Direct and Indirect Methods for Calculating Thermal Emission From Layered Structures With Nonuniform Temperatures

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
L. P. Wang ◽  
S. Basu ◽  
Z. M. Zhang
Keyword(s):  
Temperature Distribution ◽  
Thermal Emission ◽  
Local Density ◽  
Direct Method ◽  
Direct Methods ◽  
Layered Structures ◽  
Nonuniform Temperature ◽  
Indirect Methods ◽  
Nonuniform Temperature Distribution ◽  
Direct And Indirect Methods

The determination of emissivity of layered structures is critical in many applications, such as radiation thermometry, microelectronics, radiative cooling, and energy harvesting. Two different approaches, i.e., the “indirect” and “direct” methods, are commonly used for computing the emissivity of an object. For an opaque surface at a uniform temperature, the indirect method involves calculating the spectral directional-hemispherical reflectance to deduce the spectral directional emissivity based on Kirchhoff’s law. On the other hand, a few studies have used a combination of Maxwell’s equations with the fluctuation-dissipation theorem to directly calculate the emissivity. The present study aims at unifying the direct and indirect methods for calculating the far-field thermal emission from layered structures with a nonuniform temperature distribution. Formulations for both methods are given to illustrate the equivalence between the indirect and the direct methods. Thermal emission from an asymmetric Fabry–Pérot resonance cavity with a nonuniform temperature distribution is taken as an example to show how to predict the intensity, emissivity, and the brightness temperature. The local density of states, however, can only be calculated using the direct method.

Direct and Indirect Methods for Calculating Thermal Emission From Layered Structures With Nonuniform Temperatures

2010 ◽  
Author(s):  
L. P. Wang ◽  
S. Basu ◽  
Z. M. Zhang
Keyword(s):  
Temperature Distribution ◽  
Thermal Emission ◽  
Local Density ◽  
Direct Method ◽  
Direct Methods ◽  
Layered Structures ◽  
Nonuniform Temperature ◽  
Indirect Methods ◽  
Nonuniform Temperature Distribution ◽  
Direct And Indirect Methods

The determination of emissivity of layered structures is critical in many applications, such as radiation thermometry, microelectronics, radiative cooling, and energy harvesting. Two different approaches, i.e., the “indirect” and “direct” methods, are commonly used for computing the emissivity of an object. For an opaque surface at a uniform temperature, the indirect method involves calculating the spectral directional-hemispherical reflectance to deduce the spectral directional emissivity based on Kirchhoff’s law. On the other hand, a few studies have used a combination of Maxwell’s equations with the fluctuation-dissipation theorem to directly calculate the emissivity. The present study aims at unifying the direct and indirect methods for calculating thermal emission from layered structures with a nonuniform temperature distribution. Formulations for both methods are given to illustrate the equivalence between the indirect and the direct methods. Thermal emission from an asymmetric Fabry-Perot resonance cavity with a nonuniform temperature distribution is taken as an example to show how to predict the intensity, emissivity, and the brightness temperature. The local density of states, however, can only be calculated using the direct method.

scholarly journals DIRECT METHOD AND INDIRECTNESS METHOD: COMMUNICATION STRATEGY IN CARTOON

2020 ◽  
Vol 2 (4) ◽  
pp. 01-12
Author(s):  
Rohaidah Mashudi ◽  
Norishamsawati Ishak ◽  
Hawa Rahmat ◽  
Faizuniza Mashhod ◽  
Isma Suhaila Ismail ◽  
...  
Keyword(s):  
Data Analysis ◽  
Language Use ◽  
Direct Method ◽  
Direct Methods ◽  
Study Data ◽  
Communication Strategy ◽  
Indirect Methods ◽  
The Press ◽  
Descriptive Approach ◽  
Direct And Indirect Methods

