The Performance and Service Life Prediction of High Performance Concrete in Sulfate and Acidic Environments

Concrete substructures are often subjected to environmental deterioration, such as sulfate and acid attack, which leads to severe damage and causes structure degradation or even failure. In order to improve the durability of concrete, the High Performance Concrete (HPC) has become widely used by partially replacing cement with pozzolanic materials. However, HPC degradation mechanisms in sulfate and acidic environments are not completely understood. It is therefore important to evaluate the performance of the HPC in such conditions and predict concrete service life by establishing degradation models. This study began with a review of available environmental data in the State of Florida. A total of seven bridges have been inspected. Concrete cores were taken from these bridge piles and were subjected for microstructural analysis using Scanning Electron Microscope (SEM). Ettringite is found to be the products of sulfate attack in sulfate and acidic condition. In order to quantitatively analyze concrete deterioration level, an image processing program is designed using Matlab to obtain quantitative data. Crack percentage (Acrack/Asurface) is used to evaluate concrete deterioration. Thereafter, correlation analysis was performed to find the correlation between five related variables and concrete deterioration. Environmental sulfate concentration and bridge age were found to be positively correlated, while environmental pH level was found to be negatively correlated. Besides environmental conditions, concrete property factor was also included in the equation. It was derived from laboratory testing data. Experimental tests were carried out implementing accelerated expansion test under controlled environment. Specimens of eight different mix designs were prepared. The effect of pozzolanic replacement rate was taken into consideration in the empirical equation. And the empirical equation was validated with existing bridges. Results show that the proposed equations compared well with field test results with a maximum deviation of ± 20%. Two examples showing how to use the proposed equations are provided to guide the practical implementation. In conclusion, the proposed approach of relating microcracks to deterioration is a better method than existing diffusion and sorption models since sulfate attack cause cracking in concrete. Imaging technique provided in this study can also be used to quantitatively analyze concrete samples.

Novel hybrid columns made of ultra-high performance concrete and fiber reinforced polymers

The application of advanced materials in infrastructure has grown rapidly in recent years mainly because of their potential to ease the construction, extend the service life, and improve the performance of structures. Ultra-high performance concrete (UHPC) is one such material considered as a novel alternative to conventional concrete. The material microstructure in UHPC is optimized to significantly improve its material properties including compressive and tensile strength, modulus of elasticity, durability, and damage tolerance. Fiber-reinforced polymer (FRP) composite is another novel construction material with excellent properties such as high strength-to-weight and stiffness-to-weight ratios and good corrosion resistance. Considering the exceptional properties of UHPC and FRP, many advantages can result from the combined application of these two advanced materials, which is the subject of this research. The confinement behavior of UHPC was studied for the first time in this research. The stress-strain behavior of a series of UHPC-filled fiber-reinforced polymer (FRP) tubes with different fiber types and thicknesses were tested under uniaxial compression. The FRP confinement was shown to significantly enhance both the ultimate strength and strain of UHPC. It was also shown that existing confinement models are incapable of predicting the behavior of FRP-confined UHPC. Therefore, new stress-strain models for FRP-confined UHPC were developed through an analytical study. In the other part of this research, a novel steel-free UHPC-filled FRP tube (UHPCFFT) column system was developed and its cyclic behavior was studied. The proposed steel-free UHPCFFT column showed much higher strength and stiffness, with a reasonable ductility, as compared to its conventional reinforced concrete (RC) counterpart. Using the results of the first phase of column tests, a second series of UHPCFFT columns were made and studied under pseudo-static loading to study the effect of column parameters on the cyclic behavior of UHPCFFT columns. Strong correlations were noted between the initial stiffness and the stiffness index, and between the moment capacity and the reinforcement index. Finally, a thorough analytical study was carried out to investigate the seismic response of the proposed steel-free UHPCFFT columns, which showed their superior earthquake resistance, as compared to their RC counterparts.

Development of thresholds for surface preparation in repair systems with wet lay -up fiber reinforced polymers

