Electromagnetic waves as a mechanism of heat generation in the reservoir is a concept that has great potential to efficiently produce heavy oil and bitumen. However, as a result of large wave attenuation, the penetration depth of the wave is relatively small. This limits the economic viability of an otherwise technically proven technology. Taking advantage of the inherent piezoelectric phenomenon in quartz crystals enables the manipulation of the penetration depth of the wave. Acoustic waves were introduced simultaneously with a microwave to the core samples where the presence of the mechanical wave generated an infinitesimal stress. Mechanical stress achieved by the acoustic wave triggered piezoelectricity in two sandstone samples with a limestone sample serving as the control. All consolidated core samples were fully saturated with either oil or water to capture the effect of the pore space. The incremental stress manifests itself through change in the complex permittivity of the sample measured with a vector network analyzer. The penetration depth of the microwave was calculated as a function of the measured complex permittivity. Comparative analysis of the penetration depth of the varying imposed stress states illustrates the additive penetration achieved due to piezoelectricity. Piezoelectricity as the fundamental mechanism of penetration increase was further demonstrated by isolation of the quartz contribution through use of the limestone. Increase in penetration depth was realized for all oil-saturated sandstone cores. The presence of the acoustic wave introduced a stress component across the quartz crystals, generating a change in the electric potential. This created a dynamic polarization that corresponded to an absorption environment more conducive to microwave penetration.

A microfluidic paper-based analytical device (μPAD) is a cost-effective platform to implement assays, especially for point-of-care testing. Developing μPADs with fluidic control is important to implement multistep assays and provide high sensitivities. However, current localized delays in μPADs made of sucrose have a limited ability to decrease the flow rate. In addition, existing μPADs for automatic multistep assays are limited by their need for auxiliary instruments, their false activation, or their unavoidable tradeoff between available fluid volumes and temporal differences between steps. Here, a novel μPAD composed of a localized dissolvable delay and a horizontal motion mechanical valve for use as an automatic multistep assay is reported. A mixture of fructose and sucrose was used in the localized dissolvable delay and it provided an effective decrease in the flow rate to ensure adequate sensitivity in an assay. The dissolvable delay effectively doubled the flow time. A mechanical valve using a horizontal movement was developed to automatically implement a multistep process. Two-step and four-step processes were enabled with the μPAD. Cardiac troponin I (cTnI), a gold-standard biomarker for myocardial infarction, was used as a model analyte to show the performance of the developed μPAD in an assay. The designed μPAD, with the simple-to-make localized dissolvable delay and the robust mechanical valve, provides the potential to automatically implement high-performance multistep assays toward a versatile platform for point-of-care diagnostics.

Without intending a value judgment, I would say this book can best be called an encyclopedia of contemporary methods of instrumental analysis. In 936 pages of text (excluding experiments and answers to problems) essentially all instrumental methods relevant to present-day analytical chemistry are covered, including atomic absorption and emission spectroscopy, UV, VIS, and IR spectrophotometry, Raman, NMR, and ESR spectroscopy, X-ray methods, mass spectrometry, chromatography, electrochemistry, electronics, computer applications, and automation. The amount of discussion given to each topic is generally in proper proportion to its importance in the field of analytical chemistry; that is, .there is no apparent bias toward a particular area as seen in many other texts. Topics discussed

Electromagnetic waves as a viable means of introducing heat energy to reservoirs to allow for transmission of heavy or extra-heavy oil have been gaining prominence and notoriety in recent years due to its applicability to a wide variety of reservoirs. However, how reservoir properties affect the electromagnetic wave penetration is not well defined. This study investigates the impact of different reservoir rock and fluid combinations on the electromagnetic wave penetration and also introduces the dependency of dielectric properties on pressure. Several different reservoir rock samples (quartz rich, carbonate rich) with varying lithology and porosity were used in this study. The contribution of the fluid type was investigated by saturating the cores with water as well as measuring the responses on dry cores as a control. Air and water saturated rock samples were irradiated electromagnetically at varying frequencies (200 MHz to 6 GHz) under pressure. Frequency dependent dielectric properties were measured for each sample utilizing a coaxial dielectric probe and a vector network analyzer. Dielectric constant (ε′), loss index (ε″), and loss tangent of test mediums were utilized to generate the penetration depth of each sample as a function of frequency. The loss index and dielectric constant comprise the complex permittivity which is the foundation for microwave absorbance and penetration depth. Penetration depth is highly frequency dependent and exhibits an exponential decay where as the wave travels further into the sample more energy is gradually absorbed by the material and thus the energy content of the wave continually diminishes. With lower frequencies, higher penetration depth was obtained for all samples where less energy has been dissipated and absorbed by the formation. The utilization of both water and air represent both a very effective absorber of microwaves as well as a material transparent to microwaves respectively. Therefore, the dry cores (air saturated) realized greater penetration depths as less attenuation occurred due to the transparent nature of the saturating fluid. The quartz rich sandstone achieved lower penetration depths than the limestone core utilized which is indicative of greater capability of the sandstone samples to absorb microwave energy. Reservoir properties will affect the dielectric response of the material and so it becomes necessary to account for the presence of pressure due to overburden while taking laboratory measurements. The pressurized samples for both the sandstones were found to cause disparity between the control experiments when saturated with water. Introducing pressure of the water saturated sandstone samples effectively lowers the loss tangent resulting in a decreased capability to absorb microwave energy.