Penetration Depth Research Papers - Academia.edu (original) (raw)

Wood coatings are widely used for aesthetic and protective reasons. Assessment of coating performance during service life is crucial in order to establish a knowledge database for product optimization. A vast amount of techniques is... more

Wood coatings are widely used for aesthetic and protective reasons. Assessment of coating performance during service life is crucial in order to establish a knowledge database for product optimization. A vast amount of techniques is available for analysis of a coating's behavior of which micro-imaging is an important tool. In addition to standard microscopy techniques, high-resolution X-ray tomography is presented as a modality offering non-destructive visualization of a coating and the substrate applied on. Combined with analysis of the 3D volumetric data, surface roughness, structure and thickness of the coating layer, penetration depth and related mechanical anchoring can be studied in relation with the underlying substrate. To provide a clear illustration of the possibilities and limitations of this technique, both an opaque solvent-borne and an opaque water-borne coating applied on two different wood types were scanned and analyzed. Clearly, three-dimensional X-ray imaging at high resolution produces valuable information merely by visualization. Moreover by proper analysis quantitative data is obtained taking into account the limitations of Xray computed tomography and of automated image processing.

The effect of the radial rotor surface grooves on rotor losses, in the case of a 3-phase, 4-pole, 24000 rpm, axially slitted solid rotor induction motor has been studied numerically and experimentally. The study shows that through radial... more

The effect of the radial rotor surface grooves on rotor losses, in the case of a 3-phase, 4-pole, 24000 rpm, axially slitted solid rotor induction motor has been studied numerically and experimentally. The study shows that through radial grooving of the rotor outer surface and thereby cutting the path for high frequency rotor harmonic currents results in considerable reduction of

tests. This process is not only time consuming, but the solid dosage forms are destroyed. Tablets from the batch of formulation will normally be completed before the results of quantitative analysis for content uniformity of the tablets... more

tests. This process is not only time consuming, but the solid dosage forms are destroyed. Tablets from the batch of formulation will normally be completed before the results of quantitative analysis for content uniformity of the tablets are known. If the analysis on unit dosage or content uniformity fails to satisfy the acceptance criteria, then no remedial action can be taken except to regrind, remix, and repress the tablets.

We investigate the critical speeding up of heat equilibration by the piston effect (PE) in a nearly supercritical van der Waals (vdW) fluid confined in a homogeneous porous medium. We perform an asymptotic analysis of the averaged... more

We investigate the critical speeding up of heat equilibration by the piston effect (PE) in a nearly supercritical van der Waals (vdW) fluid confined in a homogeneous porous medium. We perform an asymptotic analysis of the averaged linearized mass, momentum and energy equations to describe the response of the medium to a boundary heat flux. While nearing the critical point (CP), we find two universal crossovers depending on porosity, intrinsic permeability and viscosity. Closer to the CP than the first crossover, a pressure gradient appears in the bulk due to viscous effects, the PE characteristic time scale stops decreasing and tends to a constant. In infinitly long samples the temperature penetration depth is larger than the diffusion one indicating that the PE in porous media is not a finite size effect as it is in pure fluids. Closer to the CP, a second cross over appears which is characterized by a pressure gradient in the thermal boundary layer (BL). Beyond this second crossover, the PE time remains constant, the expansion of the fluid in the BL drops down and the PE ultimately fades away.

Grinding often plays the role of final machining, and, therefore, its parameters significantly affect the properties of the treated surface. In this study, the state of surface residual stresses (RSs) and their depth distribution into the... more

Grinding often plays the role of final machining, and, therefore, its parameters significantly affect the properties of the treated surface. In this study, the state of surface residual stresses (RSs) and their depth distribution into the bulk is investigated with respect to various cooling environments during grinding. In order to acquire complete stress tensors, the sample surfaces were analysed using the X-ray diffraction technique. Since ε (sin 2 ) dependences in grinding direction are non-linear and exhibit psi-splitting, the method proposed by Dölle and Hauk was used to evaluate the tensors of anisotropic triaxial state of RS. The effective penetration depth of Cr K␣ X-ray radiation into ferrous materials is approximately 4 m, and, therefore, removal of surface layers is necessary in order to pinpoint the distribution of RSs beneath the surface. The process of electro-chemical polishing ensures that the impact of material removal causes minimal or negligible mechanical and thermal distortions of the investigated state of stress.

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Solute transport rates within the uppermost 2 cm of a rippled continental shelf sand deposit, with a mean grain size of 400-500 mm and permeabilities of 2.0-2.4 Â 10 À11 m 2 , have been measured in situ by detecting the breakthrough of a... more

Solute transport rates within the uppermost 2 cm of a rippled continental shelf sand deposit, with a mean grain size of 400-500 mm and permeabilities of 2.0-2.4 Â 10 À11 m 2 , have been measured in situ by detecting the breakthrough of a pulse of iodide after its injection into the bottom water. These tracer experiments were conducted on the USA Middle Atlantic Bight shelf at a water depth of B13 m using a small tethered tripod that carried a close-up video camera, acoustic current meter, motorized 1.5 liter ''syringe'', and a microprofiling system for positioning and operating a solidstate voltammetric microelectrode. When triggered on shipboard, the syringe delivered a 0.21 M solution of potassium iodide and red dye through five nozzles positioned around and above the buried tip of the voltammetric sensor for 0.65-5 min. Bottom turbulence rapidly mixed and dispersed the tracer, which then was carried into the bed by interfacial water flows associated with ripple topography. The advective downward transport to the sensor tip was timed by a sequence of repetitive voltammetric scans. The distance-averaged vertical velocity, expressed as the depth of the sensor tip in the sand divided by the time to iodide breakthrough, was found to vary from 6 to 53 cm h À1 and generally to decrease with sediment depth. Because of episodic pumping and dispersion associated with the greatest 5% of wave heights and current speeds recorded, some concentration vs. time responses showed evidence of uneven solute migration. For reasons of mass balance, the advective flow field in the surface layers of permeable beds includes regions of water intrusion, horizontal pore-water flow and upwelling which also may explain some of the observed uneven migration. Pore-water advection was also evident in oxygen profiles measured before and after tracer injection with the voltammetric sensor. These profiles showed irregular distributions and oxygen penetration depths of 4-4.5 cm.

