Application of Food-grade Ingredient Treated Nets to Control Tyrophagus Putrescentiae (Schrank) (Sarcoptiformes: Acaridae) Infestations on Dry Cured Hams

Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae), also known as the ham mite, may infest dry cured hams during the aging process. The fumigant methyl bromide is currently used to control mite infestations, but eventually will not be available for use since it contributes to the depletion of the ozone layer. The use of ham nets treated with xanthan gum, carrageenan, propylene glycol alginate, propylene glycol (PG), and lard were evaluated for their impact on mite orientation to or oviposition on treated or untreated ham cubes, mite reproduction and population growth over a 10-week period. When nets were infused with gum and PG, behavioral tests indicated that greater than 95% of the mites oriented to the ham cubes that were wrapped in untreated nets when compared to treated nets and no eggs were laid on the latter. The reproduction assays indicated that there were fewer (P \u3c 0.05) T. putrescentiae produced over a two-week period on ham cubes covered with both gum and PG treated nets when compared to the untreated or gum-only treated nets over the 10-week storage period of the experiment. Medium and high concentrations of PG treatments had the lowest mite reproduction rates. No more than four mites could be found on each of these treatments in comparison to 200-300 mites that were on the untreated ham cubes. When nets were infused with gum, PG, and lard, behavioral tests indicated that fewer mites oriented to the ham cubes that were wrapped with gum, lard, and medium PG than those with untreated nets. The oviposition assays revealed that on average less than three eggs were laid on the ham cubes with treated nets in comparison to 69-165 eggs on the untreated ham cubes. Reproduction assays demonstrated that fewer T. putrescentiae (P \u3c 0.05) were on ham cubes with treated nets containing PG when compared to the number of mites on ham cubes with untreated nets over 10 weeks of storage. Lard infused nets without PG did not decrease the mite population (P \u3e 0.05). The net without coating slowed the growth and reproduction of T. putrescentiae since net controls had fewer mites (P \u3c 0.05) than controls without nets. With a few exceptions, fungi were not present on ham cubes that were treated with PG-containing nets over 10 weeks of storage. This research demonstrated the efficacy of using nets treated with food-grade ingredients during ham aging to control mite infestations on a laboratory scale. Further research will be conducted to determine the effectiveness of the same treated nets on whole hams in commercial aging rooms

Inspection of Flexible Fillers in Post-Tensioned Bridges

The Florida Department of Transportation (FDOT) is currently pushing toward the use of flexible fillers (FF) in new post-tensioned (PT) bridges. Flexible fillers have several advantages compared to the currently used cementitious grouts (CG) and can offer longer-lasting structures by providing better corrosion protection and allowing for replaceable tendons, which reduces the overall maintenance costs over the structure’s lifespan. Due to these fillers being used in new bridges, FDOT needs effective nondestructive evaluation (NDE) methods to employ in their biennial inspections. There are currently numerous NDE methods available to inspectors that have been used to identify defects in PT bridges that use CG, but the NDE methods identified in this study are specifically for PT bridges that use FFs. These methods are Visual Inspections, Radiography, and Thermoelasticity. After an extensive literature review, these methods became the most promising and feasible to perform given the resources available. It was found that visual inspections and radiography are both highly effective methods in evaluating these bridges, whereas thermoelasticity was not as successful. Visual examinations are currently performed on all bridge inspections, but it is important to identify visual indicators that are unique to PT bridges that use FF. Radiography is also an effective method in identifying defects, however there are some major drawbacks, such as the price and accessibility to the internal components of the bridge. Thermoelasticity also seemed like a promising NDE method due to its success in the mining industry, but after completing tests in the lab it was found that the results were inconsistent and inconclusive, therefore this method would not be beneficial to employ in the field. Based on the testing performed in this study, visual inspections and radiography are both recommended methods to use in future bridge inspections and more research should be conducted to create standardized inspection procedures for inspectors

