NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 9: Information intermediaries and the transfer of aerospace Scientific and Technical Information (STI): A report from the field

From the NASA/DOD survey data, there can be no way of inferring what strategy for knowledge transfer is best; indeed, given the fact that the respondents were all presumably well qualified professionals, the data tend to call into serious question the idea that any one model might meet the needs of more than a distinct minority of possible users. The evidence to date appears to reinforce the concept that different information environments take many different shapes, and interact with each other and with formal data transmission sources in many different and equally valuable ways. Any overall strategy for improving the effectiveness and efficiency of scientific and technical information sharing must take this divergence into account, and work toward the creation of systems that reinforce true interactive knowledge utilization rather than simply disseminating data

A review and evaluation of the Langley Research Center's Scientific and Technical Information Program: Results of phase 6: The technical report. A survey and analysis

Current practice and usage using selected technical reports; literature relative to the sequential, language, and presentation components of technical reports; and NASA technical report publications standards are discussed. The effctiveness of the technical report as a product for information dissemination is considered

Travelling-waves consistent with turbulence-driven secondary flow in a square duct

We present numerically determined travelling-wave solutions for pressure-driven flow through a straight duct with a square cross-section. This family of solutions represents typical coherent structures (a staggered array of counter-rotating streamwise vortices and an associated low-speed streak) on each wall. Their streamwise average flow in the cross-sectional plane corresponds to an eight vortex pattern much alike the secondary flow found in the turbulent regime

Agronomic and environmental impacts of a single application of heat-dried sludge on an Alfisol

A field experiment was conducted on Alfisols in South-West France to assess the agronomic and environmental impacts of a single application of heat-dried sludge pellets at 11.1 Mg dry matter ha-1. The sludge pellets, with a moisture level of 9.5%, were spread on an irrigated crop of maize (Zea mays L.). This treatment was compared with inorganic fertilization (urea and diammonium phosphate mixed with KCl). Soil properties, yield and the composition of maize and the quality of drained water were monitored over 1 year to detect any changes resulting from sludge application. Amongst several determined soil properties, only two were significantly modified by the sludge application: The nitric nitrogen stock of the soil was higher in the inorganic fertilized plot, whereas Olsen-P soil content was higher in the sludge-amended plot. Agronomic recovery rates of N and P added by sludge were high: For the first crop following application, total amounts of N and P supplied by the sludge had the same efficiency as approximately 45% of the N and P amounts supplied by inorganic fertilizer. This ratio was 7% for the N uptake by the second maize crop. The quality and quantity of maize were equally good with both types of fertilization. During the 2 years following sludge spreading, N leaching remained as low in the sludged plot as in the inorganically fertilized one. The Cu, Zn, Cr, Cd, Pb and Ni composition of the drainage water was affected by neither of the types of amendment. From the heavy-metal contents of the soil, water and maize monitored over 1 year in the field experiment and from literature data for cow manure and atmospheric emissions, a theoretical balance between crop soil heavy-metal input and output over one century was drawn up. The long-term impact of cow manure on Zn, Ni and Cr in soil is higher than that of the studied heat-dried sludge. Obviously, sludge tended to cause a strong increase in soil Cu storage, valued for these soils, which are otherwise very Cu deficient

Environmental/occupational exposure to radon and non-pulmonary neoplasm risk: A review of epidemiologic evidence

Although Radon (Rn) is a known agent for lung cancer, the link between Rn exposure and other non-pulmonary neoplasms remains unclear. The aim of this review is to investigate the role of Rn in the development of tumors other than lung cancer in both occupational and environmental exposure. Particularly, our attention has been focused on leukemia and tumors related to brain and central nervous system (CNS), skin, stomach, kidney, and breast. The epidemiologic literature has been systematically reviewed focusing on workers, general population, and pediatric population. A weak increase in leukemia risk due to Rn exposure was found, but bias and confounding factors cannot be ruled out. The results of studies conducted on stomach cancer are mixed, although with some prevalence for a positive association with Rn exposure. In the case of brain and CNS cancer and skin cancer, results are inconclusive, while no association was found for breast and kidney cancers. Overall, the available evidence does not support a conclusion that a causal association has been established between Rn exposure and the risk of other non-pulmonary neoplasms mainly due to the limited number and heterogeneity of existing studies. To confirm this result, a statistical analysis should be necessary, even if it is now not applicable for the few studies available