Cartoons are not only seen as a media channel to provide entertainment to the community. This is because cartoons play an important role as a very effective medium of information delivery to all groups. The message in the cartoon is conveyed either through the language use and illustrations or mere illustrations from a cartoonist. The display of illustrations with the language used in cartoons in the press indirectly brings current issues in various aspects. Even though these illustrations can help stimulate one's ideas and maturity in evaluating a message. The purpose of this study is to examine language use as a communication strategy in cartoons and describe the use of direct and indirect methods in cartoons. As such, the use of language as a communication strategy is examined based on the language use used in cartoons, namely the language use through direct methods and indirectness methods. The study was conducted qualitatively through a descriptive approach. Study data were taken and collected from cartoons or illustrations produced by Maro cartoonists in the Malaysia Kita column, Mingguan Malaysia. The illustration taken as study data is an illustration that gives an overview of the current situation of the country in Mingguan Malaysia every Sunday for the July and August issues in 2019 and August 2020. Data analysis is done through an approach that presented by Asmah Hj Omar through research on the language use through indirectness methods and the language use through direct methods. The results of this study can be observed that the cartoon in the newspaper clearly shows that there is an emphasis on these two methods as a communication strategy used through language use as a way to ensure that the message conveyed can be understood by all parties. Thus, language use through this indirectness method is the main choice in the delivery of storytelling through cartoons. The study of language on cartoon illustrations needs to be given a wider focus because there are still many vacancies that need to be examined.

scholarly journals Estimating emission from gas power plant in palembang, indonesia using direct and indirect methods

2018 ◽  
Vol 67 ◽  
pp. 02037
Author(s):  
Gabriel Andari Kristanto ◽  
Alditho Farrasi Anantoputra
Keyword(s):  
Power Plant ◽  
Emission Factor ◽  
Indirect Method ◽  
Emission Inventory ◽  
Direct Method ◽  
Total Particulate Matter ◽  
Indirect Methods ◽  
Gas Power Plant ◽  
A Direct Method ◽  
Direct And Indirect Methods

Nowadays, almost every daily activity is supported by the availability of energy, especially electricity. As the Borang 60 MW Gas Power Plant in Palembang, Indonesia emits air pollutants such as SO2, NOx, CO, and total particulate matter (total PM), an emission inventory needs to be developed. Various methods can be used in the inventory of emissions; among others are a direct method based on direct measurement and an indirect method which involves the calculation of total emissions by emission factor. This study aims to estimate the emissions from the gas power plant in Palembang using direct and indirect methods and analyze the most suitable emission factor for Indonesian conditions. The comparison between emissions measured by direct and indirect methods found that the indirect method using the emission factor of AP-42 gives more accurate results for SO2 and NOx, whereas the total emission of CO is more accurately calculated based on the indirect method using the emission factor developed by Kurokawa et al. (2013); the median value of total PM is more accurately calculated based on the indirect method using the emission factor developed by the IPCC.

scholarly journals Measurement the “Q” angle through the application of direct method and indirect method

2016 ◽  
Vol 33 (03) ◽  
pp. 168-170
Author(s):  
C. Vanzeli ◽  
A. Reis ◽  
A. Pereira ◽  
M. Tavares ◽  
V. Fazan
Keyword(s):  
Direct Method ◽  
Objective Measure ◽  
Angle Measurement ◽  
Global Alignment ◽  
Ordinary People ◽  
Lateral Deviation ◽  
Indirect Methods ◽  
Q Angle ◽  
Direct And Indirect Methods ◽  
Physiotherapy Clinic

Abstract Introduction: The “Q” angle is used to measure global alignment of the kneecap, representing the kneecap normal alignment. The average of 15 degrees in ordinary people is accepted as “Q” angle value, 14 degrees for men and 17 degrees for women. Anatomic changes caused by variants produces converging kneecaps or lateral deviation of the tibial tuberosity, changing the “Q” angle value and causing pathologies. Objective: Measure the “Q” angle of asymptomatic people, comparing obtained results. Materials and Methods: The “Q” angle measurement was taken from 12 subjects (6 males and 6 females), with ages from 18 to 35, at the Physiotherapy Clinic of José do Rosario Vellano College, in Alfenas, MG. Results: After evaluating the 12 subjects following ANOVA test, using p < 0.05, no significant statistic difference could be observed among examiners, gender or right and left limbs, considering both direct and indirect methods. Conclusion: Data obtained in this research allows us suggest that there is no difference between “Q” angle values among genders, direct and indirect methods and lateral symmetry.

scholarly journals The usefulness of operating cash flow information: Does format matter?