We present a new approach for computing generalized proximity information of arbitrary 2D objects using graphics hardware. Using multi-pass rendering techniques and accelerated distance computation, our algorithm performs proximity... more

We present a new approach for computing generalized proximity information of arbitrary 2D objects using graphics hardware. Using multi-pass rendering techniques and accelerated distance computation, our algorithm performs proximity queries not only for detecting collisions, but also for computing intersections, separation distance, penetration depth, and contact points and normals. Our hybrid geometry and image-based approach balances computation between the CPU and graphics subsystems. Geometric object-space techniques coarsely localize potential intersection regions or closest features between two objects, and image-space techniques compute the low-level proximity information in these regions. Most of the proximity information is derived from a distance field computed using graphics hardware. We demonstrate the performance in collision response computation for rigid and deformable body dynamics simulations. Our approach provides proximity information at interactive rates for a variety of simulation strategies for both backtracking and penalty-based collision responses.

As the introduction of piezoelectric materials into micro electromechanical systems increases, there is a correlating requirement for understanding the mechanical properties of these films. We have investigated the mechanical properties... more

As the introduction of piezoelectric materials into micro electromechanical systems increases, there is a correlating requirement for understanding the mechanical properties of these films. We have investigated the mechanical properties of unpoled PZT [Pb(Zr,Ti)O 3 ] and PMNT [Pb(Mg 1/3 Nb 2/3 ) 1−x Ti x O 3 ] thin films deposited by sputtering. In this study, nano-indentation, a technique which allows determination of the transverse mechanical properties, is used. It is the easiest method for assessing the biaxial elastic modulus and the hardness of thin films. It was confirmed that neither cracks, nor pile-ups, were observed for indentation depths below 20% of the film's thickness.

The light does not penetrate deeply into the skin tissue because of tissue turbidity. Light penetration depth in skin tissue can be increased by using optical clearing agents such as glycerol, glucose and dimethyl sulfoxide(DMSO). The... more

The light does not penetrate deeply into the skin tissue because of tissue turbidity. Light penetration depth in skin tissue can be increased by using optical clearing agents such as glycerol, glucose and dimethyl sulfoxide(DMSO). The stratum corneum prevents most optical skin clearing agent from diffusing into the tissue. Previous studies demonstrated the optical tissue clearing effect using optical clearing agents and presented several physical methods to improve transdermal delivery of optical clearing agents. In previous study, we introduced a micro-needling method to enhance optical clearing efficacy against skin barrier and suggested quantitative analysis method to evaluate the optical tissue clearing efficacy. In this study, we present a new physical micro-needling method combined with sonophoresis to further enhance the optical tissue clearing efficacy. The optical tissue clearing effect was quantitatively evaluated with a modulation transfer function target placed under ex-vivo porcine skin samples. To improve transdermal delivery of glycerol, 70% glycerol solution as optimal concentration was topically applied. In conclusion, the samples treated with micro-needling method and sonophoresis resulted in noticeable optical tissue clearing effect.

The frequency response of pinned vortex lattice in type-II superconductors is investigated. If frequency is not too low than the AC-absorption is caused by oscillations of the vortex lattice near equilibrium state (Campbell regime). We... more

The frequency response of pinned vortex lattice in type-II superconductors is investigated. If frequency is not too low than the AC-absorption is caused by oscillations of the vortex lattice near equilibrium state (Campbell regime). We calculate the field and temperature dependencies ofboth Campbell penetration depth and surface resistance, taking into account the effect of the thermal depinning. In the region of low frequencies jumps of lattice regions between different metastable states (two-level systems) come into play and give main contribution to the AC-response. The field and temperature dependencies of the penetration depth and surface resistance in the last region are also found.

The photosynthetic performance and pigment content of Gracilaria chilensis Bird, McLachlan, and Oliveira were measured under natural solar radiation in the Quempillen river estuary (southern Chile) in order to assess the short-term... more

The photosynthetic performance and pigment content of Gracilaria chilensis Bird, McLachlan, and Oliveira were measured under natural solar radiation in the Quempillen river estuary (southern Chile) in order to assess the short-term acclimation of this species to the current levels of ultraviolet (UV) radiation during midsummer. The effect of the tidal fluctuation was evaluated in algae exposed for 3 days to two light climates in cages suspended at two depths (0.5 and 1.5 m from the bottom). Responses to high solar radiation at noon were also assessed to gain insights into rapid photochemical kinetics and the degree of photoinhibition. Results indicated that G. chilensis is a shade-adapted species with a high content of photosynthetic pigments (Chl a and phycobilins), high quantum efficiency (a), and low light saturating point (E k ) between 60 and 170 Amol m À2 s À1 reflecting the high turbidity and marked light attenuation (K d ) of both UV and photosynthetically active radiation (PAR): 1% of the UVB radiation (280-320 nm) reaches 1.8 m depth only during high tide, whereas during ebb tide, UVB can only be detected at 30 cm depth. In the case of PAR, 1% penetration depth was close to 2.7 m during low tide. Under these conditions decreases in rates of photosynthesis at noon did not exceed 23%, even in the presence of UVB. When algae were exposed to full solar radiation at noon for 3 h and then incubated under shaded conditions for recovery, evidence for photoinhibition was observed: in algae exposed to PAR+UVA+UVB, photosynthesis decreased by 16%, while recovery was close to 88% of the control. In treatments deprived of UVB, recovery was close to 100%. These results suggest that G. chilensis is not commonly exposed to high irradiances in the field and that UVB is potentially detrimental for photosynthesis when algae are maintained close to the surface, at least during summer. This was corroborated by the low content of UV-absorbing compounds (mycosporine-like amino acids, or MAAs; between 0.89 and 1.75 mg g DW).

