This study calculate the frictional temperature of the dissimilar metal pair by theoretical analysis. Analyze the frictional temperature rise at interface dividing into the flash temperature rise and the bulk temperature rise. According the frictional temperature rise, establish the model of the temperature rise at the first cycle and the quasi-steady state cycle. And then discuss the condition of asperity contact by the measurement of experimental temperature rise. In the bulk temperature rise and the flash temperature rise, compare with the exact solution, the approximate solution of the average temperature rise that we derived have little error in specific range of Peclet number. Combine the approximate solution of the bulk temperature rise and the flash temperature rise to calculate the temperature rise of asperity contact at rubbing interface. We can evaluate the average contact length of asperity by measured values.

The purpose of my thesis is to establish a simple thermal model for a Parker GVM 210-150P motor and a SEVCON Gen4 Size8 inverter. These models give temperature variations of critical components in the motor and the inverter. My thesis will help Georgia Tech's EcoCAR-3 team in understanding the physics behind thermal modeling and why thermal study is necessary. This work is a prerequisite for Software in the Loop (SIL) simulations or Hardware in the Loop (HIL) simulations for a hybrid electric vehicle.

This thesis contains two parts. In the first part, four kinds of dental baseplates were obtained after curing at 70 ¢XC in water bath or curing in microwave oven. Pressure vent polymerizing Meta-cera (PVPM) methods were performed at 500 watts using Y-Z flask, then the specimens in the flasks were cooled in two different ways. Additionally, the samples in GC FRP flask were separately cured by three different microwave-energy powers: 85, 255 or 595 watts. Each of these curing conditions has six specimens. Adaptation, porosity, and fracture strength of these specimens were evaluated. Optilon-399, a rubber-toughed dental baseplate, was chosen to study the effect of curing conditions on the morphology of the stained specimens using transmission electron microscope (TEM). The results indicate that dispersed rubber- enriched phase is observed. Most of the dispersed phase has a mean-diameter ranging from 210 to 1440 nm and smaller domains have a mean-diameter of 80-100 nm. These dispersed domains observed in TEM micrographs are statistically analyzed and compared using one-way analysis of variance (ANOVA) method. The specimens cured in water bath (reference) have the largest mean-diameter, 456 ¡Ó 131 nm, for the dispersed phase. There is no significant difference in mean-diameters between the reference method and 595-watts method. Mean-diameters of the specimens (408~442 nm) cured by the other four methods are significantly less than that of the reference method. Differences are also found among three different microwave-energy powers. Mean-diameter increases from 408 to 432 to 454 nm and the number of domains drops from 35.7 to 34.1 to 32.1 per TEM micrograph when microwave-energy power increases from 85 to 255 to 595 watts. However, 595-watts specimens have the problem of porosity and 85-watts specimens have the highest adaptation discrepancy. Therefore, 255-watts specimens have a relatively high fracture strength (388 kgf versus 354 or 369 kgf). There is no difference in mean-diameter (440 versus 442 nm) and the number of domains (32.9 per TEM micrograph) between PVPM systems. Low adaptation discrepancy and no porosity result in a higher fracture strength (395 and 381 kgf) compared with the reference method (284kgf). From this study, PVPM method in a bench cooled type is suggested to prepare dental baseplates. In the second part, restorative materials for tooth were polymerized and cured using a blue light emitting diode (LED) unit. Five kinds of light-curing hybrid composite resins (Premisa, Esthet-X micro matrix restorative, Z100 Restorative, Filtek Z250 and Filtek Z350) were processed by four different operating modes of LED as follows: control mode- 500 mW/cm2 for 20 s; pulse cure mode - 500 mW/cm2 for 10s, 0 mW/cm2 for 10s, then 500 mW/cm2 for the next 10 s; soft-start (ramp) mode- initially 600 mW/cm2 for 10 s, then jump to 1400 mW/cm2 for 10 s; turbo (high) mode-1400 mW/cm2 for 10 s. Each of light-curing dental materials and LED operating modes has six specimens. Temperature variation of resins in a period of 60 s was measured during and after activating the light. Vicker¡¦s hardness of both top and bottom sides of specimens after curing was measured. Both temperature rise and hardness of specimens are statistically analyzed and compared using two-way ANOVA method. Soft-start mode induced an average