scholarly journals Analysis of Seafloor Sediment Distribution using Multibeam Backscatter Data

2018 ◽  
Vol 177 ◽  
pp. 01026
Author(s):  
Danar G Pratomo ◽  
Khomsin ◽  
Mokhammad N Cahyadi ◽  
Kamila Akbar ◽  
Evasari Aprilia

Multibeam sonars use an acoustic wave to provide a view of seafloor topography and collect its backscatter. Seafloor backscatter image can be used as a means of quantitative classification of seafloor lithology. This allows sediment expert to examine spatial distributions of seafloor sediment types and discriminate among them. This method is expected to reduce expensive bottom-sampling programs. The research examined multibeam data collected from Indonesia Exploration 2010 Project. This project employed a Kongsberg EM302 multibeam system to collect seafloor topography and backscatter data at Sangihe Talaud Sea, North Sulawesi. The average depth of the area study is approximately 2400 m. The research applied the Angular Response Curve (ARC) method to analyze the echo strength of the backscatter as a function of the grazing angle. The range of backscatter intensity in this area is from -9dB to - 67dB. Based on the backscatter data, there are five types of sediment in this area: clay, mud, gravel, sand, and boulder.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel A. Colozza-Gama ◽  
Fabiano Callegari ◽  
Nikola Bešič ◽  
Ana C. de J. Paviza ◽  
Janete M. Cerutti

AbstractSomatic mutations in cancer driver genes can help diagnosis, prognosis and treatment decisions. Formalin-fixed paraffin-embedded (FFPE) specimen is the main source of DNA for somatic mutation detection. To overcome constraints of DNA isolated from FFPE, we compared pyrosequencing and ddPCR analysis for absolute quantification of BRAF V600E mutation in the DNA extracted from FFPE specimens and compared the results to the qualitative detection information obtained by Sanger Sequencing. Sanger sequencing was able to detect BRAF V600E mutation only when it was present in more than 15% total alleles. Although the sensitivity of ddPCR is higher than that observed for Sanger, it was less consistent than pyrosequencing, likely due to droplet classification bias of FFPE-derived DNA. To address the droplet allocation bias in ddPCR analysis, we have compared different algorithms for automated droplet classification and next correlated these findings with those obtained from pyrosequencing. By examining the addition of non-classifiable droplets (rain) in ddPCR, it was possible to obtain better qualitative classification of droplets and better quantitative classification compared to no rain droplets, when considering pyrosequencing results. Notable, only the Machine learning k-NN algorithm was able to automatically classify the samples, surpassing manual classification based on no-template controls, which shows promise in clinical practice.


Structures ◽  
2022 ◽  
Vol 35 ◽  
pp. 780-791
Author(s):  
Dahai Zhao ◽  
Huiwei Wang ◽  
Ding Wang ◽  
Ruiguang Zhu ◽  
Jinghui Zhang

2009 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
J. O. Navarro Lozano ◽  
E. H. Nava Sánchez ◽  
L. Godinez-Orta ◽  
J. Murillo-Jimenez

Bahía San Lucas está localizada en la punta sur de la Península de Baja California, por lo que recibe el oleaje de alta energía del Océano Pacífico. El análisis morfológico y sedimentológico del litoral y del fondo marino de la Bahía San Lucas, a partir del levantamiento batimétrico y del análisis de los parámetros texturales del sedimento permitió conocer la relación que existe entre las geoformas y el comportamiento sedimentológico. La morfología y orientación de las puntas que protegen a la bahía, así como la presencia temporal del abanico-delta El Salto en la porción central de la misma, condicionan los procesos de refracción y difracción del olaje. Así, el litoral de la bahía se puede dividir en dos zonas, en donde los procesos energéticos del oleaje y agente transportante son diferentes entre ellas y determinan la morfología y distribución de sedimentos en el sistema playero. El relieve del fondo marino de la bahía está dominado por la presencia del cañón submarino San Lucas, cuya cabecera se proxima hasta el pie de la playa, en la zona más interna de la bahía. Dicho cañón condiciona el desarrollo de la plataforma, la cual es de sólo 1.5 km de ancho, con profundidad máxima de 50 m. La poca profundidad de la plataforma, que permite que el oleaje interactúe con el fondo, así como la presencia del cañón submarino, condicionan la distribución de sedimentos del fondo marino de la bahía. Morphology and sediments of the beach and shelf of the Bahía San Lucas, Baja California Sur, México Bahía San Lucas is located at the southern tip of the Baja California peninsula, thus it receives high energy waves from the Pacific Ocean. The morphology of the coastline and marine bottom of the bay was interpreted based on a bathymetric survey and beach profiles, while the characteristics of the sediments were obtained through a textural analysis. Both, morphology and sedimentology allowed us to know the relationship between landforms and the sedimentological behavior. The geometry and orientation of the limiting points of the bay and the temporary presence of the fan-delta El Salto in the central portion, control the processes of wave refraction and diffraction. Thus, the coastline of the bay can be divided into two areas, where the wave energy processes and the transporting agent are different from each other and determine the morphology and sediment distribution of the beach. Seafloor topography of the bay is dominated by the presence of the San Lucas submarine canyon, whose head is just at the foot of he beach, in the innermost area of the bay. This canyon controls the development of the peninsular shelf, which is only 1.5 km wide with a maximum depth of 50m. This shallow depth of the shelf, which allows the waves interact with seabed, and the presence of the submarine canyon are the responsible for the distribution of sediments in the seabed of the bay.


1974 ◽  
Vol 25 (1) ◽  
pp. 25
Author(s):  
Κ. ΣΚΟΥΝΤΖΟΣ ◽  
Ι. ΑΣΙΚΗΣ

Laboratory examination of 828 samples of four typss of Greek cheese («telemes» : 415, «kasseri» : 164, «kefalotyrion» : 170, «gruyère» : 79) obtained from the Attikan market area, revealed, that : a. There is great variation relative to the water as well as the fat contents of the various types of cheese, resulting in the lack of standardized organoleptic and quantitative characteristics in the types of cheeses sold. b. The «kefalotyrion» cheese in particular contains significantly high quantities of sodium chloride. The authors suggest that ins criterion of fat content established so far for the quantitative classification of Greek cheese types be replaced by the criterion of protein content.


Geoadria ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. 17 ◽  
Author(s):  
Tomislav Šegota ◽  
Anita Filipčić

In this didactic article a systematic review of Köppen's climatic classification is given. The aim is to accept this most rational and quantitative classification of climates widely accepted all over the world. Like in all other languages the present Croatian terminology is confused. This is the reason why we accepted the original Köppen's terms. 


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