The penetration of light into a photobioreactor and its relation to hydrogen production were analyzed using a photosynthetic bacterium, Rhodobacter sphaeroides. A photobioreactor composed of four compartments aligned along the light... more

The penetration of light into a photobioreactor and its relation to hydrogen production were analyzed using a photosynthetic bacterium, Rhodobacter sphaeroides. A photobioreactor composed of four compartments aligned along the light penetration axis, each with a OS-cm light path, was used to examine the hydrogen evolution at various light penetration depths. The light energy decreased quasi-exponentially upon passage through the bacterial suspension (1.5 mg dry wt./ml). In the first compartment (O-O.5 cm), 69% of the incident light energy was absorbed, 21% in the second one (OS-l.0 cm) and 7% in the third one (1.0-1.5 cm). However, the hydrogen evolution rates did not decrease as the light energy. The efficiency of the conversion of light to hydrogen increased with the depth in the reactor and the third compartment showed the highest efficiency. Excess absorption of light energy in the shaliow region reduced the total efficiency of the reactor. Alteration of the light spectrum upon passage of the light through the bacterial suspension greatly affected the hydrogen production. In the deep region of the reactor, energy of light of wavelength around the absorption maxima of the bacterium (800-850 nm) was lost. Light reaching the deep region was mainly of wavelength between 600 and 780 nm, and was also used for hydrogen production.

Vertical cylindrical vessel-chambers as a part of coal — drying plants, whose purpose is to collect wastewater, are supported at 3 points in upper dish head area and are made of fine-grained Mn steel plates, joined by welding. Significant... more

Vertical cylindrical vessel-chambers as a part of coal — drying plants, whose purpose is to collect wastewater, are supported at 3 points in upper dish head area and are made of fine-grained Mn steel plates, joined by welding. Significant thinning and leaking in upper dish head area of the vessel occurred due to original design provoking an intensive abrasion, cracking and rupture. After reconstruction, in the upper zone of cylindrical shell, two new joints were made in sity by manual arc welding, with subsequent, local post-weld heat treatment. However, cracks appeared firstly in new welded zones in radial and axial joints, and then in zones of openings. Later, the similar failure features began to appear in the area of original welded joints. All of these cracks were repaired by properly specified technology. Unfortunately, after some period of exploitation the initiation of new cracks was observed, at first by the visual inspection. This problem was detected in the repaired areas...

From measurements of the magnetic penetration depth, lambda(T)\lambda(T)lambda(T), from 1.6 K to TcT_cTc in films of electron-doped cuprates La$_{2-x}$Ce$_x$CuO$_{4-y}$ and Pr$_{2-x}$Ce$_x$CuO$_{4-y}$ we obtain the normalized density of states, Ns(E)N_s(E)Ns(E) at... more

From measurements of the magnetic penetration depth, lambda(T)\lambda(T)lambda(T), from 1.6 K to TcT_cTc in films of electron-doped cuprates La$_{2-x}$Ce$_x$CuO$_{4-y}$ and Pr$_{2-x}$Ce$_x$CuO$_{4-y}$ we obtain the normalized density of states, Ns(E)N_s(E)Ns(E) at T=0 by using a simple model. In this framework, the flat behavior of lambda−2(T)\lambda^{-2}(T)lambda−2(T) at low TTT implies Ns(E)N_s(E)Ns(E) is small, possibly gapped, at low energies. The upward curvature in lambda−2(T)\lambda^{-2}(T)lambda−2(T) near TcT_cTc seen in overdoped films implies that superfluid comes from an anomalously small energy band within about 3kBTc3k_BT_c3kBTc of the Fermi surface.

This paper presents a comprehensive analysis on microwave power absorption and associated heating characteristics for various food materials. The analysis is based on a closed form solution, which is derived from the first principle. It... more

This paper presents a comprehensive analysis on microwave power absorption and associated heating characteristics for various food materials. The analysis is based on a closed form solution, which is derived from the first principle. It has been shown that both absorbed power distributions and average absorbed power exhibit three distinct behaviors as sample length (2L) is varied from 2L ( k m /2p to 2L ) D p , where k m and D p are wavelength and penetration depth within the material, respectively. These three regimes are termed as thin (2L ( k m /2p), resonating (k m /2p 2L D p ) and thick (2L ) D p ) samples. A complete characterization of absorbed power has been established in all the three regimes. This work also provides a correlation for the prediction of resonating sample lengths, which for the first time takes into account the effect of dielectric properties (k m and D p ) of the material and free space and also the influence of various distributions of microwave incidence. It has been shown that the closed form analysis on absorbed power presented in this work can be used to forecast the heating characteristics and various distributions of microwave incidence may be used to suitably alter the heating characteristics. Overall, the analysis presented in this work can be used as a guideline to predict optimal heating strategy for microwave assisted food processing.

