Fractional Curves Research Articles

Heterogeneous kinetics: from solid–gas reaction to solid–liquid dissolution

The extension of the formal kinetics of solid–gas reactions to solid–liquid dissolution is investigated theoretically. The work is based on modelling the dissolution of a solid in a closed system by a stoichiometrically simple chemical reaction A solid⇄A liquid proceeding up to either an equilibrium state if the solid phase is initially in excess or exhaustion in the reverse situation. The initial amount of solid compared to the capacity of the liquid phase appears as a major factor of complexity. First, the rate equation is formulated in terms of the intensive variables without any assumption about the mechanism and the rate-limiting step. The resulting equations are compared to those derived from Nersnt boundary-layer theory of dissolution. Only when the solid phase is initially in deficit does the kinetic approach turn to be in the wrong if the rate of dissolution is assumed to depend on the maximum of the concentration gap. At this stage, the dissolution mechanism has to be taken into consideration and the rate equation adjusted accordingly. Finally, algebraic expressions for the fractional dissolution curves can be obtained. Except for particular solid liquid ratios they are not superimposable by an affinity relation.

Does instrumented anterior scoliosis surgery lead to kyphosis, pseudarthrosis, or inadequate correction in adults?

Retrospective review of cases in which a single solid rod was used for the anterior correction of thoracolumbar and lumbar idiopathic scoliosis in adults. To evaluate the efficacy and outcomes in these patients. Anterior spinal fusion with instrumentation has been found to be kyphogenic in the treatment of scoliosis. Recent reports have shown an extremely high rate of pseudarthrosis and implant failure even in adolescents who have undergone anterior spinal fusion with a single flexible or rigid rod. Fifteen consecutive adult patients with (average age, 37.5 years) had undergone anterior spinal fusion with a rigid rod were included in this study. One was lost to follow-up, leaving 14 patients with a complete radiographic follow-up of 44 months and clinical follow-up of 61 months. Patients were sent the Modified Scoliosis Research Society (SRS) Outcomes Instrument, charts were reviewed, and preoperative, postoperative, and final follow-up films of the entire spine were evaluated by independent reviewers uninvolved in the care of the patients. The average preoperative major curve was 50 degrees, which improved to 16 degrees at follow-up (a 66% correction). The average correction of the upper compensatory curve and lower fractional curve were 40% and 61%, respectively. The thoracolumbar sagittal plane alignment was maintained or improved in all patients (i.e., this surgery did not induce kyphosis in any patient). On average 0.9 levels were "saved" compared with levels chosen by the authors for posterior surgery. All patients achieved a solid fusion. Follow-up Modified SRS questionnaires revealed a satisfaction score 4.5 out of a possible score of 5, a pain score of 4.1 out of 5, a self-image score of 4.1 out of 5, a function score of 4.1 out of 5, and a mental health score of 4.0 out of 5, with an overall score of 82%. All patients but one were satisfied or extremely satisfied with the results of surgery. There was no incidence of implant breakage. The results of anterior spinal fusion using a single solid rod in adults with idiopathic scoliosis in this series are excellent, with 100% fusion rate, no development of kyphosis, and no incidence of hardware failure.

Influence of upstream flow characteristics on filter efficiency

This study investigated the effect of upstream flow conditions on the efficiency of a reversible, two-layer filter composed of one layer of coarse and one layer of fine fibres. Efficiency was higher when the leading layer of the filter contained fine fibres, but the drop was the same regardless of which fibres led. Efficiency was higher and the fractional efficiency curve was shallower when the upstream velocity profile was non-uniform and very turbulent. Three phenomena were identified that account for these observations: (1) non-uniformity of the upstream velocity profile, (2) mean velocities tangential to the filter's surface and (3) fluctuating components of velocity, inherent to a turbulent airflow. Air entering a filter becomes generallly perpendicular to the filter face as fibres dissipate non-uniform and tangential velocity components; this disipation is greatest in the leading layer of the filter. Fine fibres have a higher efficiency that coarse fibres, so efficiency was higher when the region of greatest dissipation contained fine fibres. Innovative housing designs, based on these observations, could be made to promote upstream airflow conditions that maximize filter performance.

