Outer Sidewall Research Articles

Evaluation of the Correlation Between Distribution Location and Vulnerability of Carotid Plaque in Patients with Transient Ischemic Attack.

To analyze the relationship among distribution location, characteristics, and vulnerability of carotid plaque using CTA and provide more information on the risk factors of carotid atherosclerotic plaque. We retrospectively analyzed the CTA images of the head and neck of 93 patients with carotid atherosclerosis. Atherosclerosis was developed in 148 carotid arteries. The plaques were divided into a high-risk plaque group and a low-risk plaque group according to whether the plaques had high-risk characteristics. The maximum cross-sectional area of carotid artery bifurcation plaque on the axial image was selected, and the cross-sectional lumen was equally divided into four 90-degree sectors, ventral side wall, dorsal side wall, inner side wall, and outer side wall. The differences in the characteristics and distribution locations of the plaques in the two groups were analyzed. The characteristic parameters of the cross-sectional plaques at the bifurcation of the carotid artery. The logistic regression analysis was used to further analyze the risk factors associated with plaque vulnerability. Among 148 carotid arteries,80 were classified as high-risk and 68 as low-risk groups. There were significant differences between the two groups concerning the thickness, length, maximum cross-sectional area, burden, and cross-sectional distribution of the plaques (P < 0.05). The plaque distribution on the dorsal side wall of the carotid bifurcation was higher in the high-risk group than that in the low-risk group (P < 0.05), dorsal side wall plaque-independent risk factors for the development of vulnerability of plaques in transient ischemic attack (TIA) patients (95% CI:1.522~6.991, P<0.05). High-risk plaques tend to occur on the dorsal side wall of the carotid bifurcation, whereas low-risk plaques tend to occur on the outer side wall of the carotid bifurcation.

Research on performance of solid-liquid triboelectric nanogenerators based on anti-rolling tank

In this article, we present an anti-rolling tank solid-liquid triboelectric nanogenerators (ART-SL-TENGs) harvesting dissipated kinetic energy from the ocean in ship stabilizer to tackle the electric energy replenishment problem. The harvester mainly consists of several L-damping plates and U-tank equipped with TENGs. This paper investigates the dynamic processes of water within the tank and the potential distribution of TENGs using parameterized modeling, simulations, and experiments. The effects of external excitation, tank's initial water level, and TENG layout on the performance of ART-SL-TENGs are analyzed. During the roll motion of the tank, the water hits the outer side wall and rebounds towards the inner side wall upon collision. Due to a larger water-TENG contact area, the outer side wall generates more charges transfer than the inner side wall, resulting in a higher open-circuit voltage and a higher power. Under low-frequency excitation, the dynamic processes of water make it easier to have sufficient contact with the TENGs, exchange charges, and generate a higher voltage. The results show that the harvester generates maximum average output voltage of about 39.26 V and instantaneous power 6.49 μW under the excitation of 0.7 Hz and 90 mm amplitude at 30 mm initial water level. The ART-SL-TENGs take into account both anti-rolling characteristics and the electric energy replenishment, providing significantly a reference for the design of self-powered marine equipment in ship stabilizer.

Numerical Investigation of Hydrodynamics in Inline Mixers

The utilization of inline mixers for continuous fluid mixing is a common practice in chemical industries. Information related to hydrodynamics condition in inline mixers is found to be limited while it is crucial for inline mixer type selection. Evaluation of hydrodynamic characteristics in several commercial inline mixers is analyzed in this study, including Y-type, T-type, elbow type, and internal injection mixer types. The analysis is conducted using computational fluid dynamics (CFD) for various Reynolds number conditions from 5,000 to 200,000. Mesh independence tests and model validation with experimental results are performed to ensure simulation accuracy. The CFD results showed that the Y-type mixer type provides the shortest distance i.e., about 12 times diameter. The internal injection type mixer has the most extended hydrodynamic region length to reach a fully-developed region for the same Reynolds number. The highest wall stress is indicated by the injection inline mixer type that located at the outer side wall of the injection pipe. The wall stress at that region is observed to be around twice as large compared to the other mixer type. Meanwhile, the mixer joint in the T-type and Y-type mixers were found to have a wall stress hotspot. Logarithmic correlation formulas were successfully formulated to correlate hydrodynamic region length and Reynolds number for all mixer types. The study results are essential in serving as the basis for inline mixer selection in the industrial sector

