High performance alloy electroforming

Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718

Methanol:Association behaviour, third-law entropy analysis and determination of the enthalpy of formation

Chemical equilibrium constants for the methanol from CO/H 2 reaction calculated from literature ther- modynamic parameters are too high as compared to experimental results. Therefore, both the entropy value and the enthalpy of formation value of methanol were reviewed. A rigorous analysis of the associa- tion behaviour of methanol vapour confirms that dimers and cyclic tetramers play an important role, but physical non-ideal gas behaviour must also be taken into account. Accurate relationships for the asso- ciation equilibrium constants and the physical contribution to the second virial coefficient were derived with the use of a combined fit of multiple experimental data sources including heat capacity, speed of sound, thermal conductivity, excess molar enthalpy of methanol and nitrogen and heat of vaporization. Additionally, high temperature second virial coefficients and measures for the consistent temperature de- pendencies of the entropy and enthalpy of formation were included in the parameter optimization to support the accuracy of the model. All experimental results and supporting data were taken or derived from the literature. The resulting virial equation of state was used to calculate new ideal-gas entropy and enthalpy of formation values of methanol, which now turn out to be consistent with values derived from experimental chemical equilibrium data. Furthermore, the new third-law entropy value turns out to be consistent with the current literature value. A new enthalpy of formation value is recommended and an improved chemical equilibrium relationship for the methanol from CO/H 2 reaction is presented

Citizenship Education and American Nationalism

Scholars typically think of the United States as an example of civic nationalism, a relatively inclusive nation that is held together by a shared commitment to the civic principles of freedom, equality and toleration. I argue to the contrary, that the American nation is a culturally particular nation whose citizens must conform to more than belief in those principles. To make this case, I examine the process by which non-Americans are assimilated and educated for citizenship, reviewing citizenship education materials— manuals, handbooks and textbooks—from three periods of particularly intense nationalism from the early twentieth century to today. Through this review, I show that citizenship in the United States has historically meant assuming a much more comprehensive identity than the one a civic nationalist account of the American nation might suggest

A Working Democracy: Progressivism and the Politics of Work

This study is an interpretation of the democratic thought of the Progresive-era United States, focusing on the role of work in the writings of Jane Addams, Herbert Croly, and John Dewey. Many other thinkers of the period turned their attention to questions of work, but Addams, Croly, and Dewey played public roles that made them uniquely influential. This study is a close reading of the work of these three Progressive thinkers. It focuses exclusively on their writings that bridge the nineteenth and twentieth centuries, identifying the period between the Pullman Strike of 1894 and World War I as a critical juncture in the development of their thought. Relying on a close reading of their academic writings, periodical pieces, public addresses and social commentary, the analysis critically examines themes of labor, occupation, and vocation, using the writers' own words to illustrate and interpret not only what they thought about work, but also how central it was to how they thought about democracy

Relationships Between Traits Other Than Production and Longevity in New Zealand Dairy Cows

Reduced longevity in dairy cattle is recognised world-wide to be a considerable cost to the dairy industry, especially in seasonal calving grazing production environments. The objective of the present study was to investigate the relationships among traits other than production (TOP) and true and functional longevity in purebred and crossbred New Zealand cows from commercial herds operating seasonal calving grass-based systems of milk production. This study made use of survival analysis, a technique used to allow the inclusion of incomplete (i.e., censored) longevity data in the analysis while simultaneously accounting for the skewed distribution of longevity data and the changing environmental and genetic effects over time

Nutritional Rehabilitation: Practical Guidelines for Refeeding the Anorectic Patient

Weight restoration is crucial for successful treatment of anorexia nervosa. Without it, patients may face serious or even fatal medical complications of severe starvation. However, the process of nutritional rehabilitation can also be risky to the patient. The refeeding syndrome, a problem of electrolyte and fluid shifts, can cause permanent disability or even death. It is essential to identify at-risk patients, to monitor them carefully, and to initiate a nutritional rehabilitation program that aims to avoid the refeeding syndrome. A judicious, slow initiation of caloric intake, requires daily management to respond to entities such as liver inflammation and hypoglycemia that can complicate the body's conversion from a catabolic to an anabolic state. In addition, nutritional rehabilitation should take into account clinical characteristics unique to these patients, such as gastroparesis and slowed colonic transit, so that measures can be taken to ameliorate the physical discomforts of weight restoration. Adjunct methods of refeeding such as the use of enteral or parenteral nutrition may play a small but important role in a select patient group who cannot tolerate oral nutritional rehabilitation alone

The effectiveness of a trauma-focused psycho-educational secondary prevention program for children exposed to interparental violence: study protocol for a randomized controlled trial