temperature rise of 7.70 ¡Ó 0.77 ¢XC which is significantly (P<0.05) higher than the other three modes. Pulse cure mode yielded average 4.49 ¡Ó 0.84 ¢XC rise which is lowest (P<0.05). There is no difference in temperature rise between control and turbo modes (P>0.05). Comparing five dental materials, Z350 had an average temperature rise of 7.04 ¡Ó 1.10¢XC that is the highest and significantly different from the other materials (P<0.05). Average temperature rise of the other materials was about 5.3 ¢XC without significant difference, except Premise versus Z100. Both top and bottom sides¡¦ hardness of the cured specimens are determined by dental materials (P<0.05), not by LED operating modes (P>0.05). Z100 has the highest hardness (top: 181.6¡Ó8.9kgf/mm2, bottom: 149.1¡Ó6.0 kgf/mm2). Hardness decreases in the order of Z250, Esthet-X, Premise, Z350. Additionally, the results of isothermal polymerization and curing of resins at 165 ¢XC for 3 hr indicate that the high temperature rise (7 ¢XC) of Z350 resins is due to the high exothermic enthalpy (- 61 J/g). The trend of temperature rise of other dental materials can also be explained from the exothermic value which is measured using differential scanning calorimeter (DSC). Degree of polymerization conversion of resins after light-curing was also evaluated using DSC. Z100 specimens yielded the complete conversion (100%) for all of LED operating modes. From the viewpoints of complete conversion and high hardness, it is suggested to process Z100 specimens in a pulse cured mode because the temperature rise is only 4.65 ¢XC.

The thesis is focused on a temperature-rise of a low-voltage switchgear. The first part of the work deals with a technical standard related to the chosen topic, compares software used for designing switchgear in practice and familiarizes with the working environment of the software selected for this work. The main part of the work is dedicated to a measurement and a simulation of the temperature-rise of the low-voltage switchgear. The measurement involved testing of the switchgear with regard to the individual functional units and to the whole switchgear. Subsequently, the simulation of the temperature-rise of the switchgear followed. Software used in this work is SolidWorks Flow Simulation chosen due to a wide range of functions. According to the findings there were proposed adjustments of the switchgear with respect to the technical parameters and the economic aspect in the last part of the thesis.

A proposta deste trabalho foi avaliar in vitro a alteração da temperatura durante o preparo cavitário em esmalte de dentes decíduos utilizando-se diferentes energias e freqüências do laser Er:YAG. Foram selecionados 40 molares decíduos humanos hígidos, cujas raízes, quando presentes, foram removidas. As porções coronárias foram seccionadas no sentido mésio-distal e a partir das superfícies vestibular e lingual de cada dente, foram obtidos 80 fragmentos (3,5 mm largura, 3,5 mm de altura e 2,0 mm espessura). Na porção dentinária de cada fragmento foram confeccionados dois orifícios (profundidade média de 0,1 mm) para acomodar os termo-sensores. Após estes procedimentos, os espécimes foram fixados com cera termoplástica para escultura em orifícios confeccionados em placas de acrílico. Os conjuntos dente/placa foram divididos aleatoriamente em grupos, de acordo com a energia e freqüência utilizadas (n=10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz e G8 - 300 mJ/ 6 Hz. Na superfície de esmalte previamente delimitada com fita isolante (4 mm2) foram confeccionadas cavidades com (1,0 mm de profundidade, 2,0 mm de altura e 2,0 mm de comprimento) utilizando-se laser Er:YAG, focado a uma distância de 12 mm, sob refrigeração 1,5 mL/min. A temperatura aferida foi registrada por meio de um microtermopar do tipo K interligado a uma placa de aquisição e a um computador configurado com Software programado para fazer a leitura de temperatura a cada 3 segundos, do início da irradiação ao final do preparo. Os dados experimentais foram analisados estatisticamente por ANOVA e teste de Mann-Whitney para averiguar a influência da frequência e energia. O teste de Tukey (P&le;0,05) foi utilizado para múltiplas comparações. Os grupos com as energias de 250 e 300 mJ e frequência de 3 e 4 Hz foram semelhantes entre si e apresentaram os menores valores médios de alteração de temperatura. A frequência de 250 mJ com 10 e 15 Hz, apresentaram os maiores valores médios de temperatura acima do valor crítico aceitável (5,5 °C). Com as energias de 250 e 300 mJ e 6 Hz os valores foram intermediários e menores que o valor crítico aceitável. Assim, pode-se concluir que para o preparo cavitário em esmalte de dentes decíduos pode-se indicar os parâmetros de 250 e 300 mJ com 6 Hz de