Indiana University-Purdue University Indianapolis (IUPUI) / This thesis work aims to make a better knowledge on the insights of physics on microbubble coalescence process, using experimental and numerical approaches. The neck growth and bubble surface wave propagation at the early stage of coalescence, merging preference, as well as a reaction-channel modified microfluidic gas generator are presented in the thesis. Coalescence of unequal-sized microbubbles captive on solid substrate was observed from cross-section view using synchrotron high speed imaging technique and a mi- crofluidic gas generation device. The bridging neck growth and surface wave propaga- tion at the early stage of coalescence were investigated by experimental and numerical methods. The results show that theoretical half power law of neck growth rate is still valid when viscous effect is neglected. However, the inertial-capillary time scale is based on the radius of smaller parent microbubble. The surface wave propagation rate is proportional to the inertial-capillary time scale, which is based on the radius of larger parent microbubble of a coalescence pair. Meanwhile, the relationship of preference distance and size inequality microbub- bles were studied using the same micrfluidic gas generator and observation facilities. The size inequality of parent microbubbles would affect the preference distance of merged bubble in between. The merged bubble gets less closer to the larger parent bubble with an exponent of 1.82 as a reference, which largely affected by shear stress begotten on the solid interface. To express this phenomenon distinguished with free merging bubble pair, we propose the wall shear stress hinders the process of that parent bubbles move towards to each other during coalescence Our hypothesis was confirmed by identical coalescence simulation via ANSYS Fluent. To address the multiple measurement, utilization of Java based photography pro- cessing software ImageJ was applied as a key point to the thesis work. To acquire more microbubble coalescence cases on experiment for study, we enhanced the perfor- mance of microfluidic gas generator with reaction channel optimization. An optimized design on increasing the number of parallel reaction channel from single to triple, was applied to obtain a higher gas generation rate. Also the gas vent shape was modified from triangle to rectangle to provide more information on reaction channel optimiza- tion. The gas generation rate and H2O2 conversion rate were provided to further discuss.

Föreliggande kvantitativa studie ämnade undersöka huruvida respondenter som fått vilseledande information uppgav sig minnas ett förlopp som skilde sig från respondenter som fått neutralt ställda frågor. Studien var ett utfört experiment med mellangruppsdesign där 40 deltagare fick se en film gällande ett rånförsök och efter filmen fick besvara ett frågeformulär gällande huruvida förövare respektive offer upplevs mest pådrivande till brottet. Hälften av deltagarna fick neutralt ställda frågor och den andra hälften fick suggestivt ställda frågor. Som mätinstrument utformades en enkät utifrån en fempunkts Likert-skala, där ett högt värde pekar ut rånaren som mest skyldig och där ett lågt värde pekar ut offren som mest pådrivande till rånförsöket. Resultatet visade ingen signifikant skillnad mellan experimentgruppen och kontrollgruppens totala bedömning gällande vem som i filmen upplevdes mest pådrivande. Gällande frågan om vem som använde mest våld visade studien en signifikant skillnad mellan kontrollgruppen och experimentgruppens bedömning där experimentgruppen bedömde offren som mest våldsamma. / The present quantitative study aimed to investigate whether respondents who received misleading information reported remembering a course of events that differed from respondents who were asked neutral questions. The study was a conducted experiment with a between-group design in which 40 participants were shown a film about an attempted robbery and after the film were asked to answer a questionnaire regarding whether the perpetrator or the victim was perceived as the most motivating factor for the crime. Half of the participants were asked neutral questions and the other half were asked suggestive questions. As a measuring instrument, a questionnaire was designed based on a five-point Likert scale, where a high value points out the robber as most culpable and where a low value points out the victims as most inciting to the robbery attempt. The results showed no significant difference between the experimental group and the control group in terms of who in the film initiated the robbery, who was considered most guilty of the crime or who had the most weapon possession. Regarding the question of who used the most violence, the study showed a significant difference between the control group and the experimental group, with the experimental group rating the victims as the most violent.