Background: Children who witness interparental violence are at a heightened risk for developing psychosocial, behavioral and cognitive problems, as well as posttraumatic stress symptoms. For these children the psycho-educational secondary prevention program 'En nu ik...!' ('It's my turn now!') has been developed. This program includes specific therapeutic factors focused on emotion awareness and expression, increasing feelings of emotional security, teaching specific coping strategies, developing a trauma narrative, improving parent-child interaction and psycho-education. The main study aim is to evaluate the effectiveness of the specific therapeutic factors in the program. A secondary objective is to study mediating and moderating factors. Methods/design: This study is a prospective multicenter randomized controlled trial across cities in the Netherlands. Participants (N = 140) are referred to the secondary preventive intervention program by police, social work, women shelters and youth (mental health) care. Children, aged 6-12 years, and their parents, who experienced interparental violence are randomly assigned to either the intervention program or the control program. The control program is comparable on nonspecific factors by offering positive attention, positive expectations, recreation, distraction, warmth and empathy of the therapist, and social support among group participants, in ways that are similar to the intervention program. Primary outcome measures are posttraumatic stress symptoms and emotional and behavioral problems of the child. Mediators tested are the ability to differentiate and express emotions, emotional security, coping strategies, feelings of guilt and parent-child interaction. Mental health of the parent, parenting stress, disturbances in parent-child attachment, duration and severity of the domestic violence and demographics are examined for their moderating effect. Data are collected one week before the program starts (T1), and one week (T2) and six months (T3) after finishing the program. Both intention-to-treat and completer analyses will be done. Discussion: Adverse outcomes after witnessing interparental violence are highly diverse and may be explained by multiple risk factors. An important question for prevention programs is therefore to what extent a specific focus on potential psychotrauma is useful. This trial may point to several directions for optimizing public health response to children's exposure to interparental violence

Lactic Acid Extraction and Mass Transfer Characteristics in Slug Flow Capillary Microreactors

Capillary microreactors operated under the slug flow regime were investigated for the separation of lactic acid from the aqueous phase using liquid–liquid reactive extraction. The experiments were performed at a 1:1 flow ratio of the aqueous to organic phases in a setup consisting of an inlet Y-type mixer connected with a poly(tetrafluoroethylene) capillary microreactor and subsequently an outlet Y-shape phase splitter. The extraction of lactic acid (intake: 0.11 and 0.055 M in water) using 15% (v/v) tri-n-octylamine in n-octanol under ambient conditions approached equilibrium after about 90 s in microreactors without noticeable emulsion formation. The measured reactive extraction performance in microreactors can be well described by a physical mass transfer model according to the penetration theory (developed from a model experimental study for the extraction of acetanilide from water to n-octanol) combined with an instantaneous irreversible reaction assumption

A Hierarchical Hybrid Method for Screening Ionic Liquid Solvents for Extractions Exemplified by the Extractive Desulfurization Process

A hierarchical hybrid method combining experimental-database-derived estimation of extraction performance, quantitative structure-property relationship (QSPR)-based assessment of IL physical and environmental properties, liquid-liquid extraction (LLE) measurement, and process evaluation is proposed to screen practically suitable ionic liquid (IL) solvents for different extractions. From the literature, 47 424 infinite dilution activity coefficient (IDAC) data including 12 IL families (e.g., imidazolium, pyridinium, ammonium, etc.) and 13 organic families (e.g., alkanes, aromatics, alcohols, etc.) are collected. On the basis of the IDAC data, the extraction performance of ILs for a specific separation can be estimated in terms of the distribution ratio and selectivity at infinite dilution. The ILs with potentially high extraction performance and meeting the physical and environmental properties criteria are selected to perform LLE experiments. Subsequently, process simulation and evaluation using the selected IL solvents are performed by Aspen Plus. To exemplify the proposed method, the extractive desulfurization (EDS) process is taken as a case study, where [EMIM][MESO3] (1-ethyl-3-methylimidazolium methanesulfonate) and [EIM][NO3] (1-ethylimidazolium nitrate) are selected after IDAC database searching and QSPR analysis. Experimental LLE with the two ILs are determined, demonstrating their promising extraction performance with the maximum selectivity (S-23(max)) for thiophene/heptane of 420 and 281.9, respectively. By fitting the NRTL model correspondingly, two processes using the screened ILs and sulfolane are developed and compared using Aspen Plus. It turns out that the two ILs save 66% and 48% in solvent requirements and 54% and 55% in energy consumption compared to those of sulfolane for the EDS task, respectively

Impact of wastewater treatment plant effluent on the winter thermal regime of two urban Colorado South Platte tributaries

Wastewater treatment plant effluent can increase stream water temperature from near freezing to 5°C–12°C in winter months. Recent research in the South Platte River Basin in Colorado showed that this warming alters the reproductive timing of some fishes. However, the spatial extent and magnitude of this warming are unknown. Thus, we created winter water temperature models both upstream and downstream of effluent inputs for two urban tributaries of the South Platte River, the Big Thompson River, and St. Vrain Creek. We examined the influence of air temperature, discharge, effluent temperature, and distance downstream on water temperature over the winter period (December–February). The models were also used to predict water temperature in the absence of effluent and based on air temperature predictions in 2052 and 2082. Effluent temperature was the largest driver of water temperature downstream of the effluent, while the impact of air temperature was comparatively small. Streams cooled after an initially sharp temperature increase, though were still predicted to be ∼2°C greater than they would be in the absence of effluent at ∼0.5 km. Predicted air temperatures in 2052 and 2082 had a negligible effect on water temperature, suggesting that mitigating effluent temperature is key to protecting the winter thermal regimes of effluent-impacted rivers. Our models can be used to gain insight into the magnitude and downstream extent of the impact of effluent temperature on small urban streams in winter and provide a baseline for models in other watersheds and at larger scales