and colony development in Pseudomonas putida.

We investigate the phase sensitivity of the fundamental mode of hollow-core photonic bandgap fibers to strain and acoustic pressure. A theoretical model is constructed to analyze the effect of axial strain and acoustic pressure on the effective refractive index of the fundamental mode. Simulation shows that, for the commercial HC-1550-02 ...

We studied cavitation in metastable fluids drawing on the example of liquid nitrogen confined to spheroidal pores of specially prepared well-characterized mesoporous silica materials with mean pore diameters ranging from approximately 6 to approximately 35 nm. Cavitation was monitored in the process of evaporation/desorption from fully saturated samples with gradually ...

Inertial suction feeding is the most common method of prey capture among aquatic vertebrates. However, it had been unclear whether the aquatic frogs in the family Pipidae also used inertial suction for prey capture. In this study, we examined feeding behavior in four species of pipids, Pipa pipa, Xenopus laevis, ...

The variety of excipients from different sources and prices to which we have access gives rise to the necessity to evaluate their functional characteristics. The aim of this work is to determine some physical and technological characteristics of celluloses from different sources, India and United States, to ascertain their functionality ...

We experimentally demonstrate that the flow rate of granular material through an aperture is controlled by the exit velocity imposed on the particles and not by the pressure at the base, contrary to what is often assumed in previous work. This result is achieved by studying the discharge process of ...

Environmental pressures may vary over the geographic range of a species, exposing subpopulations to divergent functional demands. How does exposure to competing demands shape the morphology of species and influence the divergence of populations? We explored these questions by performing selection experiments on juveniles of the Hawaiian goby Sicyopterus stimpsoni, ...

To investigate the pressure changes in the transferred load during mock ET. Experimental setup. Academic Research Institute of Mechanical Engineering and private centers of reproductive medicine. None. None. Laboratory simulations of ET into a rigid transparent uterine model equipped with a pressure sensor. Injection of a transferring load during mock ...

In this study, we evaluated the feasibility of solid-state fermentation (SSF) on polyurethane foam (PUF) for xanthan production. The effects of air pressure pulsation (APP) on biomass accumulation and final xanthan concentration were also studied. Under suitable conditions (15% inoculum, 0.5-cm (side length) PUF cubes, 15 mL medium per gram ...

It is well known that cavitation collapse can generate intense concentrations of mechanical energy, sufficient to erode even the hardest metals and to generate light emissions visible to the naked eye [sonoluminescence (SL)]. Considerable attention has been devoted to the phenomenon of "single bubble sonoluminescence" (SBSL) in which a single ...

Self-focused acoustic ejectors using the Fresnel zone plate (FZP) have been developed for ejecting viscous liquids, without nozzle, in the drop-on-demand mode. The FZP is composed of a lead zirconate titanate piezoelectric plate patterned with a series of annular electrodes, with the unelectroded region of the plate removed. Our results ...

Hydrogels have been demonstrated to swell in response to a number of external stimuli including pH, CO(2), glucose, and ionic strength making them useful for detection of metabolic analytes. To measure hydrogel swelling pressure, we have fabricated and tested novel perforated diaphragm piezoresistive pressure sensor arrays that couple the pressure ...

A wireless sensor based on the magnetoelastic, magnetically soft ferromagnetic alloy was constructed for remote measurement of pressure in flowing fluids. The pressure sensor was a rectangular strip of ferromagnetic alloy Fe(40)Ni(38)Mo(4)B(18) adhered on a solid polycarbonate substrate and protected by a thin polycarbonate film. Upon excitation of a time-varying ...

An experimental study on (14)N and (15)N simultaneous separation using the chemical exchange in NO, NO(2)-HNO(3) system under pressure is presented. The influence of the pressure and of the interstage 10 M HNO(3) flow rate on the separation of (14)N and (15)N was measured on a packed column with product ...

The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) grams plus sign in circlemol(-1) were measured over the temperature range of (301 to 486) Kelvin using the isothermal Knudsen effusion technique. The compounds measured include: anthraquinone, 9-fluorenone, 9-fluorenone oxime, phenoxazine, phenoxathiin and ...

This work presents experimental responses of single ultrasound contrast agents to short, large amplitude pulses, characterized using double passive cavitation detection. In this technique, two matched, focused receive transducers were aligned orthogonally to capture the acoustic response of a microbubble from within the overlapping confocal region. The microbubbles were categorized ...

Pressure influences both magma production and the failure of magma chambers. Changes in pressure interact with the local tectonic settings and can affect magmatic activity. Present-day reduction in ice load on subglacial volcanoes due to global warming is modifying pressure conditions in magmatic systems. The large pulse in volcanic production ...