frequência. Além disso, houve uma relação direta entre o aumento da temperatura e o aumento da frequêcia. / This study aimed to assess in vitro thermal alterations occurred during the Er:YAG laser cavity preparation of primary teeth enamel at different energies and pulse repetition rates. Forty sound human primary molars were selected and roots, when present, were sectioned. Crowns were bisected longitudinally in a mesio-distal direction, thus providing 80 fragments with standard dimensions of 3.5mm long x 3.5mm wide and 2mm thick. Two small orifices (0.1mm mean depth) were made at the dentin surface, where thermocouples were attached. Afterwards, the fragments were individually fixed with wax in a cylindrical Plexiglas® abutment. The specimens were randomly assigned to eight groups, according to the Er:YAG laser energies and pulse rates performed for cavity preparation (n=10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz and G8 - 300 mJ/ 6 Hz. To demarcate the ablation sit (4 mm2), a piece of insulating tape was attached to the enamel surface. Then, cavities were done (2-mm long/ 2-mm wide/1-mm thick) by an Er:YAG laser device, in non-contact (12mm) and focused mode, with a fine water mist at 1.5mL/min. Temperature values were registered by thermocouples type K connected to a portable USB-based data acquisition module and to a computer configured to read the temperature rise every 3 seconds, from starting laser irradiation until the end of the cavity preparation. Data were analyzed by two-way ANOVA and Mann-Whitney test using a factorial design with energy and pulse rate as independent factors. Multiple comparisons among groups were done by Tukey test (P&le;0,05). The groups irradiated with 250 and 300mJ/ 3 and 4 Hz were statistically similar and showed the lower temperature rise means. The set 250mJ/10 and 15 Hz yielded the highest values of temperature, above the critical value acceptable (5.5°C). The setting 250 and 300mJ and 6 Hz provide temperature with mean values below the critical value acceptable, suggesting these parameters to ablate the primary teeth enamel. Moreover, the temperature rise was directly related to the increase of the pulse repetition rates employed.

Este estudo teve como objetivo avaliar in vitro a alteração da temperatura durante a remoção de dentina hígida e desmineralizada de dentes decíduos humanos com o laser Er:YAG. Foram selecionados 30 molares decíduos hígidos, cujas raízes, quando presentes, foram removidas, e as coroas seccionadas no sentido mésio-distal, obtendose 60 fragmentos. Os fragmentos foram fixados em matriz cilíndrica de Teflon®, levados à politriz para desgaste do esmalte e planificação da dentina, obtendo-se fragmentos com espessura de 2,0 mm. Os espécimes foram então divididos aleatoriamente em 2 grupos (n=30): A-dentina hígida e B-dentina desmineralizada. Cada grupo foi dividido em 3 subgrupos (n=10), de acordo com as freqüências utilizadas: I-4 Hz; II-6 Hz e III-10 Hz. Os espécimes no grupo B foram submetidos pelo método de ciclagem de pH, durante 21 dias consecutivos até a obtenção de lesões com aproximadamente 1,0 mm de profundidade. Os parâmetros de irradiação dos espécimes foram de 250 mJ de energia no modo não contato, focado, a uma distância de 12 mm, sob refrigeração 1,5 mL/min e tempo de irradiação de 30 segundos. A temperatura aferida foi registrada por um microtermopar do tipo K adaptado na dentina correspondente à câmara pulpar, por meio do orifício da lâmina de pexiglass, e interligado a uma placa de aquisição, calibrado com 0,2ºC de precisão e tempo de resposta de 0,6 segundos. Os dados foram submetidos ao teste não-paramétrico Kruskal-Wallis e avaliação qualitativa foi realizada em Microscopia Eletrônica de Varredura. A análise dos dados demonstrou que no grupo A houve diferença estatisticamente significante entre todos os subgrupos. E no grupo B, não houve diferença na temperatura entre os subgrupos I e II. A avaliação morfológica da superfície revelou irregularidades superficiais, túbulos dentinários abertos, ausência de smear layer, protrusão da dentina peritubular, independente do substrato, sendo que na frequência de 6Hz e 10 Hz a dentina desmineralizada adquiriu um padrão morfológico semelhante ao da dentina hígida, sugerindo que provavelmente houve remoção da dentina desmineralizada. Concluiu-se que o aumento da temperatura está diretamente relacionado com o aumento da frequência. As alterações superficiais observadas na dentina irradiada em MEV demonstraram ser cada vez mais acentuadas com o aumento da frequência. / The purpose of this study was to assess in vitro the thermal alteration occurred during the removal of sound and demineralized dentin in human primary teeth by the Er:YAG laser. Thirty sound primary molars were selected and roots, when