Bonded repair of concrete structures with fiber reinforced polymer (FRP) systems is increasingly being accepted as a cost-efficient and structurally viable method of rapid rehabilitation of concrete structures. However, the relationships between long-term performance attributes, service-life, and details of the installation process are not easy to quantify. Accordingly, there is currently a lack of generally accepted construction specifications, making it difficult for the field engineer to certify the adequacy of the construction process. ^ The objective of the present study, as part of the National Cooperative Highway Research Program (NCHRP) Project 10-59B, was to investigate the effect of surface preparation on the behavior of wet lay-up FRP repair systems and consequently develop rational thresholds that provide sufficient performance. ^ The research program was comprised of both experimental and analytical work for wet lay-up FRP applications. The experimental work included flexure testing of sixty-seven (67) reinforced concrete beams and bond testing of ten (10) reinforced concrete blocks. Four different parameters were studied: surface roughness, surface flatness, surface voids and bug holes, and surface cracks/cuts. The findings were analyzed from various aspects and compared with the data available in the literature. As part of the analytical work, finite element models of the flexural specimens with surface flaws were developed using ANSYS. The purpose of this part was to extend the parametric study on the effects of concrete surface flaws and verify the experimental results based on nonlinear finite element analysis. ^ Test results showed that surface roughness does not appear to have a significant influence on the overall performance of the wet lay-up FRP systems with or without adequate anchorage, and whether failure was by debonding or rupture of FRP. Both experimental and analytical results for surface flatness proved that peaks on concrete surface, in the range studied, do not have a significant effect on the performance of wet lay-up FRP systems. However, valleys of particular size could reduce the strength of wet lay-up FRP systems. Test results regarding surface voids and surface cracks/cuts revealed that previously suggested thresholds for these flaws appear to be conservative, as also confirmed by analytical study. ^

The effect of a breakfast program on nutritional status, quality of life, and health care use among frail homebound older adults

The population of older adults is rapidly increasing, creating a need for community services that assist vulnerable older adults in maintaining independence and quality of life. Recent evidence confirms the importance of food and nutrition in reaching this objective. The Elderly Nutrition Program (ENP) is part of a system of federally funded community based programs, authorized through the Older Americans Act. ENP services include the home-delivered meals program, which targets frail homebound older adults at nutritional risk. Traditionally, ENP services provide a noon meal 5 days/week. This study evaluated the impact of expanding the home-delivered meals service to include breakfast + lunch, on the nutritional status, quality of life and health care utilization of program participants. ^ This cross-sectional study compared 2 groups. The Breakfast group (n = 167) received a home-delivered breakfast + lunch, 5 days/week. The Comparison group (n = 214) received lunch 5 days/week. Participants, recruited from 5 ENP programs, formed a geographically, racially/ethnically diverse sample. Participants ranged in age from 60–100 years, they were functionally limited, at high nutritional risk, low income, and they lived alone and had difficulty shopping or preparing food. Participant data were collected through in-home interviews and program records. A 24-hour food recall and information on participant demographics, malnutrition risk, functional status, health care use, and applicable quality of life factors were obtained. Service and cost data were collected from program administrators. ^ Breakfast group participants had greater energy/nutrient intakes (p < .05), fewer health care contacts (p < .05), and greater quality of life measured as food security (p < .05) and fewer depressive symptoms (p < .05), than comparison group participants. These benefits were achieved for $1.30/person/day. ^ The study identified links from improvements in nutritional status to enhanced quality of life to diminished health care utilization and expenditures. A model of health, loneliness, food enjoyment, food insecurity, and depression as factors contributing to quality of life for this population, was proposed and tested (p < .01). ^ The breakfast service is an inexpensive addition to traditional home-delivered meals services and can improve the lives of frail homebound older adults. Agencies should be encouraged to expand meals programs to include a breakfast service. ^

Making Life More Satisfying for Hospitality Managers

Because of the considerable amount of time that hospitality managers spend at work, the relationship between life satisfaction and job satisfaction is of particular interest. Dissonance may result when the role at work conflicts with the role at home of with the family. Food service managers indicate that the top inter-role conflicts area is that work time takes up time that they would like to spend with family and others; that they are too tired to do some of the things they would like to do after work; and that the job makes it difficult to be the kind of friend, spouse, or parent that they would like to be.

