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Customized Porous Materials for Selective Separation via Confinement Effect

Customized Porous Materials for Selective Separation via Confinement Effect

Primary Author: Derek Deming

Faculty Sponsor: Qiang Zhang

 

Primary College/Unit: Arts and Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

 

Metal–organic frameworks (MOFs) have been subject to extensive research in recent years owing to their diverse porous molecular frames and adaptability to targeted applications. MOFs are comprised of inorganic nodes and organic linkers that can be tailored to suit a prodigious scope of applications, such as catalysis, sensing and separations. One of the most important separations is isolating xenon (Xe) from a mixture of xenon and krypton (Kr). Not only is Xe scarce and an important inert gas used in a variety of purposes (i.e., aerospace, electrical, and medical industries), the capture of Xe from gas mixtures embodies one of the most challenging molecular gas separations. In this work, we have designed a series of novel MOFs based on customized “v-shaped” organic linkers with electron donating and/or withdrawing groups to investigate the role of structure and functional groups in the separation of Xe via the “confinement effect”. Computational results suggested that a series of symmetrical diaryl sulfone and dimethyl-4,4’-oxalyldibenzoate linkers provide the most promising selectivity due to their ideal pore size, approximately 5 Å, to immobilize Xe molecules. These MOFs were comprehensively characterized via x-ray diffraction (single crystal and powder x-ray diffraction), nitrogen adsorption isotherm analysis, ultraviolet-visible and Fourier transform infrared spectroscopy. The role of pore size, shape, and functional groups will be extensively explored to help us gain deep insights into the vital factors influencing Xe adsorption. The goal of the project was to design and synthesize ideal materials for the separation of Xe from gas mixtures.

 

High Performance and Stability Solid Oxide Electrolysis Cell without Hydrogen as Safe Gas

High Performance and Stability Solid Oxide Electrolysis Cell without Hydrogen as Safe Gas

Primary Author: Martinus Dewa

Faculty Sponsor: Su Ha

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Engineering and Environmental Science

Campus: Pullman

 

Abstract:

 

Solid oxide electrolysis cell (SOEC) is a device that can transform CO2 and water into hydrogen (H2) and carbon monoxide (CO) using electricity through co-electrolysis process. H2 is often added during the SOEC operation as a safe gas to prevent the SOEC degradation. Removing H2 from the system can reduce the capital cost of the process. Nickel (Ni)/yttria-stabilized zirconia (YSZ) is a state-of-the-art electrode material for SOEC due to its good catalytic performance and electrical conductivity. However, many researchers claimed that it will rapidly deactivate under co-electrolysis without hydrogen since the Ni can be oxidized and becomes electrically non-conductive. CuFe2O4 has been recently investigated to substitute Ni/YSZ in SOECs since it has better stability under highly oxidizing condition such as co-electrolysis.

We fabricated the SOEC using both Nickel (Ni)/yttria-stabilized zirconia (YSZ) and CuFe2O4 by screen printing method. The electrochemical performance was measured under 1:1 ratio of CO2 and H2O at 800°C.

Our Ni/YSZ cell shows a decent performance of -400 mA/cm2 at 1.5 V and was stable after 24 h. However, Ni/YSZ requires activation by H2 during start up. CuFe2O4 cell can run without H2 activation and shows a slightly better performance of -475 mA/cm2 at 1.5 V. However, the stability was lower due to interface compatibility. Applying an additional La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) barrier layer successfully solved the stability issue, but electrochemical performance is compromised (-275 mA/cm2). Therefore, optimization of the design and fabrication method for the CuFe2O4 cell needs to be conducted to get both good performance and stability.

 

An examination of emoji usage in news teasers on Facebook

An examination of emoji usage in news teasers on Facebook

Primary Author: Rebecca Donaway

Faculty Sponsor: Jessica Willoughby

 

Primary College/Unit: Edward R. Murrow College of Communication

Category: Business, Communication, and Politial Sciences

Campus: Pullman

 

Abstract:

 

