Magnetic Evidence of Ridge Construction and Use at Poverty Point

2007 ◽  
Vol 72 (4) ◽  
pp. 757-770 ◽  
Author(s):  
Michael L. Hargrave ◽  
Tad Britt ◽  
Matthew D. Reynolds
Keyword(s):  
Magnetic Field Gradient ◽  
Magnetic Anomalies ◽  
The Other ◽  
Survey Area ◽  
Large Area ◽  
Magnetic Gradient ◽  
Ground Truthing ◽  
Circular Arrangements ◽  
Topographic Relief ◽  
Poverty Point

A magnetic field gradient survey was conducted at Poverty Point to determine if that technique could detect discrete subsurface features and differentiate the ridges and swales in an area that today exhibits very little topographic relief. The survey area (280 m long by 20 to 60 m wide) crossed Ridges 1 through 5 in the southwest portion of the site. The ridges were revealed as variegated bands of positive and negative magnetic anomalies whereas the swales appeared to be relatively homogeneous. Ridge 1, nearest the plaza, is wider and higher but has less of a flank midden than the other ridges. Two roughly circular arrangements of anomalies on Ridge I are potentially important but cannot be reliably interpreted without ground truthing excavations. Future large-area, high-resolution magnetic gradient surveys could dramatically enhance our understanding of this enigmatic site.

THE ECOLOGY AND DISTRIBUTION IN SINGAPORE OF BIDENS PILOSA L. (ASTERACEAE)

COSMOS ◽  
2010 ◽  
Vol 06 (01) ◽  
pp. 39-44 ◽  
Author(s):  
A. F. S. L. LOK ◽  
K.-X. TAN ◽  
H. T. W. TAN
Keyword(s):  
The Other ◽  
Large Area ◽  
Bidens Pilosa ◽  
Suitable Habitats

Bidens pilosa is less widespread than the other composites commonly found in Singapore as it is animal-dispersed, as opposed to wind-dispersed like most of the Asteraceae. However, this species has been observed to spread over a large area within a year in suitable habitats of sandy or rocky moist substrate with adequate sunlight, such as Jalan Chichau and Jalan Lam Sam. Judging by its invasive success in other tropical and subtropical countries, it should do well in Singapore. More studies can be done on this species, and the populations in the abovementioned localities should be closely monitored to determine the success, and the spread of the species.

scholarly journals Measurements of vector magnetic anomalies on board the icebreaker Shirase and the magnetization of the ship

1999 ◽  
Vol 42 (2) ◽  
Author(s):  
Y. Nogi ◽  
K. Kaminuma
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Magnetic Anomalies ◽  
The Other ◽  
South Indian Ocean ◽  
Permanent Magnetic Field ◽  
South Indian ◽  
Antarctic Research ◽  
Permanent Magnetization ◽  
Made In

Vector measurements of the geomagnetic field have been made in the South Indian Ocean since 1988 when a Shipboard Three Component Magnetometer (STCM) was installed on board the icebreaker Shirase by the 30th Japanese Antarctic Research Expedition (JARE-30). Twelve constants related to the ship's induced and permanent magnetic field were determined by the data obtained from the JARE-30 to the JARE-35. The constants related to the ship's magnetic susceptibility distribution are almost stable throughout the cruise and mostly depend on the ship's shape. On the other hand, the constants related to the ship's permanent magnetization are variable. However, absolute values of total intensity geomagnetic field calculated from vector geomagnetic field is possible to use, if the constraints from total intensity geomagnetic field measured by the proton magnetometer and/or satellite derived magnetic anomalies are applied.

A Study on Reliability of Pillar-Shaped Intermetallic Compounds Dispersed Lead-Free Solder Joint

2018 ◽  
Vol 941 ◽  
pp. 2087-2092
Author(s):  
Yusuke Nakata ◽  
Motoki Kurasawa ◽  
Tomihito Hashimoto ◽  
Kenji Miki ◽  
Ikuo Shohji
Keyword(s):  
Solder Joint ◽  
Intermetallic Compounds ◽  
Thermal Cycle ◽  
The Other ◽  
Lead Free ◽  
Lead Free Solder ◽  
Large Area ◽  
Longitudinal Elastic Modulus ◽  
Free Solder ◽  
The Ideal