The Food Service Industry: Beliefs Held by Academics

In his study - The Food Service Industry: Beliefs Held by Academics - by Jack Ninemeier, Associate Professor, School of Hotel, Restaurant and Institutional Management at Michigan State University, Associate Professor Ninemeier initially describes his study this way: “Those in the academic sector exert a great deal of influence on those they are training to enter the food service industry. One author surveyed educational institutions across the country to ascertain attitudes of teachers toward various segments of the industry.” Those essential segments of the industry serve as the underpinnings of this discussion and are four-fold. They are lodging, institutional, multi-unit, and single-unit properties. For each segment the analysis addressed factors relating to Marketing, management and operating concerns: Marketing, operations, fiscal management, innovation, future of the segment Employee-related concerns: quality of work life, training/education opportunities, career opportunities The study uses a survey of academicians as a guide; they point to segments of the food service industry students might be inclined to enter, or even ignore. The survey was done via a questionnaire sent from the campus of the School of Hotel, Restaurant and Institutional Management at Michigan State University to 1850 full-time faculty members in two and four-year hospitality programs in the United States. Through the survey, Ninemeier wishes to reasonably address specific problems now confronting the food service industry. Those problems include but are not limited to: reducing employee turnover, retaining staff, increasing productivity and revenue, and attracting new staff. “Teachers in these programs are, therefore, an important plank in industry's platform designed to recruit students with appropriate background knowledge and interest in their operations,” Ninemeier says. Your author actually illustrates the survey results, in table form. The importance to an employee, of tangibles and intangibles such as morale, ego/esteem, wages, and benefits are each explored through the survey. According to the study, an interesting dichotomy exists in the institutional property element. Although, beliefs the academics hold about the institutional element suggest that it offers low job stress, attractive working conditions, and non-demanding competitive pressures, the survey and Ninemeier also observe: “Academics do not believe that many of their graduates will enter the institutional segment.” “If academic beliefs are incorrect, an educational program to educate academics about management and employee opportunities in the segment may be in order,” Ninemeier waxes philosophically.

Children with special health care needs: Comparison of the effects of home care setting, prescribed pediatric extended care setting, and long-term care setting on child and family health outcomes and health care service use

Technological advances during the past 30 years have dramatically improved survival rates for children with life-threatening conditions (preterm births, congenital anomalies, disease, or injury) resulting in children with special health care needs (CSHCN), children who have or are at increased risk for a chronic physical, developmental, behavioral, or emotional condition and who require health and related services beyond that required by children generally. There are approximately 10.2 million of these children in the United States or one in five households with a child with special health care needs. Care for these children is limited to home care, medical day care (Prescribed Pediatric Extended Care; P-PEC) or a long term care (LTC) facility. There is very limited research examining health outcomes of CSHCN and their families. The purpose of this research was to compare the effects of home care settings, P-PEC settings, and LTC settings on child health and functioning, family health and function, and health care service use of families with CSHCN. Eighty four CSHCN ages 2 to 21 years having a medically fragile or complex medical condition that required continual monitoring were enrolled with their parents/guardians. Interviews were conducted monthly for five months using the PedsQL™ Generic Core Module for child health and functioning, PedsQL™ Family Impact Module for family health and functioning, and Access to Care from the NS-CSHCN survey for health care services. Descriptive statistics, chi square, and ANCOVA were conducted to determine differences across care settings. Children in the P-PEC settings had a highest health care quality of life (HRQL) overall including physical and psychosocial functioning. Parents/guardians with CSHCN in LTC had the highest HRQL including having time and energy for a social life and employment. Parents/guardians with CSHCN in home care settings had the poorest HRQL including physical and psychosocial functioning with cognitive difficulties, difficulties with worry, communication, and daily activities. They had the fewest hours of employment and the most hours providing direct care for their children. Overall health care service use was the same across the care settings.

Recruiting and developing technicians for hotel food service operations

The thesis which follows is a study of recruiting and developing skilled workers for Hotel Food Service Operations in the Miami area. The aim of the study is to bring to the attention of personnel management the role of recruiting and training in providing the skilled people needed for their operation in the short and long run as well. The study was done as a case study of the medium and large size hotels which have a minimum of 250 units each in the Miami area. However, the study has been generalized where it is possible, and when data permitted. The primary data was collected by the use of the questionnaire survey method composed of key questions about recruiting, training and sources of skilled people, turnover reasons, etc. Eight tables have been constructed, analyzed and interpreted. A personal opinion was mentioned in the interpretation of each table's data. It was found that personnel management should provide a better recruiting and developing procedures in order to attract more qualified people, particularly among the youngsters who are potential skilled workers for the future. It was concluded that the quality of work life, the benefits, and the opportunities for advancement in the food and beverage operations play a significant role in an employee's decision to stay with a particular job, and to acquire the necessary skills.