Online news use is growing at a rapid rate. This study is particularly interested in news exposure on social networking sites (SNSs) like Facebook. The physical layout of news on social media is such that the teaser (status message) allows news organizations to add additional text to shared news posts. In some cases, the language used in the news teaser is subjective, more emotional, and less formal that traditional news norms would suggest. Political communication research has not thoroughly explored the teaser space or how this relaxed formality affects user engagement with the news online (likes, comments, shares). The goals of this mixed methods study are two-fold. First, using focus group data from young adults, the research explores user impressions of various features of the news teaser that communicate emotion, namely exaggerated punctuation, uppercase text, and the use of emojis. The results for emojis in news teasers were the most complex. While users recognize that emojis are less formal, they are interested in their use, especially the descriptive emojis.  To further study this, an experiment will be conducted to test the effect of four different emoji conditions: no emoji, descriptive emoji, positive emoji, and negative emoji. The research posits the role of anger and enthusiasm will mediate message exposure and engagement outcomes. Thus, this second study will contribute to our collective understanding of the antecedents of emotional reactions within the Affective Intelligence Theory, as well as informs news and content creators alike on the effects of the teaser space.

 

Survival of the quickest: Pathogen pressure drives rapid evolution at a barley resistance gene cluster

Survival of the quickest: Pathogen pressure drives rapid evolution at a barley resistance gene cluster

Primary Author: Karl Effertz

Faculty Sponsor: Robert Brueggeman

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

Principal topic

Net form net blotch (NFNB), caused by the fungal pathogen Pyrenophora teres f. teres (Ptt), results in significant yield loss in effected barley fields worldwide. An important region on barley chromosome 6H has been reported in several studies investigating Ptt resistance and susceptibility. Our group investigated this region, which confers susceptibility or resistance to Ptt, depending on fungal isolate and barley cultivar. Our research has uncovered a unique adaptive mechanism that allows barley plants to rapidly exchange resistance genes in response to pathogen attack.

 

Method

Using DNA markers, we analyzed three separate barley populations to delimit the 6H region associated with Ptt resistance by correlating marker alleles with disease outcome.

 

Results/Implications

Our results indicate that the 6H disease resistance cluster covers 3 MB of the genome, containing 36 genes. Of these, four genes resemble disease resistance genes that have been previously characterized. Strikingly, this resistance cluster consistently transfers as a block, with ~5% of individuals from each population harboring a double recombination event where only this block of genes transfers from parent to progeny. The conserved nature of recombination at this site suggests an evolutionary mechanism where the barley plant can rapidly exchange resistance genes in the face of pathogen pressure. This directed recombination bears similarity to mammalian VDJ recombination, an adaptive mechanism allowing for diverse immune responses. The discovery of this mechanism in plants would create a new paradigm for describing host-parasite evolution and breeding for disease resistance.

 

Whole lentil flours exhibit their highest puffing ability at low processing temperature during extrusion

Whole lentil flours exhibit their highest puffing ability at low processing temperature during extrusion

Primary Author: Pichmony Ek

Faculty Sponsor: Girish Ganjyal

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Principal topic

Extrusion processing is commonly used to produce breakfast cereals and puffed snacks. These products are typically made from cereal flours with a high amount of starch which has high caloric bulk. Lentil is one of the attractive crops that can be used as an alternative ingredient for these products because of their high protein content and bioactive compounds. The source of raw materials including their varieties, can significantly affect the product qualities.

Method

This study was to evaluate the qualities of the puffs made from three varieties of lentils (Brewer, Crimson, and Richlea). Whole seeds of the lentils were ground into flours and then processed with different extrusion processing conditions. Expansion ratio, water absorption index (WAI), and water solubility index (WSI) of the puffs were evaluated. The products with high expansion ratio (high puffing ability) generally provide crispy texture which consumers like. The products with low WAI could be produced as breakfast cereals because they can be crispy longer in milk and the products with high WSI are suitable for the foods for kids and old people.

Results/implications

The three lentils had relatively lower expansion compared to other cereals such as corn, but they exhibited their highest expansion at lower processing temperatures. Richlea variety was found to be the most suitable to produce these puffed products. The product characteristics of Crimson and Brewer varieties were comparable. The result of this study is useful for the food industry to select the lentil varieties for their specific products using extrusion.