Investigation on the wall thickness variation of an eccentric tube in the rotary draw bending process

PurposeWhen bending a large diameter thin-walled tube, the thickn ess of outer side wall will reduce greatly, which leads to a decrease of structural strength of the tube. To solve this problem, this paper investigated the deformation principles of an eccentric tube in the rotary draw bending process, trying to find a way to reduce the wall thickness difference between inner and outer diameters.Design/methodology/approachAn finite element model is established for analyzing the deformation of an eccentric tube in rotary draw bending process. The wall thickness distribution of the formed pipe was analyzed along the axis and diameter, respectively.FindingsIt is found that there exists an optimal eccentricity between the inner and outer circle center of the tube cross-section. If the eccentricity of the tube is chosen properly, it is possible to get a bent tube with equal thickness of inner and outer side walls. In addition, it is also found the optimal eccentricity on the cross-section can be influenced by bending radius, wall thickness, diameter and bending angle. The optimal eccentricity increases greatly with the decreasing of bending radius, the increase of outer diameter and the increase of wall thickness. The influence of bending angle on the optimal eccentricity can be divided into two situations. When the bending angle is small, the optimal eccentricity increases with the increase of bending angle. When the bending angle exceeds a certain value, the pipe enters a stable forming state. The optimal eccentricity of the stable forming region does not change with the bending angle.Originality/valueSuch a research is beneficial for reducing the thickness difference between inner and outer side walls in the rotary draw bending process.

An optimization study on the performance of hot water tank integrated phase change material

In this paper, a new structure of a phase change thermal storage tank is proposed with the aim of enhancing the thermal storage capacity of the domestic hot water tank without occupying the water storage volume. The structure of the proposed tank is that the phase change material is filled in the outer side wall of the tank and the cavity formed by an insulation layer, which does not occupy the water storage space inside the tank. The cavity is equipped with metal spacers in parallel with each other as a method to strengthen heat transfer. The effects of three structural design parameters, namely the thickness of phase change material, the number and thickness of spacers on the charging and discharging process were investigated by the means of numerical calculations. A numerical model was developed by using COMSOL Multiphysics, and the accuracy of the model was verified with experimental data from the literature. The average temperature of phase change material, average water temperature, and liquid/solid phase fraction were used to evaluate the thermal performance of the phase change thermal storage tank.It was found that the low thermal conductivity of the phase change material affected the thermal performance. When the thickness of the phase change material was 30 mm, the discharging time was prolonged by 10 %, which was 5 h longer than the common water tank. The installation of metal spacers was an effective method to enhance heat transfer. During the charging process, the phase change material had a stronger liquefaction trend, and the lowest value of the solid fraction was 0.25. During the discharging process, when the number of spacers was 17 and the thickness was 5 mm, the discharging time was extended to 80 h, which was 1.5 times of the common water tank. The results help to understand the optimized design parameters of the phase change thermal storage tank from the perspective of the structural design.

Numerical studies of the simultaneous development of forced convective laminar flow with heat transfer inside a microtube at a uniform temperature

Abstract Conjugate heat transfer is a complex problem because heat is transferred from a solid medium to a liquid medium through their interfaces. The steady-state laminar flow formed inside the microtubules is subjected to a constant temperature at the outer sidewall surface. These images cover a wide range of wall-to-fluid thermal conductivity ratios (ksf = 1, 2, 3, 4, and 5) and wall thickness-to-inner diameter ratios (δ/Ri = 0.25, 0.5, 0.75, 1, 1.25, and 1.5) and Reynolds numbers (Re = 200, 400, 600, 800, and 1,000). The results are processed by a Fluent program based on the finite volume method to numerically integrate the driver’s differential equations. The results show that increasing the wall-to-fluid thermal conductivity ratio ksf increases the inner wall dimensionless temperature and decreases the average Nusselt number. Conversely, an increase in the ratio of wall thickness to inner diameter results in a decrease in the dimensionless temperature of the inner wall and an increase in the average Nusselt number.