The role of facilitated diffusion in oxygen transport by cell-free hemoglobins: implications for the design of hemoglobin-based oxygen carriers

We compared rates of oxygen transport in an in vitro capillary system using red blood cells (RBCs) and cell-free hemoglobins. The axial P o 2 drop down the capillary was calculated using finite-element analysis. RBCs, unmodified hemoglobin (HbA 0), cross-linked hemoglobin (αα-Hb) and hemoglobin conjugated to polyethylene-glycol (PEG-Hb) were evaluated. According to their fractional saturation curves, PEG-Hb showed the least desaturation down the capillary, which most closely matched the RBCs; HbA 0 and αα-Hb showed much greater desaturation. A lumped diffusion parameter, K*, was calculated based on the Fick diffusion equation with a term for facilitated diffusion. The overall rates of oxygen transfer are consistent with hemoglobin diffusion rates according to the Stokes–Einstein Law and with previously measured blood pressure responses in rats. This study provides a conceptual framework for the design of a ‘blood substitute’ based on mimicking O 2 transport by RBCs to prevent autoregulatory changes in blood flow and pressure.

The Effect of Changing Mobility Ratio on Displacement Efficiency in Polymer Flooding

ABSTRACT The effect of changing mobility ratio on displacement efficiency in polymer flooding was investigated. For this purpose, experiments on unsteady-state displacement were conducted with two Berea sand cores of different permeabilities. Each core was flooded by displacing fluids of three different viscosity ratios. Relative permeability ratio curves measured on the core by changing the viscosity of displacing fluid, showed similar pattern in the same saturation path regardless of changing the viscosity of displacing fluid. Fractional flow curves measured on the core showed that higher viscosity of displacing fluid resulted in more efficient displacement; that is, as the viscosity of displacing fluid was increased, mobility ratio was decreased and displacement efficiency was increased. The effect of changing viscosity ratio on mobility ratio was considerably higher on low permeability core than on high permeability core. The displacement efficiency measured on low permeability core was higher than that of high permeability core by 26 percent at the time of breakthrough. It was shown from the experiment that polymer flooding would be applied more effectively in low permeability reservoirs.

Fission gas release and volume diffusion enthalpy in UO 2 irradiated at low and high burnup

Samples of UO 2, irradiated in LWRs at burnups from 25 000 to 95 000 MWd/t at in-pile temperatures below 800 K, were submitted to Knudsen-effusion experiments. In addition to the equilibrium vapour pressure of non-volatile species, release of fission gas was measured as a function of temperature and time up to approximately 2700 K, where complete vaporisation of the sample was eventually achieved. The fractional release curves of the main isotopes of Kr and Xe were measured and analysed with an algorithm adequate to discriminate between the relevant release stages, one of which, controlled by atomic diffusion, is analysed in this paper. The obtained enthalpy of diffusion – the same for all the examined nuclides – decreases from 4.6 eV/atom, at low burnup, to 2.95 eV/atom, at the highest burnup. Furthermore, the fraction of fission gas released via atomic diffusion markedly increases with increasing burnup, indicating a dramatic attenuation of the intragranular sink strength.

Collection Performance of an Electret Cabin Air Filter for Fine Particles

An electret filter is composed of permanently charged electret fibers and is widely used in applications requiring high collection efficiency and low-pressure drop. In this work, the fractional collection efficiency of the filter media used in manufacturing cabin air filters was investigated by using highly monodisperse particles ranging from 0.02 to 0.6 in diameter at three different charging states: singly charged, uncharged, and equilibrium charged. The face velocity was varied from 2.4 to 20.4 crus. It was fecund that the fractional efficiency curve fur singly charged particles shows a typical trend that the collection efficiency is minimum at about 0.3 in diameter. The fractional efficiency of equilibrium charged particles were not severely varied with the particle diameter. The collection efficiency curve fur uncharged particles has a minimum near 0.1 in diameter. Another experiment was conducted for a cartridge filter to examine the effect of charge depletion on the collection efficiency in a cabin air filter. The result shows that the charge depletion of the cartridge filter can significantly lower the collection efficiency.

A fetal growth standard derived from multiple modalities.

To create a fetal weight growth standard from published data on ultrasound-dated pregnancies. A fetal growth standard was calculated from published birth weight data, sonographic weight standards, and one MRI study. The birth weights from the East Midlands Obstetric Database were modified by an incremental function to compensate for the lower weights of preterm infants. Published sonographic and MRI standards, and the modified birth weight curve were transformed to yield fractional growth curves that express fetal size as a proportion of the expected term weight. These three curves were then averaged, and the standard deviation was taken as 12% of the median. Curves for Europeans and Chinese were then generated. The average curve for fetal weight is a virtually linear function of gestational age, with a weekly weight gain of 5.2% of the expected term birth weight. Ultrasound-derived fetal growth curves are subject to bias inherent in weight estimation formulae. A standard derived from multiple modalities is likely to be a more robust estimate of normal fetal growth.