A pillar shaped intermetallic compounds (IMCs) dispersed solder joint is a highly durable joint to achieve large area joining. The aim of this study is to investigate the ideal dispersion amount of pillar shaped IMCs. The dispersion rate of pillar shaped IMCs depend on the joining temperature. Pillar shaped IMCs dispersion rates are 3.5% and 5.5% when the joining temperature are 300 °C and 330 °C, respectively. Longitudinal elastic modulus are improved by forming pillar shaped IMCs. As a result of examination of the durability by the thermal cycle test, the durability of the joint with the dispersion rate of 3.5% was similar to that without pillar shaped IMCs, while that with the dispersion rate of 5.5% was remarkably improved. In the case of the dispersion rate of 3.5%, pillar shaped IMCs unevenly distributed and cracks tend to progress. On the other hand, in the case of the dispersion rate of 5.5%, pillar shaped IMCs were uniformly dispersed throughout the joint and suppressed crack propagation. Comparison of durability between pillar shaped IMCs solder and indium added solder to verify the effect of pillar shaped IMCs demonstrated that pillar shaped IMCs solder were more durable than indium added solder.

The 1949 algorithm for the rapid interpretation of aeromagnetic data

Geophysics ◽  
1996 ◽  
Vol 61 (2) ◽  
pp. 608-611
Author(s):  
Nelson C. Steenland
Keyword(s):  
Oil And Gas ◽  
Magnetic Anomalies ◽  
Central Basin ◽  
General Area ◽  
Aeromagnetic Data ◽  
West Texas ◽  
Central Basin Platform ◽  
Topographic Relief

In the early 1920s, magnetic anomalies were thought to be caused by topographic relief at the base of the sedimentary section. The drilling of the Hobbs anomaly on the Central Basin Platform in West Texas was successful, but the anomaly, primarily intrabasement in origin, could not quantitatively be related to the structure that was found. Moreover the drilling of similar anomalies in the general area proved unsuccessful as far as oil and gas were concerned, so the method acquired a bad reputation rather quickly (Heiland, 1940).

The Interpretation of the Land Tenure Law of Northern Nigeria

1970 ◽  
Vol 14 (3) ◽  
pp. 155-177
Author(s):  
C. M. McDowell
Keyword(s):  
Land Tenure ◽  
The Other ◽  
Customary Law ◽  
Northern Nigeria ◽  
Large Area ◽  
English Law ◽  
Relationship Of ◽  
The Relationship ◽  
New System

English law, as limited or modified, applies as one of the residual systems of law in Northern Nigeria, the other being customary law. The assumption underlying both the reception of English law and the retention of customary law was that both would be eroded and a new system would be created by local legislation and local decisions. While some erosion of both systems has taken place, such a process is necessarily slow and there remains a large area of law where the relationship of the received and retained law to local legislation is difficult to elaborate with any degree of precision. This is particularly true of the relationship of English law to the provisions of the Land Tenure Law and its predecessor, the Land and Native Rights Ordinance. The primary difficulty encountered in this context is the analogy which can be drawn between a lease in English form and the statutory right of occupancy, since the latter interest is granted by the appropriate authority normally, although not necessarily, for a definite term of years and may be governed by covenants which relate to rent, use and occupation, assignment and subletting, recovery of possession and so on.

scholarly journals AUTOMATIC DETECTION OF CLOUDS AND SHADOWS USING HIGH RESOLUTION SATELLITE IMAGE TIME SERIES

2016 ◽  
Vol XLI-B3 ◽  
pp. 475-479 ◽  
Author(s):  
Nicolas Champion
Keyword(s):  
Time Series ◽  
Satellite Images ◽  
Satellite Image ◽  
Region Growing ◽  
Shadow Detection ◽  
The Other ◽  
Landsat 8 ◽  
Cloud Detection ◽  
Large Area ◽  
The Difference

