Estudo de cargas térmicas de uma aeronave e dimensionamento de um sistema de ar condicionado

This work deals with the thermal load study of a fictitious aircraft as well as scaling, in terms of the airflow and temperature of the air conditioning system, for heating and cooling of the its internal environment, aiming the thermal comfort of occupants. The first part is presented the techniques and methods utilized for modeling different heat exchanges that occur in the aircraft and then allowed to calculate the total heat load and the airflow and temperature necessary to comply with the requirements of the thermal comfort. Techniques to determine the basic parameters, as convection coefficient and global coefficient of heat exchange, are also presented. The work aims to develop a program, using a computational tool, to automate the calculations so that facilitate this study. It also allows to be used for other airplanes just changing parameters and the control variables related to the specific project. Finally the program performs calculations for a fictitious airplane, to analyze its functionality and the influence of parameters involved in the temperature controls. The program allowed analyzing the sensitivity of portions of the thermal load and the corresponding parameters of influence, as well as the scaling of the air conditioning in terms of airflow and temperature. It was considered, despite the simplifications, a good approximation to the actual values and then can be used in development of the other airplanes

Eficiência energética em ar condicionado e refrigeração através da aplicação da termoacumulação

The use of refrigeration and air conditioning systems is of fundamental importance when it comes to air-conditioning of environments. Also important is the use of electricity for equipments’ operation related to these systems. Due to high cost of charging for this type of energy, factors economy and efficiency occupy key roles among design parameters of a system. One of the ways to get this economy is the use of a technique called thermal storage, or cold storage, which intends to move the required loads during peak time and also their equalizing, so that the energy is transferred from the peak time to non-peak time, thereby reducing the cost of energy consumed. Cold can be stored in the form of ice or ice water. This work aims to perform a technical-economic analysis of a mall located in Vale do Paraíba checking the feasibility of deploying a thermal storage system to achieve an economy in the cost of the energy used by the establishment. Through the parameters measured by the concessionaire of energy we can get the values of energy demand and power consumed, which will serve as basis for calculation for the study. The results obtained allow the development of two alternative proposals to the current configuration, one chosen by the criteria and results presented by technical-economic and energy analysis

Um estudo de novos paradigmas na realização de projetos de instalação elétrica residencial (automação)

Through awareness of new trends of consumption of the population with regard to housing, comfort, entertainment, security and sustainability, it was crafted a work that set out to study and develop the concept of home automation and how it will revolutionize the electrical installation projects and energy savings. A pre-wiring project, taking into account, basically, the installed load, is presented as a basis for comparison. The protocols for communication between intelligent devices in an automation environment, used in the work, are the X-10, LonWorks and UPnP. The home network is studied and divided into subsystems, for a better understanding, which are the lighting, audio, video and multimedia system, security, air conditioning and central vacuum system, and the idea of integrated design and system integrator is introduced, showing the change necessity in the design philosophy of electrical installations. The main means of energy savings in an automated home, such as dimerization, master off and smart meters are presented and, finally, it was concluded that there is a need to structure electrical installation projects more comprehensive with regard to home automation, in order to become more efficient and useful to users

Proposta de metodologia para aplicação de eficiência energética em uma usina hidrelétrica

Pós-graduação em Engenharia Mecânica - FEG

Avaliação energética do ciclo de refrigeração por absorção utilizando biogás de aterros sanitários e gás natural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Feasibility Study of Solar Driven Underground Cooling System

In the United States the peak electrical use occurs during the summer. In addition, the building sector consumes a major portion of the annual electrical energy consumption. One of the main energy consuming components in the building sector is the Heating, Ventilation, and Air-Conditioning (HVAC) systems. This research studies the feasibility of implementing a solar driven underground cooling system that could contribute to reducing building cooling loads. The developed system consists of an Earth-to-Air Heat Exchanger (EAHE) coupled with a solar chimney that provides a natural cool draft to the test facility building at the Solar Energy Research Test Facility in Omaha, Nebraska. Two sets of tests have been conducted: a natural passively driven airflow test and a forced fan assisted airflow test. The resulting data of the tests has been analyzed to study the thermal performance of the implemented system. Results show that: The underground soil proved to be a good heat sink at a depth of 9.5ft, where its temperature fluctuates yearly in the range of (46.5°F-58.2°F). Furthermore, the coupled system during the natural airflow modes can provide good thermal comfort conditions that comply with ASHRAE standard 55-2004. It provided 0.63 tons of cooling, which almost covered the building design cooling load (0.8 tons, extreme condition). On the other hand, although the coupled system during the forced airflow mode could not comply with ASHRAE standard 55-2004, it provided 1.27 tons of cooling which is even more than the building load requirements. Moreover, the underground soil experienced thermal saturation during the forced airflow mode due to the oversized fan, which extracted much more airflow than the EAHE ability for heat dissipation and the underground soil for heat absorption. In conclusion, the coupled system proved to be a feasible cooling system, which could be further improved with a few design recommendations.