Measurements and model prediction of the solid–liquid equilibria of organic binary mixtures

Solid–liquid equilibria of three binary mixtures consisting of benzoic acid, 2-aminobenzoic acid and 1-naphthol were measured in this study using differential scanning calorimetry (DSC). Simple eutectic phase diagrams were observed, and the experimental data were well correlated by either the Wilson equation or the UNIFAC activity coefficient model. A new method by employing the DSC experiment and the theoretical calculations to detect the fractional transformation of solid–liquid equilibrium of organic mixture is proposed. Deconvolution method was employed to obtain the ideal equilibrium solid–liquid DSC curve. The heat generation rate and fraction of transformation were calculated using the Gray's model. Applying this theoretical approach, the eutectic points and the equilibrium liquidus temperatures were easily determined from the fractional transformation curve. An easier procedure to confirm the composition of eutectic point is presented. It is also demonstrated that the solid–liquid equilibrium phase boundaries are predicted with good agreement to the experimental results.

Inhibition of pressure natriuresis in mice lacking the AT2 receptor

Inhibition of pressure natriuresis in mice lacking the AT2 receptor. Angiotensin II type 2 (AT2) receptor knockout mice have higher blood pressures than wild-type mice; however, the hypertension is imperfectly defined. We tested the hypothesis that renal mechanisms could be contributory. We conducted pressure-natriuresis-diuresis experiments, measured renal cortical and medullary blood flow by laser Doppler methods, and explored cytochrome P450-dependent arachidonic acid metabolism by means of reverse transcription-polymerase chain reaction. Blood pressure was 15 mm Hg higher in AT2 receptor knockout mice than in controls, and pressure diuresis and natriuresis curves were shifted rightward. At similar renal perfusion pressures (113 to 118 mm Hg), wild-type mice excreted threefold more sodium and water than AT2 receptor knockout mice. Fractional sodium and water excretion curves were shifted rightward in parallel. Renal blood flow ranged between 6.72 and 7.88 mL/min/g kidney wet weight (kwt) in wild-type and between 5.84 and 6.15 mL/min/g kwt in AT2 receptor knockout mice. Renal vascular resistance was increased in AT2A receptor knockout mice. Cortical blood flow readings leveled at 2.5 V in wild-type and 1.5 V in AT2 receptor knockout mice. Medullary blood flow readings ranged between 0.8 and 1.0 V and increased 116% in wild-type mice as renal perfusion pressure was increased. This increase did not occur in AT2 receptor knockout mice. The glomerular filtration rate (GFR) was similar in both groups at approximately 1 mL/min/g kwt. Renal microsomes from AT2 receptor knockout mice had less activity in hydroxylating arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-meter) than controls, whereas renal AT1 receptor gene expression was increased in AT2 receptor knockout mice. Hemodynamic and tubular factors modify renal sodium handling in AT2 receptor knockout mice and may cause hypertension. AT2 receptor disruption induces alterations of other regulatory systems, including altered arachidonic acid metabolism, that may contribute to the intrarenal differences observed between AT2 receptor knockout and wild-type mice.

Waterflooding Performance of Communicating Stratified Reservoirs With Log-Normal Permeability Distribution

Summary An analytical solution is developed for waterflooding performance of layered reservoirs with a log-normal permeability distribution with complete crossflow between layers. The permeability distribution is characterized by the Dykstra-Parsons (DP) variation coefficient VDP or the standard deviation of the distribution σk. The performance is expressed in terms of vertical coverage as function of the producing water-oil ratio. Also an expression for the dimensionless time (pore volumes of injected water) at a given water-oil ratio is derived. Expressions are also derived for pseudorelative permeability functions and fractional flow curves that can be used in reservoir simulation. Correlation charts are also presented to enable graphical determination of the performance. The variables are combined in such a way that a single chart is constructed for the entire range of water-oil ratio, mobility ratio and permeability variation. Analogy to the Buckley-Leverett (BL) multiple-valued saturation profile is found to occur at low mobility ratios (M<1) where a multiple-valued displacement front is formed. A procedure similar to the BL discontinuity is suggested to handle this situation. Successive layers with different permeabilities are allowed to move with the same velocity resulting in a single-valued profile with a discontinuity. No such behavior is observed for mobility ratios greater than unity. A criterion for the minimum mobility ratio at which this behavior occurs is presented as a function of the variation coefficient VDP.

