Suspension of apatite particles in a self-aerated Denver laboratory flotation cell

Effective solids suspension is a necessary precondition for particle collection, and solids suspension is largely dependent on the hydrodynamics of the flotation cell. This study attempted to correlate the status of the suspension of apatite particles of different sizes in a Denver laboratory flotation cell versus the impeller rotational speed (N) adopted to operate the machine. The latter variable (N) influences the impeller capacity to lift the particles from the bottom of the tank and also to disperse them throughout the volume of the vessel. Such an impeller capacity can be characterized by the critical impeller speed for the accomplishment of solids off-bottom suspension (N(z)) and also by the velocity of the radial water flow discharged by the impeller (U) divided by the particle terminal settling velocity (U(s)). This way, the status of the suspension of apatite particles inside the flotation cell can be characterized by one of three categories: ""segregation"" (N/N(2) < 0.60 and U(s)/U > 0.08); ""suspension"" (0.60 <= N/N(2) < 1 and 0.06 < U(s)/U < 0.10); and ""dragging"" (N/N(2) >= 1 and U(s)/U <= 0.03). The range of impeller rotational speed (N), which was able to suspend the finest particles (D(p) = 90,mu m), was unable to suspend the coarsest particles (D(P) = 254 mu m). Conversely, the high value of N (N > 1,300 rpm), which is adequate to suspend the coarsest particles, may promote the entrainment of the finest particles to the froth layer.

Denver and Rio Grande Railway schedule

Denver and Rio Grande Railway schedule, 1881.

Union Pacific Railway from Kansas City , Omaha, St. Joseph to Denver, San Francisco, Portland, Helena, Butte, Boise, Leadville, Durango, Deadwood and all cities and mining camps in the west schedule

Union Pacific Railway from Kansas City , Omaha, St. Joseph to Denver, San Francisco, Portland, Helena, Butte, Boise, Leadville, Durango, Deadwood and all cities and mining camps in the west schedule, Jan. 15, 1882.

Avaliação do desenvolvimento neuropsicomotor em crianças na rede básica de saúde utilizando o teste de Denver II: identificação de fatores de risco materno

Alterations in the neuropsychomotor development of children are not rare and can manifest themselves with varying intensity at different stages of their development. In this context, maternal risk factors may contribute to the appearance of these alterations. A number of studies have reported that neuropsychomotor development diagnosis is not an easy task, especially in the basic public health network. Diagnosis requires effective, low-cost, and easy - to-apply procedures. The Denver Developmental Screening Test, first published in 1967, is currently used in several countries. It has been revised and renamed as the Denver II Test and meets the aforementioned criteria. Accordingly, the aim of this study was to apply the Denver II Test in order to verify the prevalence of suspected neuropsychomotor development delay in children between the ages of 0 and 12 months and correlate it with the following maternal risk factors: family income, schooling, age at pregnancy, drug use during pregnancy, gestational age, gestational problems, type of delivery and the desire to have children. For data collection, performed during the first 6 months of 2004, a clinical assessment was made of 398 children selected by pediatricians and the nursing team of each public health unit. Later, the parents or guardians were asked to complete a structured questionnaire to determine possible risk indicators of neuropsychomotor development delay. Finally the Denver II Developmental Screening Test (DDST) was applied. The data were analyzed together, using Statistical Package for Social Science (SPSS) software, version 6.1. The confidence interval was set at 95%. The Denver II Test yielded normal and questionable results. This suggests compromised neuropsychomotor development in the children examined and deserves further investigation. The correlation of the results with preestablished maternal risk variables (family income, mother s schooling, age at pregnancy, drug use during the pregnancy and gestational age) was strongly significant. The other maternal risk variables (gestational problems, type of delivery and desire to have children) were not significant. Using an adjusted logistic regression model, we obtained the estimate of the greater likelihood of a child having suspected neuropsychomotor development delay: a mother with _75 4 years of schooling, chronological age less than 20 years and a drug user during pregnancy. This study produced two manuscripts, one published in Acta Cirúrgica Brasileira , in which an analysis was performed of children with suspected neuropsychomotor development delay in the city of Natal, Brazil. The other paper (to be published) analyzed the magnitude of the independent variable maternal schooling associated to neuropsychomotor development delay, every 3 months during the first twelve months of life of the children selected.. The results of the present study reinforce the multifactorial characteristic of development and the cumulative effect of maternal risk factors, and show the need for a regional policy that promotes low-cost programs for the community, involving children at risk of neuropsychomotor development delay. Moreover, they suggest the need for better qualified health professionals in terms of monitoring child development. This was an inter- and multidisciplinary study with the integrated participation of doctors, nurses, nursing assistants and professionals from other areas, such as statisticians and information technology professionals, who met all the requirements of the Postgraduate Program in Health Sciences of the Federal University of Rio Grande do Norte

Through the Eyes of Visitors: Understanding the Contexts of the Visitor Photo Study at the Denver Museum of Nature & Science

This case study describes the analysis of the Visitor Photo Study, a study in which visitors to the Denver Museum of Nature & Science documented their visit through pictures. The origins, implementation, and findings of the Visitor Photo Study are considered within the contexts of the fields of Community-Based Research (Strand, Marullo, Cutforth, Stoecker, & Donohue, 2003b), Visual Studies (Marshall & Rossman, 2011; Pink, 2007), and Visitor Studies (Visitor Studies Association, 2012). This study considers the extent to which the principles and elements of each of these fields were present in the Visitor Photo Study, which elements were not fully realized or were missing from the study, and ways in which the Visitor Photo Study extends each of these fields. The value of this type of analysis and implications for museums, faculty, and students are also discussed.

