JT9D performance deterioration results from a simulated aerodynamic load test

The results of testing to identify the effects of simulated aerodynamic flight loads on JT9D engine performance are presented. The test results were also used to refine previous analytical studies on the impact of aerodynamic flight loads on performance losses. To accomplish these objectives, a JT9D-7AH engine was assembled with average production clearances and new seals as well as extensive instrumentation to monitor engine performance, case temperatures, and blade tip clearance changes. A special loading device was designed and constructed to permit application of known moments and shear forces to the engine by the use of cables placed around the flight inlet. The test was conducted in the Pratt & Whitney Aircraft X-Ray Test Facility to permit the use of X-ray techniques in conjunction with laser blade tip proximity probes to monitor important engine clearance changes. Upon completion of the test program, the test engine was disassembled, and the condition of gas path parts and final clearances were documented. The test results indicate that the engine lost 1.1 percent in thrust specific fuel consumption (TSFC), as measured under sea level static conditions, due to increased operating clearances caused by simulated flight loads. This compares with 0.9 percent predicted by the analytical model and previous study efforts

Do Homebuyers Care about the 'Quality' of Natural Habitats?

We study if homebuyers in Tucson, Arizona care about the condition of natural habitats and if they have preferences between natural and manmade habitats. Using field work data we examine whether homebuyers willingness to pay is influenced by the biological condition of the neighboring riparian habitat and how homebuyers value alternative manmade green areas, specifically golf courses. We also explore the relationship between the field data and remote sensing vegetation indices. The results of a hedonic analysis of houses that sold within 0.2 miles of 51 stratified-random selected riparian survey sites in Tucson, Arizona reveals that homebuyers significantly value habitat quality and negatively value manmade park-like features. Homebuyers are willing to pay twenty percent more to live near a riparian corridor that is densely vegetated and contains more shrub and tree species, particularly species that are dependent on perennial water flow. These environmental premiums are significant, outweighing structural factors such as an additional garage or swimming pool. Likewise, proximity to a riparian habitat with low biological quality or to a golf course lowers property values.Land Economics/Use,

Application of multispectral radar and LANDSAT imagery to geologic mapping in death valley

Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quaternary alluvial and evaporite deposits in Death Valley, California. Unprocessed radar imagery revealed considerable variation in microwave backscatter, generally correlated with surface roughness. For Death Valley, LANDSAT imagery is of limited value in discriminating the Quaternary units except for alluvial units distinguishable by presence or absence of desert varnish or evaporite units whose extremely rough surfaces are strongly shadowed. In contrast, radar returns are most strongly dependent on surface roughness, a property more strongly correlated with surficial geology than is surface chemistry

The Origin of the External Basins of the Betics, Southern Spain, and Their Use in Interpreting the Orogenic History