Water-Cut and Fractional-Flow Logs From Array-Induction Measurements

Summary Despite the importance of relative permeabilities in reservoir simulation, no information regarding them is available from current logs. In this paper, for the first time, we demonstrate a continuous log of multiphase flow properties. Mud filtrate invasion is usually regarded as a process that corrupts the true logs. In reality, the multiphase flow characteristics that influence filtrate flow also determine the subsequent reservoir performance. We propose the notion that invasion is an experiment, albeit uncontrolled, that may be used to invert for multiphase flow properties. Thus, in principle, inversion of array induction measurements in terms of the fractional flow curve is possible. The forward model for filtrate invasion is based on two-phase (aqueous and oleic), three-component (oil, water and salt) transport. Hysteretic behavior of relative permeability functions is included. The radial conductivity profiles calculated from the flow model are converted to induction logs using radial response functions. An algorithm for rapid calculations of the forward logs by combining the electromagnetic and flow models is developed. A nonlinear least squares method is used for parameter inversion from measurements. Additional data of near-wellbore resistivity, or logs obtained during drilling, may be included. Presentations for several output logs have been developed: a reserves estimate that partitions porosity into residual and movable saturations, initial water cut in the production stream, the fractional flow curve as a function of saturation, filtrate loss per unit depth, and a quality indicator. A field example of the processing, and its comparison with production data is also discussed.

Conformational diversity of acid-denatured cytochrome c studied by a matrix analysis of far-UV CD spectra.

The singular value decomposition (SVD) analysis was applied to a large set of far-ultraviolet circular dichroism (far-UV CD) spectra (100-400 spectra) of horse heart cytochrome c (cyt c). The spectra were collected at pH 1.7-5.0 in (NH4)2SO4, sorbitol and 2,2,2-trifluoroethanol (TFE) solutions. The present purpose is to develop a rigorous matrix method applied to far-UV CD spectra to resolve in details conformational properties of proteins in the non-native (or denatured) regions. The analysis established that three basis spectral components are contained in a data set of difference spectra (referred to the spectrum of the native state) used here. By a further matrix transformation, any observed spectrum could be decomposed into fractions of the native (N), the molten-globule (MG), the highly denatured (D), and the alcohol-induced helical (H) spectral forms. This method could determine fractional transition curves of each conformer as a function of solution conditions, which gave the results consistent with denaturation curves of cyt c monitored by other spectroscopic methods. The results in sorbitol solutions, for example, suggested that the preferential hydration effect of the co-solvent stabilizes the MG conformer of cyt c. This report has found that the systematic SVD analysis of the far-UV CD spectra is a powerful tool for the conformational analysis of the non-native species of a protein when it is suitably supplemented with other experimental methods.

Effects of aminooxyacetate on glutamate compartmentation and TCA cycle kinetics in rat hearts.

The nonspecific transaminase inhibitor aminooxyacetate (AOA) has multiple influences on the dynamics of 13C appearance in glutamate in rat hearts as measured by 13C nuclear magnetic resonance (NMR) without altering O2 consumption or tricarboxylic acid (TCA) cycle flux. These include the following: 1) a reduced rate of 13C enrichment at glutamate C3 and C4; 2) a near coalescence of the C3 and C4 fractional enrichment curves; 3) a dramatic alteration in the time-dependent evolution of the glutamate C4 multiplets, C4S and C4D34; and 4) a decrease in the NMR visibility of glutamate. A fit of the 13C fractional enrichment curves of glutamate C4 and C3 in the absence of inhibitor to a kinetic model of the TCA cycle gave values for transaminase flux of 7.5 mumol.min-1.g dry wt-1 and TCA cycle flux of 7.5 mumol.min-1.g dry wt-1, thereby confirming reports by others that the kinetics of 13C enrichment of glutamate C3 and C4 in heart tissue is significantly affected by flux through reactions other than TCA cycle. The 13C fractional enrichment data collected in the presence of 0.5 mM AOA could not be fitted using this same kinetic model. However, kinetic simulations demonstrated that the time-dependent changes in C4S and C4D34 are only consistent with a 10-fold reduction in the size of intermediate pools undergoing rapid turnover in the TCA cycle. We conclude that inhibition of glutamic-oxalacetic transaminase by AOA effectively reduces the size of the alpha-ketoglutarate pool in rapid exchange with the TCA cycle. Our data indicate that changes in glutamate multiplet areas in the 13C NMR spectra of heart (as demonstrated by glutamate C4S and C4D34) are more sensitive to alterations in metabolic pool sizes in exchange with the TCA cycle than are measurements of 13C fractional enrichment at glutamate C3 and C4.