Merging Cellular Automata for Simulating Surface Effects

International audienceThis paper describes a model of three-dimensional cellular automata allowing to simulate different phenomena in the fields of com- puter graphics and image processing, and to combine them together in order to produce complex effects such as automatic multitexturing, sur- face imperfections, or biological retina multi-layer cellular behaviours. Our cellular automaton model is defined as a network of connected cells arranged in a natural and dynamic way, which affords multi-behavior ca- pabilities. Based on cheap and widespread computing systems, real-time performance can be reached for simulations involving up to a hundred thousand cells. Our approach efficiency is illustrated through a set of CA related to computer graphics –e.g. erosion, sedimentation, or vegetal growing processes– and image analysis –e.g. pipeline retina simulation

A sharp interface isogeometric strategy for moving boundary problems

The proposed methodology is first utilized to model stationary and propagating cracks. The crack face is enriched with the Heaviside function which captures the displacement discontinuity. Meanwhile, the crack tips are enriched with asymptotic displacement functions to reproduce the tip singularity. The enriching degrees of freedom associated with the crack tips are chosen as stress intensity factors (SIFs) such that these quantities can be directly extracted from the solution without a-posteriori integral calculation. As a second application, the Stefan problem is modeled with a hybrid function/derivative enriched interface. Since the interface geometry is explicitly defined, normals and curvatures can be analytically obtained at any point on the interface, allowing for complex boundary conditions dependent on curvature or normal to be naturally imposed. Thus, the enriched approximation naturally captures the interfacial discontinuity in temperature gradient and enables the imposition of Gibbs-Thomson condition during solidification simulation. The shape optimization through configuration of finite-sized heterogeneities is lastly studied. The optimization relies on the recently derived configurational derivative that describes the sensitivity of an arbitrary objective with respect to arbitrary design modifications of a heterogeneity inserted into a domain. The THB-splines, which serve as the underlying approximation, produce sufficiently smooth solution near the boundaries of the heterogeneity for accurate calculation of the configurational derivatives. (Abstract shortened by ProQuest.

Intrafield dispersal of adult corn rootworms

The trivial movements of adult corn rootworms within 5 Iowa cornfields were examined by aerially applying Sevin(\u27(REGTM)) 4 Oil to the perimeter of 12.6-ha areas leaving the central 6.4-ha portion untreated. The initial, emerging, and final beetles per plant were determined for successive time intervals, varying from 1-5 days. The western corn rootworm was the predominant species at all sites. The sharp decline of the beetle population in the unsprayed area was attributed to movement into the spray zone. A diffusion model was modified to express instantaneous population change due to trivial movements. The average instantaneous net displacement rate of the adult population was 17 m/day with values ranging from no movement to 64 m/day. Mean daily temperature and mean beetle density had a significant positive effect on net displacement rates observed in the field;Dispersal-selection chambers, consisting of a central 40-dram plastic container connected to 3 similar compartments with Tygon(\u27(REGTM)) tubing, were used to evaluate the relative effects of density and temperature on western corn rootworm female activity. Laboratory densities of 10, 20, and 40 females per chamber did not have a significant effect on percent dispersal rates in 3 of 4 trials. Percent dispersal was greater at higher densities in the significant trial. Significantly more activity occurred in chambers exposed to a temperature range of 28-34(DEGREES)C than in chambers at 20-26(DEGREES)C. The density-temperature interaction was not significant;The effects of intraspecific interactions on western corn rootworm female activity were examined by placing 30 females in the center compartment of dispersal-selection chambers and observing their preferences for stimuli confined in plastic zipper cases that were located in peripheral compartments. Beetles were not significantly attracted to other females confined in zipper cases, and the addition of a food attractant did not change the results. The existence of an aggregation pheromone was not supported by this study. Beetles were significantly attracted to zipper cases with corn silks, even when the beetles could not see or physically contact the food source

Constructing living buildings: a review of relevant technologies for a novel application of biohybrid robotics

