Response of FPSO Systems to Squalls

2011 ◽  
Author(s):  
Arun Duggal ◽  
Caspar Heyl ◽  
Amir H. Izadparast ◽  
Joerik Minnebo
Keyword(s):  
Wind Speed ◽  
Global Analysis ◽  
Single Degree Of Freedom ◽  
Transient Phenomena ◽  
Analysis Techniques ◽  
Extreme Response ◽  
Speed Up ◽  
The Difference ◽  
The Impact

Squalls are mesoscale sudden wind-speed increases that can occur worldwide and are a design driver for FPSO systems in areas the other design environmental conditions are relatively benign, e.g. offshore West Africa. Squalls are transient winds which rapidly reach a peak wind speed (up to 50 m/s) and then decay to low speeds in a span of 60 to 90 minutes. As squalls are transient phenomena traditional steady-state analysis techniques cannot be used for the global analysis or the development of the extreme response estimates. This paper focuses on the characterization of the squall environment and the impact of various parameters on the response of FPSOs. The responses of both spread and turret moored FPSOs are presented and the difference in response is discussed. The paper then focuses on a parametric study on a representative single degree of freedom model of a spread-moored FPSO with an emphasis on the estimation of the extreme response and its dependence on sample size.

scholarly journals A Novel Multiscale Intensity Metric for Evaluation of Tropical Cyclone Intensity Forecasts

2014 ◽  
Vol 71 (4) ◽  
pp. 1292-1304 ◽  
Author(s):  
Tomislava Vukicevic ◽  
Eric Uhlhorn ◽  
Paul Reasor ◽  
Bradley Klotz
Keyword(s):  
Wind Speed ◽  
Tropical Cyclone ◽  
Microwave Radiometer ◽  
Maximum Speed ◽  
Forecast Errors ◽  
Cyclone Intensity ◽  
Maximum Wind ◽  
Tropical Cyclone Intensity Forecasts ◽  
The Difference ◽  
The Impact

Abstract In this study, a new multiscale intensity (MSI) metric for evaluating tropical cyclone (TC) intensity forecasts is presented. The metric consists of the resolvable and observable, low-wavenumber intensity represented by the sum of amplitudes of azimuthal wavenumbers 0 and 1 for wind speed within the TC vortex at the radius of maximum wind and a stochastic residual, all determined at 10-m elevation. The residual wind speed is defined as the difference between an estimate of maximum speed and the low-wavenumber intensity. The MSI metric is compared to the standard metric that includes only the maximum speed. Using stepped-frequency microwave radiometer wind speed observations from TC aircraft reconnaissance to estimate the low-wavenumber intensity and the National Hurricane Center’s best-track (BT) intensity for the maximum wind speed estimate, it is shown that the residual intensity is well represented as a stochastic quantity with small mean, standard deviation, and absolute norm values that are within the expected uncertainty of the BT estimates. The result strongly suggests that the practical predictability of TC intensity is determined by the observable and resolvable low-wavenumber intensity within the vortex. Verification of a set of high-resolution numerical forecasts using the MSI metric demonstrates that this metric provides more informative and more realistic estimates of the intensity forecast errors. It is also shown that the maximum speed metric allows for error compensation between the low-wavenumber and residual intensities, which could lead to forecast skill overestimation and inaccurate assessment of the impact of forecast system change on the skill.

scholarly journals Ocean Surface Albedo and Its Impact on Radiation Balance in Climate Models

2006 ◽  
Vol 19 (24) ◽  
pp. 6314-6333 ◽  
Author(s):  
J. Li ◽  
J. Scinocca ◽  
M. Lazare ◽  
N. McFarlane ◽  
K. von Salzen ◽  
...  
Keyword(s):  
Wind Speed ◽  
Radiative Transfer ◽  
Surface Albedo ◽  
Ocean Surface ◽  
Radiation Budget ◽  
Climate Modelling ◽  
Negative Bias ◽  
Clear Sky ◽  
The Difference ◽  
The Impact