Electrostatic Precipitator Penetration Function for Pulverized Coal Combustion

ABSTRACT The penetration of fly ash particles through an electrostatic precipitator (ESP) was measured as a function of particle size in the range of 0.02–0.7 μm (divided into 32 mobility channels) with a combination of an electrostatic classifier (DMA) and a condensation nucleus counter (CNC), but in the size range of 1.0–10 μm with the Berner type low-pressure impactor (BLPI). The measurements were carried out at a 300 MW power plant firing Polish bituminous coal during several operating conditions for coal combustion and ESP, data being acquired by both instruments and ranges. Gas composition (NOx, SO2, CO2, CO, and O2) was monitored by gas analyzers located downstream from the ESP. The ESP's operating voltage and currents were recorded. Electrical mobility distributions were measured with prime apparatus, the DMPS system. These data were reduced to the desired number size distributions with the commercial TSI-algorithm. D50-method was applied to impactor data. Fractional penetration curves were calculated from the size distributions channel by channel as the ratio of outlet concentration to that at inlet, respectively. Penetration functions appeared to depend on the boiler load, ESP voltages, and the operation of coal mill. The highest penetration was achieved with highest boiler load. The penetration dependence as a function of particle size was bimodal, reproducible, and compared against the conventional theories. Bimodal structure of the penetration curve was detected first when the first section of the ESP had low current density, and reproduced when the last section of ESP was turned totally off in an experiment to imitate the electrical conditions of the first experiment. These data add consistently to the experimental studies previously made with an industrial sized ESP. However, the resolution of the instrumentation of this study is better and confirms the doubts of theoretical suspicion against the conventional Deutsch model and its variants.

Effect of macropore convection on mass transfer in a bidisperse adsorbent particle

The importance of adsorption induced convection in the macropores of a bidisperse adsorbent particle is studied for a step change in mole fraction or total pressure at the surface of the particle. Material balance equations for a binary gas mixture are written for both the macropores and the macropores with allowance for convection in the macropores, which is described by Darcy's law. The coupled set o1' partial differential equations is solved by orthogonal collocation. The enhancement in mass transfer as a result of convection is assessed by comparing the fractional uptake curves obtained with and without allowance for convection. Both equilibrium-based and kinetic-based separation processes are considered. The effect of the presence of convection in determining the controlling diffusional resistance (macropore or micropore) is also examined. Due to inclusion of convection no single non-dimensional group alone can determine the relative importance of macropore and micropore resistances. Results show that convection can significantly affect the performance of an equilibrium-based macropore diffusion controlled process and that the enhancement in mass transfer is more for a particle with a high value of Darcy permeability.

Formation producibility and fractional flow curves from radial resistivity variation caused by drilling fluid invasion

In order to characterize conductivity profiles due to drilling fluid invasion into a hydrocarbon formation, a model for radial fluid transport is presented. The model assumes a water-based mud and accounts for the convective movement of oil, water, and salt. A mathematical analysis of the model using the method of characteristics is given. An equivalent graphical construction is also provided. Computations of radial conductivity profiles for specified formation characteristics and total filtrate loss are given. For typical fractional flow curves, it is shown that three qualitatively different profiles may occur depending on the initial water saturation. These results are compared with numerical simulations that include capillary pressure and gravity segregation. Next, the important issue of the inverse problem is analyzed. It is shown that from a single snapshot of the conductivity profile, an exact calculation of filtrate loss and formation fractional flow curve is possible. The calculation is valid provided there is a resistivity contrast between the drilling fluid filtrate and the formation water. For practical application, we show the limits of applicability of this result with complete numerical calculations. Thus, if wireline logs of resistivity variation away from the wellbore are available, formation oil producibility and water cut at native conditions may be estimated.