Detecting clouds and their shadows is one of the primaries steps to perform when processing satellite images because they may alter the quality of some products such as large-area orthomosaics. The main goal of this paper is to present the automatic method developed at IGN-France for detecting clouds and shadows in a sequence of satellite images. In our work, surface reflectance orthoimages are used. They were processed from initial satellite images using a dedicated software. The cloud detection step consists of a region-growing algorithm. Seeds are firstly extracted. For that purpose and for each input ortho-image to process, we select the other ortho-images of the sequence that intersect it. The pixels of the input ortho-image are secondly labelled <i>seeds</i> if the difference of reflectance (in the blue channel) with overlapping ortho-images is bigger than a given threshold. Clouds are eventually delineated using a region-growing method based on a radiometric and homogeneity criterion. Regarding the shadow detection, our method is based on the idea that a shadow pixel is darker when comparing to the other images of the time series. The detection is basically composed of three steps. Firstly, we compute a synthetic ortho-image covering the whole study area. Its pixels have a value corresponding to the median value of all input reflectance ortho-images intersecting at that pixel location. Secondly, for each input ortho-image, a pixel is labelled <i>shadows</i> if the difference of reflectance (in the NIR channel) with the <i>synthetic</i> ortho-image is below a given threshold. Eventually, an optional region-growing step may be used to refine the results. Note that pixels labelled <i>clouds</i> during the cloud detection are not used for computing the median value in the first step; additionally, the NIR input data channel is used to perform the shadow detection, because it appeared to better discriminate shadow pixels. The method was tested on times series of Landsat 8 and Pléiades-HR images and our first experiments show the feasibility to automate the detection of shadows and clouds in satellite image sequences.

Hot pressing of germanium monochromator crystals

2004 ◽  
Vol 37 (2) ◽  
pp. 339-340 ◽  
Author(s):  
S. F. Treviño ◽  
D. F. R. Mildner
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Hot Pressing ◽  
The Other ◽  
Large Area ◽  
Vacuum Hot Pressing ◽  
Neutron Monochromator ◽  
Double Focusing

The method and parameters for vacuum hot pressing of single-crystal germanium, suitable for a large-area double-focusing neutron monochromator, are presented. The square virgin crystals have a mosaic that is less than 0.01° and isotropic. After appropriate pressing at high temperature (1073 K at a pressure of 10.7 MPa) the mosaic becomes anisotropic, about 0.5° in one direction and 0.2° in the other. The distribution of the mosaic widths of the crystals in the two directions are given, together with their composite values.

Boots on the Ground at Yaxnohcah

2016 ◽  
Vol 4 (3) ◽  
pp. 314-338 ◽  
Author(s):  
Kathryn Reese-Taylor ◽  
Armando Anaya Hernández ◽  
F. C. Atasta Flores Esquivel ◽  
Kelly Monteleone ◽  
Alejandro Uriarte ◽  
...  
Keyword(s):  
Surface Model ◽  
Large Area ◽  
Vegetation Zones ◽  
Digital Elevation ◽  
Major Species ◽  
Ground Truthing ◽  
Elevation Model ◽  
Accuracy Of Results ◽  
Type 2 Errors

AbstractThis study proposes a sampling method for ground-truthing LiDAR-derived data that will allow researchers to verify or predict the accuracy of results over a large area. Our case study is focused on a 24 km2area centered on the site of Yaxnohcah in the Yucatan Peninsula. This area is characterized by a variety of dense tropical rainforest and wetland vegetation zones with limited road and trail access. Twenty-one 100 x 100 m blocks were selected for study, which included examples of several different vegetation zones. A pedestrian survey of transects through the blocks was conducted, recording two types of errors. Type 1 errors consist of cultural features that are identified in the field, but are not seen in the digital elevation model (DEM) or digital surface model (DSM). Type 2 errors consist of features that appear to be cultural when viewed on the DEM or DSM, but are caused by different vegetative features. Concurrently, we conducted an extensive vegetation survey of each block, identifying major species present and heights of stories. The results demonstrate that the lidar survey data are extremely reliable and a sample can be used to assess data accuracy, fidelity, and confidence over a larger area.

Low-background single-crystal silicon sample holders for neutron powder diffraction

2007 ◽  
Vol 40 (3) ◽  
pp. 489-495 ◽  
Author(s):  
M. Potter ◽  
H. Fritzsche ◽  
D. H. Ryan ◽  
L. M. D. Cranswick
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Neutron Powder Diffraction ◽  
The Other ◽  
Silicon Sample ◽  
Large Area ◽  
Crystal Silicon ◽  
Low Background ◽  
Plate Geometry ◽  
Null Matrix

Neutron diffraction measurements on weakly scattering or highly absorbing samples may demand custom mounting solutions. Two low-background sample holders based on inexpensive single-crystal silicon are described. One uses a conventional cylindrical geometry and is optimized for weakly scattering materials, while the other has a large-area flat-plate geometry and is designed for use with highly absorbing samples. Both holders yield much lower backgrounds than more conventional null-matrix or null-scattering materials and are essentially free from interfering Bragg peaks.

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