2012 ◽  
Vol 10 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Shadi Farshadfar
Keyword(s):  
Cash Flow ◽  
Indirect Method ◽  
Direct Method ◽  
Cash Flows ◽  
Indirect Methods ◽  
Flow Information ◽  
Operating Cash Flow ◽  
Future Cash Flows ◽  
Direct And Indirect Methods ◽  
Level Analysis

This study investigates whether the direct method of presenting cash flows from operations is superior to the indirect method in its ability to forecast future cash flows. It also considers the effect of industry characteristics on the relative usefulness of direct and indirect methods of cash flow presentation. The study, which uses a sample of Australian firms, finds that both the direct and indirect methods improve the forecast of future cash flows. However, the indirect method of reporting cash flows from operations is more relevant than the direct method in predicting future cash flows. Evidence from the industry-level analysis overall reinforces the main results.

scholarly journals Methane Production in Ruminant Animals

2021 ◽  
pp. 177-211
Author(s):  
M. Zaman ◽  
K. Kleineidam ◽  
L. Bakken ◽  
J. Berendt ◽  
C. Bracken ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Direct Methods ◽  
Animal Waste ◽  
Agricultural Activities ◽  
Approximate Methods ◽  
Indirect Methods ◽  
Tracer Techniques ◽  
Ruminant Animals ◽  
Direct And Indirect Methods ◽  
Ghg Fluxes

AbstractAgriculture is a significant source of GHGsglobally and ruminant livestock animals are one of the largest contributors to these emissions, responsible for an estimated 14% of GHGs (CH4and N2O combined) worldwide. A large portion of GHG fluxes from agricultural activities is related to CH4 emissions from ruminants. Both direct and indirect methods are available. Direct methods include enclosure techniques, artificial (e.g.  SF6) or  natural  (e.g.  CO2)  tracer techniques,  and   micrometeorological methods using open-path lasers. Under the indirect methods, emission mechanisms are understood, where the CH4 emission potential is estimated based on the substrate characteristics and the digestibility (i.e. from volatile fatty acids). These approximate methods are useful if no direct measurement is possible. The different systems used to quantify these emission potentials are presented in this chapter. Also, CH4 from animal waste (slurry, urine, dung) is an important source: methods pertaining to measuring GHG potential from these sources are included.

scholarly journals Gıdalarda Bulunan 3-Monokloropropan-1,2-diol ve Glisidil Esterlerinin Analiz Yöntemleri, Azaltılmalarına Yönelik Çalışmalar ve Sağlık Üzerine Etkilerine İlişkin Güncel Gelişmeler

2017 ◽  
Vol 5 (12) ◽  
pp. 1497
Author(s):  
Aslı Yıldırım ◽  
Aslı Yorulmaz
Keyword(s):  
Direct Methods ◽  
Food Products ◽  
General Information ◽  
The Novel ◽  
Analysis Method ◽  
Food Contaminants ◽  
Indirect Methods ◽  
New Developments ◽  
Direct And Indirect Methods ◽  
Proper Analysis

Chloropropanols are known as undesired food contaminants liberated during the processing of various food products. When the adverse effects of chloropropanols, especially 3-monochloropropane-1,2-diol (3-MCPD), 2-monochloropropane-1,3-diol (2-MCPD) and glycidols along with their esters were first understood, the studies about the detection and mitigation of these compounds were accelerated. 3-MCPD, which was detected in food products in higher amounts when compared to other chloropropanols, usually occurs during refining process of vegetable oils, especially in deodorisation step. The novel methods in terms of the analysis of 3-MCPD and other chloropropanols are continuously updated. However, there are two basic methods today namely direct and indirect methods. Direct methods enable to detect all of the esters individually, yet, due to the necessity of a huge number of reference standards, indirect methods are currently more preferred. The first essential step of reducing chloropropanols in food products is to determine the proper analysis method. In this review, general information, new developments in analysis methods, mitigation studies and the toxigolocial data about various chloropropanols were summarized.

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