Abstract An analysis of several ocean surface albedo (OSA) schemes is undertaken through offline comparisons and through application in the Canadian Centre for Climate Modelling and Analysis (CCCma) fourth-generation atmospheric general circulation model (AGCM4). In general, each scheme requires different input quantities to determine the OSA. Common to all schemes is a dependence on the solar zenith angle (SZA). A direct comparison of the SZA dependence of the schemes reveals significant differences in the predicted albedos. Other input quantities include wind speed and aerosol/cloud optical depth, which are also analyzed. An offline one-dimensional radiative transfer model is used to quantitatively study the impact of ocean surface albedo on the radiative transfer process. It is found that, as a function of SZA and wind speed, the difference in reflected solar flux at the top of the atmosphere is in general agreement between OSA schemes that depend on these quantities, with a difference <10 W m−2. However, for simpler schemes that depend only on SZA the difference in this flux can approach 10–20 W m−2. The impact of the different OSA schemes is assessed through multiyear simulations of present-day climate in AGCM4. Five-year means of the reflected clear-sky flux at the top of the atmosphere reveal local differences of up to several watts per meters squared between any of the schemes. Globally, all schemes display a similar negative bias relative to the Earth Radiation Budget Experiment (ERBE) observations. This negative bias is largely reduced by comparison with the recently released Clouds and the Earth’s Radiant Energy System (CERES) data. It is shown that the local upward clear-sky flux at the surface is more sensitive to the OSA formulation than the clear-sky upward flux at the top of atmosphere. It is found that the global energy balance of the model at the top of the atmosphere and at the surface is surprisingly insensitive to which OSA scheme is employed.

scholarly journals Study on the Influence of Slope on Pollutant Diffusion Characteristics during Tunnel Construction Period

2019 ◽  
Vol 118 ◽  
pp. 04005
Author(s):  
Zubin Ai ◽  
Zhongqiang Song ◽  
Fan Chen ◽  
Song Yang ◽  
Zhensheng Cao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Traffic Safety ◽  
Reduction Rate ◽  
Tunnel Construction ◽  
Tunnel Length ◽  
Construction Period ◽  
Diffusion Characteristics ◽  
Speed Up ◽  
The Impact ◽  
Dust Reduction

. The relative elevation of the beginning and end of the Jianyuan Expressway exceed 1000m. In order to overcome the impact of the large slope on traffic safety, a spiral tunnel was designed in the middle of the expressway. The tunnel length is 3970m and the radius is 710~730m with its slope being up to 2.08%. The occurrence of large slope has a great impact on ventilation and smoke during tunnel construction, but little research has been done before. In this paper, numerical simulation and field test were used to study the effect of slope on the diffusion characteristics of pollutants. It was found that as the slope increased, the wind speed and CO dilution rate also increased. However, the dust dilution characteristics were different. Especially in the case of the downward tunnel, the effect of wind speed on the sedimentation rate of dust was minimal. Simply increasing the wind speed cannot speed up the dust reduction rate.

scholarly journals G. E. LESSING'S LAOCOON: THE POTENTIAL OF THE SEMANTIC APPROACH

2020 ◽  
pp. 23-27
Author(s):  
H. D. Mylenka
Keyword(s):  
Large Array ◽  
Semantic Approach ◽  
Key Concepts ◽  
Different Types ◽  
The Difference ◽  
Organic Combination ◽  
The Impact ◽  
Semantic Aspect ◽  
Theoretical Developments