The widespread expansion of online markets in the past decade poses several questions for platforms, firms and customers alike. An important dimension to be explored in this domain is the provision of information on e-commerce platforms - given the increasing ease with which product pages can be customized to include a vast variety of content, how do these pieces of information interact? Further, what are the specific channels through which this information eventually influences consumer decision-making? My dissertation is situated in this space, and aims to look at how consumers respond to various “cues” that are being introduced by e-commerce platforms which offer products or services that can be purchased online, and how these cues might eventually influence decision-making. In my first dissertation project, the cue I focus on is user generated content. More specifically, I study how the introduction of the Q&A technology (which enables customers to ask product-specific questions before purchase, and receive answers either from other customers or the platform itself) affects the more widely established reviews and ratings feature on e-commerce platforms. I find that the addition of Q&As leads to better matches between customers and products, higher customer satisfaction, and resultantly higher ratings. My second project examines another cue that is common in online markets, which is the advertised reference price. My goal in this project is to examine how users react to a specific variant of such prices, namely the “Starting from...” price, using data from a large scale field experiment conducted on Holidu.com. My results indicate that raising “From” prices gives users a more accurate price estimate, but it negatively impacts outbound clicks and other engagement metrics. Taken together, the two projects aim to shed light on factors that influence consumer decision-making in an e-commerce setting, and the possible mechanisms underlying this influence.

This study is set out to explore how cognitive biases, gambler’s fallacy and hot hand effect, exert an effect on individual crop insurance purchase decision. A laboratory experiment comprised of two separate games was used to establish an insurance purchase environment to induce individual’s behavior. The gambler’s fallacy and hot hand effect failed to be found in the experiment. But the subjects’ perceived probability of loss plays a significant role in determine their purchase decisions—the higher probability they predicted, the more likely to buy insurance they were. It is also fascinating to find that the longer the exposure to random risks the subjects had, the more willing to engage in insurance protection they were.

In a world with diverse consumer preferences, it can be challenging for producers to determine marketing strategies and production practices that maximize their profits while meeting consumer demand for fresh products. Consumers could be willing to pay for products that reduce environmental impact, but producers must know whether these changes will pay off. This study estimated consumers’ willingness to pay for specific environmental factors pertaining to fresh tomato production using a choice experiment survey. This study found that Southeastern consumers are willing to pay a price premium for specific environmental factors: water conservation, reduced pesticide residue, fewer miles between production location and purchase location, and tomatoes grown without petroleum-based fertilizers. The results of this study are beneficial to regional tomato producers, who could incorporate specific environmental practices into current production schedules that lead to incremental changes in the environmental attributes that were evaluated in this survey.

Within the East coast and West Coast oyster market, oysters are generally marketed using product attributes and brand name. However the Gulf oyster market does not involve branding. Using choice experiment method and online survey data, the study estimated the effect of branding Gulf oysters on Gulf and Non-Gulf consumers’ willingness to pay. Alternative-specific conditional logit, Nested logit and Alternative-specific multinomial probit methods of analysis were used to investigate the Independence of Irrelevant Alternative assumption made about consumers. Pooled and scaled models were used to analyze the identified data categories from which consumers were found to share the same oyster preferences. The results found that consumers on the average were willing to pay more for the oysters harvested from their own region relative to those harvested from outside their region. They were willing to pay a less for oysters harvested outside their region.

To improve meat quality and consistency, cattle feeders have moved towards implementing end-point marketing strategies (EPM) based on visual estimates of physiological characteristics. A commonly used 0.5 inch backfat target was used in this analysis. Recognizing that physiological targets will not necessarily result in profit maximization; this research developed a profit maximization rule (PMR) that accounts for the dynamics of animal growth, output prices and costs. A natural field experiment was conducted in Iowa to evaluate the potential for the PMR. One hundred twenty three fed cattle were randomly assigned into two treatments (PMR and EPM). Realized profit results indicate that EPM outperformed the PMR methodology by $24.35 per head. However, simulations that relax some experimental constraints resulted in the PMR outperforming EPM by $102.06 per head. Interestingly, the PMR did not negatively affect carcass quality. Therefore, relaxing PMR constraints in future experimental studies is expected to improve realized profitability.