 

Roles of Chickpea Protein (PGIP) in Defense Against Pathogenic Fungi

Roles of Chickpea Protein (PGIP) in Defense Against Pathogenic Fungi

Primary Author: Vishnutej Ellur

Faculty Sponsor: Weidong Chen

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Plant diseases and pests continue to cause as much as 40% losses during production, storage, and transport of staple crops affecting food security worldwide. Ensuring food security in an environmentally sustainable way is imperative. Over the years, the mainstay of disease management strategies came to rely on the use of pesticides. However, pesticide usage can be detrimental to the environment and continuous use resulted in targeted pathogens developing resistance. Therefore the use of disease-resistant varieties is the most effective and environmentally sustainable approach and it requires plant genes that can produce proteins with pathogen inhibiting properties.

 

Pathogenic fungi produce several tissue macerating enzymes to penetrate plant tissue and polygalacturonase (PG) being very significant among them. To counteract PGs, plants produce inhibitory proteins called polygalacturonase inhibiting proteins (PGIP). The purpose of this study is to understand the pathogen inhibiting potential of PGIP in chickpea (CaPGIP1). Studying homology, location and expression of any protein is important in understating its role and function. Using a technique called homology modeling we observed that CaPGIP1 contains domains crucial in interacting with pathogen enzymes. Further, its location was investigated using the subcellular localization method and found the protein to be located in the cell wall, a critical defense location of plant proteins. An increased expression of the CaPGIP1 gene was observed when infected with Ascochyta rabiei fungus, using a relative expression technique. These results indicate that chickpea PGIP has a potential role to combat pathogens, our further research will help to gain a better understanding.

 

Humidity Controlled Micro Direct Ink Writing of Polymeric Bio-Ink for Drug Delivery and Bio-mimetic Tissue Synthesis

Humidity Controlled Micro Direct Ink Writing of Polymeric Bio-Ink for Drug Delivery and Bio-mimetic Tissue Synthesis

Primary Author: Kevin Estelle

Faculty Sponsor: Arda Gozen

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Engineering and Environmental Science

Campus: Pullman

 

Abstract:

 

Principal topic

Bio-inks are biocompatible hydrogels and water-soluble polymers that are used to additively manufacture next-generation medical and pharmaceutical products. Through additive manufacturing, bio-inks loaded with biomaterials are extruded and assembled layer-by-layer to fabricate personalized artificial tissues and drug delivery vehicles. Success of such technologies relies on how precisely they mimic the complex microscale features of the native tissues, and there is a need to advance the current bio-printing technologies which do not possess this high manufacturing resolution. At lower size scales, the process suffers from rapid ink-drying and induced flow rate inconsistencies. This project can lead to more precise personalized drug delivery devices and artificial tissues.

 

Method

We propose a novel bio-printing implementation where the humidity at the end of the extrusion nozzle is controlled to overcome such issues. A co-axial nozzle design is implemented where the inner nozzle is used to extrude the bio-inks and the outer nozzle dispenses water saturated air. This system increases the relative humidity up to 100% and beyond at the deposition site. The controlled humidity effects are observed through changes in volume flow rate, height, width, aspect ratio, and layer-to-layer cohesion and associated sidewall morphology obtained via imaging of the printed structures.

 

Results/implications

It is shown that the deposited material volume, ink spreading, and layer-to-layer fusion is a strong function of the humidity level at the end of the nozzle. With increasing humidity, stacked layers are more fused, the stackability remains intact, and clogging is prevented, which all increase the printability of bio-inks.

 

Effective erosion conservation screening tool: sharpening conservation placement by marrying physical modeling and stakeholder validation.

Effective erosion conservation screening tool: sharpening conservation placement by marrying physical modeling and stakeholder validation.

Primary Author: Ames Fowler

Faculty Sponsor: Jan Boll

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

Principal topic:

Persistent, unsustainable erosion rates on agricultural land and limited conservation funds motivate the identification of critical source areas for the effective selection and placement of best management practices (BMPs). Currently, national conservation funds are available on a case-by-case basis. There is no watershed-planning approach that identifies hydrologically sensitive areas at the field scale. The Hydrologic Character Tool (HCT) is a simplified formulation of the Water Erosion Prediction Project (WEPP) model previously developed to fit this need but has yet to be adopted for spatial use.

 

Method:

In this study, the HCT framework is applied to the Palouse River Watershed to determine 30-year average distributed erosion and hydrological flows. Publicly available data for climate, slope, and soil depth at a 30-meter resolution allow field scale erosion “hotspots” to be identified. Three tillage practice scenarios evaluate current conservation effectiveness. The tool was assessed by a global parameter sensitivity and infield stakeholder verification.