Effect of the external beveled tip angle of the bucket foundation in clay on its penetration resistance considering soil large deformation and strain softening

In offshore wind energy industry, the bucket foundation in clay has been considered as an alternative to conventional foundations due to their unique features such as high overturning resistance. However, it cannot be installed to the pre-determined depth due to the soil plug generated during the penetration, which will significantly affect its bearing capacity. By setting the external beveled tip at the bottom of the bucket, the height of the soil plug can be reduced effectively. In order to study the influence of external beveled tip on the soil plug, soil softening and penetration resistance, the Coupled Eulerian-Lagrangian approach is used in this study to establish the bucket foundation penetration resistance models in correlation with different angles of external beveled tip considering soil large deformation and strain softening. It was found that as the angle increases, more soil are directed and flows out of the bucket, and the height of soil surface inside the bucket obviously decreases. When the angle increases to 60°, the soil plug inside the bucket is very small and hardly changes. As the angle increases from 0° to 60°, the degree of softening and amount of soil inside the bucket decreases, while that the trend is opposite for the soil outside the bucket. In addition, due to the influence of soil flow and strength degradation, the end bearing capacity factor and the frictional coefficient of inner side wall decrease as the angle increases, while the coefficient of outer side wall increases due to the reduction of softening effect. However, the total penetration resistance of the bucket foundation does not obviously change with the external beveled tip angle. 60° is recommended as the optimal angle for the external beveled tip in order to avoid the soil plug inside the bucket.

CFD-DEM investigation of fluid and particle motion behaviors in initial stage of spiral separation process at low solids concentration

ABSTRACT The evolution law of fluid and solid motion in the initial stage of spiral separation process is critical for mineral particle separation. The current research intends to investigate the fluid and particle motion behaviors in the initial stage of a spiral separation process using a CFD-DEM approach. The results show that the motion behaviors of fluids and particles in the initial stage of spiral separation process could be separated into three states: the development state, the transition state, and the relatively stable state. In the development state, water flows outward with a rapid change of velocity and film thickness. Meanwhile, fluid forced particles to move outward rapidly with no obvious trajectory difference. In the transition state, a collision between the slurry and the outer trough sidewall happens with changing the moving direction of fluids and particles. Following the collision, the flow field distribution tends to be relatively constant, and the light particles progressively migrate to the spiral trough’s outer edge, while heavy particles gradually move to the spiral trough’s inner edge.

Failure analysis of AISI 430 stainless steel sheet under stretching and bending conditions

Ferritic stainless steels have been widely used to substitute austenitic steels because of their lower cost and higher deep drawing capacity. However, failures, such as shear fracture, have been observed in parts with small radii during the drawing process in applications where both bending and stretching occurs. Conventional techniques, such as failure criterion consideration, finite element method, and forming limit diagram, are unable to predict this type of fracture, which has hampered the development of new processes and products. To overcome this limitation, herein, we investigated the effects of tool radius, direction, and test speed on the formability to fracture of an AISI 430 stainless steel sheet under bending and stretching conditions. An equipment was used to perform the draw-bend fracture (DBF) test based on the bending under tension test. The DBF test efficiently reproduced the tensile, mixed, and shear fractures. Furthermore, we determined the fracture limit strain on the outer surface, thickness, and sidewall of the sample, as well as the coefficient of friction. The data showed that the radius to thickness ratio related to the process parameters had a direct impact on the experimental results. In addition, the results can be utilized for setting design guidelines and failure prevention.

Investigation on the evolution of flow field stability in a spiral separator

The liquid film in a spiral separator undergoes an evolution from unsteady to steady flow with increasing trough length. Understanding the process of the flow field evolution is a prerequisite for revealing the mechanism of particle segregation. In this study, a numerical investigation of the flow field evolution in a spiral separator with the cross-sectional profile of cubic parabola is conducted. The distribution profiles of the liquid film thickness, surface tangential velocity, and net radial flux along the trough length are used to characterize the stability of the liquid film shape, primary flow, and secondary flow, respectively. The results indicate that the flow field characteristics at the inner and middle troughs will reach a stable state earlier than that of the outer trough with the increase in trough length. Before reaching a fully developed steady state, the instability of the flow field characteristics at the outer trough exhibits damped oscillations. The instability of the flow field in the first turn is mainly caused by the collision between the fluid and the outer trough sidewall, which leads to large fluctuations in the flow field characteristics at the outer trough. Moreover, the unbalanced inward and outward flows generated from the collision may be the primary reason for the formation of the secondary flow. After the first turn, the flow field characteristics have approximately stabilized, but a certain transitional trough length is still required to reach a fully developed steady state. The secondary flow shows poorer stability compared with the liquid film shape and primary flow. These observations provide insight into the physics of the fluid flow in a spiral separator.