Methodology of CO2 emission evaluation in the life cycle of office building facades

The construction industry is one of the greatest sources of pollution because of the high level of energy consumption during its life cycle. In addition to using energy while constructing a building, several systems also use power while the building is operating, especially the air-conditioning system. Energy consumption for this system is related, among other issues, to external air temperature and the required internal temperature of the building. The facades are elements which present the highest level of ambient heat transfer from the outside to the inside of tall buildings. Thus, the type of facade has an influence on energy consumption during the building life cycle and, consequently, contributes to buildings' CO2 emissions, because these emissions are directly connected to energy consumption. Therefore, the aim is to help develop a methodology for evaluating CO2 emissions generated during the life cycle of office building facades. The results, based on the parameters used in this study, show that facades using structural glazing and uncolored glass emit the most CO2 throughout their life cycle, followed by brick facades covered with compound aluminum panels or ACM (Aluminum Composite Material), facades using structural glazing and reflective glass and brick facades with plaster coating. On the other hand, the typology of facade that emits less CO2 is brickwork and mortar because its thermal barrier is better than structural glazing facade and materials used to produce this facade are better than brickwork and ACM. Finally, an uncertainty analysis was conducted to verify the accuracy of the results attained. (C) 2011 Elsevier Inc. All rights reserved.

Analysis of a new cross flow heat exchanger flow arrangement - Extension to several rows

The present paper presents a theoretical analysis of a cross flow heat exchanger with a new flow arrangement comprehending several tube rows. The thermal performance of the proposed flow arrangement is compared with the thermal performance of a typical counter cross flow arrangement that is used in chemical, refrigeration, automotive and air conditioning industries. The thermal performance comparison has been performed in terms of the following parameters: heat exchanger effectiveness and efficiency, dimensionless entropy generation, entransy dissipation number, and dimensionless local temperature differences. It is also shown that the uniformity of the temperature difference field leads to a higher thermal performance of the heat exchanger. In the present case this is accomplished thorough a different organization of the in-tube fluid circuits in the heat exchanger. The relation between the recently introduced "entransy dissipation number" and the conventional thermal effectiveness has been obtained in terms of the "number of transfer units". A case study has been solved to quantitatively to obtain the temperature difference distribution over two rows units involving the proposed arrangement and the counter cross flow one. It has been shown that the proposed arrangement presents better thermal performance regardless the comparison parameter. (C) 2012 Elsevier Masson SAS. All rights reserved.

Solid electrolytes for electrochromic devices based on reversible metal electrodeposition

Air conditioning and lighting costs can be reduced substantially by changing the optical properties of "intelligent windows." The electrochromic devices studied to date have used copper as an additive. Copper, used here as an electrochromic material, was dissolved in an aqueous animal protein-derived gel electrolyte. This combination constitutes the electrochromic system for reversible electrodeposition. Cyclic voltammetry, chronoamperometric and chromogenic analyses indicated that were obtained good conditions of transparency (initial transmittance of 70%), optical reversibility, small potential window (2.1 V), variation of transmittance in visible light (63.6%) and near infrared (20%) spectral regions. Permanence in the darkened state was achieved by maintaining a lower pulse potential (-0.16 V) than the deposition potential (-1.0 V). Increasing the number of deposition and dissolution cycles favored the transmittance and photoelectrochemical reversibility of the device. The conductivity of the electrolyte (10(-3) S/cm) at several concentrations of CuCl2 was determined by electrochemical impedance spectroscopy. A thermogravimetric analysis confirmed the good thermal stability of the electrolyte, since the mass loss detected up to 100 degrees C corresponded to water evaporation and decomposition of the gel started only at 200 degrees C. Micrographic and small angle X-ray scattering analyses indicated the formation of a persistent deposit of copper particles on the ITO. (C) 2012 Elsevier B.V. All rights reserved.

