MODELING OF BIOMASS TORREFACTION AND PYROLYSIS AND ITS APPLICATIONS

Utilizing biomass provides a possible near-term alternative solution for fossil energy dependence in both electricity generation and transportation. Though thermochemical conversion can produce solid/liquid fuels that are compatible in existing infrastructure, detailed scientific chemical and mechanistic understanding are still being developed. In contribution to these efforts, this work is focused on development of a semiempirical, lumped parameter, chemical kinetic model to describe the degradation of woody biomass. The initial kinetic model was developed in the torrefaction region to describe the gas-phase evolution of products (water, organic acids, permanent gases, and furfural) through a three consecutive reaction model. In this model, the initial biomass degrades through several solid intermediates that represent of partially degraded polymers to produce the observed gas-phase species through product detachment. The model was able to well describe the measured species transients, and revealed important considerations between processing severity (time, temperature) and enhancement of solid fuel properties. After the model was calibrated to predict the weight distribution between products, it was able to describe the elemental composition of the solid material up to removal of approximately thirty percent of the initial dry sample mass. Engineering considerations such as process efficiency based on the intrinsic reaction (mass and energy yield) were explored. The model was then extended into a more traditional pyrolysis range (up to 425°C), while avoiding any significant secondary thermal reactions. Here the model was extended in similar fashion to six consecutive reactions to describe to observed product evolution. It was found that the model not only describes the gas-phase species from cellulose, hemicellulose, and lignin, but also the entirety of torrefaction and pyrolysis within a single unified mechanism, implying that they are similar processes that occur at kinetically different rates due to process temperature. The presented kinetic parameters, process chemistry, and dynamic product removal traces offer unique insight into the thermal degradation mechanism. The unified model predictions were then explored to present product distribution/composition over the complete processing range, and obtain model validation. Also of great importance, the presented model is able to account for differences in solid degradation due to variation in woody feedstock

Widespread habitat change through paludification as an interactive mechanism in mass extinction events

The study of mass extinction events has largely focused on defining an environmental factor or factors that might account for specific patterns of faunal demise. Several hypotheses elaborate on how a given environmental factor might affect fauna directly, but differentially, causing extinction in certain taxa but not others. Yet few studies have considered specific habitat changes that might result from natural vegetation processes or from perturbations of vegetation. The role of large-scale habitat change induced by natural successional change from forest to bog (paludification) is examined and how large perturbations (e.g., volcanism, bolide impacts) might favor increased rates of paludification and consequent mass extinctions is considered. This hypothesis has an advantage over other hypotheses for mass extinctions in that modern day analogs of paludification are common throughout the world, thus allowing for considerable testing

Autologous Fat Grafting Reduces Pain in Irradiated Breast: A Review of Our Experience

Introduction. Pain syndromes affect women after conservative and radical breast oncological procedures. Radiation therapy influences their development. We report autologous fat grafting therapeutical role in treating chronic pain in irradiated patients. Materials and Methods. From February 2006 to November 2014, we collect a total of 209 patients who meet the definition of "Postmastectomy Pain Syndrome" (PMPS) and had undergone mastectomy with axillary dissection (113 patients) or quadrantectomy (96 patients). Both procedures were followed by radiotherapy. We performed fat grafting following Coleman's procedure. Mean amount of adipose tissue injected was 52\u2009cc (\ub18.9\u2009cc) per breast. Seventy-eight in 209 patients were not treated surgically and were considered as control group. Data were gathered through preoperative and postoperative VAS questionnaires; analgesic drug intake was recorded. Results. The follow-up was at 12 months (range 11.7-13.5 months). In 120 treated patients we detected pain decrease (mean \ub1 SD point reduction, 3.19 \ub1 2.86). Forty-eight in 59 patients stopped their analgesic drug therapy. Controls reported a mean \ub1 SD decrease of pain of 1.14 \ub1 2.72. Results showed that pain decreased significantly in patients treated (p < 0.005, Wilcoxon rank-sum test). Conclusion. Our 8-year experience confirms fat grafting effectiveness in decreasing neuropathic pain

Error modeling of precision orientation sensors in a fixed base simulation

Models of noise and dynamic characteristics of gyro and autocollimator for very small signal levels are presented. Measurements were evaluated using spectral techniques for identifying noise from base motion. The experiment was constructed to measure the precession, due to relativistic effects, of an extremely precise earth-orbiting gyroscope. The design goal for nonrelativistic gyro drift is 0.001 arcsec per year. An analogous fixed base simulator was used in developing methods of instrument error modeling and performance evaluation applicable to the relativity experiment sensors and other precision pointing instruments. Analysis of autocollimator spectra uncovered the presence of a platform gimbal resonance. The source of resonance was isolated to gimbal bearing elastic restraint properties most apparent at very small levels of motion. A model of these properties which include both elastic and coulomb friction characteristics is discussed, and a describing function developed