The Betic mountain chain of Southern Spain, together with the Rif Mountains of N.W. Africa forms the western-most extension of the Alpine mountain chain in Europe. The Orogen formed as a direct result of the interaction between the African and Iberian plates which took place from the late Cretaceous onwards. The origin of the Betics is far from understood and there are several conflicting hypotheses concerning the origin of the Orogen. There are two major external basins to the Betic Orogen in Southern Spain, the Guadalquivir Basin and the Gibraltar Arc Flysch, and both provide important insights into its tectonic history. The Guadalquivir Basin lies on the northern margin of the External Zone Tertiary fold-thrust belt of the Betic Orogen and south of the Palaeozoic Iberian Meseta. It can be subdivided into structurally distinct regions, an undeformed autochthonous basin which lies to the north of a deformed allochthonous basin. The origin of the Guadalquivir Basin (previously interpreted as being the foreland basin to the Orogen) is questioned. Structured sedimentological and provenance studies demonstrate that the Guadalquivir Basin is not a foreland basin because; 1. It formed as an integral part of the destruction of the Iberian passive margin during which time thin skinned thrusting generated a basin on the northern margin of the External Zones, 2. The fill and unconformities of this basin were controlled by eustasy rather by the tectonic incursion of an orogenic wedge being driven onto the Iberian Margin, 3. The basin did not form by the downward flexure of the lithosphere in response to an orogenic load. Therefore the basin cannot be considered to be a true foreland basin. The clastic sedimentation in the Guadalquivir Basin was controlled by the emergence of the External Zone thrust sheet, during the late Miocene, which was related to the thin skinned thrusting. During this time the recycling of material, that had originally been derived from the Palaeozoic Iberian Meseta. took place. A thrusting event at the the end of the Miocene/ early Pliocene led to the destruction of the Guadalquivir Basin which was subdivided into the allochthon and autochthon seen today. The Gibraltar Arc flysch nappes link the External Rif of North Africa to the External Zone of Southern Spain. The largest unit of the Gibraltar Arc is the Aljibe Flysch which can be subdivided into the Beneiza Flysch and Aljibe Arenites, which are Oligo-Miocene in age. The Beneiza Flysch is characterised by thin sandstones and siltstones that are interpreted to have been deposited by turbiditic currents. These pass rapidly upwards into the thick bedded and super-mature Aljibe Arenites, which are entirely dominated by water escape- structures. The contact between these two units marks a dramatic change in the depositional environment at the beginning of the Miocene. The Aljibe Flysch is interpreted as recording the development of a basin plain that became tectonically segregated at the beginning of the Miocene, at which time new and tectonically confined basins developed. Tectonic instabilities created elsewhere in the External Zone resulted in mobilisation of large amounts of sediment which was rapidly deposited in the newly created basins. The flysch units have subsequently been thrust westwards post-Lower Miocene during which time peridotites were emplaced into mid-crustal levels Consideration of the tectonic and sedimentary history of the Guadalquivir Basin and Gibraltar Arc Flysch provides an important insight into the tectonic history of the Betic Orogen. Data collected during the study of these basins, combined with important new published data from the Alboran Sea and Ronda Peridotites, has resulted in the rejection of the widely accepted 'extensional collapse' model and in the identification of strike-slip tectonism and transcurrent movements as the main mechanism for the building of the Betic Orogen. Miocene transcurrent movements in the Betic area resulted in the break up the Iberian passive margin, the emplacement of metamorphic terranes and in the formation of thrusts in the Gibraltar Arc through a complicated history of transtension and transpression in the region of the Alboran sea

Predictors of Arterial Stiffness in Law Enforcement Officers

Background: Compare arterial stiffness among law enforcement officers (LEOs) versus general population normative values and identify predictors of arterial stiffness in LEOs. Methods: Seventy male LEOs (age: 24–54 years) completed body composition, blood pressures, physical activity level, and carotid-femoral pulse wave velocity (cfPWV) measurements. T-tests and regression analyses were utilized to compare LEO data to normative data and predict cfPWV, respectively. Results: Compared to similar age strata within the general population, cfPWV was lower among LEO’s under 30-years (mean difference = −0.6 m·s−1), but higher among LEOs 50–55-years (mean difference = 1.1 m·s−1). Utilizing regression, age, relative body fat, and diastolic blood pressure explained the greatest variance in LEO’s cfPWV (adj. R2 = 0.56, p \u3c 0.001). Conclusion: This investigation demonstrated that arterial stiffness may progress more rapidly in LEOs and LEOs’ relative body fat and blood pressure may primarily affect arterial stiffness and risk of CVD

The persistence of a chlorophyll spectral biosignature from Martian evaporite and spring analogues under Mars-like conditions

Spring and evaporite deposits are considered two of the most promising environments for past habitability on Mars and preservation of biosignatures. Manitoba, Canada hosts the East German Creek (EGC) hypersaline spring complex, and the post impact evaporite gypsum beds of the Lake St. Martin (LSM) impact. The EGC complex has microbial mats, sediments, algae and biofabrics, while endolithic communities are ubiquitous in the LSM gypsum beds. These communities are spectrally detectable based largely on the presence of a chlorophyll absorption band at 670 nm; however, the robustness of this feature under Martian surface conditions was unclear. Biological and biology-bearing samples from EGC and LSM were exposed to conditions similar to the surface of present day Mars (high UV flux, 100 mbar, anoxic, CO_2 rich) for up to 44 days, and preservation of the 670 nm chlorophyll feature and chlorophyll red-edge was observed. A decrease in band depth of the 670 nm band ranging from ∼16 to 80% resulted, with correlations seen in the degree of preservation and the spatial proximity of samples to the spring mound and mineral shielding effects. The spectra were deconvolved to Mars Exploration Rover (MER) Pancam and Mars Science Laboratory (MSL) Mastcam science filter bandpasses to investigate the detectability of the 670 nm feature and to compare with common mineral features. The red-edge and 670 nm feature associated with chlorophyll can be distinguished from the spectra of minerals with features below ∼1000 nm, such as hematite and jarosite. However, distinguishing goethite from samples with the chlorophyll feature is more problematic, and quantitative interpretation using band depth data makes little distinction between iron oxyhydroxides and the 670 nm chlorophyll feature. The chlorophyll spectral feature is observable in both Pancam and Mastcam, and we propose that of the proposed EXOMARS Pancam filters, the PHYLL filter is best suited for its detection