Investigation of the Pristine and Functionalized Carbon Nanotubes as a Delivery System for the Anticancer Drug Dacarbazine: Drug Encapsulation.

Carbon Nanotubes (CNTs) have been used as the systems in drug delivery due to their exceptional physical and chemical properties. In this study, the adsorption of an anticancer drug Dacarbazine (DAC) into the inner and outer surface of pristine and Functionalized Carbon Nanotubes (FCNTs) with four carboxylic acid groups was investigated in aqueous solution using the Molecular Dynamics (MD) simulations. Our simulation results showed that in spite of the adsorption of drug molecules on the outer sidewall of pristine and functionalized nanotubes, the spontaneous encapsulation of DAC molecule into the cavity of CNTs and FCNTs is observed. The simulations show that the arrangement of the DAC molecule into the CNTs and FCNTs is controlled by π-π interactions.

Preparation of sidewall-insulation layer on micro-hollow electrodes for ECM by asymmetric-timed bipolar electrophoretic coating method and its application

There are still some problems in the electrochemical machining (ECM) of micro-deep holes with a diameter of 100–200 μm. For example, it is difficult to prepare an insulation layer on the outer sidewall of a micro-hollow electrode. Under the influence of high-pressure liquid flushing and bubble tearing in a small machining gap, the prepared insulation layer is easily damaged/fallen off. And the micro-hollow part of the electrode is also easily blocked in the preparation. In order to solve the above problems, a novel method for preparing an insulation layer by asymmetric-timed bipolar electrophoretic coating in an aqueous epoxy acrylic solution was presented. In this method, the liquid-supplied technique that the interior of the micro-hollow electrode was completely filled up with the still deionized water, was ingeniously combined with the repeated and alternating process, in which the positive electrophoretic coating undergoes for a longer period of time and the negative electrophoretic stripping undergoes for a shorter period of time. Through simulation and orthogonal tests, the process parameters of the electrophoretic coating were optimized. Comparative verification experiments were conducted using the prepared sidewall-insulation electrodes. The surface morphology, the electrical insulating property, the size and morphology of the fabricated holes, and the surface morphology of the electrodes after machining were used as indicators for comparing and analyzing the performance of the insulation layers. Finally, a micro-deep hole array was machined on a stainless steel 304 plate with a thickness of 500 μm. The typical hole diameter of the inlet and outlet is about 168 μm. Compared to the machined holes of the sidewall-insulation electrodes prepared by the traditional electrophoretic coating method, the taper is reduced by more than 60%, and the surface quality is improved by about 30%. The results show that the sidewall-insulation layer prepared by the method proposed in this paper has higher compactness, uniformity, durability and consistency, and its performance meets the special requirements of the micro ECM for the electrode sidewall-insulation layer.

Functional nasolacrimal duct decompression for chronic dacryocystitis

Objective:To investigate the feasibility of endoscopic nasolacrimal decompression for chronic dacryocystitis. Method:22 patients with chronic dacryocystitis hospitalized at Longgang ENT hospital were participated in this study. An injection of 30% iohexol was administered to conduct lacrimal sac angiography. The injection was stopped when the agent reflux from the lacrimal duct, and a computed tomography（CT） scan of the lacrimal duct was performed immediately. Sinuses Trachea Isoftware was used to reconstruct a three-dimensional（3D） view of the lacrimal passage and its surrounding structures. The software was used to simulate the "cutting" of the lacrimal sac and nasolacrimal duct; the lacrimal sac and nasal lacrimal duct were removed after 1/2-3/4 circumferences to decompress the passage and expose the membranous nasolacrimal duct. CT scans were performed on ten adult frozen cadaveric heads, and the nasolacrimal duct decompression operation was simulated. Then, the bone of the nasolacrimal duct was removed, membranous nasolacrimal duct was exposed, and the capsular nasolacrimal duct was dilated. Result:①The lacrimal angiography study revealed that lacrimal duct obstruction occurred in the nasolacrimal duct segment, accounting for 72.7%（16/22） of the study cases. ② The anatomical examination showed that the outer sidewall of the nasolacrimal duct was composed of the tear groove of the maxilla, and the inner wall was composed of the descending process of the lacrimal bone. ③ In cadaveric heads, decompression of the osseous nasolacrimal duct was performed, exposing the membranous nasolacrimal duct. ④ A balloon catheter could dilate the membranous nasolacrimal duct and allow the lacrimal passage to be flushed. Conclusion:Endoscopic nasolacrimal decompression preserves the integrity of the lacrimal duct, allows drainage of the lacrimal duct, and avoids obstruction of the lacrimal duct by preventing lacrimal granulation.