Análise do conforto térmico na obra de João Filgueiras Lima, Lelé: Hospitais Sarah de Salvador e do Rio de Janeiro

Estratégias passivas de projeto reduzem significativamente o uso de ar condicionado e melhoram o conforto térmico dos usuários. Isto pode ser ilustrado através dos hospitais da Rede Sarah Kubitschek projetados pelo arquiteto João Filgueiras Lima, Lelé, cujas soluções além de propiciarem ambientes mais agradáveis e salubres, evitam o uso de sistemas mecânicos de resfriamento, reduzindo o consumo de energia elétrica. Deste modo, o presente artigo tem como objetivo avaliar o conforto térmico dos hospitais Sarah de Salvador e do Rio de Janeiro, através de medições in loco da temperatura do ar, umidade relativa do ar e velocidade do ar. A análise dos resultados foi baseada em leituras de projeto, na norma ASHRAE Standard 55/2004 e em parâmetros adquiridos na literatura especializada. Os resultados demonstram a preocupação de Lelé na incorporação de aspectos bioclimáticos nos projetos. No Sarah - Salvador, alguns ambientes permaneceram fora da zona de conforto no período do meio dia, devido ao ganho de calor pela cobertura. No entanto, o uso da ventilação natural auxilia no efeito de resfriamento, melhorando o conforto térmico nos espaços internos. Já no Sarah - Rio, todos os ambientes permanecem dentro da zona de conforto proposta pela ASHRAE 55.

Sistemi per la climatizzazione mediante pompe di calore geotermiche e pali energetici

We need a large amount of energy to make our homes pleasantly warm in winter and cool in summer. If we also consider the energy losses that occur through roofs, perimeter walls and windows, it would be more appropriate to speak of waste than consumption. The solution would be to build passive houses, i.e. buildings more efficient and environmentally friendly, able to ensure a drastic reduction of electricity and heating bills. Recently, the increase of public awareness about global warming and environmental pollution problems have “finally” opened wide possibility in the field of sustainable construction by encouraging new renewable methods for heating and cooling space. Shallow geothermal allows to exploit the renewable heat reservoir, present in the soil at depths between 15 and 20 m, for air-conditioning of buildings, using a ground source heat pump. This thesis focuses on the design of an air-conditioning system with geothermal heat pump coupled to energy piles, i.e. piles with internal heat exchangers, for a typical Italian-family building, on the basis of a geological-technical report about a plot of Bologna’s plain provided by Geo-Net s.r.l. The study has involved a preliminary static sizing of the piles in order to calculate their length and number, then the project was completed making the energy sizing, where it has been verified if the building energy needs were met with the static solution obtained. Finally the attention was focused on the technical and economical validity compared to a traditional system (cost-benefit analysis) and on the problem of the uncertainty data design and their effects on the operating and initial costs of the system (sensitivity analysis). To evaluate the performance of the thermal system and the potential use of the piles was also used the PILESIM2 software, designed by Dr. Pahud of the SUPSI’s school.

Food safety and zoonotic enteric pathogens: sources, risk factors and transmission routes of human salmonellosis and campylobacteriosis

