280 research outputs found

    Ionospheric refraction effects on orbit determination using the orbit determination error analysis system

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    The influence of ionospheric refraction on orbit determination was studied through the use of the Orbit Determination Error Analysis System (ODEAS). The results of a study of the orbital state estimate errors due to the ionospheric refraction corrections, particularly for measurements involving spacecraft-to-spacecraft tracking links, are presented. In current operational practice at the Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF), the ionospheric refraction effects on the tracking measurements are modeled in the Goddard Trajectory Determination System (GTDS) using the Bent ionospheric model. While GTDS has the capability of incorporating the ionospheric refraction effects for measurements involving ground-to-spacecraft tracking links, such as those generated by the Ground Spaceflight Tracking and Data Network (GSTDN), it does not have the capability to incorporate the refraction effects for spacecraft-to-spacecraft tracking links for measurements generated by the Tracking and Data Relay Satellite System (TDRSS). The lack of this particular capability in GTDS raised some concern about the achievable accuracy of the estimated orbit for certain classes of spacecraft missions that require high-precision orbits. Using an enhanced research version of GTDS, some efforts have already been made to assess the importance of the spacecraft-to-spacecraft ionospheric refraction corrections in an orbit determination process. While these studies were performed using simulated data or real tracking data in definitive orbit determination modes, the study results presented here were obtained by means of covariance analysis simulating the weighted least-squares method used in orbit determination

    Film Blowing of Biodegradable Polymer Nanocomposites for Agricultural Applications

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    Films for agricultural applications, such as greenhouses films or mulching films are generally made of polyolefins such as linear low-density polyethylene (LLDPE) or low-density polyethylene. However, the use of biodegradable and/or compostable polymers is increasing, which enjoy the additional advantage that they can be left on the site since a fine life would be gradually assimilated to the underlying soil. Nevertheless, biodegradable polymeric films often do not have suitable mechanical performances. In this work, biodegradable polymer-based nanocomposite films are prepared by film blowing and compared with traditional LLDPE based nanocomposites. In particular, a biodegradable polymer blend and two different inorganic nanofillers (an organo-modified clay and a calcium carbonate with a hydrophobic coating) are used for the preparation of the nanocomposites. A detailed investigation of obtained materials is performed through rheological, mechanical, and optical characterizations. Adding nanofillers led to an increase of rigidity and tear strength of blown films without negatively affecting their ductility

    Life cycle inventory data for the Italian agri-food sector: background, sources and methodological aspects

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    Purpose: For the development of any life cycle assessment study, the practitioner frequently integrates primary data collected on-field, with background data taken from various life cycle inventory databases which are part of most commercial LCA software packages. However, such data is often not generally applicable to all product systems since, especially concerning the agri-food sector, available datasets may not be fully representative of the site specificity of the food product under examination. In this context, the present work investigates the background, sources and methodological aspects that characterise the most known commercial databases containing agri-food data, with a focus on four agri-food supply chains (olive oil, wine, wheat products and citrus fruit), which represent an important asset for the Italian food sector. Methods: Specifically, the paper entails a review of currently available LCI databases and their datasets with a twofold scope: firstly, to understand how agri-food data is modelled in these databases for a coherent and consistent representation of regional scenarios and to verify whether they are also suitable for the Italian context and, secondly, to identify and analyse useful and relevant methodological approaches implemented in the existing LCI databases when regional data are modelled. Results: Based on the aforementioned review, it is possible to highlight some problems which may arise when developing an LCI pertaining to the four Italian agri-food supply chains, namely: 1. The need for specific inventory datasets to tackle the specificities of agri-food product systems. 2. The lack of datasets, within the existing DBs, related to the Italian context and to the abovementioned supply chains. In fact, at present, in the currently available LCI DBs, there are very few (or in some cases none) datasets related to Italian wine, olive oil, wheat-based products and citrus fruit. The few available datasets often contain some data related to the Italian context but also approximate data with that of product systems representing other countries. Furthermore, the present study allowed to identify and discuss the main aspects to be used as starting elements for modelling regional data to be included in a future Italian LCI database of the abovementioned four supply chains. Conclusions: The results of the present study represent a starting point for the collection of data and its organisation, in order to develop an Italian LCI agri-food database with datasets which are representative of the regional specificities of four agri-food supply chains which play an important role in the Italian economy

    Life cycle inventory data for the Italian agri-food sector: background, sources and methodological aspects

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    AbstractPurposeFor the development of any life cycle assessment study, the practitioner frequently integrates primary data collected on-field, with background data taken from various life cycle inventory databases which are part of most commercial LCA software packages. However, such data is often not generally applicable to all product systems since, especially concerning the agri-food sector, available datasets may not be fully representative of the site specificity of the food product under examination. In this context, the present work investigates the background, sources and methodological aspects that characterise the most known commercial databases containing agri-food data, with a focus on four agri-food supply chains (olive oil, wine, wheat products and citrus fruit), which represent an important asset for the Italian food sector.MethodsSpecifically, the paper entails a review of currently available LCI databases and their datasets with a twofold scope: firstly, to understand how agri-food data is modelled in these databases for a coherent and consistent representation of regional scenarios and to verify whether they are also suitable for the Italian context and, secondly, to identify and analyse useful and relevant methodological approaches implemented in the existing LCI databases when regional data are modelled.ResultsBased on the aforementioned review, it is possible to highlight some problems which may arise when developing an LCI pertaining to the four Italian agri-food supply chains, namely:1. The need for specific inventory datasets to tackle the specificities of agri-food product systems.2. The lack of datasets, within the existing DBs, related to the Italian context and to the abovementioned supply chains. In fact, at present, in the currently available LCI DBs, there are very few (or in some cases none) datasets related to Italian wine, olive oil, wheat-based products and citrus fruit. The few available datasets often contain some data related to the Italian context but also approximate data with that of product systems representing other countries.Furthermore, the present study allowed to identify and discuss the main aspects to be used as starting elements for modelling regional data to be included in a future Italian LCI database of the abovementioned four supply chains.ConclusionsThe results of the present study represent a starting point for the collection of data and its organisation, in order to develop an Italian LCI agri-food database with datasets which are representative of the regional specificities of four agri-food supply chains which play an important role in the Italian economy