present, were removed and the crowns sectioned in mesiodistal direction, resulting in 60 fragments. The fragments were fixed in a cylinder matrix of Teflon®. The surfaces were ground on a polishing machine at low-speed to remove the overlying enamel and expose flat dentin surfaces, resulting in fragments of 2.0 mm thickness. Then, the fragments were randomly assigned to 2 groups (n=30): A-sound dentin (control) and B-demineralized dentin. Each group was divided into 3 subgroups (n=10) according to the frequencies used: I-4 Hz; II-6 Hz and III-10Hz. Specimens in group B were submitted to a pH-cycling regimen during 21 consecutive days until perform a 1 mm thick depth demineralized dentin. The irradiation was performed with a 250 mJ pulse energy in non-contact and focused mode, with a fine water mist at 1,5 mL/min for 30 seconds at a constant working distance from the target site (12 mm). The measured temperature was recorded by thermocouples type K adapted to the pulp chamber corresponding dentin connected to a potable USB based data acquisition module, calibrated with 0.2ºC of accuracy and response time of 0.6 seconds. The data were submitted to the non-parametric Kruskal-Wallis test and a qualitative analysis by Scanning Electron Microscopy. Data analysis demonstrated that in the group A there was statistically significant difference among all subgroups. And in the group B, there was no difference in temperature between subgroup I and II. The morphological evaluation of the surface showed superficial irregularities, open dentinal tubules, absence of smear layer, dentin peritubular protusion, independent of the substrate. A the frequency of 6 and 10 Hz the irradiated demineralized dentin was similar to sound dentin, showing that probably the removal of demineralized dentin occurred. In conclusion, the increase in the temperature is directly related to the frequency´s increment, in both demineralized and sound dentin. The superficial dentin alterations observed in SEM increased pulse repetition rates yield greater alterations morphological of the irradiated dentin.

A proposta deste trabalho foi avaliar in vitro a alteração da temperatura durante o preparo cavitário em esmalte de dentes decíduos utilizando-se diferentes energias e freqüências do laser Er:YAG. Foram selecionados 40 molares decíduos humanos hígidos, cujas raízes, quando presentes, foram removidas. As porções coronárias foram seccionadas no sentido mésio-distal e a partir das superfícies vestibular e lingual de cada dente, foram obtidos 80 fragmentos (3,5 mm largura, 3,5 mm de altura e 2,0 mm espessura). Na porção dentinária de cada fragmento foram confeccionados dois orifícios (profundidade média de 0,1 mm) para acomodar os termo-sensores. Após estes procedimentos, os espécimes foram fixados com cera termoplástica para escultura em orifícios confeccionados em placas de acrílico. Os conjuntos dente/placa foram divididos aleatoriamente em grupos, de acordo com a energia e freqüência utilizadas (n=10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz e G8 - 300 mJ/ 6 Hz. Na superfície de esmalte previamente delimitada com fita isolante (4 mm2) foram confeccionadas cavidades com (1,0 mm de profundidade, 2,0 mm de altura e 2,0 mm de comprimento) utilizando-se laser Er:YAG, focado a uma distância de 12 mm, sob refrigeração 1,5 mL/min. A temperatura aferida foi registrada por meio de um microtermopar do tipo K interligado a uma placa de aquisição e a um computador configurado com Software programado para fazer a leitura de temperatura a cada 3 segundos, do início da irradiação ao final do preparo. Os dados experimentais foram analisados estatisticamente por ANOVA e teste de Mann-Whitney para averiguar a influência da frequência e energia. O teste de Tukey (P&le;0,05) foi utilizado para múltiplas comparações. Os grupos com as energias de 250 e 300 mJ e frequência de 3 e 4 Hz foram semelhantes entre si e apresentaram os menores valores médios de alteração de temperatura. A frequência de 250 mJ com 10 e 15 Hz, apresentaram os maiores valores médios de temperatura acima do valor crítico aceitável (5,5 °C). Com as energias de 250 e 300 mJ e 6 Hz os valores foram intermediários e menores que o valor crítico aceitável. Assim, pode-se concluir que para o preparo cavitário em esmalte de dentes decíduos pode-se indicar os parâmetros de 250 e 300 mJ com 6 Hz de frequência. Além disso, houve uma relação direta entre o aumento da temperatura e o aumento da frequêcia. / This study aimed to assess in vitro thermal alterations occurred during the Er:YAG laser cavity preparation of primary teeth enamel at different energies and pulse repetition rates. Forty sound human primary molars were selected and roots, when present, were sectioned. Crowns were bisected longitudinally