Modeling of primary dendrite arm spacing variations in thin-slab casting of low carbon and low alloy steels

Solidification structure of a High Strength Low Alloy (HSLA) steel, in terms of dendrite arm spacing distribution across the shell thickness, is studied in a breakout shell from a thin-slab caster at Tata Steel in IJmuiden. Columnar dendrites were found to be the predominant morphology throughout the shell with size variations across the shell thickness. Primary Dendrite Arm Spacing (PDAS) increases by increasing the distance from meniscus or slab surface. Subsequently, a model is proposed to describe the variation of the PDAS with the shell thickness (the distance from slab surface) under solidifiction conditions experienced in the primary cooling zone of thin-slab casting. The proposed relationship related the PDAS to the shell thickness and, hence, can be used as a tool for predicting solidifcation structure and optimizing the thin-slab casting of low alloy steels

Disentangling the heterogeneous income elasticity and dynamics of health expenditure.

In this article, we empirically study the impact of per capita income on health-care expenditure and its dynamics over time in a sample of 14 OECD countries for the period 1971 to 2009. A simple model, built upon one developed by Newhouse (1977), suggests that health care is a necessity in the short run but it cannot be rejected to be a luxury good in the long run. Our findings provide strong empirical evidence that a year’s health expenditure is conditioned by the previous one. Interestingly, our results reveal increasing income inelasticity over time along with huge heterogeneity across countries. Finally, this article supports the hypothesis of conditional convergence in health-care spending among countries. In designing policies which facilitate the sustainability of national health systems, we emphasize that ceteris paribus the greater the participation of public health, the lower the growth rate of health spending. High share of children and elderly over working age population opposite influences. We also provide evidence that technological progress could reduce the long-run income elasticity for health care, which in turn threaten the sustainability of health-care systems

Estrogen/Estrogen Receptor Alpha Signaling in Mouse Posterofrontal Cranial Suture Fusion

BACKGROUND: While premature suture fusion, or craniosynostosis, is a relatively common condition, the cause is often unknown. Estrogens are associated with growth plate fusion of endochondral bones. In the following study, we explore the previously unknown significance of estrogen/estrogen receptor signaling in cranial suture biology. METHODOLOGY/PRINCIPAL FINDINGS: Firstly, estrogen receptor (ER) expression was examined in physiologically fusing (posterofrontal) and patent (sagittal) mouse cranial sutures by quantitative RT-PCR. Next, the cranial suture phenotype of ER alpha and ER beta knockout (alphaERKO, betaERKO) mice was studied. Subsequently, mouse suture-derived mesenchymal cells (SMCs) were isolated; the effects of 17-beta estradiol or the estrogen antagonist Fulvestrant on gene expression, osteogenic and chondrogenic differentiation were examined in vitro. Finally, in vivo experiments were performed in which Fulvestrant was administered subcutaneously to the mouse calvaria. Results showed that increased ERalpha but not ERbeta transcript abundance temporally coincided with posterofrontal suture fusion. The alphaERKO but not betaERKO mouse exhibited delayed posterofrontal suture fusion. In vitro, addition of 17-beta estradiol enhanced both osteogenic and chondrogenic differentiation in suture-derived mesenchymal cells, effects reversible by Fulvestrant. Finally, in vivo application of Fulvestrant significantly diminished calvarial osteogenesis, inhibiting suture fusion. CONCLUSIONS/SIGNIFICANCE: Estrogen signaling through ERalpha but not ERbeta is associated with and necessary for normal mouse posterofrontal suture fusion. In vitro studies suggest that estrogens may play a role in osteoblast and/or chondrocyte differentiation within the cranial suture complex

A novel selective flue gas SO2 removal with an amine absorbent

Wet flue gas desulfurization (WFGD) is the most widespread one among all SO2 removal methods. A novel desulfurization method is presented throughout this paper in which an amine based absorber is used to reduce SO2 concentration, from 8000ppm to less than 200 ppm. In this study, the selectivity of the new desulfurization method with consideration of operational parameters such as: SO2 concentration, column pressure, temperature of absorption process and final released SO2 emission are investigated in a steady-state condition. According to the experiments, sulfur dioxide which was in range of 4000 ppm to 8000 ppm in gas mixture. and was reduced to less than 200 ppm and 1000 ppm respectively was reduced from 4000-8000ppm to an amount of less than 200 ppm in the outlet of the pilot. During the scrubbing process, SO2 absorption was performed in atmospheric pressure and a temperature between 52 to 73 degrees Celsius. influences of PH, gas to liquid ratio (G/L) and the stripper temperature at certain condition are investigated

Lower Extremity Osseous Oncologic Reconstruction with Composite Microsurgical Free Fibula Inside Massive Bony Allograft

BACKGROUND: Lower extremity reconstruction after resection of long bone tumors in children is challenging because of the unique functional demands and growth potential of the lower extremity. The use of a free fibula flap inside a massive bone allograft provides a reliable reconstructive option. The authors evaluate the surgical and functional outcomes of using this technique. METHODS: This is a retrospective review of 12 consecutive patients who underwent reconstruction of segmental femur or tibia defects using a free fibula flap inside a massive bone allograft between 2003 and 2011. Complications and functional outcomes are reported. RESULTS: Twelve patients with a mean age of 15.8 years (range, 3 to 49 years) were included in the study. Eight femur defects and four tibia defects were reconstructed. The mean follow-up time was 41.4 months. Two constructs were removed because of infection, three patients required bone grafting for nonunion, one patient required an additional operation to excise a skin paddle, and one patient experienced a lower extremity deep vein thrombosis. The mean time to achieve full weight bearing was 14.3 months. CONCLUSIONS: The use of a free fibula flap inside a massive bone allograft after bone tumor resection provides an option for lower extremity reconstruction. The allograft component increases the initial strength of the reconstruction, whereas the vascularized fibula component is thought to increase the biologic potential for osteosynthesis and ultimately provide a potentially lifelong durable reconstruction. Patients who achieve oncologic control are likely to enjoy a highly functional long-term outcome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV