Hyperspectral Satellite Remote Sensing of Aerosol Parameters: Sensitivity Analysis and Application to TROPOMI/S5P

Precise knowledge about aerosols in the lower atmosphere (optical properties and vertical distribution) is particularly important for studying the Earth’s climatic and weather conditions. Measurements from satellite sensors in sun-synchronous and geostationary orbits can be used to map distributions of aerosol parameters in global or regional scales. The new-generation sensor Tropospheric Monitoring Instrument (TROPOMI) onboard the Copernicus Sentinel-5 Precursor (S5P) measures a wide variety of atmospheric trace gases and aerosols that are associated with climate change and air quality using a number of spectral bands between the ultraviolet and the shortwave infrared. In this study, we perform a sensitivity analysis of the forward model parameters and instrument information that are associated with the retrieval accuracy of aerosol layer height (ALH) and optical depth (AOD) using the oxygen (O2) A-band. Retrieval of aerosol parameters from hyperspectral satellite measurements requires accurate surface representation and parameterization of aerosol microphysical properties and precise radiative transfer calculations. Most potential error sources arising from satellite retrievals of aerosol parameters, including uncertainties in aerosol models, surface properties, solar/satellite viewing geometry, and wavelength shift, are analyzed. The impact of surface albedo accuracy on retrieval results can be dramatic when surface albedo values are close to the critical surface albedo. An application to the real measurements of two scenes indicates that the retrieval works reasonably in terms of retrieved quantities and fit residuals.

Wnt Pathway Extracellular Components and Their Essential Roles in Bone Homeostasis

The Wnt pathway is involved in several processes essential for bone development and homeostasis. For proper functioning, the Wnt pathway is tightly regulated by numerous extracellular elements that act by both activating and inhibiting the pathway at different moments. This review aims to describe, summarize and update the findings regarding the extracellular modulators of the Wnt pathway, including co-receptors, ligands and inhibitors, in relation to bone homeostasis, with an emphasis on the animal models generated, the diseases associated with each gene and the bone processes in which each member is involved. The precise knowledge of all these elements will help us to identify possible targets that can be used as a therapeutic target for the treatment of bone diseases such as osteoporosis.

On the Solution of Generalized Banach Space Valued Equations

We develop a class of Steffensen-like schemes for approximating solution of Banach space valued equations. The sequences generated by these schemes are, converging to the solution under certain hypotheses that are weaker than in earlier studies. Hence, extending the region of applicability of these schemes without additional hypotheses. Benefits include: more choices for initial points; the computation of fewer iterates to reach a certain accuracy in the error distances, and a more precise knowledge of the solution. Technique is applicable on other schemes our due to its generality.

ROS-based Toolbox for Motor Parameter Identification of Robotic Manipulators

For many applications, a precise knowledge of the model of the robot is necessary for accurate and stable control. However, it is not always feasible or desirable to perform from scratch an in-depth study of the robot model, especially if it is not an element of concern for the respective application. In this article we present a methodology for identifying motor parameters of a robotic manipulator. We discuss the mathematical model and introduce an extensible toolbox with velocity-control based methodology for a fast identification of individual motor parameters. The results show that we can identify individual parameters even for joints that are commercialised as of the same type.

Structural Features of the Mental Foramen in a Saudi Subpopulation: A Retrospective CBCT Study

Introduction. Accurate and precise knowledge about the position, size, and shape of the mental foramen (MF) are critical in avoiding procedural complications. The MF’s anatomical features vary among different ethnic groups, and various radiographic techniques have been used to determine these variations. Aims. To evaluate the MF’s shape, vertical and horizontal positions, and distance from the border of the mandible. To evaluate the differences among genders as they pertain to the right and left sides of the mandible and research the bilateral symmetry regarding the same variables. Materials and Methods. Cone beam computer tomography (CBCT) scans of 155 Saudi patients (69 males and 86 females) who visited the college of dentistry’s clinics were obtained from the college database for this retrospective study. All the scans were analyzed by 3 calibrated examiners. The data collected was analyzed statistically, and results were obtained. Results. The MF was located under the mandibular second premolar in 56.9% of cases, whereas in 26.9% of cases, it was located between the first and second mandibular premolar. The most prevalent position was below the level of the apices of the mandibular premolar teeth (87.2%). The round shape was most frequent (44.9%) compared to the H-oval (34.7%) and V-oval (20.4%). The V-oval shape was more frequent in males, while the H-oval shape was more frequent in females. The average distance from the center of the MF to the mandibular border was 14.03 ± 1.58 mm , with males exhibiting a greater distance than females. Overall, there were no significant differences between the bilateral symmetry and the right and left sides for all parameters. Conclusion. The most common position of the MF was under the root apex of the mandibular second premolar, with an average distance of about 14 mm from the border of the mandible. The position and shape of the MF were the same bilaterally in the majority of individuals.

A Bibliometric Analysis of COVID-19 Across Economics and Business Research Landscape

The Coronavirus disease which generated the unique virus appeared first in Port city of Hubei, China at the close of 2019, which significantly changed the whole humankind around the globe. Because of it’s rapid outspread, it taken into consideration as a global issue such as health, wellness, social and economic, eventually it ended up being a significant global health as a result of its pathogenicity. In spite of an expanding rate, modest is investigated about the present state, The lack of understanding on this has motivated academic element for detailed check out, This bibliometric examined the peer scientific literary works to figure out the procedure of noesis on COVID-19, The research study is based upon bibliometric researches on Coronavirus, published data were collected from Scopus data source, quantitative assessment was carried out to evaluate the features of the present learning and generate visualizations for understanding, 668 documents were preserved. Web of writers, as well as nations were picturized in maps. However, COVID-19 search discloses special archeozoic use knowledge, spot a spaciotemporal as well as extensive introduction continues to be untended.. The precise knowledge on n-Cov is helpful for evidence-based policymakers in direction to avert and also resolve the pandemic.

