scholarly journals Variation of Individual Location Radiance in VIIRS DNB Monthly Composite Images

2018 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Sharolyn Anderson ◽  
Kimberly Baugh ◽  
Christopher Elvidge ◽  
Harald Schernthanner ◽  
...  
Keyword(s):  
Large Scale ◽  
Infrared Imaging ◽  
Light Emission ◽  
Light Sources ◽  
Light Emitters ◽  
Local Factors ◽  
The Mean ◽  
The Stability ◽  
Night Lights ◽  
Monthly Variations

With the growing size and use of night lights time series from the Visible Infrared Imaging Radiometer Suite Day/Night Band (DNB), it is important to understand the stability of the dataset. All satellites observe differences in pixel values during repeat observations. In the case of night lights data, these changes can be due to both environmental effects and changes in light emission. Here we examine the stability of individual locations of particular large scale light sources (e.g. airports, prisons) in the monthly composites of DNB data from April 2012 to September 2017. The radiances for individual pixels of most large light emitters are approximately normally distributed, with a standard deviation of typically 15-20% of the mean. We observe geospatial autocorrelation in the monthly variations for nearby sites, while the correlation for sites separated by large distances is small. This suggests that local factors contribute most to the variation in the pixel radiances, and furthermore that averaging radiances over large areas will reduce the total variation. A better understanding of the causes of temporal variation would improve the sensitivity of DNB to lighting changes.

scholarly journals Variation of Individual Location Radiance in VIIRS DNB Monthly Composite Images

2018 ◽  
Vol 10 (12) ◽  
pp. 1964 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Sharolyn Anderson ◽  
Kimberly Baugh ◽  
Christopher Elvidge ◽  
Harald Schernthanner ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Infrared Imaging ◽  
Light Emission ◽  
Light Sources ◽  
Light Emitters ◽  
Local Factors ◽  
The Mean ◽  
The Stability ◽  
Monthly Variations

With the growing size and use of night light time series from the Visible Infrared Imaging Radiometer Suite Day/Night Band (DNB), it is important to understand the stability of the dataset. All satellites observe differences in pixel values during repeat observations. In the case of night light data, these changes can be due to both environmental effects and changes in light emission. Here we examine the stability of individual locations of particular large scale light sources (e.g., airports and prisons) in the monthly composites of DNB data from April 2012 to September 2017. The radiances for individual pixels of most large light emitters are approximately normally distributed, with a standard deviation of typically 15–20% of the mean. Greenhouses and flares, however, are not stable sources. We observe geospatial autocorrelation in the monthly variations for nearby sites, while the correlation for sites separated by large distances is small. This suggests that local factors contribute most to the variation in the pixel radiances and furthermore that averaging radiances over large areas will reduce the total variation. A better understanding of the causes of temporal variation would improve the sensitivity of DNB to lighting changes.

scholarly journals Testing for changes in light emissions from certified International Dark Sky Places

2019 ◽  
Vol 21 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Emilee Hyde ◽  
Sabine Frank ◽  
John C Barentine ◽  
Helga Kuechly ◽  
Christopher C. M. Kyba
Keyword(s):  
Infrared Imaging ◽  
Light Emission ◽  
Rate Of Change ◽  
Light Pollution ◽  
Voluntary Certification ◽  
Sky Brightness ◽  
Legislative Changes ◽  
Night Lights ◽  
Reduced Light ◽  
Night Sky Brightness

The International Dark-Sky Places (IDSP) program of the International Dark-Sky Association is a voluntary certification in which communities commit via legislative changes to move towards more sustainable lighting that reduces light pollution. As over 115 IDSP have now been certified, it is interesting to ask the extent to which this certification results in reduced light emissions. In this paper, we compared trends in upward light emission of 98 communities located in or near IDSP to those of 98 similarly sized communities further away from the IDSP, using a night lights observing satellite (the Visible Infrared Imaging Radiometer Suite Day-Night Band). The current dataset is not sufficient to distinguish the hypothesis that IDSP certification results in a lower rate of change in upward light emissions from the null hypothesis that IDSP certification has no impact. This result is with regard to upward light emissions only: it is possible that certification has resulted in decreases in night sky brightness that the satellite is not able to observe.

scholarly journals Reducing Variability and Removing Natural Light from Nighttime Satellite Imagery: A Case Study Using the VIIRS DNB