A method to retrieve the surface emissivity of sea ice at the window channels of the Advanced Microwave Sounding Unit (AMSU) radiometers in the polar region is presented. The instruments are on the new-generation satellites of the U.S.... more

A method to retrieve the surface emissivity of sea ice at the window channels of the Advanced Microwave Sounding Unit (AMSU) radiometers in the polar region is presented. The instruments are on the new-generation satellites of the U.S. National Oceanic and Atmospheric Administration (NOAA-15, NOAA-16, and NOAA-17). The method assumes hypothetical surfaces with emissivities zero and one and simulates brightness temperatures at the top of the atmosphere using profiles of atmospheric parameters, e.g., from the European Centre for Medium-Range Weather Forecasts (ECMWF) model runs, as input for a radiative transfer model. The retrieval of surface emissivity is done by combining simulated brightness temperatures with the satellite-measured brightness temperature. The AMSU window channels differ in surface penetration depths and, thus, in the surface microphysical parameters that they depend on. Lowest layer air temperatures from ECMWF are used to infer temperatures of emitting layers at different frequencies of sea ice. A complete yearly cycle of monthly average emissivities in two selected regions (first-and multiyear ice) is giving insight into the variation of emissivities in various development stages of sea ice.

Quantification of drugs within the skin is essential for topical and transdermal delivery research. Over the last two decades, horizontal sectioning, consisting of tape stripping throughout the stratum corneum, has become one of the... more

Quantification of drugs within the skin is essential for topical and transdermal delivery research. Over the last two decades, horizontal sectioning, consisting of tape stripping throughout the stratum corneum, has become one of the traditional investigative techniques. Tape stripping of human stratum corneum is widely used as a method for studying the kinetics and penetration depth of drugs. This paper shows the applications of the tape stripping technique to quantify drug penetration through the skin, underlining its versatile application in the area of topical and transdermal drugs.

Significant progress has been made on the Mega Ampere Spherical Tokamak (MAST) towards a fundamental understanding of transport, stability and edge physics and addressing technological issues for future large devices. Collaborative... more

Significant progress has been made on the Mega Ampere Spherical Tokamak (MAST) towards a fundamental understanding of transport, stability and edge physics and addressing technological issues for future large devices. Collaborative studies of the L-H transition with NSTX and ASDEX Upgrade confirm that operation in a connected double-null configuration significantly reduces the threshold power, P thr . The MAST data provide support for a theory for the transition based on finite β drift wave turbulence suppression by self-generated zonal flows. Analysis of low and high field side density gradients in the H-mode pedestal provides support for an analytical model of the density pedestal width dependent on the neutral penetration depth. Adding MAST data to international confinement databases has enhanced confidence in scalings for ITER by significantly expanding the range of β and ε explored and indicates a slightly stronger ε dependence than in current scalings. Studies of core transport have been conducted for well-diagnosed L-mode, H-mode and internal transport barrier (ITB) discharges using TRANSP, and microstability and turbulence studies have been carried out using GS2. Linear micro-stability analysis indicates that ITG modes are typically unstable on all flux surfaces with growth rates that are comparable to the equilibrium E × B flow shearing rate. Mixing length estimates of transport coefficients from ITG (neglecting flow shear) give diffusion coefficients that are broadly comparable with observed thermal diffusivities. Non-linear, collisionless ETG calculations have been performed and suggest radially extended electrostatic streamers up to 100ρ e across in radius. Transport from ITG could easily be suppressed in regions where the E × B shear flow rate,

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy An experimental helical-tubular photobioreactor for continuous production of Nannochloropsis sp.

Dielectric properties of apple, pear, orange, grape and pineapple juices were studied from 20 to 4500 MHz at 15-95°C. The dielectric constants e 0 of fruit juices decreased as frequency increased. The loss factors e 00 decreased with... more

Dielectric properties of apple, pear, orange, grape and pineapple juices were studied from 20 to 4500 MHz at 15-95°C. The dielectric constants e 0 of fruit juices decreased as frequency increased. The loss factors e 00 decreased with increasing frequency to a minimum between about 1000 and 3000 MHz, depending on temperature, and then increased as frequency increased. The frequency of that turning point increased, whereas the minimum e 00 decreased with increasing temperature. The e 00 values increased with increasing temperature below about 1000 MHz, and decreased with increasing temperature above 3000 MHz. Dielectric constants decreased consistently and linearly with increasing temperature. Linear or polynomial correlations for the dependence of dielectric properties on temperature were developed. The power penetration depth of all fruit juices decreased with increasing frequency. The depth decreased as temperature increased at lower frequencies and increased with temperature above 3000 MHz. The dielectric properties obtained in the study provide important parameters for juice pasteurization by dielectric heating.

The lateral force interaction between a permanent bar magnet and a large slab of high T, superconductor has been investigated at 77 K, under conditions of a constant vertical separation of 2 mm. The restoring force as a function of... more

The lateral force interaction between a permanent bar magnet and a large slab of high T, superconductor has been investigated at 77 K, under conditions of a constant vertical separation of 2 mm. The restoring force as a function of lateral displacement rises very steeply, and reaches 90% of its saturation value, 5.1 mN, after 1.8 mm. The profile of the force-displacement curve is in qualitative agreement with the existing theory. A significant quantitative discrepancy is interpreted as due to a theoretical penetration depth exceeding the sample thickness. The lateral magnetic stiffness or spring constant, is found to be independent of displacement away from lateral equilibrium.

We review some aspects of the isotope effect (IE) in superconductors. Our focus is on the influence of factors not related to the pairing mechanism. After summarizing the main results obtained for conventional superconductors, we review... more

We review some aspects of the isotope effect (IE) in superconductors. Our focus is on the influence of factors not related to the pairing mechanism. After summarizing the main results obtained for conventional superconductors, we review the effect of magnetic impurities, the proximity effect and non-adiabaticity on the value of the isotope coefficient (IC). We discuss the isotope effect of T c and of the penetration depth δ. The theory is applied to conventional and high-T c superconductors. Experimental results obtained for YBa 2 Cu 3 O 7−δ related materials (Zn and Pr-substituted as well as oxygen-depleted systems) and for La 2−x Sr x CuO 4 are discussed.