in a mesio-distal direction, thus providing 80 fragments with standard dimensions of 3.5mm long x 3.5mm wide and 2mm thick. Two small orifices (0.1mm mean depth) were made at the dentin surface, where thermocouples were attached. Afterwards, the fragments were individually fixed with wax in a cylindrical Plexiglas® abutment. The specimens were randomly assigned to eight groups, according to the Er:YAG laser energies and pulse rates performed for cavity preparation (n=10): G1 - 250 mJ/ 3 Hz, G2 - 250 mJ/ 4 Hz, G3 - 250 mJ/ 6 Hz, G4 - 250 mJ/10 Hz, G5 - 250 mJ/ 15 Hz, G6 - 300 mJ/ 3 Hz, G7 - 300 mJ/ 4 Hz and G8 - 300 mJ/ 6 Hz. To demarcate the ablation sit (4 mm2), a piece of insulating tape was attached to the enamel surface. Then, cavities were done (2-mm long/ 2-mm wide/1-mm thick) by an Er:YAG laser device, in non-contact (12mm) and focused mode, with a fine water mist at 1.5mL/min. Temperature values were registered by thermocouples type K connected to a portable USB-based data acquisition module and to a computer configured to read the temperature rise every 3 seconds, from starting laser irradiation until the end of the cavity preparation. Data were analyzed by two-way ANOVA and Mann-Whitney test using a factorial design with energy and pulse rate as independent factors. Multiple comparisons among groups were done by Tukey test (P&le;0,05). The groups irradiated with 250 and 300mJ/ 3 and 4 Hz were statistically similar and showed the lower temperature rise means. The set 250mJ/10 and 15 Hz yielded the highest values of temperature, above the critical value acceptable (5.5°C). The setting 250 and 300mJ and 6 Hz provide temperature with mean values below the critical value acceptable, suggesting these parameters to ablate the primary teeth enamel. Moreover, the temperature rise was directly related to the increase of the pulse repetition rates employed.

Este estudo teve como objetivo avaliar in vitro a alteração da temperatura durante a remoção de dentina hígida e desmineralizada de dentes decíduos humanos com o laser Er:YAG. Foram selecionados 30 molares decíduos hígidos, cujas raízes, quando presentes, foram removidas, e as coroas seccionadas no sentido mésio-distal, obtendose 60 fragmentos. Os fragmentos foram fixados em matriz cilíndrica de Teflon®, levados à politriz para desgaste do esmalte e planificação da dentina, obtendo-se fragmentos com espessura de 2,0 mm. Os espécimes foram então divididos aleatoriamente em 2 grupos (n=30): A-dentina hígida e B-dentina desmineralizada. Cada grupo foi dividido em 3 subgrupos (n=10), de acordo com as freqüências utilizadas: I-4 Hz; II-6 Hz e III-10 Hz. Os espécimes no grupo B foram submetidos pelo método de ciclagem de pH, durante 21 dias consecutivos até a obtenção de lesões com aproximadamente 1,0 mm de profundidade. Os parâmetros de irradiação dos espécimes foram de 250 mJ de energia no modo não contato, focado, a uma distância de 12 mm, sob refrigeração 1,5 mL/min e tempo de irradiação de 30 segundos. A temperatura aferida foi registrada por um microtermopar do tipo K adaptado na dentina correspondente à câmara pulpar, por meio do orifício da lâmina de pexiglass, e interligado a uma placa de aquisição, calibrado com 0,2ºC de precisão e tempo de resposta de 0,6 segundos. Os dados foram submetidos ao teste não-paramétrico Kruskal-Wallis e avaliação qualitativa foi realizada em Microscopia Eletrônica de Varredura. A análise dos dados demonstrou que no grupo A houve diferença estatisticamente significante entre todos os subgrupos. E no grupo B, não houve diferença na temperatura entre os subgrupos I e II. A avaliação morfológica da superfície revelou irregularidades superficiais, túbulos dentinários abertos, ausência de smear layer, protrusão da dentina peritubular, independente do substrato, sendo que na frequência de 6Hz e 10 Hz a dentina desmineralizada adquiriu um padrão morfológico semelhante ao da dentina hígida, sugerindo que provavelmente houve remoção da dentina desmineralizada. Concluiu-se que o aumento da temperatura está diretamente relacionado com o aumento da frequência. As alterações superficiais observadas na dentina irradiada em MEV demonstraram ser cada vez mais acentuadas com o aumento da frequência. / The purpose of this study was to assess in vitro the thermal alteration occurred during the removal of sound and demineralized dentin in human primary teeth by the Er:YAG laser. Thirty sound primary molars were selected and roots, when present, were removed and the crowns sectioned in mesiodistal direction, resulting in 60 fragments. The fragments were fixed in a cylinder matrix of Teflon®. The surfaces were ground on a polishing machine at low-speed to remove the overlying enamel and expose flat dentin surfaces, resulting in fragments of 2.0 mm