Delay-sensitive service request scheduling for cloud computing

Cloud computing realizes the long-held dream of converting computing capability into a type of utility. It has the potential to fundamentally change the landscape of the IT industry and our way of life. However, as cloud computing expanding substantially in both scale and scope, ensuring its sustainable growth is a critical problem. Service providers have long been suffering from high operational costs. Especially the costs associated with the skyrocketing power consumption of large data centers. In the meantime, while efficient power/energy utilization is indispensable for the sustainable growth of cloud computing, service providers must also satisfy a user's quality of service (QoS) requirements. This problem becomes even more challenging considering the increasingly stringent power/energy and QoS constraints, as well as other factors such as the highly dynamic, heterogeneous, and distributed nature of the computing infrastructures, etc. ^ In this dissertation, we study the problem of delay-sensitive cloud service scheduling for the sustainable development of cloud computing. We first focus our research on the development of scheduling methods for delay-sensitive cloud services on a single server with the goal of maximizing a service provider's profit. We then extend our study to scheduling cloud services in distributed environments. In particular, we develop a queue-based model and derive efficient request dispatching and processing decisions in a multi-electricity-market environment to improve the profits for service providers. We next study a problem of multi-tier service scheduling. By carefully assigning sub deadlines to the service tiers, our approach can significantly improve resource usage efficiencies with statistically guaranteed QoS. Finally, we study the power conscious resource provision problem for service requests with different QoS requirements. By properly sharing computing resources among different requests, our method statistically guarantees all QoS requirements with a minimized number of powered-on servers and thus the power consumptions. The significance of our research is that it is one part of the integrated effort from both industry and academia to ensure the sustainable growth of cloud computing as it continues to evolve and change our society profoundly.^

Delay-Sensitive Service Request Scheduling for Cloud Computing

Cloud computing realizes the long-held dream of converting computing capability into a type of utility. It has the potential to fundamentally change the landscape of the IT industry and our way of life. However, as cloud computing expanding substantially in both scale and scope, ensuring its sustainable growth is a critical problem. Service providers have long been suffering from high operational costs. Especially the costs associated with the skyrocketing power consumption of large data centers. In the meantime, while efficient power/energy utilization is indispensable for the sustainable growth of cloud computing, service providers must also satisfy a user's quality of service (QoS) requirements. This problem becomes even more challenging considering the increasingly stringent power/energy and QoS constraints, as well as other factors such as the highly dynamic, heterogeneous, and distributed nature of the computing infrastructures, etc. In this dissertation, we study the problem of delay-sensitive cloud service scheduling for the sustainable development of cloud computing. We first focus our research on the development of scheduling methods for delay-sensitive cloud services on a single server with the goal of maximizing a service provider's profit. We then extend our study to scheduling cloud services in distributed environments. In particular, we develop a queue-based model and derive efficient request dispatching and processing decisions in a multi-electricity-market environment to improve the profits for service providers. We next study a problem of multi-tier service scheduling. By carefully assigning sub deadlines to the service tiers, our approach can significantly improve resource usage efficiencies with statistically guaranteed QoS. Finally, we study the power conscious resource provision problem for service requests with different QoS requirements. By properly sharing computing resources among different requests, our method statistically guarantees all QoS requirements with a minimized number of powered-on servers and thus the power consumptions. The significance of our research is that it is one part of the integrated effort from both industry and academia to ensure the sustainable growth of cloud computing as it continues to evolve and change our society profoundly.

Children with Special Health Care Needs: Comparison of the Effects of Home Care Setting, Prescribed Pediatric Extended Care Setting, and Long-Term Care Setting on Child and Family Health Outcomes and Health Care Service Use

Technological advances during the past 30 years have dramatically improved survival rates for children with life-threatening conditions (preterm births, congenital anomalies, disease, or injury) resulting in children with special health care needs (CSHCN), children who have or are at increased risk for a chronic physical, developmental, behavioral, or emotional condition and who require health and related services beyond that required by children generally. There are approximately 10.2 million of these children in the United States or one in five households with a child with special health care needs. Care for these children is limited to home care, medical day care (Prescribed Pediatric Extended Care; P-PEC) or a long term care (LTC) facility. There is very limited research examining health outcomes of CSHCN and their families. The purpose of this research was to compare the effects of home care settings, P-PEC settings, and LTC settings on child health and functioning, family health and function, and health care service use of families with CSHCN. Eighty four CSHCN ages 2 to 21 years having a medically fragile or complex medical condition that required continual monitoring were enrolled with their parents/guardians. Interviews were conducted monthly for five months using the PedsQL TM Generic Core Module for child health and functioning, PedsQL TM Family Impact Module for family health and functioning, and Access to Care from the NS-CSHCN survey for health care services. Descriptive statistics, chi square, and ANCOVA were conducted to determine differences across care settings. Children in the P-PEC settings had a highest health care quality of life (HRQL) overall including physical and psychosocial functioning. Parents/guardians with CSHCN in LTC had the highest HRQL including having time and energy for a social life and employment. Parents/guardians with CSHCN in home care settings had the poorest HRQL including physical and psychosocial functioning with cognitive difficulties, difficulties with worry, communication, and daily activities. They had the fewest hours of employment and the most hours providing direct care for their children. Overall health care service use was the same across the care settings.