    Transganglionic transport of HRP from the circumvallate papilla of the rat

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    To learn whether horseradish peroxidase (HRP) injections in gustatory papillae on the tongue can be used to study central topographical projections of taste buds and papillae, injections were made into the circumvallate papilla in rats. Labeled central projections after papilla injections were compared to projections after applying HRP to the cut glossopharyngeal nerve. Papilla injections result in HRP transport by afferent and efferent fibers of the glossopharyngeal nerve, and the pattern of central projections is similar to that after labeling the cut nerve. Projections include a separation in the brainstem of afferent, dorsally located fibers and efferent, ventrally located fibers. Afferent fibers project to the solitary nucleus and the trigeminal system. Efferent projections label muscle motorneurons in the nucleus ambiguus and the cells of origin of parasympathetic preganglionic fibers, which form the inferior salivatory nucleus. The parasympathetic neurons labeled after papilla projections are preganglionic fibers to Remak's ganglia in the tongue; postganglionic fibers of these ganglia are the secretomotor supply to the von Ebner's glands. In summary, injections of HRP into gustatory papillae reliably label central projections of the papilla and can be used for studies to discern topography in central projections of the taste system. Injections into the circumvallate papilla also have demonstrated that the parasympathetic neurons innervating von Ebner's glands are located in the inferior salivatory nucleus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25463/1/0000001.pd

    PHIL photoinjector test line

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    LAL is now equiped with its own platform for photoinjectors tests and Research and Developement, named PHIL (PHotoInjectors at LAL). This facility has two main purposes: push the limits of the photoinjectors performances working on both the design and the associated technology and provide a low energy (MeV) short pulses (ps) electron beam for the interested users. Another very important goal of this machine will be to provide an opportunity to form accelerator physics students, working in a high technology environment. To achieve this goal a test line was realised equipped with an RF source, magnets and beam diagnostics. In this article we will desrcibe the PHIL beamline and its characteristics together with the description of the first two photoinjector realised in LAL and tested: the ALPHAX and the PHIN RF Guns

    Impact of Age on Outcomes of Patients With Pure Carcinoma In Situ of the Bladder: Multi-Institutional Cohort Analysis

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    Introduction: The aim of this multicenter study was to investigate the role of age (cut-off 70 years) at diagnosis in predicting oncologic behavior of pure carcinoma in situ of the bladder. Material and methods: Inclusion criteria were: patients with pure CIS confirmed and that followed intravesical BCG treatment. Pure CIS was defined at any CIS not associated with another urothelial cancer. Exclusion criteria were: any CIS associated with invasive urothelial carcinoma. A total of 172 with pure CIS treated between January 1, 2002 and December 31, 2012 at 8 academic institutions met the inclusion criteria. The maintenance schedule was generally according to the EAU guidelines at the time RESULTS: A total of 99 (57.6%) patients had an age >70 years prior to TURBT. There was no difference between clinico-pathologic features among groups (group 1, age ≤ 70 years and group 2, age > 70 years), except that patients aged ≤ 70 years presented a larger size of CIS (35.6% vs. 21.2%), P = .02. In multivariable Cox regression analyses, the same clinico-pathologic factors (age, multifocality, and recurrent tumor state) were independently associated with worse RFS. Harrell's C-index was 65.75.In multivariable Cox regression analyses in addition to age (P = .006) and multifocality (P < .001) also BMI (P = .04) was independently associated with worse PFS. Harrell's C-index was 74.71 CONCLUSION: Advanced age at diagnosis appears to be associated with an increased risk of recurrence and progression of pure carcinoma in situ of the bladder. Elderly patients might fail to respond to BCG therapy

    Impact of Age on Outcomes of Patients With Pure Carcinoma In Situ of the Bladder: Multi-Institutional Cohort Analysis

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    Introduction: The aim of this multicenter study was to investigate the role of age (cut-off 70 years) at diagnosis in predicting oncologic behavior of pure carcinoma in situ of the bladder. Material and Methods: Inclusion criteria were: patients with pure CIS confirmed and that followed intravesical BCG treatment. Pure CIS was defined at any CIS not associated with another urothelial cancer. Exclusion criteria were: any CIS associated with invasive urothelial carcinoma. A total of 172 with pure CIS treated between January 1, 2002 and December 31, 2012 at 8 academic institutions met the inclusion criteria. The maintenance schedule was generally according to the EAU guidelines at the time Results: A total of 99 (57.6%) patients had an age >70 years prior to TURBT. There was no difference between clinico-pathologic features among groups (group 1, age ≤ 70 years and group 2, age > 70 years), except that patients aged ≤ 70 years presented a larger size of CIS (35.6% vs. 21.2%), P =.02. In multivariable Cox regression analyses, the same clinico-pathologic factors (age, multifocality, and recurrent tumor state) were independently associated with worse RFS. Harrell's C-index was 65.75.In multivariable Cox regression analyses in addition to age (P =.006) and multifocality (P <.001) also BMI (P =.04) was independently associated with worse PFS. Harrell's C-index was 74.71 Conclusion: Advanced age at diagnosis appears to be associated with an increased risk of recurrence and progression of pure carcinoma in situ of the bladder. Elderly patients might fail to respond to BCG therapy
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