scholarly journals PENCITRAAN PEMETAAN PANAS PENYERAPAN RADIASI TERAHERTZ (THz) DALAM JARINGAN BIOLOGIS MENGGUNAKAN MODEL SIMULINK-MATLAB

Author(s):  
Dewi Kurnia ◽  
Muhammmad Hamdi ◽  
Juandi M

ABSTRAKRadiasi THz memiliki sifat yang membuatnya lebih menarik dan efektif dalam bidang teknik pencitraan biomedis. Hal ini dikarenakan radiasi THz tidak mengionisasi dan merusak jaringan. Penelitian ini menggunakan sampel jaringan biologis sapi yaitu  jaringan kulit, lemak, tumor dan otot. Tujuan dari penelitian untuk mengetahui suatu jaringan terindikasi abnormal atau normal dengan melihat pemetaan panas yang dihasilkan dari penyerapan radiasi THz dalam jaringan biologis sapi dengan cara pemodelan. Penelitian ini menggunakan teknik komputasi biofisik dengan medel simulink-matlab. Rentang frekuensi radiasi THz yang digunakan 0,1 - 1 THz, daya 50 – 150 mW serta kerapatan daya 5 - 25 mW/mm3. Rasio dan temperatur dari masing-masing jaringan yaitu lemak 0,25 T/25 oC (T = 6,25 oC ), kulit 0,432 T/25oC (10,8 oC), otot 0,675 T/25oC (16,88 oC) dan Tumor 0,9 T/25oC (22,50 oC). Hasil penelitian menunjukkan bahwa Jaringan lemak memiliki produksi panas yang lebih kecil dan temperatur yang lebih rendah dari jaringan kulit dan otot. Hal ini dikarenakan jaringan lemak memiliki kadar air yang tinggi dengan konsentrasi yang lebih encer sehingga radiasi THz lebih banyak terserap dengan energi yang lebih cepat habis sesuai penetrasi jaringan. Kata kunci:  terahertz; pemetaan panas; jaringan biologis; simulink-matlab.                                                                                                                                       ABSTRACTTerahertz (THz) radiation has properties that make it more attractive and effective in the field of biomedical imaging techniques. This is because THz radiation does not ionize and damage tissue. This study used a sample of bovine biological tissue, namely skin, fat, tumor and muscle tissue. The aim of this research is to find out whether a tissue is indicated as abnormal or normal by looking at the heat mapping generated from the absorption of THz radiation in the biological tissue of cattle by means of modeling. This study uses biophysical computation techniques with the simulink-matlab method. The range of THz radiation frequency used is 0.1 - 1 THz, power 50 - 150 mW and power density 5 - 25 mW / mm3. The ratio and temperature of each tissue were fat 0.25 T / 25 oC (T = 6.25 oC), skin 0.432 T / 25oC (10.8 oC), muscle 0.675 T / 25oC (16.88 oC) and Tumor 0.9 T / 25oC (22.50 oC). The results showed that fat tissue has less heat production and a lower temperature than skin and muscle tissue. This is because the fat tissue has a high water content with a more dilute concentration so that more THz radiation is absorbed with energy that runs out faster according to tissue penetration. Keywords: terahertz; heat mapping; biological networks; simulink-matlab.

Author(s):  
A. Bykov ◽  
D. Palatov ◽  
I. Studenov ◽  
D. Chupov

The article provides information about the features of spring feeding of sterlet in the spawning grounds of the middle course of the Northern Dvina river in may 2019. The main and secondary groups of forage objects in the diet of this species of sturgeon are characterized. The article considers the variability of the sterlet food composition with an increase in the size of fish from 30 to 60 cm. In the process of fish growth in the diet of the Severodvinsk sterlet, the main components in terms of occurrence and mass in all size groups are the larvae of Brooks and chironomids. A minor occurrence was the larvae of midges, biting midges, stoneflies, mayflies and small clams. To random and seasonal food are the larvae of water bugs, butterflies, flies, beetles and eggs of other fish. The feeding intensity of the smaller sterlet (30–40 cm) was significantly higher than that of the fish in the size groups 40–50 and 50–60 cm. Fundamental changes in the diet of the Severodvinsk sterlet for the main food objects for more than sixty years of observations have not been established. During periods of high water content of the Northern Dvina due to seasonal changes in the structure of benthic communities, the value of Brooks in the diet of sterlet increases and the proportion of chironomids decreases.