thickness. Then, the fragments were randomly assigned to 2 groups (n=30): A-sound dentin (control) and B-demineralized dentin. Each group was divided into 3 subgroups (n=10) according to the frequencies used: I-4 Hz; II-6 Hz and III-10Hz. Specimens in group B were submitted to a pH-cycling regimen during 21 consecutive days until perform a 1 mm thick depth demineralized dentin. The irradiation was performed with a 250 mJ pulse energy in non-contact and focused mode, with a fine water mist at 1,5 mL/min for 30 seconds at a constant working distance from the target site (12 mm). The measured temperature was recorded by thermocouples type K adapted to the pulp chamber corresponding dentin connected to a potable USB based data acquisition module, calibrated with 0.2ºC of accuracy and response time of 0.6 seconds. The data were submitted to the non-parametric Kruskal-Wallis test and a qualitative analysis by Scanning Electron Microscopy. Data analysis demonstrated that in the group A there was statistically significant difference among all subgroups. And in the group B, there was no difference in temperature between subgroup I and II. The morphological evaluation of the surface showed superficial irregularities, open dentinal tubules, absence of smear layer, dentin peritubular protusion, independent of the substrate. A the frequency of 6 and 10 Hz the irradiated demineralized dentin was similar to sound dentin, showing that probably the removal of demineralized dentin occurred. In conclusion, the increase in the temperature is directly related to the frequency´s increment, in both demineralized and sound dentin. The superficial dentin alterations observed in SEM increased pulse repetition rates yield greater alterations morphological of the irradiated dentin.

Coral colonies, from a reef near Abu Dhabi, United Arab Emirates (UAE), were counted and assessed for condition using photo-transects. An epidemic model, used to track how a communicable disease moves through a population, was constructed to help predict the future condition of this coral reef. In situ data from a disease outbreak that occurred in September 2011 provided a baseline for the model. Coral Populations of Porites, Platygyra, Acropora and Dipsastrea were modelled using condition categories that included Healthy, Black Band Disease Infected, Cyanobacteria Infected, Recovered, Recruits or Dead. Results from the modelling indicate that populations of Platygyra and Dipsastrea are healthy and growing, even with continued presence of diseases, due to the high rates of recovery (chance for host colony to overcome infection; high recovery rate = high chance of colony recovering from the infection) and low mortality rates (chance of dying from an infection; low mortality rate = low chance of a infected colony dying from the infection) in the genus. Porites showed no signs of population growth, but stabilized near its initial population size, despite having a high infection rate because population growth (recruitment) and recovery rate were canceled by a high mortality rate. Acropora showed a loss in population numbers over time, losing 25% of its population before the disease was eliminated. Diseases may have been eliminated from the Acropora population because population density was low and coral died quickly after becoming infected with a disease, due to the high mortality rate of this genus, before infecting other colonies. Acropora was the only genus to display what seems to be a density dependent infection rate, since chance of infection was reduced and then eliminated by the rapid mortality of infected colonies, if the population was higher disease spread may have been higher. In addition to results obtained using in situ data, higher modified infection rates were used to assess how they might impact these coral populations. Results suggest that all four genera seem to be resilient, shown by in situ modeling and parameters extracted from the phototransects, and able to withstand acute (rapid increase of infection rate which was then again quickly brought back to normal infection rate, an infection “spike”) increases of disease infection, which is shown by either a high recovery rate (Dipsastrea and Platygyra), a high recruitment/low mortality rate (Porites), or a high mortality rate (Acropora) that may not allow for the diseases to spread. However, all four genera would be slowly driven to extinction by a sustained (chronic) increase of disease infection rate brought on by growing stressors such as an increase in average water temperature or pollutants within the Gulf. These results demonstrate fragility of Gulf coral genera when exposed to chronic episodes of disease, which over time causes total collapse of the coral populations.

No description available.