In the late nineteenth century most dairy farmers went about their work in much same manner as had their predecessors centuries earlier. However, by 1940 most farmers practiced recognizably modern dairying techniques. Use of mechanical milking machines was widespread and growing, farmers compounded rations by combining feeds that blended precise proportions of proteins, carbohydrates, fats, and vitamins, and breeders, eager to maximize the influence of productive bloodlines, evaluated their animals with the use of scientific scorecards and employed intense breeding plans that relied on various forms of inbreeding in order to fix the desirable aspects of prized cattle. Yet the majority of these changes were instigated not by the dairy farmers who actually performed the tasks but by agricultural scientists working in the laboratories of the nation’s agricultural colleges and experiment stations. Agricultural science emerged in Germany in the 1840’s; Americans pursuing advanced degrees in Europe brought these ideas to the United States War and received an official imprimatur with the passage of the Hatch Act in 1892, which dedicated federal funds to the establishment and maintenance of agricultural experiment stations. The focus of this study is the work performed by these scientists in shaping the development of American dairy farms between 1890 and 1940. Researchers not only made scientific advances, such as the discovery of vitamins, that led to new methods of feeding and breeding dairy cattle but also invented and evaluated technological advances such as the Babcock Milkat test and mechanical milking machines that would revolutionize American dairying. This work contributes to our understanding of the emergence of the modern dairy farm by demonstrating that it was agricultural scientists, more so than farmers, who established the outlines of the modern dairy. They did so not only by adopting common techniques and methodologies that fostered communication and cooperation between and among researchers but by employing a number of rhetorical devices that broke down the barriers between laboratory and farm. While farmers enjoyed the benefits of scientific advances, they did so at the cost of their autonomy as scientists increasingly dictated what constituted modern dairying.

The purpose of this project is to develop a statistical method for use in rapid detection of biological agents using portable gas chromatography mass spectrometry (GC/MS) devices. Of particular interest is 2,6-pyridinedicarboxylic acid (dipicolinic acid, or DPA), a molecule that is present at high concentrations in spores of Clostridium and Bacillus, the latter of which includes the threat organism Bacillus anthracis, or anthrax. Dipicolinic acid may be useful as a first-step discriminator of the biological warfare agent B. anthracis. The results of experiments with B. anthracis Sterne strain and Bacillus thuringiensis spores lead to a conceptual model for the chemical phenomena that are believed to occur between Calcium, DPA and its esters, water, acid, and alkali during treatment of spores by a novel analytical procedure. The hypothesized model for chemical phenomena is tested using a compound study in the form of a mixture experiment.

Paterae cover approximately 2% of the surface of Io, Jupiter’s volcanically active moon. To understand the formation of these volcano-tectonic depressions we created a geologic map of a key region and compared this map with experimental models for Io paterae. Our mapping region is Tupan Patera, a patera that has experienced recent activity and is a detected hot spot. We identified four primary types of geologic materials: plains, patera floors, flows, and diffuse deposits. We constructed an experimental model to test previous suggestions that paterae may form as volatiles in the silicate crust are vaporized by rising magma, creating instability, and subsequent collapse. The apparatus is a scaled model that uses sand (silicate crust analog), ice or snow (volatile analog), a hotplate (magma chamber analog), and a moveable paddle (to simulate extension). Our experimental collapse features exhibit many characteristics of paterae on Io, such as “islands,” terraces, straight margins, and steep scarps. Our model suggests that the role of volatiles in Io’s crust is a significant part of paterae formation.Comparative studies between our map and model show it is possible Tupan is an emerging lava lake or one in a state of quiescence. Our studies have also culminated in the completion of a theoretical cross section for the geologic history of Tupan Patera. This cross section displays a sequence of events including the rise of magma as it preferentially volatilizes sulfurous layers in the crust, subsequent thinning, instability, and collapse, the likelihood of the patera floor sinking as a stoped block, and the more recent flow and diffuse deposits. This study gives some insight to the general formation of paterae on Io.