Development of a continuous-flow anaerobic co-digestion process of olive mill wastewater and municipal sewage sludge

BACKGROUND: Olive mill wastewater (OMW) represents an environmental problem due to its high organic load and relevant concentration of phenolic compounds (PCs). OMW treatment and disposal represents a relevant challenge and cost for olive mills and multi-utilities in charge of waste management in Mediterranean countries. The goal of this study was to develop an anaerobic co-digestion (co-AD) process of OMW and sewage sludge (SwS) from municipal wastewater treatment. RESULTS: Different volumetric OMW:SwS ratios up to 100% OMW were fed in continuous 1.7-L bioreactors. The reactors fed with raw OMW (rOMW) performed better than those fed with OMW dephenolized by adsorption (dOMW). At a 23-day hydraulic retention time, the best performances were obtained in the reactor fed with 25% rOMW, with a 105% increase in methane yield in comparison to the 100% SwS test. At a 40-day hydraulic retention time, the reactor fed with 40% rOMW attained a 268 NLCH4/kgvolatile solids methane yield. The conversion of phenolic compoundsreached 70% when the hydraulic retention time was increased from 23 to 40 days. A cost\u2013benefit analysis indicated that both rOMW co-AD in existing digesters and phenolic compounds recovery from OMW followed by co-AD of dOMW can lead to relevant additional revenues for the multi-utilities in charge of wastewater management. CONCLUSION: This work proves that, using the existing network of SwS anaerobic digesters, it is feasible to co-digest the entire OMW production in regions characterized by intense olive oil production, thus attaining a relevant increase in methane production yield (a 144% increase in comparison to 100% SwS)

Continuous flow adsorption of phenolic compounds from olive mill wastewater with resin XAD16N: life cycle assessment, cost\u2013benefit analysis and process optimization

BACKGROUND: Olive mill wastewaters (OMWs) represent a major environmental concern due to their high organic load and phytotoxic activity. The selective recovery of phenolic compounds (PCs) from OMW is promising, thanks to the antioxidant and antimicrobial properties of PCs. The goal of this work was to perform a life cycle assessment (LCA) and cost\u2013benefit analysis (CBA) of a full-scale process of PC adsorption/desorption on resin Amberlite XAD16N. The industrial process was designed on the basis of laboratory tests aimed at performing a preliminary process optimization. RESULTS: Adsorption tests were conducted at different velocities in a 1.8-m column packed with XAD16N. The optimal superficial velocity and retention time (2.78 m h \u20131 and 0.56 h) allowed the attainment of satisfactory performances in terms of resin operating capacity (0.46), PC adsorption yield (0.92), PC mass fraction in the sorbed product (0.50 g PC /g VS ) and specific antioxidant activity (3\u20136 g ascorbic acid /g PC ). Six consecutive adsorption/desorption cycles, operated with the same resin load, resulted in stable process performances. The LCA indicated that the environmental impact of the process could be decreased markedly through the addition of an anaerobic digestion step for the production of irrigation-quality water and fertilizers from the dephenolized OMW. The PC market price required for the generation of a positive business case resulted relatively low (\u20ac1.7\u201313.5 kg PC\u20131 ). CONCLUSION: The results indicate that the proposed PC adsorption/desorption technology, if integrated with an anaerobic digestion step, represents a promising solution for the treatment and valorization of OMW, a major agro-industrial waste in Mediterranean countries