The successful application of finite element analysis to ultrafast optoelectronic devices is demonstrated. Finite element models have been developed for both an alloyed-and surface-contact metal-semiconductor-metal photodetectors. The... more

The successful application of finite element analysis to ultrafast optoelectronic devices is demonstrated. Finite element models have been developed for both an alloyed-and surface-contact metal-semiconductor-metal photodetectors. The simulation results agree with previously reported experimental data. The alloyed device, despite having a somewhat larger capacitance, has a non-illuminated region of lower resistance with a more-uniform and deeper-penetrating electric field and carrier transport current. The latter explains, in terms of the equivalent lumped parameters, the experimentally observed faster response of the alloyed device. The model is further used to predict improved responsivity, based on electrode spacing and antireflective coating. We project that increasing the depth of the alloyed contact beyond approximately half of the optical penetration depth will not yield significantly improved responsivity.

This paper places focus on the special properties of pure boron chemical-vapor deposition (CVD) thin-film layers that, in several device applications, have recently been shown to augment the potentials of silicon device integration.... more

This paper places focus on the special properties of pure boron chemical-vapor deposition (CVD) thin-film layers that, in several device applications, have recently been shown to augment the potentials of silicon device integration. Besides forming a reliable an efficient dopant source for both ultrashallow and deep p + n junctions, the deposited amorphous boron (a-B) layer itself, even for sub-nm thicknesses, is instrumental in suppressing minority electron injection from the n-region into the p + contact. Therefore, even for nm-shallow junctions where the current levels mainly will approach high Schottky-like values, the diodes exhibit saturation current levels that can become as low as that of conventional deep junctions.

The additional optical absorption in tissue resulting from the uptake of exogenous photosensitizers increases the effective attenuation of photoactivating light. This may be significant for the irradiation of solid tumours in photodynamic... more

The additional optical absorption in tissue resulting from the uptake of exogenous photosensitizers increases the effective attenuation of photoactivating light. This may be significant for the irradiation of solid tumours in photodynamic therapy, since it reduces the depth or volume of tissue treated. The effect has been studied in vitro by using dihaematoporphyrin ether (DHE) and 630 nm light in tissues representing a wide range of absorption and scattering conditions. While the attenuation may be markedly changed by small concentrations of DHE in pure scattering media, tissues with significant inherent light absorption are little affected by the additional absorption of DHE at concentrations relevant to clinical photodynamic therapy. However, it is shown that for other potential photosensitizers such as the phthalocyanines, which have substantially greater absorption at the treatment wavelength than DHE, the penetration of light in tissues may be significantly reduced.

This paper deals with milling sound information. In milling operations, cutting edge impacts excite vibrations due to the interaction between the cutter and the workpiece, and because of the system's lack of dynamic stiffness. It is... more

This paper deals with milling sound information. In milling operations, cutting edge impacts excite vibrations due to the interaction between the cutter and the workpiece, and because of the system's lack of dynamic stiffness. It is possible to distinguish between free, forced and self-excited vibrations. During a milling operation these three different types of mechanical vibrations propagate through air and generate a sound that intrinsically contains information about the process.

This review presents the state of the art regarding the possible intensification of desorption processes by use of microwave irradiation. The most important experimental and modeling results reported in the literature on the laboratory... more

This review presents the state of the art regarding the possible intensification of desorption processes by use of microwave irradiation. The most important experimental and modeling results reported in the literature on the laboratory scale as well as on the industrial scale were collected in this paper. It follows from the review that microwave heating is a powerful novel method proving many advantages when utilized for regeneration of loaded adsorbents. In general, a short penetration depth could be a drawback of this very efficient heating method. Hence, it seems that the fluidized bed adsorbers are better choice than the fixed-bed ones when the microwave-assisted desorption step is carried out because more homogenous temperature distribution would be guaranteed. 7 8 9 10 11 12

The gamma ray energy absorption ( EABF) and exposure buildup factors ( EBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean... more

The gamma ray energy absorption ( EABF) and exposure buildup factors ( EBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameter geometric progression (G-P) fitting approximation has been used to calculate both EABF and EBF. Variations of EABF and EBF with incident photon energy, penetration depth and weight fraction of elements have been studied. While the significant variations in EABF and EBF for amino acids and fatty acids have been observed at the intermediate energy region where Compton scattering is the main photon interaction process, the values of EABF and EBF appear to be almost the same for all carbohydrates in the continuous energy region. It has been observed that the fatty acids have the largest EABF and EBF at 0.08 and 0.1 MeV, respectively, whereas the maximum values of EABF and EBF have been observed for aminoacids and carbohydrates at 0.1 MeV. At the fixed energy of 1.5 MeV, the variation of EABF with penetration depth appears to be independent of the variations in chemical composition of the amino acids, fatty acids and carbohydrates. Significant variations were also observed between EABF and EBF which may be due to the variations in chemical composition of the given materials.

Purpose: This study is conducted to develop a simplified mathematical model to describe the lift mechanics of downhill skiing and snowboarding, where the lift contributions due to both the transiently trapped air and the compressed solid... more

Purpose: This study is conducted to develop a simplified mathematical model to describe the lift mechanics of downhill skiing and snowboarding, where the lift contributions due to both the transiently trapped air and the compressed solid phase (snow crystals) are determined. To our knowledge, this is the first time that anyone has attempted to realistically estimate the relative contribution of the transiently trapped air to the total lift in skiing and snowboarding. Methods: The model uses Shimizu's empirical relation to predict the local variation in Darcy permeability due to the compression of the solid phase. The forces and moments on the skier or snowboarder are used to predict the angle of attack of the planing surface, the penetration depth at the leading edge, and the shift in the center of pressure for two typical snow types, fresh and wind-packed snow. We present numerical solutions for snowboarding and asymptotic analytic solutions for skiing for the case where there are no edging or turning maneuvers. The force and moment balance are then used to develop a theory for control and stability in response to changes in the center of mass as the individual shifts his/her weight. Results: Our model predicts for fine-grained, windpacked snow that when the velocity (U) of the snowboarder or skier is 20 mIs j1 , approximately 50% of the total lift force is generated by the trapped air for snowboarding and 40% for skiing. For highly permeable fresh powder snow, the lift contribution from the pore air pressure drops substantially. Conclusion: This paper develops a new theoretical framework for analyzing the lift mechanics and stability of skis and snowboards that could have important applications in future ski and snowboard design.