Despite the large array of studies of the theoretical heritage of the German enlightener, this aspect has been most fully developed in the works of I.G. Gerder (article "Critical forests"), R. Ingarden (monograph "Research in aesthetics") and E. Basin (monograph "Art and communication"). In updating the potential of the semantic problematic of Laocoon, considerable assistance is provided by the recourse to studies in which the fruitfulness and relevance of this aspect of the Lessing tract is emphasized to one degree or another. There is an attempt to analyze, in one theoretical space, works on Lessing theory of signs. In order to identify the essence of the disagreement between I.G. Gerder and G.E. Lessing in the field of establishing boundaries between the kinds of art, special attention is paid to the consideration of Gerder concept of comparative analysis of painting, music and poetry, which is based on the difference of their ways of influence on the recipient – "in space", "in time "and" by force". In the process of analyzing Gerder's reflections, not only his critical attitude to the theory of signs developed by Lessing was considered, but also an attempt by the opponent of "Laokoon" author to justify the use of key concepts of metaphysics to compare the impact of different kinds of art. When comparing the views of E. Basin and R. Ingarden on the semantic aspect of "Laocoon", the debatable nature of their judgments about the characterization of the characters used in poetry by Lessing is identified. In addition, the article analyzes Lessing's thinking about the possibility of connecting different types of art, the organic combination of which depends on the specifics of the signs used by one or the other art, as well as emphasizes the productivity of the German thinker's idea. This aspect is revealed not only through the analysis of "Laokoon" in the works of E. Basin and R. Ingarden, but also by turning to the theoretical developments of E. Cassirer, B. Balash, A. Vartanova. Thus, the study of the semantic issues of Laokoon has shown the prominence of its conceptual landmarks for theoretical search, both in the field of aesthetics and art.

Privatisasi dan Dampaknya Terhadap Kinerja Keuangan Badan Usaha Milik Negara (BUMN) di Bursa Efek Indonesia

2020 ◽  
Vol 16 (2) ◽  
pp. 48-60
Author(s):  
Crystha Armereo ◽  
Pipit Fitri Rahayu ◽  
Hisbullah Basri
Keyword(s):  
Financial Performance ◽  
Sampling Method ◽  
Stock Exchange ◽  
Secondary Data ◽  
Wilcoxon Test ◽  
Data Sources ◽  
Analysis Techniques ◽  
Activity Ratios ◽  
The Difference ◽  
The Impact

This research aims to determine the impact of privatization on the financial performance of State-Owned Enterprises (SOEs) in the Indonesia Stock Exchange. This type of research is comparative, data sources using secondary data with data collection techniques using documentation and literature studies.The population in this research is all State-Owned Enterprises (SOEs) that have been privatized in IDX. The sampling method uses purposive sampling with 5 companies. Data analysis techniques using normality testing, independent sample T-test, and Wilcoxon test. The results showed that there was a difference in the financial performance of SOES after privatization was seen from the ratio of solvency, activity, and solvency with significance values of 0.030, 0.170, and 0.001. Whereas if viewed from the liquidity ratio, the privatization does not give the difference in the financial performance of the State-Owned Enterprises (SOEs) in IDX with a significance value of 0.088. This insulation also finds that privatization has a bad impact on the performance of State-Owned Enterprises (SOEs) from profitability and activity ratios, but has a good impact when viewed from the ratio of solvency and liquidity.

Characterization of Highway Traffic Noise Generated by Rigid Pavement Contraction Joints

2003 ◽  
Author(s):  
Lawrin Ellis ◽  
Christopher Niezrecki ◽  
David Bloomquist
Keyword(s):  
Traffic Noise ◽  
Test Methods ◽  
Concrete Pavements ◽  
Highway Traffic ◽  
Rigid Pavement ◽  
Contraction Joints ◽  
The Difference ◽  
Current Concerns ◽  
The Impact

Contraction joints in rigid (concrete) pavements are required to permit expansion of each monolithic section of roadway. At higher speeds, the major source of highway noise is attributed to vehicle tire/roadway interaction. Current concerns about limiting the impact of highway traffic noise, has forced transportation agencies to consider strategies to control noise generated by tire/roadway interaction. Within this work the difference in noise generated by 1/4 versus 3/8-inch joint widths is conducted. The study focuses on passenger vehicles including a sedan and a light duty van/truck. Both vehicle in-cabin and roadside noise levels are measured for vehicle speeds of 50, 60, and 70 miles per hour. For the sedan, the minimum and maximum observed in-cabin differences were determined to be 1.08 and 1.82 dB(A), respectively. Minimum and maximum observed roadside differences are 1.19 and 2.58 dB(A), respectively. Van tests resulted in minimum and maximum observed in-cabin differences of 0.60 and 1.09 dB(A) and minimum and maximum observed roadside differences of 1.05 and 3.18 dB(A), respectively. This paper contains details of reference standards, test methods, and the results obtained.