Salmonella and Campylobacter are common causes of human gastroenteritis. Their epidemiology is complex and a multi-tiered approach to control is needed, taking into account the different reservoirs, pathways and risk factors. In this thesis, trends in human gastroenteritis and food-borne outbreak notifications in Italy were explored. Moreover, the improved sensitivity of two recently-implemented regional surveillance systems in Lombardy and Piedmont was evidenced, providing a basis for improving notification at the national level. Trends in human Salmonella serovars were explored: serovars Enteritidis and Infantis decreased, Typhimurium remained stable and 4,[5],12:i:-, Derby and Napoli increased, suggesting that sources of infection have changed over time. Attribution analysis identified pigs as the main source of human salmonellosis in Italy, accounting for 43–60% of infections, followed by Gallus gallus (18–34%). Attributions to pigs and Gallus gallus showed increasing and decreasing trends, respectively. Potential bias and sampling issues related to the use of non-local/non-recent multilocus sequence typing (MLST) data in Campylobacter jejuni/coli source attribution using the Asymmetric Island (AI) model were investigated. As MLST data become increasingly dissimilar with increasing geographical/temporal distance, attributions to sources not sampled close to human cases can be underestimated. A combined case-control and source attribution analysis was developed to investigate risk factors for human Campylobacter jejuni/coli infection of chicken, ruminant, environmental, pet and exotic origin in The Netherlands. Most infections (~87%) were attributed to chicken and cattle. Individuals infected from different reservoirs had different associated risk factors: chicken consumption increased the risk for chicken-attributed infections; animal contact, barbecuing, tripe consumption, and never/seldom chicken consumption increased that for ruminant-attributed infections; game consumption and attending swimming pools increased that for environment-attributed infections; and dog ownership increased that for environment- and pet-attributed infections. Person-to-person contacts around holiday periods were risk factors for infections with exotic strains, putatively introduced by returning travellers.

Screening of Swiss hot spring resorts for potentially pathogenic free-living amoebae

Free-living amoebae (FLA) belonging to Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Sappinia pedata are known to cause infections in humans and animals leading to severe brain pathologies. Worldwide, warm aquatic environments have been found to be suitable habitats for pathogenic FLA. The present study reports on screening for potentially pathogenic FLA in four hot spring resorts in Switzerland. Water samples were taken from water filtration units and from the pools, respectively. Amoebae isolated from samples taken during, or before, the filtration process were demonstrated to be morphologically and phylogenetically related to Stenoamoeba sp., Hartmannella vermiformis, Echinamoeba exundans, and Acanthamoeba healyi. With regard to the swimming pools, FLA were isolated only in one resort, and the isolate was identified as non-pathogenic and as related to E. exundans. Further investigations showed that the isolates morphologically and phylogenetically related to A. healyi displayed a pronounced thermotolerance, and exhibited a marked in vitro cytotoxicity upon 5-day exposure to murine L929 fibroblasts. Experimental intranasal infection of Rag2-immunodeficient mice with these isolates led to severe brain pathologies, and viable trophozoites were isolated from the nasal mucosa, brain tissue, and lungs post mortem. In summary, isolates related to A. healyi were suggestive of being potentially pathogenic to immunocompromised persons. However, the presence of these isolates was limited to the filtration units, and an effective threat for health can therefore be excluded.

Razor Thin Win: The 1972 Constitution Ballot, Campaign, Ratification & the Courts -- Mae Nan (Robinson) Ellingson & Mick McKeon “In the Crucible of Change”