The study of thiazole adsorption upon BC2N nanotube: DFT/TD-DFT investigation

Herein, we evaluated the adsorption of thiazole over the surface of BC2N nanotube using PBE and M06-2X functionals and 6-311G** standard basis set. We considered one and two thiazole molecules over the outer sidewall of BC2N nanotube. Furthermore, we found that the adsorption energy of thiazole (state II) from its nitrogen head on the boron atom of BC2N nanotube is greater than other states (about − 0.90 eV by PBE and − 1.09 eV by M06-2X functional). It was found that the energy gap of BC2N nanotube is significantly reduced from 0.61 to 0.25 eV after the thiazole adsorption (state II). Our results also indicated that the electronic and optical properties of BC2N nanotube are significantly altered on the adsorption of thiazole.

Bottom-up Cu filling of annular through silicon vias: Microstructure and texture

Microstructural and morphological evolution during bottom-up Cu filling of annular through silicon vias (TSV) in a CuSO4–H2SO4–Cl-–poloxamine electrolyte is examined. Deposition proceeds in two distinct stages beginning with a passive-to-active state transition on the via sidewalls whose depth and ultimate thickness depends on the polymer flux. Growth is conformal or tapered with columnar grains whose width and texture differ between the outer and inner sidewalls of the annulus due to area reduction and expansion respectively. The outer sidewall and bottom surface have a preferred texture; ⟨111⟩//ND (via normal) and ⟨110⟩//CD (via circumferential). With time the sidewalls passivate while further deposition is localized to the via bottom. Bottom-up growth then fills the TSV with the formation and selective expansion of the ⟨110⟩//ND textured grains. At higher suppressor concentrations the initial onset and transient period of sidewall deposition is displaced to greater depth and the subsequent shift to bottom-up filling with large ⟨110⟩//ND texture grains occurs earlier. The dominant ⟨110⟩//ND texture during bottom-up filling is congruent with Cl− stabilized texture development. The absence of suppression indicates that the polymeric suppressor does not adsorb on the active upward propagating surface.

Study of passively stable, fully detached divertor plasma regimes attained in innovative long-legged divertor configurations

Numerical modeling of divertor configurations with radially or vertically extended, tightly baffled, outer divertor legs has demonstrated the existence of a passively-stable fully detached divertor regime. In the simulations, long-legged divertors provide up to an order-of-magnitude increase in peak power handling capability compared to conventional divertors. The key physics for attaining the passively stable, fully detached regime in these simulations involves the interplay of strong convective plasma transport to the divertor leg outer sidewall, confinement of neutral gas in the divertor volume, geometric effects including a secondary X-point, and atomic radiation. New analysis shows that in this regime the detachment front location is set by the balance between the power entering the divertor leg and the losses to the walls of the divertor channel. Correspondingly, the maximum power that can be accommodated by the divertor, while still staying detached, increases with the poloidal length of the leg. The detached regime access window in terms of input power, density and impurity seeding concentration varies quantitatively depending on divertor geometry and modeling assumptions most specifically, cross-field transport to the side walls.

Multifunctional Branched Nanostraw-Electroporation Platform for Intracellular Regulation and Monitoring of Circulating Tumor Cells.