Characterization of Mo-Containing Systems Supported on AlPO4-5 and Aluminium Phosphate and Their Behavior in Thiophene Conversion

1992 ◽  
Vol 57 (4) ◽  
pp. 836-844 ◽  
Author(s):  
Alla A. Spojakina ◽  
Nina G. Kostova ◽  
Ljubomir Dimitrov
Keyword(s):  
Hydrogen Sulfide ◽  
Ir Spectroscopy ◽  
Chemical Interaction ◽  
Aluminium Phosphate ◽  
Thiophene Conversion ◽  
The Difference ◽  
The Impact

The properties of AlPO4-5 with zeolite-like structure and amorphous aluminium phosphate modified by nickel and/or molybdenum (1 wt.% and 10 wt.%, respectively) have been studied using ESR and IR spectroscopy and catalytic testing in hydrodesulfurization (HDS) of thiophene. The chemical interaction between all components of catalysts with formation of polymolybdate structures is revealed. The impact of the support is reflected in the difference of composition of polymolybdates, and different interactions with the hydrogen sulfide eliminated in thiophene conversion. The selectivity of the thiophene conversion and adsorption of H2S eliminated depend on the method of introduction of components only for AlPO4-5.

Material analysis techniques using the ion mill

1996 ◽  
Vol 54 ◽  
pp. 1034-1035
Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis
Keyword(s):  
Polished Surface ◽  
Surface Material ◽  
Analysis Techniques ◽  
Material Analysis ◽  
Optical Inspection ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Argon Ions ◽  
The Impact ◽  
Scanning Electron

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.

Evaluation of the impact of public investment programs on social and economic performance of territories

2019 ◽  
pp. 109-123
Author(s):  
I. E. Limonov ◽  
M. V. Nesena
Keyword(s):  
Bayesian Modeling ◽  
Positive Impact ◽  
Public Investment ◽  
Difference In Differences ◽  
The Public ◽  
Export Activity ◽  
Regional Investment ◽  
The Difference ◽  
The Impact ◽  
Development Institution

The purpose of this study is to evaluate the impact of public investment programs on the socio-economic development of territories. As a case, the federal target programs for the development of regions and investment programs of the financial development institution — Vnesheconombank, designed to solve the problems of regional development are considered. The impact of the public interventions were evaluated by the “difference in differences” method using Bayesian modeling. The results of the evaluation suggest the positive impact of federal target programs on the total factor productivity of regions and on innovation; and that regional investment programs of Vnesheconombank are improving the export activity. All of the investments considered are likely to have contributed to the reduction of unemployment, but their implementation has been accompanied by an increase in social inequality.

INDONESIA LANGUAGE INTERFERENCE FORM IN BASIC PPL LEARNING THAILAND UNHASY COLLEGE SYUDENTS

2020 ◽  
Vol 8 (2) ◽  
pp. 38
Author(s):  
Siti Mariana Ulfa
Keyword(s):  
Qualitative Research ◽  
Data Analysis ◽  
Data Collection ◽  
Teaching Practice ◽  
Data Presentation ◽  
Analysis Techniques ◽  
Thai Students ◽  
The Impact ◽  
Collection Methods ◽  
Recording Techniques

AbstractHumans on earth need social interaction with others. Humans can use more than one language in communication. Thus, the impact that arises when the use of one or more languages is the contact between languages. One obvious form of contact between languages is interference. Interference can occur at all levels of life. As in this study, namely Indonesian Language Interference in Learning PPL Basic Thailand Unhasy Students. This study contains the form of interference that occurs in Thai students who are conducting teaching practices in the classroom. This type of research is descriptive qualitative research that seeks to describe any interference that occurs in the speech of Thai students when teaching practice. Data collection methods in this study are (1) observation techniques, (2) audio-visual recording techniques using CCTV and (3) recording techniques, by recording all data that has been obtained. Whereas the data wetness uses, (1) data triangulation, (2) improvement in perseverance and (3) peer review through discussion. Data analysis techniques in this study are (1) data collection, (2) data reduction, (3) data presentation and (4) conclusions. It can be seen that the interference that occurs includes (1) interference in phonological systems, (2) interference in morphological systems and (3) interference in syntactic systems. 

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