The literacy of empathy : building a culture of care in classrooms

x, 137 leaves ; 29 cmThis study explores students’ capacity to develop a literacy of empathy, which contributes to a caring classroom culture. The primary goal of the work has been to instill the capacity for care in children, the capability of building a culture of care in the classroom and an awareness of empathy’s impact on others as a moral, life-long skill. Provoking contextual and personally relevant discussions in empathy with the class community, developing vocabulary related to emotion and an evaluation of written responses in journal form are considered. The study has been conducted in a grade four public school classroom setting. The findings indicate the potential for empathic instruction to transcend grade level and indicate the relevance for inclusion of instruction around a literacy of empathy as a reconceptualization of general classroom curriculum

Friction Reducers Fresh Rheological Insights Married to Performance

Abstract Rheological experiments have been conducted with commercial and experimental friction reducers indicating certain profiles are advantageous for performance. In these profiles the factors of time and concentration are important in predicting the maximum performance window. These windows become apparent without the use of sophisticated rheological instrumentation. The viscosity profile of a friction reducer is dependent on factors such as polymer charge, charge distribution, molecular weight, polymer concentration, solvent properties, specific shear rate and time. Often it is difficult to measure properties such as molecular weight and viscosity, both quite sensitive to the specific test method and many assumptions are made. In this study, the viscosity of the system depends on the shear history, concentration, and time of measurement. Most traditional viscosity methods assume a thermodynamic definition of polymer configuration. This assumption is valid for measurement of friction reduction after significant duration. However, in a hydraulic fracture, this time may not be realized during the volumetric transfer of the fluid from the pumps to the perforations. In a recirculating friction loop measurement, the friction reduction performance of an ideal candidate rapidly increases and then sometimes diminishes with recirculation time. A possible correspondence between this phenomenon can be linked to the measurement conducted in this study. Shear rate sweeps were conducted on a variety of synthetic polymers with a Couette rheometer and a microchip rheometer. Variables studied were polymer type, concentration, shear history, time, solvent, make-down procedure, and atmosphere. Both inverse emulsion and dry friction reducers were studied. Friction reduction was measured on a once through system. From this study, ideal friction reducer candidates can be selected by simply and rapidly examining the rheological profile and rheological nuances realized when conducting the measurements. When choosing an ideal friction reducer, it must perform rapidly and maintain the necessary friction reduction required for the time frame needed.</jats:p

Study of the morphology and its effects on the mechanical properties of linear low density polyethylene

Typescript (photocopy)VitaMajor subject: ChemistryA linear low density polyethylene, with 1-octene as the co-unit, forms a semicrystalline matrix when cooled from the melt. This matrix is composed of a spherulitic superstructure with a lamellar microstructure. The careful study of characterized fractions allowed the quantitative description of the melting profile of the whole copolymer, which corresponds to the crystallite size distribution. This description was achieved by the calculation of the most probable unbranched ethylene sequence, and whereby it was assumed that the lamellar thickness is directly linked to this sequence. This lamellar thickness had to be adjusted by the number average molecular weight to achieve the final distribution. Another method extrapolated the effect of branching on this sequence from a region of low branching frequency to a region of high frequency. This lamellar thickness also had to be adjusted by the number average molecular weight to achieve the final distribution. The crystallite size distribution of the fractions and the whole copolymer was changed by annealing procedures. The rate of change was accelerated by the use of cool-raise and cool-raise-cool procedures. The rate and extent of change is governed by the branch and molecular weight distribution. The total crystallinity was rather invariant for this copolymer. This was explained by segregation of low-molecular weight fractions. At very low strain, the stress relaxation was found to be dependent on the total crystallinity, but independent of the crystallite size distribution. Frequency-temperature studies indicated that the modulus may be predicted, at least up to the melting point, by the extrapolation of low temperature data and by taking into account changes in the degree of crystallinity. However, the imaginary modulus is affected more than the real modulus by the distribution change

Clay Stabilizers Performance in a Comprehensive Matrix of Bentonite and Silica Flour

Abstract A systematic study of various temporary and permanent clay stabilizers was conducted with assorted binary blends of bentonite and silica flour. A specific stabilizer's performance is directly correlated to the type and loading of the inhibitor and particular ratio of existing inorganic substrate. Results exhibited high performance correlation; response surface general topography is dependent upon the temporary or permanent characteristics of the stabilizer. Studies comprised combined mixture, single numeric, optimal, design of experiment and performance test data gathering utilizing a low-pressure fluid loss cell. A predetermined concentration of unadulterated sodium bentonite and 325-mesh silica flour were blended into water at a specific RPM and duration in the presence of a particular stabilizer then placed into a the cell, sealed, and pressure was applied. Increased Darcy leak off slope values are reliable, accurate indicators of increased stabilizer performance thus each slope was calculated and plotted versus stabilizer dosage and inorganic substrate ratio. KCl was studied from 0 to 8 weight percent and used as a comparative guide for all stabilizers tested with the balance tested in their "as is" state from 0.0 to 2.0 gallons per thousand gallons. Temporary stabilizers typically provided a consistent topography with respect to performance, with a 20/80 bentonite/ silica flour ratio yielding the highest performance. Bimodal maximum performance inorganic ratios were present for permanent stabilizers tested. KCl dosage offset lab results correlate well with reported field application results. At higher stabilizer loadings superior performance relative to KCl was evident. Traditionally clay stabilizer selection is based upon Capillary Suction Time and Roller Oven testing methods. This alternate bentonite and silica flour comprehensive matrix clay stabilizer selection method is consistent, continuous, portable, field friendly and applicable over a wide range of stabilizer and variable inorganic matrix types.</jats:p