 

Results/implications:

Model results suggest a small area of the Palouse River Watershed produces disproportionally high erosion rates. The mean erosion rates decrease sharply with decreases in soil disturbance, but the erosion rate distribution from the land type patterning associated with landscape features (e.g. soil depth, slope, etc.) persist. In addition to field scale heterogeneity – regional scale patterning associated with climate and soil formation create a gradient of critical source area density. This erosion and hydrology screening tool provides a linkage between watershed processes and field-by-field conservation efforts serving to make conservation planning more physically robust and cost effective.

 

The genetic consequences of dam removal on the Elwha River for recolonizing Steelhead

The genetic consequences of dam removal on the Elwha River for recolonizing Steelhead

Primary Author: Alexandra Fraik

Faculty Sponsor: Joanna Kelley

 

Primary College/Unit: Arts and Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

 

Dam construction and riverscape habitat fragmentation disrupt important life-histories and movement of aquatic species. Functionally, dams disrupt the movement of water, sediments, nutrients, and species between upstream and downstream. The Elwha and Glines Canyon dams in Washington state, constructed in the early 1900s, fragmented the Elwha River, restricting migratory species such as Oncorhynchus mykiss from ocean. Oncorhynchus mykiss exhibits multiple life-history phenotypes including a migratory form (anadromous Steelhead) and a freshwater non-migratory form (resident Rainbow Trout). The negative effects of dams on O. mykiss have been extensively documented (including population declines, loss of genetic diversity, extirpation), however few have studied their population genetics following dam removal. In 2012 and 2015, the Elwha River dams were removed and anadromous Steelhead recolonized formerly dammed regions. In this study, we characterized the genetic ancestry of recolonizing Steelhead into the previously dammed portions of the Elwha River watershed. Single nucleotide polymorphism genetic data were produced from 1,003 samples collected prior to, during and post dam removal from both life-history forms. Population structure analyses supported three genetic clusters primarily explained by dam location. Following dam removal genetic structure decreased. Using genetic stock identification, we determined recolonizing Steelhead were of mixed genetic ancestry with individuals derived from formerly dammed populations as well as below dam populations. Alleles putatively involved in the anadromous phenotype were detected in formerly dammed populations both prior to and post dam removal. These results have significant evolutionary implications for the conservation of migratory adaptive potential in O. mykiss populations facing changing riverscapes.

 

Development and Validation of Analytical Chart for 915 MHz Single-mode Microwave Assisted Thermal Processing Conditions

Development and Validation of Analytical Chart for 915 MHz Single-mode Microwave Assisted Thermal Processing Conditions

Primary Author: Yonas Gezahegn

Faculty Sponsor: JumingTang

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Engineering and Environmental Science

Campus: Pullman

 

Abstract:

 

Microwave thermal processing has wide applications in the food industries such as drying, pasteurization and sterilization. In microwave heating understanding the relation between dielectric properties and processing conditions is key in accurately predicting the heating rate that ensures food safety. Hence, this research aims to develop an analytical chart that will relate the dielectric properties and processing conditions to accurately predicted the cold spot temperature in the center layer of food. By measuring some physical properties of food samples (mashed potato, rice and pea) and applying analytical equations the chart was developed using MATLAB2019a software. In predicting dielectric constant, the chart was accurate with 0 – 1.2%, 0.1 – 2.3% and 0 – 4.6% error, for the products respectively. The optimum salt content of 0.1%, 1% and 0.5% were discovered for higher heating rates, respectively. The best preheating temperatures were also determined, where higher salt content foods have a less preheating temperature for maximum heating rate. It was also possible to related dissipation power and heating rate to predict the cold spot temperature at a given microwave heating time. Using mashed potato sample 0% salt and 22 mm, 0.6% salt and 22 mm, 0.6% salt and 40 mm, 0.1% salt and 40 mm, 0% salt and 35 mm the temperature prediction error was only 0 – 2%,  0 – 3%, 0 – 6%, 0 – 9%, and 0 – 6%, respectively. In conclusion, the analytical chart accurately predicts dielectric properties and processing conditions that can save time and resources