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3287 ◽  
Author(s):  
Jacqueline Coesfeld ◽  
Theres Kuester ◽  
Helga U. Kuechly ◽  
Christopher C. M. Kyba
Keyword(s):  
Web Application ◽  
Infrared Imaging ◽  
Light Emission ◽  
Natural Light ◽  
Artificial Light ◽  
Light Sources ◽  
Data Services ◽  
The Earth ◽  
Using Data

Temporal variation of natural light sources such as airglow limits the ability of night light sensors to detect changes in small sources of artificial light (such as villages). This study presents a method for correcting for this effect globally, using the satellite radiance detected from regions without artificial light emissions. We developed a routine to define an approximate grid of locations worldwide that do not have regular light emission. We apply this method with a 5 degree equally spaced global grid (total of 2016 individual locations), using data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB). This code could easily be adapted for other future global sensors. The correction reduces the standard deviation of data in the Earth Observation Group monthly DNB composites by almost a factor of two. The code and datasets presented here are available under an open license by GFZ Data Services, and are implemented in the Radiance Light Trends web application.

Injuries to the Coronoid Process of the Ulna with Involvement of the Lesser Sigmoid Notch

2020 ◽  
Author(s):  
Valentin Rausch ◽  
Sina Neugebauer ◽  
Tim Leschinger ◽  
Lars Müller ◽  
Kilian Wegmann ◽  
...  
Keyword(s):  
Fragment Size ◽  
Coronoid Process ◽  
Annular Ligament ◽  
Concomitant Injuries ◽  
Proximal Ulna ◽  
Sigmoid Notch ◽  
Coronoid Fractures ◽  
The Mean ◽  
The Stability ◽  
Arthritic Changes

Abstract Introduction This study aimed to describe the involvement of the lesser sigmoid notch in fractures to the coronoid process. We hypothesized that injuries to the lateral aspect of the coronoid process regularly involve the annular ligament insertion at the anterior lesser sigmoid notch. Material and Methods Patients treated for a coronoid process fracture at our institution between 06/2011 and 07/2018 were included. We excluded patients < 18 years, patients with arthritic changes or previous operative treatment to the elbow, and patients with concomitant injuries to the proximal ulna. In patients with involvement of the lesser sigmoid notch, the coronoid height and fragment size (anteroposterior, mediolateral, and craniocaudal) were measured. Results Seventy-two patients (mean age: 47 years ± 17.6) could be included in the study. Twenty-one patients (29.2%) had a fracture involving the lateral sigmoid notch. The mean anteroposterior fragment length was 7 ± 1.6 mm. The fragment affected a mean of 43 ± 10.8% of the coronoid height. The mean mediolateral size of the fragment was 10 ± 5.0 mm, and the mean cranio-caudal size was 7 ± 2.7 mm. Conclusion Coronoid fractures regularly include the lesser sigmoid notch. These injuries possibly affect the anterior annular ligament insertion which is important for the stability of the proximal radioulnar joint and varus stability of the elbow.

Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha
Keyword(s):  
Sodium Hydroxide Solution ◽  
Normal Subjects ◽  
Organ Distribution ◽  
Stable Complex ◽  
Scintillation Camera ◽  
Ph Adjustment ◽  
The Mean ◽  
The Stability ◽  
Kidney Imaging ◽  
Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

scholarly journals The force effects of two types of polyethylene terephthalate glyc-olmodified clear aligners immersed in artificial saliva

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Biao Xiang ◽  
Xingxing Wang ◽  
Gang Wu ◽  
Yichen Xu ◽  
Menghan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyethylene Terephthalate ◽  
Artificial Saliva ◽  
Orthodontic Force ◽  
The Mean ◽  
The Stability ◽  
Scanning Electron

AbstractNumerous factors can influence the force exerted by clear aligners on teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased, but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P < 0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.

scholarly journals Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1021
Author(s):  
Bernhard Dorweiler ◽  
Pia Elisabeth Baqué ◽  
Rayan Chaban ◽  
Ahmed Ghazy ◽  
Oroa Salem
Keyword(s):  
Wall Thickness ◽  
Large Scale ◽  
Fused Deposition Modeling ◽  
Vascular Anatomy ◽  
3D Models ◽  
Patient Specific ◽  
Stl File ◽  
Fused Deposition ◽  
3D Printed ◽  
The Mean

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

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