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp... more

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp allowed obtaining gloss levels down to 0.5 units (at 60 • ) depending on the acrylate formulation and curing conditions. Moreover, UV matt-finished sample showed enhanced surface hardness and increased chemical resistance. It is assumed that 172 nm excimer irradiation resulted in a higher network density via additional cross-linking reactions.

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp... more

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp allowed obtaining gloss levels down to 0.5 units (at 60 • ) depending on the acrylate formulation and curing conditions. Moreover, UV matt-finished sample showed enhanced surface hardness and increased chemical resistance. It is assumed that 172 nm excimer irradiation resulted in a higher network density via additional cross-linking reactions.

Tape stripping is a simple and efficient method for the assessment of quality and efficacy of cosmetical and dermatological formulations. After topical application and penetration of formulations, the cell layers of the stratum corneum... more

Tape stripping is a simple and efficient method for the assessment of quality and efficacy of cosmetical and dermatological formulations. After topical application and penetration of formulations, the cell layers of the stratum corneum are successively removed from the same skin area using adhesive films. The tape strips contain the amount of corneocytes and the corresponding amount of the penetrated formulation, which can be determined by classical analytical chemical methods. Different formulations can strongly influence the amount of stratum corneum removed with every tape strip. Therefore, it is essential for the comparison of the penetration of different formulations that the amount of formulation detected on the single tape strip is not related to the tape strip number as a relative measure of the penetration depths, but to their standardized real position in the stratum corneum. Therefore, different methods are reported for the determination of the amount of stratum corneum removed with every tape strip.

In-situ penetration tests have been widely used in geotechnical and foundation engineering for site investigation in support of analysis and design. The standard penetration test (SPT) and the cone penetration test (CPT) are two typical... more

In-situ penetration tests have been widely used in geotechnical and foundation engineering for site investigation in support of analysis and design. The standard penetration test (SPT) and the cone penetration test (CPT) are two typical in-situ penetration tests. The dynamic cone penetration test shows features of both the CPT and the SPT. The DCPT is performed by dropping a hammer from a certain fall height and measuring penetration depth per blow for each tested depth. The DCPT is a quick test to set up, run, and evaluate on site. Due to its economy and simplicity, better understanding of DCPT results can reduce efforts and cost for evaluation of pavement and subgrade soils. Present practice in determining the adequacy of a compacted subgrade is to determine the dry density and water content by either the sand-cone method or the nuclear gauge. The use of the resilient modulus (M r ) has recently become mandatory for pavement design. To find the M r , a time-consuming test is required which demands significant effort. Therefore, a faster and easier alternative for compaction control in road construction practice is desired. To this end, the present project is a step towards the generation of sufficient data to create appropriate correlations between subgrade parameters and DCPT results.

Superconducting quantum interference devices (SQUIDs) are sensitive detectors of magnetic flux. A SQUID consists of a superconducting loop interrupted by either one or two Josephson junctions for the RF or dc SQUID, respectively. Low... more

Superconducting quantum interference devices (SQUIDs) are sensitive detectors of magnetic flux. A SQUID consists of a superconducting loop interrupted by either one or two Josephson junctions for the RF or dc SQUID, respectively. Low transition temperature (Tc) SQUIDs are fabricated from thin films of niobium. Immersed in liquid helium at 4.2 K, their flux noise is typically 10 06 8 0 Hz 01=2 , where 8 0 h=2e is the flux quantum.

New generation fluorophores, also termed upconversion nanoparticles (UCNPs), have the ability to convert near infrared radiations with lower energy into visible radiations with higher energy via a non-linear optical process. Recently,... more

New generation fluorophores, also termed upconversion nanoparticles (UCNPs), have the ability to convert near infrared radiations with lower energy into visible radiations with higher energy via a non-linear optical process. Recently, these UCNPs have evolved as alternative fluorescent labels to traditional fluorophores, showing great potential for imaging and biodetection assays in both in vitro and in vivo applications. UCNPs exhibit unique luminescent properties, including high penetration depth into tissues, low background signals, large Stokes shifts, sharp emission bands, and high resistance to photo-bleaching, making UCNPs an attractive alternative source for overcoming current limitations in traditional fluorescent probes. In this review, we discuss the recent progress in the synthesis and surface modification of rare earth doped UCNPs with a specific focus on their biological applications.

The single-site two-electron exchange amplitude J sd between the Cu 4s and Cu 3d x 2 −y 2 states is found to be the pairing mechanism of high-Tc overdoped cuprates. The noninteracting part of the Hamiltonian spans the copper Cu 4s, Cu 3d... more

The single-site two-electron exchange amplitude J sd between the Cu 4s and Cu 3d x 2 −y 2 states is found to be the pairing mechanism of high-Tc overdoped cuprates. The noninteracting part of the Hamiltonian spans the copper Cu 4s, Cu 3d x 2 −y 2 and oxygen O 2px and O 2py states. Within the standard BCS treatment an explicit expression for the momentum dependence of the gap ∆p is derived and shown to fit the angle-resolved photoemission spectroscopy (ARPES) data. The basic thermodynamic and electrodynamic properties of the model [specific heat C(T ), London penetration depth λ(T )] are analytically derived. These are directly applicable to cuprates without complicating structural accessories (chains, double CuO 2 planes, etc.). We advocate that the pairing mechanism of overdoped and underdoped cuprates is the same, as Tc displays smooth doping dependence. Thus, a long-standing puzzle in physics is possibly solved.