Complex trace-element effects of mixing-fractional crystallization composite processes: applications to the Alaer granite pluton, Altay Mountains, Xinjiang, northwestern China

Complex patterns of intersection of linear with power-function curvilinear data point arrays are observed on ratio-ratio correlation plots of trace elements in the Alaer Palaeozoic granite pluton, Altay Mts., Xinjiang, northwestern China. Data points in the linear array are relatively lower in SiO 2 content and differentiation index (D.I.), and they become progressively decreased rightwards along the array in abundances of Zr and Hf, which could be better explained by mixing between zircon-rich restite and the granite melt. Data points in curvilinear arrays are higher in SiO 2 content and D.I. value and, therefore, have presumably suffered more extensive fractional crystallization. The complex patterns cannot be resolved with the classical models. Two models for the complex trace-element effects of mixing-fractional crystallization are developed in the paper, with which the patterns can be resolved. In all models, we begin with a linear data-array formed by simple two-component mixing, and then superpose fractional crystallization trends to generate a family of curves. Model (1) ( D 1 ≤ D 3, D 2 ≤ D 3 or D 1 ≥ D 3, D 2 ≥ D 3): in the general situation, fractional crystallization curves assume a cluster of concave-up or convex-up power-function curves which intersect the initial mixing line sloping positively. Special cases 1–3 ( D 1 = D 2 ≠ D 3 or D 1 ≠ D 2 = D 3 or D 2 ≠ D 1 = D 3): the fractional crystallization curve is transformed into a straight line. Special case 4 ( D 1 = D 2 = D 3): the fractional crystallization line coincides with the initial mixing line. Model (2) ( D 1 > D 3 > D 2 or D 1 < D 3 < D 2): fractional crystallization curves assume the form of hyperbolic curves which intersect the initial mixing line sloping negatively. In all of the two models the iso-fraction lines are uniformly steeper ( D 1 < D 2) or more gentle ( D 1 > D 2) than the initial mixing line. Iso-fraction lines increase ( D 1 < D 2) or decrease ( D 1 > D 2) progressively in slope with the decrease of residual liquid mass fraction F. Through modelling of the data point arrays on ratio-ratio correlation plots of trace elements, one can discern and distinguish between simple mixing, pure fractional crystallization and mixing-fractional crystallization composite processes. Initial compositions of the magma and the mixing modes can also be constrained. Through modelling the functional form, concavity or convexity, and the power index of the fractional crystallization curves, the relative incompatibility of trace elements can be estimated semi-quantitatively and the incompatibility sequence can be established. It is demonstrated through modelling that the Alaer granite pluton experienced mixing-fractional crystallization composite processes. The mixing mode is probably described by the restite model. The incompatibility sequence of the 7 concerned trace elements is D Th < D La < D Y ≈ D Nb ≈ D Ta < D Hf < D Zr. This incompatibility sequence may be applicable to the anatectic granites.

KINETICS OF REDUCTION OF NICKEL OXIDE WITH HYDROGEN GAS IN THE 230-452°C RANGE

The kinetics of reduction with hydrogen of thin, dense strips of NiO in the 230-452°C temperature range were measured by the thermogravimetric technique. Pure hydrogen gas at 1 atm was used as the reducing agent. The fractional conversion-time curves were sigmoid-shaped, indicative of the autocatalytic nature of the reduction process. As relatively thin (54 μm thick) specimens were employed, the pore-diffusion of gases offered only negligible resistance. The topochemical-reaction-rate constant kc, deduced from the measured rates using nominal surface area, is found to be given by In kc= 14.770(±0.536)−11,673(±325) T−1 where kc is in cms−1. The activation energy for the reduction process appears to be 23.2 (±0.65) kcal mole−1 in the 230-452°C range.

Gammasphere results — A californian perspective

The latest experimental data from GAMMASPHERE is presented for, (i) M1 Bands — a characteristic decrease in the B(M1) values is observed and given as evidence for the TAC model, (ii) δI = 2 Stagger in 194Hg-this new data is compared with the previous results, (iii) Observation of discrete gamma-ray links in 194Pb-yielding an unambiguous determination of spins and excitation energies, (iv) Comparative lifetime measurements in the superdeformed bands in 193Hg and 192Hg-differences in the fractional shift curves are observed between 193Hg and 192Hg.