Beyond the challenge of crafting a new state Constitution that empowered the people and modernized and opened up state and local government in Montana, the Constitutional Convention delegates, as they signed the final document, looked forward to the arduous task of getting it ratified by the electorate in a short ten week period between the end of the convention on March 24 and the ratification election of June 6, 1972. While all 100 delegates signed the draft Constitution, not all supported its adoption. But the planning about how to get it adopted went back to the actions of the Convention itself, which carefully crafted a ballot that kept “hot political issues” from potentially killing the entire document at the polls. As a result, three side issues were presented to the electorate on the ballot. People could vote for or against those side issues and still vote to ratify the entire document. Thus, the questions of legalizing gambling, having a unicameral legislature and retaining the death penalty were placed separately on the ballot (gambling passed, as did the retention of the death penalty, but the concept of a one-house legislature was defeated). Once the ballot structure was set, delegates who supported the new Constitution organized a grassroots, locally focused effort to secure ratification – thought hampered by a MT Supreme Court decision on April 28 that they could not expend $45,000 in public monies that they had set aside for voter education. They cobbled together about $10,000 of private money and did battle with the established political forces, led by the MT Farm Bureau, MT Stockgrowers’ Assn. and MT Contractors Assn., on the question of passage. Narrow passage of the main document led to an issue over certification and a Montana Supreme Court case challenging the ratification vote. After a 3-2 State Supreme Court victory, supporters of the Constitution then had to defend the election results again before the federal courts, also a successful effort. Montana finally had a new progressive State Constitution that empowered the people, but the path to it was not clear and simple and the win was razor thin. The story of that razor thin win is discussed in this chapter by the two youngest delegates to the 1972 Constitutional Convention, Mae Nan Ellingson of Missoula and Mick McKeon, then of Anaconda. Both recognized “Super Lawyers in their later professional practices were also significant players in the Constitutional Convention itself and actively participated in its campaign for ratification. As such, their recollections of the effort provide an insider’s perspective of the struggle to change Montana for the better through the creation and adoption of a new progressive state Constitution “In the Crucible of Change.” Mae Nan (Robinson) Ellingson was born Mae Nan Windham in Mineral Wells, TX and graduated from Mineral Wells High School in 1965 and Weatherford College in Weatherford, TX in 1967. Mae Nan was the youngest delegate at the 1972 Convention from Missoula. She moved to Missoula in 1967 and received her BA in Political Science with Honors from the University of MT in 1970. She was a young widow known by her late husband’s surname of Robinson while attending UM graduate school under the tutelage of noted Professor Ellis Waldron when he persuaded her to run for the Constitutional Convention. Coming in a surprising second in the delegate competition in Missoula County she was named one of the Convention’s “Ten Outstanding Constitutional Convention Delegates,” an impressive feat at such a young age. She was 24 at the time, the youngest person to serve at the ConCon, and one of 19 women out of 100 delegates. In the decade before the Convention, there were never more than three women Legislators in any session, usually one or two. She was a member of the American Association of University Women, a Pi Sigma Alpha political science honorary, and a Phi Alpha Theta historical honorary. At the Convention, she led proposals for the state's bill of rights, particularly related to equal rights for women. For years, Ellingson kept a copy of the preamble to the Constitution hanging in her office; while all the delegates had a chance to vote on the wording, she and delegate Bob Campbell are credited with the language in the preamble. During the convention, she had an opportunity that opened the door to her later career as an attorney. A convention delegate suggested to her that she should go to law school. Several offered to help, but at the time she couldn't go to school. Her mom had died in Texas, and she ended up with a younger brother and sister to raise in Missoula. She got a job teaching, but about a year later, intrigued with the idea of pursuing the law as a career, she called the man back to ask about the offer. Eventually another delegate, Dave Drum of Billings, sponsored her tuition at the UM School of Law. After receiving her JD with Honors (including the Law Review and Moot Court) from the UM Law School Ellingson worked for the Missoula city attorney's office for six years (1977-83), and she took on landmark projects. During her tenure, Missoula became the first city to issue open space bonds, a project that introduced her to Dorsey & Whitney. The city secured its first easement on Mount Sentinel, and it created the trail along the riverfront with a mix of playing fields and natural vegetation. She also helped develop a sign ordinance for the city of Missoula. She ended up working as bond counsel for Dorsey & Whitney, and she opened up the firm's full-fledged Missoula office after commuting a couple of years to its Great Falls office. She was a partner at Dorsey Whitney, working there from 1983 until her retirement in 2012. The area of law she practiced there is a narrow specialty - it requires knowledge of constitutional law, state and local government law, and a slice of federal tax law - but for Ellingson it meant working on great public projects – schools, sewer systems, libraries, swimming pools, ire trucks. At the state level, she helped form the Montana Municipal Insurance Authority, a pooled insurance group for cities. She's shaped MT’s tax increment law, and she was a fixture in the MT Legislature when they were debating equal rights. As a bond lawyer, though, Ellingson considers her most important work for the state to be setting up the Intercap Program that allowed local governments to borrow money from the state at a low interest rate. She has been a frequent speaker at the League of Cities and Towns, the Montana Association of Counties, and the Rural Water Users Association workshops on topics related to municipal finance, as well as workshops sponsored by the DNRC, the Water and Sewer Agencies Coordination Team, and the Montana State University Local Government Center. In 2002, she received an outstanding service award from the Montana Rural Water Users Association. In addition to being considered an expert on Montana state and constitutional law, local government law and local government finance, she is a frequent teacher at the National Association of Bond Lawyers (NABL) Fundamentals of Municipal Bond Law Seminar and the NABL Bond Attorney’s Workshop. For over 30 years Mae Nan has participated in the drafting of legislation in Montana for state and local finance matters. She has served on the Board of Directors of NABL, as Chairman of its Education Committee, was elected as an initial fellow in 1995 to the American College of Bond Counsel, and was recognized as a Super Lawyer in the Rocky Mountain West. Mae Nan was admitted to practice before the MT and US Supreme Courts, was named one of “America’s Leading Business Lawyers” by Chambers USA (Rank 1), a Mountain States Super Lawyer in 2007 and is listed in Best Lawyers in America; she is a member and former Board Member of NABL, a Fellow of the American College of Bond Counsel and a member of the Board of Visitors of the UM Law School. Mae Nan is also a philanthropist who serves on boards and applies her intelligence to many organizations, such as the Missoula Art Museum. [Much of this biography was drawn from a retirement story in the Missoulian and the Dorsey Whitney web site.] Mick McKeon, born in Anaconda in 1946, is a 4th generation Montanan whose family roots in this state go back to the 1870’s. In 1968 he graduated from Notre Dame with a BA in Communications and received a Juris Doctorate degree from the University of Montana Law School in 1971. Right after graduating from law school, Mick was persuaded by his father, longtime State Senator Luke McKeon, and his uncle, Phillips County Attorney Willis McKeon, to run for delegate to Montana’s Constitutional Convention and was elected to represent Deer Lodge, Philipsburg, Powell, and part of Missoula Counties. Along with a coalition of delegates from Butte and Anaconda, he fought through the new Constitution to eliminate the legal strangle hold, often called “the copper collar,” that corporate interests -- the Anaconda Company and its business & political allies -- had over state government for nearly 100 years. The New York Times called Montana’s Constitutional Convention a “prairie revolution.” After helping secure the ratification of the new Constitution, Mick began his practice of law in Anaconda where he engaged in general practice for nearly 20 years. Moving to Butte in 1991, Mick focused has practice in personal injury law, representing victims of negligence and corporate wrongdoing in both Montana district courts and federal court. As such, he participated in some of the largest cases in the history of the state. In 1992 he and his then law partner Rick Anderson obtained a federal court verdict of $11.5 million -- the largest verdict in MT for many years. Mick’s efforts on behalf of injured victims have been recognized by many legal organizations and societies. Recently, Mick was invited to become a member of the International Academy of Trial Lawyers - 600 of the top lawyers in the world. Rated as an American Super Lawyer, he has continuously been named one of the Best Lawyers in America, and an International Assn. of Trial Lawyers top 100 Trial Lawyer. In 2005, he was placed as one of Montana’s top 4 Plaintiff’s lawyers by Law Dragon. Mick is certified as a civil trial specialist by the National Board of Trial Advocacy and has the highest rating possible from Martindale-Hubble. Mick was awarded the Montana Trial Lawyers Public Service Award and provided pro bono assistance to needy clients for his entire career. Mick’s law practice, which he now shares with his son Michael, is limited to representing individuals who have been injured in accidents, concentrating on cases against insurance companies, corporations, medical providers and hospitals. Mick resides in Butte with his wife Carol, a Butte native. Mick, Carol, Michael and another son, Matthew, who graduated from Dartmouth College and was recently admitted to the Montana bar, enjoy as much of their time together in Butte and at their place on Flathead Lake.