Transformation Plasticity in Carbonitrided PM-Steels: Quantification of Plasticity Effects in Dependence of the Part Density*

To optimize heat treatment processes of case hardened components, heat treatment simulations are used to predict surface layer conditions. Only a precise knowledge and modelling of the transformation processes allows a trustworthy prediction of the hardness and residual stresses in the surface zone. The transformation plasticity mechanism plays an essential role in the heat treatment process and its correct simulation has a significant influence on the resulting calculated residual stress profiles and component distortion. Without considering transformation plasticity, simulative residual stresses are significantly overestimated [1]. In this work, powder metallurgical components are pressed and sintered and subsequently carbonitrided for a dilatometric investigation to characterize the correlation between transformation plasticity effect and the density. The results show a dependence of the austenite-martensite volume change that led to a significant difference of 0.5 Vol-%. A model describing the martensite volume change with respect to density is proposed. This also affects the description of the transformation plasticity constants (K) between K = 5 – 6 × 10–5 MPa–1 in dependence of density. With currently available data, the effect of chemical composition and density cannot be separated and quantified and further studies are therefore necessary to allow such a refinement.

Seismic anisotropy of Opalinus Clay: tomographic investigations using the infrastructure of an underground rock laboratory (URL)

Seismic anisotropy and attenuation make claystone formations difficult to characterize. On the other hand, in many geotechnical environments, precise knowledge of structure and elastic properties of clay formations is needed. In crystalline and rock salt underground structures, high-resolution seismic tomography and reflection imaging have proven a useful tool for structural and mechanical characterization at the scale of underground infrastructure (several deca- to hundreds of meters). This study investigates the applicability of seismic tomography for the characterization of claystone formations from an underground rock laboratory under challenging on-site conditions including anisotropy, strong attenuation and restricted acquisition geometry. The seismic tomographic survey was part of a pilot experiment in the Opalinus Clay of the Mont Terri Rock Laboratory, using 3-component geophones and rock anchors, which are installed 2 m within the rock on two levels, thus suppressing effects caused by the excavation damage zone. As a source, a pneumatic impact source was used. The survey covers two different facies types (shaly and carbonate-rich sandy), for which the elliptical anisotropy is calculated for direct ray paths by fitting an ellipse to the separated data for each facies. The tomographic inversion was done with a code providing a good grid control and enabling to take the seismic anisotropy into account. A-priori anisotropy can be attributed to the grid points, taking various facies types or other heterogeneities into account. Tomographic results, compared to computations using an isotropic velocity model, show that results are significantly enhanced by considering the anisotropy and demonstrate the ability of the approach to characterize heterogeneities of geological structures between the galleries of the rock laboratory.

Modelling Production Initiation from a Lazy Well by Direct Gas Injection at the Casing Head Using Dynamic Wellbore Simulator

This study deals with a lazy well completed with no packer in place. The main producing formation is showing strong signs of depletion where it lost more 2000 psig of reservoir pressure since the production started. Previous experiences in this well and other offset wells show there is demand for Nitrogen Injection Through Coiled Tubing Unit in the tubing in order to lift the well and bring it online whenever the well is shut-in for any reason. Direct natural gas injection at the casing head is a cost-effective alternative to rigless well lift operations. However, this is a challenging thing to achieve since it requires precise knowledge of injection rates and casing head pressure, additional to that formation fracture pressure and other reservoir characteristics should be taken into consideration. Data were collected and dynamic wellbore is created and linked to near well reservoir model to capture the transient behavior of the reservoir during start-up process. From Dynamic Modeling and simulation of the production system, best injection pressure, production choke, injection time and quantities are estimated and optimized for more efficient lifting process. After Initiating the well, production stability is observed in the transient simulator to ensure the success of the well lifting method. This method of production initiation is cost effective, and if implemented properly should bring the well back in production fast. Successful implementation this method demands a precise wellbore model to be created and shut-in surveys should be used to match the well status when it's not producing to tune the wellbore and fluid parameters.

Magnetic Resonance Morphometry of Normal Cerebral Aqueduct in South Indian Population

Introduction Cerebral aqueduct (of Sylvius) connects the third and fourth ventricles of the brain, and the shape of the aqueduct varies. The aim of the study is to assess the morphometry of the cerebral aqueduct in normal south Indian adult population and to look for pattern by shape, if any. Materials and Methods One hundred and fifty normal brain MR images (75 males and 75 females) using 3D heavily T2-weighted sequence were analyzed for various normal parameters of cerebral aqueduct. Mean and standard deviation were calculated. Based on the shape of the aqueduct, an attempt was made to classify them. Unpaired t-test was used to assess any significant difference between age groups and gender. The intraclass coefficient correlation was used to analyze the interobserver variability. Results The mean value of the length of the cranial and caudal part of aqueduct in males were 0.69 cm and 0.86 cm and in females 0.65 cm and 0.80 cm, respectively. The length was more in males, and it was statistically significant (p = 0.006 and 0.02). There are four types of cerebral aqueduct based on shape. Conclusion MRI is considered as the investigation of choice for preoperative planning of brain operative procedures. The MR morphometric evaluation of cerebral aqueduct provides precise knowledge about the anatomy and may be of help in the diagnosis and treatment by endoscopic neurosurgery.