CFD Simulations of Single- and Twin-Screw Machines with OpenFOAM

Over the last decade, Computational Fluid Dynamics (CFD) has been increasingly applied for the design and analysis of positive displacement machines employed in vapor compression and power generation applications. Particularly, single-screw and twin-screw machines have received attention from the researchers, leading to the development and application of increasingly efficient techniques for their numerical simulation. Modeling the operation of such machines including the dynamics of the compression (or expansion) process and the deforming working chambers is particularly challenging. The relative motion of the rotors and the variation of the gaps during machine operation are a few of the major numerical challenges towards the implementation of reliable CFD models. Moreover, evaluating the thermophysical properties of real gases represents an additional challenge to be addressed. Special care must be given to defining equation of states or generating tables and computing the thermodynamic properties. Among several CFD suite available, the open-source OpenFOAM tool OpenFOAM, is regarded as a reliable and accurate software for carrying out CFD analyses. In this paper, the dynamic meshing techniques available within the software as well as new libraries implemented for expanding the functionalities of the software are presented. The simulation of both a single-screw and a twin-screw machine is described and results are discussed. Specifically, for the single-screw expander case, the geometry will be released as open-access for the entire community. Besides, the real gas modeling possibilities implemented in the software will be described and the CoolProp thermophysical library integration will be presented

Full 3D numerical analysis of a twin screw compressor by employing open-source software

The push for having more reliable and efficient positive displacement machines (both compressors and expanders) for vapor compression and power generation (e.g., ORCs) applications has moved researchers to an always more spread employment of computational fluid dynamics (CFD). In particular, twin screw compressors, because of their high efficiency compared to other compressor types, have received interest over the last years. The numerical analysis of such machines is challenging: the deforming working chambers are very difficult to be correctly replicated. The relative motion of the rotors and the variation of the gaps during machine operation are few of the major difficulties in implementing reliable CFD models. A custom mesh generation algorithm is therefore often required for sumulating the machine operation. In this work, SCORG-V5.2.2 was used to generate the meshes of the deforming domain around rotating parts of the machines. The open-source software OpenFOAM-v1606+ is then employed to compute the flow field associated with the operation of the twin screw. The coupling of the two tools has been carried out in this work, applying the methodology to a twin screw machine

Insulin Sensitivity and Secretion in Arab Americans with Glucose Intolerance

Background: This study examined the pathophysiological abnormalities in Arab Americans with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Subjects and Methods: Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of insulin secretion (HOMA-%?), and the Matsuda Insulin Sensitivity Index composite (ISIcomposite) were calculated from the fasting and stimulated glucose and insulin concentrations measured during the oral glucose tolerance test in a population-based, representative, cross-sectional sample of randomly selected Arab Americans. Results: In total, 497 individuals (42±14 years old; 40% males; body mass index [BMI], 29±6?kg/m2) were studied. Multivariate linear regression models were performed to compare HOMA-IR, HOMA-%?, and ISIcomposite among individuals with normal glucose tolerance (NGT) (n=191) versus isolated IFG (n=136), isolated IGT (n=22), combined IFG/IGT (n=43), and diabetes (n=105). Compared with individuals with NGT (2.9±1.6), HOMA-IR progressively increased in individuals with isolated IFG (4.8±2.7, P<0.001), combined IFG/IGT (6.0±4.3, P<0.001), and diabetes (9.7±8.3, P<0.001) but not in those with isolated IGT (3.0±1.7, P=0.87). After adjustment for sex and BMI, these associations remained unchanged. Whole-body insulin sensitivity as measured by ISIcomposite was significantly lower in individuals with isolated IFG (3.9±2.3, P<0.001), isolated IGT (2.8±1.5, P<0.001), combined IFG/IGT (1.9±1.1, P<0.001), and diabetes (1.6±1.1, P<0.001) compared with those with NGT (6.1±3.5). HOMA-%? was significantly lower in diabetes (113.7±124.9, P<0.001) compared with NGT (161.3±92.0). After adjustment for age, sex, and BMI, isolated IFG (146.6±80.2) was also significantly associated with a decline in HOMA-%? relative to NGT (P=0.005). Conclusions: This study suggests that differences in the underlying metabolic defects leading to diabetes in Arab Americans with IFG and/or IGT exist and may require different strategies for the prevention of diabetes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140352/1/dia.2013.0045.pd