Screening Swiss water bodies for potentially pathogenic free-living amoebae

Free-ling amoebae (FLA) including Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris and Sappinia pedata, can cause opportunistic infections leading to severe brain pathologies. Human infections with pathogenic FLA have been increasingly documented in many countries. In Switzerland, thus far, the occurrence and distribution of potentially pathogenic FLA has not been investigated. Swiss water biotopes, including swimming pools, lakes, rivers and ponds, have now been screened for the presence of FLA, and assessment of their pathogenicity potential for a mammalian host has been undertaken. Thus, a total of 17 isolates were recovered by in vitro cultivation from these different aquatic sources. Characterization by sequence analysis of Acanthamoeba spp.-specific and 'FLA-specific PCR products amplified from 18s rDNA based on morphological traits, thermotolerance, and cytotoxicity towards murine fibroblasts yielded the following findings: Echinamoeba cf. exundans (3 isolates), Hartmannella spp. (3), Vannella spp. (4), Protacanthamoebica cf. bohemica (1), Acanthamoeba cf. castellanii (1) and Naegleria spp. (5). B. mandrillaris and N. fowleri did not range amongst these isolates. None of the isolates exhibited pronounced cytotoxicity and all failed to grow at 42 degrees C; therefore, they do not present any potential for CNS pathogenicity for humans.