Polyethylene Glycol PEG Functionalized Silane for Highly Efficient Silicate Scale Control

Abstract Sandstone reservoirs flooded with alkaline surfactant polymer (ASP) are associated with silicate scaling of production wells. Silicate scaling has been a significant problem in ASP-flooded areas in China and Canada. This paper reports a series of highly effective silicate scale inhibitors comprised of polyethylene-glycol-functionalized silane. Surface chemistry of silicate was utilized to prevent scale growth. Silane/siloxide groups bond well with the surface of silica and silicates. The introduction of a silane/siloxide group into a scale inhibitor can greatly enhance the affinity of inhibitor molecules with the silicate surface. Conversely a silicate surface also has exposed OH groups which can form hydrogen bonds with the oxygen atoms in the backbone of PEG. The PEG polymer chain is likely to wrap around the surface of silicate nuclei, thus becoming a blocking layer and inhibiting further silicate growth. Both static and dynamic tests were utilized to evaluate the performance of the silicate scale inhibitors. The PEG-functionalized silane achieved excellent inhibition percentages at low or medium pH as compared with conventional inhibitors that are based on phosphonates or polycarboxylic acids. When brine solution pH is high, magnesium (Mg) and calcium (Ca) silicate form, grow larger, and precipitate out, before effective inhibition can occur. This research found the addition of Mg/Ca sequesters help mitigate this growth/precipitation problem by slowing the initial nucleation process. This novel study supports the introduction of a silane/siloxide group that specifically binds the inhibitor with silicate nuclei providing the advantages over conventional technologies where no specific binding between an inhibitor and precipitate is established.</jats:p

Computational Modeling of Temporary Clay Stabilizers Supported by Performance Testing

Abstract The performance of systematically substituted temporary clay stabilizers has significant correlation with performances predicted by computational modeling. The model binding energies of different clay stabilizers onto various bentonite crystalline faces were independently calculated and corresponded well with a standard bench-top performance method indicating a systematic approach in the development of temporary clay stabilization performance may be realized. Various clay stabilizers are employed when stimulation requiring aqueous based fluids is necessary in water sensitive formations. Typically, if swelling or migrating clays are present, temporary or permanent stabilizers are utilized. Low molecular weight temporary stabilizers as a rule perform above a critical level concentration, but as the stabilizers concentration diminishes in the fracturing fluid due to flowback, formation fluid displacement, or other mechanisms, the clay can swell reducing porosity and permeability. Permanent stabilizers are generally higher molecular weight and can adhere to single or multiple clay platelets thus dissolution of the stabilizer into the fluid is not favored and the beneficial anti-swell effect is of higher duration. It was discovered when using binding energies of substituted ammonium ions on a bentonite interlayer, the binding energies correlated well with performance testing. The binding energy of ammonium ions substituted with 0 to 4 methyl groups or choline were calculated on the 001 crystal face(s) of bentonite. Bentonite being a 2:1 swelling clay had its inter-crystalline space gapped at 8 to 20Å. Unique molecular ions were introduced to this space and the binding energies were calculated using a Monte Carlo Isothermal Adsorption method. Performance testing was then conducted using a low pressure Bariod fluid loss cell. A set concentration of sodium bentonite was blended into water a specific RPM and duration in the presence of the particular ammonium ion, placed in the cell and pressure was applied and leak off rate were measured. The resulting leak off rates were compared to the binding energy. The design of efficient temporary clay stabilizers can be directly linked to performance. Further, the duration of the stabilization may also be modeled in a way where experimentation would be difficult in flow through porous media.</jats:p