Biohybrid robotics takes an engineering approach to the expansion and exploitation of biological behaviours for application to automated tasks. Here, we identify the construction of living buildings and infrastructure as a high-potential application domain for biohybrid robotics, and review technological advances relevant to its future development. Construction, civil infrastructure maintenance and building occupancy in the last decades have comprised a major portion of economic production, energy consumption and carbon emissions. Integrating biological organisms into automated construction tasks and permanent building components therefore has high potential for impact. Live materials can provide several advantages over standard synthetic construction materials, including self-repair of damage, increase rather than degradation of structural performance over time, resilience to corrosive environments, support of biodiversity, and mitigation of urban heat islands. Here, we review relevant technologies, which are currently disparate. They span robotics, self-organizing systems, artificial life, construction automation, structural engineering, architecture, bioengineering, biomaterials, and molecular and cellular biology. In these disciplines, developments relevant to biohybrid construction and living buildings are in the early stages, and typically are not exchanged between disciplines. We, therefore, consider this review useful to the future development of biohybrid engineering for this highly interdisciplinary application.publishe

Teadusarvutuse algoritmide taandamine hajusarvutuse raamistikele

Teadusarvutuses kasutatakse arvuteid ja algoritme selleks, et lahendada probleeme erinevates reaalteadustes nagu geneetika, bioloogia ja keemia. Tihti on eesmärgiks selliste loodusnähtuste modelleerimine ja simuleerimine, mida päris keskkonnas oleks väga raske uurida. Näiteks on võimalik luua päikesetormi või meteoriiditabamuse mudel ning arvutisimulatsioonide abil hinnata katastroofi mõju keskkonnale. Mida keerulisemad ja täpsemad on sellised simulatsioonid, seda rohkem arvutusvõimsust on vaja. Tihti kasutatakse selleks suurt hulka arvuteid, mis kõik samaaegselt töötavad ühe probleemi kallal. Selliseid arvutusi nimetatakse paralleel- või hajusarvutusteks. Hajusarvutuse programmide loomine on aga keeruline ning nõuab palju rohkem aega ja ressursse, kuna vaja on sünkroniseerida erinevates arvutites samaaegselt tehtavat tööd. On loodud mitmeid tarkvararaamistikke, mis lihtsustavad seda tööd automatiseerides osa hajusprogrammeerimisest. Selle teadustöö eesmärk oli uurida selliste hajusarvutusraamistike sobivust keerulisemate teadusarvutuse algoritmide jaoks. Tulemused näitasid, et olemasolevad raamistikud on üksteisest väga erinevad ning neist ükski ei ole sobiv kõigi erinevat tüüpi algoritmide jaoks. Mõni raamistik on sobiv ainult lihtsamate algoritmide jaoks; mõni ei sobi olukorras, kus andmed ei mahu arvutite mällu. Algoritmi jaoks kõige sobivama hajusarvutisraamistiku valimine võib olla väga keeruline ülesanne, kuna see nõuab olemasolevate raamistike uurimist ja rakendamist. Sellele probleemile lahendust otsides otsustati luua dünaamiline algoritmide modelleerimise rakendus (DAMR), mis oskab simuleerida algoritmi implementatsioone erinevates hajusarvutusraamistikes. DAMR aitab hinnata milline hajusraamistik on kõige sobivam ette antud algoritmi jaoks, ilma algoritmi reaalselt ühegi hajusraamistiku peale implementeerimata. Selle uurimustöö peamine panus on hajusarvutusraamistike kasutuselevõtu lihtsamaks tegemine teadlastele, kes ei ole varem nende kasutamisega kokku puutunud. See peaks märkimisväärselt aega ja ressursse kokku hoidma, kuna ei pea ükshaaval kõiki olemasolevaid hajusraamistikke tundma õppima ja rakendama.Scientific computing uses computers and algorithms to solve problems in various sciences such as genetics, biology and chemistry. Often the goal is to model and simulate different natural phenomena which would otherwise be very difficult to study in real environments. For example, it is possible to create a model of a solar storm or a meteor hit and run computer simulations to assess the impact of the disaster on the environment. The more sophisticated and accurate the simulations are the more computing power is required. It is often necessary to use a large number of computers, all working simultaneously on a single problem. These kind of computations are called parallel or distributed computing. However, creating distributed computing programs is complicated and requires a lot more time and resources, because it is necessary to synchronize different computers working at the same time. A number of software frameworks have been created to simplify this process by automating part of a distributed programming. The goal of this research was to assess the suitability of such distributed computing frameworks for complex scientific computing algorithms. The results showed that existing frameworks are very different from each other and none of them are suitable for all different types of algorithms. Some frameworks are only suitable for simple algorithms; others are not suitable when data does not fit into the computer memory. Choosing the most appropriate distributed computing framework for an algorithm can be a very complex task, because it requires studying and applying the existing frameworks. While searching for a solution to this problem, it was decided to create a Dynamic Algorithms Modelling Application (DAMA), which is able to simulate the implementation of the algorithm in different distributed computing frameworks. DAMA helps to estimate which distributed framework is the most appropriate for a given algorithm, without actually implementing it in any of the available frameworks. This main contribution of this study is simplifying the adoption of distributed computing frameworks for researchers who are not yet familiar with using them. It should save significant time and resources as it is not necessary to study each of the available distributed computing frameworks in detail