Polymer-coated bioactive glass S53P4 increases VEGF and TNF expression in an induced membrane model in vivo

The two-stage induced-membrane technique for treatment of large bone defects has become popular among orthopedic surgeons. In the first operation, the bone defect is filled with poly(methyl methacrylate) (PMMA), which is intended to produce a membrane around the implant. In the second operation, PMMA is replaced with autograft or allograft bone. Bioactive glasses (BAGs) are bone substitutes with bone-stimulating and angiogenetic properties. The aim of our study was to evaluate the inductive vascular capacity of BAG-S53P4 and poly(lactide-co-glycolide) (PLGA)-coated BAG-S53P4 for potential use as bone substitutes in a single-stage induced-membrane technique. Sintered porous rods of BAG-S53P4, PLGA-coated BAG-S53P4 and PMMA were implanted in the femur of 36 rabbits for 2, 4 and 8 weeks. The expression of vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF) in the induced membranes of implanted materials was analyzed with real-time quantitative polymerase chain reaction and compared with histology. Both uncoated BAG-S53P4 and PLGA-coated BAG-S53P4 increase expression of VEGF and TNF, resulting in higher amounts of capillary beds, compared with the lower expression of VEGF and less capillary beads observed for negative control and PMMA samples. A significantly higher expression of VEGF was observed for PLGA-coated BAG-S53P4 than for PMMA at 8 weeks (p <0.036). VEGF and TNF expression in the induced membrane of BAG-S53P4 and PLGA-coated BAG-S53P4 is equal or superior to PMMA, the "gold standard" material used in the induced-membrane technique. Furthermore, the VEGF and TNF expression for PLGA-coated BAG-S53P4 increased during follow-up.Peer reviewe

Presence of pathogenic Escherichia coli is correlated with bacterial community diversity and composition on pre-harvest cattle hides

Citation: Chopyk, J., Moore, R. M., DiSpirito, Z., Stromberg, Z. R., Lewis, G. L., Renter, D. G., . . . Wommack, K. E. (2016). Presence of pathogenic Escherichia coli is correlated with bacterial community diversity and composition on pre-harvest cattle hides. Microbiome, 4, 11. doi:10.1186/s40168-016-0155-4Background: Since 1982, specific serotypes of Shiga toxin-producing Escherichia coli (STEC) have been recognized as significant foodborne pathogens acquired from contaminated beef and, more recently, other food products. Cattle are the major reservoir hosts of these organisms, and while there have been advancements in food safety practices and industry standards, STEC still remains prevalent within beef cattle operations with cattle hides implicated as major sources of carcass contamination. To investigate whether the composition of hide-specific microbial communities are associated with STEC prevalence, 16S ribosomal RNA (rRNA) bacterial community profiles were obtained from hide and fecal samples collected from a large commercial feedlot over a 3-month period. These community data were examined amidst an extensive collection of prevalence data on a subgroup of STEC that cause illness in humans, referred to as enterohemorrhagic E. coli (EHEC). Fecal 16S rRNA gene OTUs (operational taxonomic units) were subtracted from the OTUs found within each hide 16S rRNA amplicon library to identify hide-specific bacterial populations. Results: Comparative analysis of alpha diversity revealed a significant correlation between low bacterial diversity and samples positive for the presence of E. coli O157:H7 and/or the non-O157 groups: O26, O111, O103, O121, O45, and O145. This trend occurred regardless of diversity metric or fecal OTU presence. The number of EHEC serogroups present in the samples had a compounding effect on the inverse relationship between pathogen presence and bacterial diversity. Beta diversity data showed differences in bacterial community composition between samples containing O157 and non-O157 populations, with certain OTUs demonstrating significant changes in relative abundance. Conclusions: The cumulative prevalence of the targeted EHEC serogroups was correlated with low bacterial community diversity on pre-harvest cattle hides. Understanding the relationship between indigenous hide bacterial communities and populations may provide strategies to limit EHEC in cattle and provide biomarkers for EHEC risk assessment

System design and implementation for the glass panel alignment and sealing tool for flat panel displays

This report describes the system designed and fabricated for the National Center for Advanced Information Component Manufacturing (NCAICM) project number 9322-135. The system is a device capable of simultaneously aligning two glass plates and sealing them together with glass frit. The process development was divided into two phases. The first was thermal sealing in an ambient environment. The second was sealing a controlled environment in a vacuum