Mobility and Aging in Denver, Colorado: Travel Behavior, Mobility Barriers, and Perceptions of Transit

The number of seniors in the U.S. today is growing rapidly because of longer life expectancies and the aging Baby Boomer generation. This age groups' travel behavior will have substantial impacts on transportation, economics, safety, and the environment. This research used a mixed-methods approach to address issues of mobility and aging in Denver, Colorado. A quantitative approach was used to answer broad questions about travel behavior and the effects of age, gender, work status, disability, residential location and socio-economic status on mobility. Qualitative interviews with seniors in the Denver metro area were conducted to identify barriers to mobility, decision-making processes and travel decisions, and seniors' perceptions of public transit. The results of the quantitative and qualitative analyses show that residential location is an important variable for determining seniors' travel behaviors and transportation options. Perceptions of public transit were positive, but accessibility and information barriers exist that prevent older adult from using transit. The findings of this study will help to provide transportation and service recommendations to policymakers and planners in the Denver area as well as to inform studies of other North American cities with large aging populations.

The Impact of Transit Oriented Development on the Travel Behaviors of Workers in Denver, Colorado

To combat unsustainable transportation systems characterized by reliance on petroleum, polluting emissions, traffic congestion and suburban sprawl, planners encourage mixed use, densely populated areas that provide individuals with opportunities to live, work, eat and shop without necessarily having to drive private automobiles to accommodate their needs. Despite these attempts, the frequency and duration of automobile trips has consistently increased in the United States throughout past decades. While many studies have focused on how residential proximity to transit influences travel behavior, the effect of workplace location has largely been ignored. This paper asks, does working near a TOD influence the travel behaviors of workers differently than workers living near a TOD? We examine the non-work travel behaviors of workers based upon their commuting mode and proximity to TODs. The data came from a 2009 travel behavior survey by the Denver Regional Council of Governments, which contains 8,000 households, 16,000 individuals, and nearly 80,000 trips. We measure sustainable travel behaviors as reduced mileage, reduced number of trips, and increased use of non-automobile transportation. The results of this study indicate that closer proximity of both households and workplaces to TODs decrease levels of car commuting and that non-car commuting leads to more sustainable personal travel behaviors characterized by more trips made with alternative modes.

Utilizing Evidence-Based Psychology Practice in the University of Denver's Professional Psychology Center: A Proposal

As acceptance of the Evidence-based Psychology Practice (EBPP) model continues to grow (Pagoto, Spring, Coups, Mulvaney, Coutu, & Ozakinci, 2007), it seems pertinent to explore how this model can be applied in different settings. This topic is timely as practitioners in the field are being held ever more accountable for the efficacy of the treatments they employ (Pagoto et al., 2007). Increased scrutiny has resulted in a need to integrate research into practice in order to ensure continued relevance in the ever-changing realm of American health care (Luebbe, Radcliffe, Callands, Green & Thorn, 2007; Collins, Leffingwell & Belar, 2007; Chwalisz, 2003). This paper explores how the requirements set forth by the American Psychological Association Presidential Task Force on Evidence-Based Practice (2006) can be implemented at the University of Denver's (DU) Professional Psychology Center (PPC), a training clinic for students enrolled in the Psy.D. program at DU's Graduate School of Professional Psychology (GSPP). In doing so, the methods employed by Collins et al. (2007) at Oklahoma State University (OSU) are used as a template and modified to accommodate differences between these two institutions.

A Fair Day's Wages: Liberty, Legality, and Liability Among Denver's Day Laborers

Day laborers occupy an essential position in Denver’s booming construction industry. Day laborers make up a highly flexible, highly effective workforce able to respond to market changes. For day laborers, informal day-labor gathering points provide increased control over working hours and employee-employer relationships when compared to traditional wage labor. Still, recent legislation and policies around irregular migration has forced large numbers of workers who may have benefited from the stability of full-time regular employment into the informal sector. The day laborers’ flexibility also exposes them to employers constantly inventing ways to deny them the wages and benefits they are owed. Despite changes in Colorado law in attempts to strengthen workers’ recourse against their employers, and despite social and individual tactics day laborers employ to mitigate their vulnerability, systematic structural, symbolic, and everyday violence continue to advantage employers.

Issues of patronage : the Denver Civic Center sculptures

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