We describe a prototype ultrawideband radar. We show how the system was designed and how the hardware was developed for the radar prototype. Waveform generation, radar parameters, and signal processing for the stepped frequency waveform... more

We describe a prototype ultrawideband radar. We show how the system was designed and how the hardware was developed for the radar prototype. Waveform generation, radar parameters, and signal processing for the stepped frequency waveform are discussed. The radar operates from 500 MHz to 3 GHz with a nominal resolution of 6 cm in air. The advantage of the stepped frequency approach over an impulse radar is better matching between the transmitted waveform and the receiver. We use range gating to improve the system dynamic range. The advantages are illustrated with laboratory measurements and field measurements from glacial ice and permafrost in Svalbard, showing penetration depths of 11 m. Antennas which do not require contact with the ground were developed and used in the experiments. has been with the Norwegian Defence Research Establishment (FFI), Kjeller, Norway, where he is working in different fields: weapon effects, security sensors, and signal processing. After a period working with research planning and strategy, he is currently involved in radar signal processing related to ultrawideband systems and inverse synthetic aperture radar.

Micro-or non-destructive analytical approach is an imperative when analysing historical artefacts. Due to its practically non-destructive character, proton induced X-ray spectrometry (PIXE) has become a method of choice for the study of... more

Micro-or non-destructive analytical approach is an imperative when analysing historical artefacts. Due to its practically non-destructive character, proton induced X-ray spectrometry (PIXE) has become a method of choice for the study of historical documents. In the present paper, use of in-air PIXE method for analysis of iron gall inks applied at handwriting of documents is evaluated. The errors arising from the non-uniform ink deposit, proton penetration depth and size of the proton beam versus width of ink lines, effects of surface roughness, as well as the importance of the PIXE set-up geometry on the accuracy of the results are discussed. It follows that the main problems can be attributed to the fact that PIXE is a surface technique and that the analysis is limited to a small amount of material, while ink deposit on the paper is usually non-uniform in depth as well as on the paper surface. Despite possible systematic uncertainties when applying the PIXE method, good correlation between determinations obtained by PIXE and atomic absorption spectroscopy (AAS) on model samples clearly demonstrate that the errors are well within a reasonable limit of a few percents.

This paper presents a combined experimental and numerical study of the flow characteristics of round vertical liquid jets plunging into a cylindrical liquid bath. The main objective of the experimental work consists in determining the... more

This paper presents a combined experimental and numerical study of the flow characteristics of round vertical liquid jets plunging into a cylindrical liquid bath. The main objective of the experimental work consists in determining the plunging jet flow patterns, entrained air bubble sizes and the influence of the jet velocity and variations of jet falling lengths on the jet penetration depth. The instability of the jet influenced by the jet velocity and falling length is also probed. On the numerical side, two different approaches were used, namely the mixture model approach and interface-tracking approach using the level-set technique with the standard two-equation turbulence model. The numerical results are contrasted with the experimental data. Good agreements were found between experiments and the two modelling approaches on the jet penetration depth and entraining flow characteristics, with interface tracking rendering better predictions. However, visible differences are observed as to the jet instability, free surface deformation and subsequent air bubble entrainment, where interface tracking is seen to be more accurate. The CFD results support the notion that the jet with the higher flow rate thus more susceptible to surface instabilities, entrains more bubbles, reflecting in turn a smaller penetration depth as a result of momentum diffusion due to bubble concentration and generated fluctuations. The liquid average velocity field and air concentration under tank water surface were compared to existing semianalytical correlations. Noticeable differences were revealed as to the maximum velocity at the jet centreline and associated bubble concentration. The mixture model predicts a higher velocity than the level-set and the theory at the early stage of jet penetration, due to a higher concentration of air that cannot rise to the surface and remain trapped around the jet head. The location of the maximum air content and the peak value of air holdup are also predicted differently.

In this paper an approach for obtaining depth and section modulus of the cantilever sheet pile wall using inverse reliability method is described. The proposed procedure employs inverse first order reliability method to obtain the design... more

In this paper an approach for obtaining depth and section modulus of the cantilever sheet pile wall using inverse reliability method is described. The proposed procedure employs inverse first order reliability method to obtain the design penetration depth and section modulus of the steel sheet pile wall in order that the reliability of the wall against failure modes must meet a desired level of safety. Sensitivity analysis is conducted to assess the effect of uncertainties in design parameters on the reliability of cantilever sheet pile walls. The analysis is performed by treating back fill soil properties, depth of the water table from the top of the sheet pile wall, yield strength of steel and section modulus of steel pile as random variables. Two limit states, viz., rotational and flexural failure of sheet pile wall are considered. The results using this approach are used to develop a set of reliability based design charts for different coefficients of variation of friction angle of the backfill (5%, 10% and 15%). System reliability considerations in terms of series and parallel systems are also studied.