An integrated study for hybrid composite beam (HCB) structures

The hybrid composite beam (HCB) consists of a self consolidating concrete (SCC) arch that is tied at the end by galvanized strands. The tied arch is encapsulated by a glass fiber reinforced polymer (GFRP) shell. A limited number of researches have studied the essential design methodologies and long-term performance of the HCB. The research presented in this dissertation aimed to more fundamentally understand the structural behavior of this new beam and evaluate its durability. This research study was conducted through four phases. A full-scale bridge load testing was conducted on a single-web HCB bridge during the first phase. The first finite element analysis of an HCB bridge superstructure was conducted. The areas that need more research and investigation were highlighted. In the second phase, double-web HCB Bridge was instrumented by various sensors. Strains induced in HCB\u27s elements during several loading stages were collected. The existing flexural analysis method was unable to estimate accurately the induce strains. Analysis methods for a simply supported HCB and an HCB that is supported on bearing pads were proposed. These methods achieved significant enhancement in estimating the HCB\u27s strains. The HCB\u27s shell was subjected to five aging regimes during the third stage. The existing voids in the laminated shell made the fibers and the interphase regions prone to chemical and moisture attacks. However, the diffusion of the chemical solutions was always found to be confined to the first lamina. This result suggested that the composite shell is able to protect the strands from a moisture attack during the HCB\u27s service life. The last stage clarified that the thermal stresses in an HCB bridge superstructure elements produced by thermal gradients are not critical and can be excluded from the design. --Abstract, page iv

Application of Polyurethane Products in Accelerated Construction of Innovative Noise Barrier

Noise barriers (sound walls) are usually constructed along roadways to mitigate the airborne noise emanating from vehicles. They are currently built using various materials including precast concrete panels, masonry, wood and transparent sheets. The main challenge in roadside construction is the obstruction of roadways during the construction, which may result in traffic congestion, public dissatisfaction, car collision and subsequently fatalities. In order to decrease the risk of roadside construction, accelerated and non-obstructive methods are highly preferred by transportation authorities. An innovative wall system comprised of polyurethane products is proposed, developed and investigated for application in accelerated construction of noise barriers. The proposed sound wall comprises stay-in-place poly-blocks as formwork, two types of polyurethane foam (PF) as structural cores and polyurea as a coating of the wall surfaces. The poly-blocks are stacked layer by layer on the wall footing and form a wall with cylindrical voids. A fast-curing liquid mixture of rigid or light PF is injected into poly-blocks voids to act as the main structural element. Steel rebars connect the PF cores to the wall footing as anchorage system. A polyurea or shotcrete coating is sprayed on both sides of the wall in order to enhance the resistance of poly-blocks surfaces against abrasion, stone impact, weathering, fire development, chemicals and penetration. This construction technique and materials result in less obstruction, faster construction and efficient sound walls in terms of sound attenuation. A comprehensive experimental program including 80 specimen and 16 full-scale tests was conducted to determine the materials mechanical properties as well as structural behavior of full-scale walls, which were constructed using different PF and rebar arrangements. In addition, three-dimensional finite element models of the laboratory specimens and the full-scale walls were simulated and verified using the experimental results. The experimental and numerical results indicated that the structural performance of the proposed wall system is satisfactory for the application of noise barrier according to the relevant building codes. Based on practical observations, the wall system can be implemented in an accelerated and non-obstructive construction method. Finally, detailed design guidelines are prepared for various practical conditions