2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.


2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shun-ichiro Karato ◽  
Bijaya Karki ◽  
Jeffrey Park

AbstractOceans on Earth are present as a result of dynamic equilibrium between degassing and regassing through the interaction with Earth’s interior. We review mineral physics, geophysical, and geochemical studies related to the global water circulation and conclude that the water content has a peak in the mantle transition zone (MTZ) with a value of 0.1–1 wt% (with large regional variations). When water-rich MTZ materials are transported out of the MTZ, partial melting occurs. Vertical direction of melt migration is determined by the density contrast between the melts and coexisting minerals. Because a density change associated with a phase transformation occurs sharply for a solid but more gradually for a melt, melts formed above the phase transformation depth are generally heavier than solids, whereas melts formed below the transformation depth are lighter than solids. Consequently, hydrous melts formed either above or below the MTZ return to the MTZ, maintaining its high water content. However, the MTZ water content cannot increase without limit. The melt-solid density contrast above the 410 km depends on the temperature. In cooler regions, melting will occur only in the presence of very water-rich materials. Melts produced in these regions have high water content and hence can be buoyant above the 410 km, removing water from the MTZ. Consequently, cooler regions of melting act as a water valve to maintain the water content of the MTZ near its threshold level (~ 0.1–1.0 wt%). Mass-balance considerations explain the observed near-constant sea-level despite large fluctuations over Earth history. Observations suggesting deep-mantle melting are reviewed including the presence of low-velocity anomalies just above and below the MTZ and geochemical evidence for hydrous melts formed in the MTZ. However, the interpretation of long-term sea-level change and the role of deep mantle melting in the global water circulation are non-unique and alternative models are reviewed. Possible future directions of studies on the global water circulation are proposed including geodynamic modeling, mineral physics and observational studies, and studies integrating results from different disciplines.


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 30
Author(s):  
María González Martínez ◽  
Estéban Hélias ◽  
Gilles Ratel ◽  
Sébastien Thiéry ◽  
Thierry Melkior

Biomass preheating in torrefaction at an industrial scale is possible through a direct contact with the hot gases released. However, their high water-content implies introducing moisture (around 20% v/v) in the torrefaction atmosphere, which may impact biomass thermochemical transformation. In this work, this situation was investigated for wheat straw, beech wood and pine forest residue in torrefaction in two complementary experimental devices. Firstly, experiments in chemical regime carried out in a thermogravimetric analyzer (TGA) showed that biomass degradation started from lower temperatures and was faster under a moist atmosphere (20% v/v water content) for all biomass samples. This suggests that moisture might promote biomass components’ degradation reactions from lower temperatures than those observed under a dry atmosphere. Furthermore, biomass inorganic composition might play a role in the extent of biomass degradation in torrefaction in the presence of moisture. Secondly, torrefaction experiments on a lab-scale device made possible to assess the influence of temperature and residence time under dry and 100% moist atmosphere. In this case, the difference in solid mass loss between dry and moist torrefaction was only significant for wheat straw. Globally, an effect of water vapor on biomass transformation through torrefaction was observed (maximum 10%db), which appeared to be dependent on the biomass type and composition.


2017 ◽  
Vol 25 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Róbert Turza ◽  
Belo B. Füri

Abstract As the number of indoor swimming pools and wellness centers are currently growing, it is necessary to concentrate on the parameters of indoor environments. These parameters are necessary for the design of the HVAC systems that operate these premises. In indoor swimming-pool facilities, the energy demand is large due to ventilation losses from exhaust air. Since water evaporates from a pool’s surface, exhaust air has a high water content and specific enthalpy. In this paper the results of the water evaporation rate measured from swimming pool surfaces at higher thermal water temperatures are described.


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