Downstream analysis of circulating tumor cells (CTCs) has provided new insights into cancer research. In particular, the detection of CTCs, followed by the regulation and monitoring of their intracellular activities, can provide valuable information for comprehensively understanding cancer pathogenesis and progression. However, current CTC detection techniques are rarely capable of in situ regulation and monitoring of the intracellular microenvironments of cancer cells over time. Here, we developed a multifunctional branched nanostraw (BNS)-electroporation platform that could effectively capture CTCs and allow for downstream regulation and monitoring of their intracellular activities in a real-time and in situ manner. The BNSs possessed numerous nanobranches on the outer sidewall of hollow nanotubes, which could be conjugated with specific antibodies to facilitate the effective capture of CTCs. Nanoelectroporation could be applied through the BNSs to nondestructively porate the membranes of the captured cells at a low voltage, allowing the delivery of exogenous biomolecules into the cytosol and the extraction of cytosolic contents through the BNSs without affecting cell viability. The efficient delivery of biomolecules (e.g., small molecule dyes and DNA plasmids) into cancer cells with spatial and temporal control and, conversely, the repeated extraction of intracellular enzymes (e.g., caspase-3) for real-time monitoring were both demonstrated. This technology can provide new opportunities for the comprehensive understanding of cancer cell functions that will facilitate cancer diagnosis and treatment.

Design and Characterization of Area-Efficient Trench Termination for 4H-SiC Devices

In this paper, the operation mechanism of trench termination is investigated through 2-D numeric simulation on Silvaco. It is found that in trench termination, the electric field is terminated by the accumulated holes at the outer trench sidewall. In order to ensure a high termination breakdown voltage, the trench is refilled with a combination of SiO2 and polyimide (PI). Through various 2-D numerical simulations, the impact of structural parameters on breakdown voltage has been discussed, namely, trench depth (TD), trench width (TW), and sidewall tilt angle. The 3-D simulations are also conducted to investigate the effect of round corner radius on the device breakdown voltage and electric field in the dielectrics. Based on these results, the trench termination is designed and then fabricated along with a p-i-n diode. The measurement results show that a $14~\mu \text{m}$ wide trench is sufficient to terminate a voltage of 1750V (>96% of the ideal planar breakdown). Comparing with conventional field limiting rings junction termination extension (FLR/JTE) technology, this trench termination can significantly reduce the termination length by a factor of 4. As a result, the area efficiency is largely improved from 62% to around 90% for a 2A device conducting at 1000 A/cm2. These results indicate that the SiC device price can be substantially lowered with such an area-efficient trench termination technology. Furthermore, the 168-h high-temperature reverse bias (HTRB) test under 1200 V and 175 °C shows the potential of this trench termination for long-term reliable operation. Finally, unclamped inductive switching (UIS) tests have been conducted on fabricated devices. Compared to commercial SiC junction barrier Schottky diodes with FLR, fabricated p-i-n diodes with trench termination show significant higher avalanche capability.

Theoretical and Experimental Heat Transfer in Solid Propellant Rocket Engine

Accurate determination of heat flux is an important task not only in the designing aspect, but also in the performance analysis of rocket engines. In this purpose, this work deals with the heat flux determination in a combustion chamber through the inverse method. In this approach, the transient heat flux is determined from the experimental temperature data measured at the outer sidewall of the rocket engine. In this work the physical phenomenon was modeled by the transient one-dimensional heat equation in cylindrical coordinates and the material properties of the chamber were considered constant. Furthermore, the model is solved using the inverse heat conduction problem with least squares modified by the addition of Tikhonov regularization term of zero-order. Moreover, the sensitivity coefficients were obtained by Duhamel’s theorem. Through the regularization parameter, it was able to generate acceptable results even when using data with considerable experimental errors.

Predicting doxorubicin drug delivery by single-walled carbon nanotube through cell membrane in the absence and presence of nicotine molecules: a molecular dynamics simulation study

In order to study the interaction of the anticancer agent Doxorubicin with the single-walled carbon nanotubes with different diameters as drug delivery systems, the molecular dynamics (MD) simulations have been used. Also, for design and development of intracellular Doxorubicin drug delivery systems, a series of steered MD simulations are applied to explore the possibility of encapsulated Doxorubicin–carbon nanotube penetration through a lipid bilayer in presence and absence of Nicotine molecules at different pulling rates. Our simulation results showed that in spite of the adsorption of drug molecules on the outer sidewall of the nanotubes, the spontaneous localization of one Doxorubicin molecule into the cavity of the nanovectors with larger diameters is observed. It is found that the presence of Nicotine molecules in extracellular medium increases the required force for pulling nanotube-encapsulated drug as well as the required time for penetration process, especially at higher velocity. Also, the entering process of the Nicotine molecules into the carbon nanotube causes that the encapsulated drug molecule is fully released in the hydrophobic phase of the lipid bilayer.Communicated by Ramaswamy H. Sarma