New Compounds for Hydrogen Sulfide Scavenging and Iron Sulfide Control

Abstract New compounds have demonstrated effective scavenging of hydrogen sulfide with potential for preventing deposition of metal sulfides. These compounds come from a variety of functional families and compete against typical scavenging technology well with respect to molar efficiency, reaction rate, and stability. These inhibitors not only work on existing sulfide but some can also be modified to change the oxidation state of the system to provide a non-scaling scenario. The presence of hydrogen sulfide is an ever increasing problem in the oilfield, whether the origin is biological or formation dependant. The presence of extremely toxic hydrogen sulfide increases the corrosion rates of many metals and makes necessary the sweetening of produced hydrocarbon. If solubilized metals such as iron, lead or zinc are present in the fluid, the deposition of sulfides may occur as flow restrictive scale on the tubulars, leading to corrosion and/or biofilm augmentation or formation damaging fine particulate in the pay zone. These single component inhibitors were tested in standard synthetic formation waters which were either sulfide laden and/or metal or sulfide laden. Waters derived were standard unadulterated species at various pHs or were acidified and then spent on carbonate. The rate of sulfide uptake was monitored and the soluble metal ions were determined. Response surfaces were generated for a few key inhibitors and the performance of the inhibitors was compared to standard inhibitors. Stability was also checked to ensure insoluble or reversible scavenging species were measured. The use of these scavengers for drilling, stimulation, completion, and produced fluids provides the service company and/or operator with a viable treatment for problems incurred when treating sour reservoirs.</jats:p

Results from Response Surface Methodology in the Study of Novel Temporary and Permanent Clay Stabilizers

Abstract The performance results from a systematic study of novel and contemporary clay stabilizers are provided. These interactions range from synergistic to antagonistic and are presented on a response surface with good correlation. Both organic and inorganic permanent and temporary clay stabilizers were studied. Some of these novel effective inhibitors have HIMS ratings lower than choline chloride. Various clay stabilizers are employed when stimulation techniques requiring aqueous based fluids are necessary in water sensitive formations. Typically, if swelling or migrating clays are present, temporary or permanent stabilizers are utilized. Low molecular weight temporary stabilizers, as a rule, perform only above a critical level concentration, but as the stabilizer's concentration diminishes in the fracturing fluid due to flowback, formation fluid displacement, or other mechanisms, the clay can swell, reducing porosity and permeability. Permanent stabilizers are generally higher molecular weight and can adhere to single or multiple clay platelets, thus dissolution of the stabilizer into the fluid is not favored, and the beneficial anti-swelling effect is of higher duration. This study was set up using Central Composite Design of Experiments. Performance testing was conducted using a low pressure Bariod fluid loss cell. A set concentration of unbenefited sodium bentonite was blended into water at a specific RPM and duration in the presence of the particular stabilizers, then placed in the cell, sealed, and pressure was applied. Finally leak off rates were measured. The slope of the leak off curve was calculated and plotted versus dosage. The slopes and response surfaces observed had excellent correlation. Additive effects and synergies were noted. The design of efficient temporary clay stabilizers can be directly linked to performance. Novel temporary clay stabilizers competitive with choline chloride in both performance and environmental profile should be welcomed in stimulation. The duration of the stabilization could also be studied using this test method since porous media experimentation is difficult to perform.</jats:p

Possibility of Flooding Polymer or Water Reuse via Innovative Selective or Total Flocculation of Enhanced Oil Recovery Produced Water

AbstractResearch has discovered systems that can selectively flocculate mineral solids from a high molecular weight polymer flood matrix while leaving the polymer intact or alternatively achieving a viable total flocculation of the polymer in the produced fluids. Modified alkaline surfactant polymer (ASP) and standard polymer (P) flood systems were studied with findings obtained by controlled variations of both well-proven and non-prevalent chemical approaches. Results concluded that selectively removing the mineral solids from polymer-laden water produces reusable enhanced oil recovery (EOR) fluid.EOR is a proven method to increase hydrocarbon yield from post-natural, stimulated, or standard flood driven reservoirs. Fluid produced from the reservoir contains the desired hydrocarbon and an aqueous phase. Previously considered a liability, properly treated, the aqueous phase can become an asset. Polymer floods have a proven history in EOR and, though complex in application, ASP also demonstrated EOR effectiveness in the laboratory. Most ASP approaches are currently in field trial stages. The produced fluid is subjected to hydrocarbon separation with the resulting aqueous system either treated for disposal or recycled into the system. The aqueous phase matrix is mainly composed of high molecular weight polymer, mineral solids, residual base, residual oil, and possibly surfactant. If the producer chooses disposal, the solids must be flocculated by a method balancing density, dewaterability, processability, process variability, and cost. However, if the producer opts to recycle the fluid for reinjection, steps must be taken to minimize polymer deviations requiring selective flocculation of all components with exception of the polymer. This undertaking is challenging as EOR polymers are also effective flocculants, therefore sensitive to standard coagulant and flocculant approaches. Utilizing controlled, standard methods and multivariable design of experiments, results were obtained for both total and selective flocculation.Total flocculation systematically studies the influence of pH, inorganic, and organic coagulants in maximizing the treatment effectiveness. The same approach was successful for selective flocculation, however unique coagulants were applied. The selective flocculation process coagulated and separated the mineral solids, and left the high molecular weight polymer intact and the fluid matrix as viscous as prior to treatment. Effectiveness of treatments were determined using standard gravimetric and viscometric methods.These discoveries will assist decision makers in determining whether total or selective flocculation is the most viable treatment for polymer based EOR, balancing environmental and economic aspects to pursue a desired treatment route. These methods, though targeting EOR, have practical applications for treatment of flowback and water produced from stimulation and potentially drilling operations as well.</jats:p