Morphological stability of a heterophase interface under electromigration conditions

The evolution of the interface between two mutually insoluble metallic phases, under the influence of a strong electric field is examined. A slight perturbation of the interface away from a plane y=h(x) leads to a component of the electric field along the interface. This creates a diffusion flux of the individual atoms along the interface which, in turn, leads to an increase in the amplitude of the initial perturbation and thus to an interfacial profile instability. The processes is expected to be controlled by interface diffusion in response to three distinct driving forces: the electric field, internal stresses (which arise due to the accumulation or depletion of matter at the interface), and the interfacial curvature. The stress distribution along the interface was found from a self‐consistent solution of the elastic problem. For the instability to occur, differences in effective atomic charges, elastic moduli and/or atomic mobilities of the two constituent metals are required. Small sinusoidal corrugations are shown to grow with time for a range of wavelengths. The corrugations can grow monotonically or vary in oscillatory manner, depending on their wavelength. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69819/2/JAPIAU-79-9-6834-1.pd

Love is the triumph of the imagination: daydreams about significant others are associated with increased happiness, love and connection

Social relationships and interactions contribute to daily emotional well-being. The emotional benefits that come from engaging with others are known to arise from real events, but do they also come from the imagination during daydreaming activity? Using experience sampling methodology with 101 participants, we obtained 371 reports of naturally occurring daydreams with social and non-social content and self-reported feelings before and after daydreaming. Social, but not non-social, daydreams were associated with increased happiness, love and connection and this effect was not solely attributable to the emotional content of the daydreams. These effects were only present when participants were lacking in these feelings before daydreaming and when the daydream involved imagining others with whom the daydreamer had a high quality relationship. Findings are consistent with the idea that social daydreams may function to regulate emotion: imagining close others may serve the current emotional needs of daydreamers by increasing positive feelings towards themselves and others

Evaluating Postfire Seeding Treatments Designed to Suppress Cheatgrass (Bromus tectorum) in a Ponderosa Pine Forest on the Colorado Plateau

The restoration of historical fuel conditions and fire regimes is one of the primary land management goals in the Shivwits Plateau region of northwestern Arizona. Fire is the primary tool used in this region to reduce fuel loads and shift landscapes back to historical conditions of a low intensity, 8- 15 year return interval, surface fire regime. However, the invasive plant cheatgrass has become the dominant understory vegetation and fuel type following initial fire treatments in many areas. There is significant concern that repeated burning at historically appropriate fire return intervals for ponderosa pine forest will benefit this invasive plant to the detriment of native species. There is additional concern that the high flammability of cheatgrass fuelbeds will lead to fire return intervals that are more frequent than occurred historically and that are prescribed in the agency fire management plans, potentially preventing recruitment of pine seedlings and leading to type conversion of native forests to alien grasslands. Federal land managers and research scientists have noted that cheatgrass does not typically cooccur with two of the dominant perennial grasses in the Shivwits plateau region, bottlebrush squirreltail (Elymus elymoides) and blue grama (Bouteloua gracilis). This suggests that these natives may be competing with and excluding the establishment of cheatgrass. If these species can be established in postfire landscapes, they may be able to pre-empt the establishment of cheatgrass and promote the restoration of native plant communities and natural fuel characteristics. This report provides results of an experimental seedings of these two perennial grasses. Seeding with or without raking had no detectable effects on any of the species or groups of species in this study as measured by: 1) the density, cover, and species diversity of standing vegetation during the first 5 post-treatment years; or 2) the density and species diversity of the soil seedbank during the first 3 post-treatment years. Blue grama had an overall low standing density and cover, and seedbank density, at the study site, whereas bottlebrush squirreltail had relatively high standing density and cover, and seedbank density, at least during some of the sampling years. Cheatgrass did not differ among treatments, including raked and unraked plots, and only increased from 1.1 seeds per 18 cubic cm of soil immediately following the fire in fall 2003 to 1.5 seeds by the fall of the third postfire year

The Effectiveness of Sophisticated Toys in Play-Therapy with Twelve Year Old Children

It is the aim of this investigation to compare the use of normally recommended toys, ordinarily used in the play-therapy setting, with more sophisticated, "grown-up" toys, when working with twelve-year-old children