The ball indentation technique based on deforming a material with a spherical indenter is an useful non-destructive tool for evaluating mechanical properties from a very small volume of material. In this work, the indentation test carried... more

The ball indentation technique based on deforming a material with a spherical indenter is an useful non-destructive tool for evaluating mechanical properties from a very small volume of material. In this work, the indentation test carried out using a 1.0 mm diameter tungsten carbide ball to penetration depths of around 100-200 mm is modeled using finite element (FE) method and analyzed for three steels having different yield stress and strain hardening exponent. The FE generated load-depth curve is compared and verified with the experimental load-depth data for the three materials. The role of the contact friction at the indenter-specimen interface on both the load-depth plot and indentation profile are examined. The development of pile-up/sink-in during indentation and its dependence on strain hardening characteristics of the material, contact friction and indentation depth are analyzed using the FE model. The indentation profiles obtained from simulation are compared with experimental profiles and the implication of pile-up phenomenon on accurate evaluation of stress-strain values from the experimental indentation load-depth data is discussed.

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp... more

For UV-curable acrylate coatings reinforced by silica nanoparticles, the effect of 172 nm excimer irradiation on the surface roughness has been studied. A dual UV lamp set-up consisting of a 172 nm excimer lamp and a mercury arc lamp allowed obtaining gloss levels down to 0.5 units (at 60 • ) depending on the acrylate formulation and curing conditions. Moreover, UV matt-finished sample showed enhanced surface hardness and increased chemical resistance. It is assumed that 172 nm excimer irradiation resulted in a higher network density via additional cross-linking reactions.

Millimeter (mm) wave reflectivity was used to determine murine skin permittivity. Reflection was measured in anesthetized Swiss Webster and SKH1-hairless mice in the 37-74 GHz frequency range. Two skin models were tested. Model 1 was a... more

Millimeter (mm) wave reflectivity was used to determine murine skin permittivity. Reflection was measured in anesthetized Swiss Webster and SKH1-hairless mice in the 37-74 GHz frequency range. Two skin models were tested. Model 1 was a single homogeneous skin layer. Model 2 included four skin layers: (1) the stratum corneum, (2) the viable epidermis plus dermis, (3) fat layer, and (4) muscle which had infinite thickness. We accepted that the permittivity of skin in the mm wave frequency range results from the permittivity of cutaneous free water which is described by the Debye equation. Using Fresnel equations for reflection we determined the skin parameters best fitting to the reflection data and derived the permittivity of skin layers. The permittivity data were further used to calculate the power density and specific absorption rate profiles, and the penetration depth of mm waves in the skin. In both murine models, mm waves penetrate deep enough into tissue to reach muscle. In human skin, mm waves are mostly absorbed within the skin. Therefore, when extrapolating the effects of mm waves found in animals to humans, it is important to take into account the possible involvement of muscle in animal effects.

In this study, effects of cement type, cement content and water/cement (W/C) ratio level on the sea water resistance of concrete were investigated. Test samples were exposed to sea water by wetting-drying manner. Residual splitting... more

In this study, effects of cement type, cement content and water/cement (W/C) ratio level on the sea water resistance of concrete were investigated. Test samples were exposed to sea water by wetting-drying manner. Residual splitting tensile and compressive strength, and chloride penetration depths of specimens after exposure were determined. Besides, energy dispersive spectrometer (EDS) analyses were performed on scanning electron microscope (SEM) images of selected mixtures. Test results indicate that blast furnace slag cement (SC) mixtures have considerably greater resistance to sea water than portland cement (PC) mixtures both from the point of mechanical properties and chloride penetration. r

A method for the calculation of the current distribution, resistance, and inductance matrices for a system of coupled superconducting transmission lines having finite rectangular cross-section is presented. These calculations allow... more

A method for the calculation of the current distribution, resistance, and inductance matrices for a system of coupled superconducting transmission lines having finite rectangular cross-section is presented. These calculations allow accurate characterization of both high-T, and low-T, superconducting strip transmission lines. For a single stripline geometry with 6nite ground planes, the current distribution, resistance, inductance, and kinetic inductance are calculated as a function of the penetration depth for various 6lm thicknesses. These calculations are then used to determine the penetration depth for Nb, NbN, and YBa,Cu,O,-, superconducting thin films from the measured temperature dependence of the resonant frequency of a stripline resonator. The calculations are also used to convert measured temperature dependence of the quality factor to the intrinsic surface resistance as a function of temperature for an Nb stripline resonator.

We report theoretical values for the unscreened plasma frequencies Ω p of several Fe pnictides obtained from density functional theory (DFT) based calculations within the local density approximation (LDA) and compare them with... more

We report theoretical values for the unscreened plasma frequencies Ω p of several Fe pnictides obtained from density functional theory (DFT) based calculations within the local density approximation (LDA) and compare them with experimental plasma frequencies obtained from reflectivity measurements on both polycrystalline samples and single crystals. The sizable renormalization observed for all considered compounds points to the presence of significant many-body effects beyond the LDA. From the large values of the empirical background dielectric constant ε ∞ ≈ 12-15 derived from reflectivity data, we estimate a large arsenic polarizabilityα As ≈ 9.5 ± 1.2Å 3 where the details depend on the polarizabilities of the remaining ions taken from the literature. This large polarizability can significantly reduce the value of the Coulomb repulsion U d ∼4 eV on iron known from iron oxides to a level of 2 eV or below. In general, independently on such details, this result points to rather strong polaronic effects as suggested by G.A. Sawatzky et al., in references arXiv:0808.1390 and arXiv:0811.0214 . Possible consequences for the conditions of a formation of bipolarons are discussed, too. From the extrapolated µSR (muon spin rotation) penetration depth data at very low-temperature and the experimental value of the unscreened plasma frequency we estimate the total coupling constant λ tot for the electron-boson interaction within the framework of the Eliashberg-theory adopting an effective single band approximation. For LaFeAsO 0.9 F 0.1 a weak to intermediately strong coupling regime and a quasi-clean limit behaviour are found. For a pronounced multiband case we obtain a constraint for various intraband coupling constants which in principle allows for a sizable strong coupling in bands with either slow electrons or holes.