scholarly journals Experimental and Numerical Evaluation of Toxic Pool Evaporation

2020 ◽  
Vol 10 (23) ◽  
pp. 8448
Author(s):  
Benjamin Truchot ◽  
André Carrau ◽  
Véronique Debuy ◽  
Thibauld Penelon ◽  
Jean-Pierre Bertrand
Keyword(s):  
Wind Velocity ◽  
Time Variation ◽  
Evaporation Rate ◽  
Atmospheric Dispersion ◽  
Ammonia Solution ◽  
Specific Aspect ◽  
Small Scale ◽  
Medium Scale ◽  
Vertical Velocity Profile ◽  
Ambient Turbulence

To date, safety distances to toxic pool evaporation as measured by known models have been quoted in hundreds of meters, without a deeper study of the time variation of the evaporation rate. In order to evaluate this specific aspect, we designed an experimental study. This study included small-scale tests with a 0.1 m2 evaporating pool, and medium-scale tests with 1 and 2 m2 evaporating pools. For both small- and medium-scale tests, the experimental vertical velocity profile was built to reproduce an atmospheric profile after applying the Froude scaling procedure. The scope of this study focused on ammonia pool evaporation, with each test lasting long enough to highlight the time evolution of the evaporation rate. While many other parameters may have strongly influenced the evaporation rate, the influence of the most classical parameters was tested, including pool concentration, wind velocity, and ambient turbulence. During these tests, the metrology was designed to enable the measuring of evaporation rates with great precision, but other important components were also measured. This series of tests clearly showed a strong variation of the evaporation rate in the first 30 minutes after the release—the evaporation rate dropped to 20% of its initial value after this 30-min period. It is therefore obvious that such reactions should strongly influence the toxic consequences of the vapor atmospheric dispersion. The known influence of other parameters was also confirmed—typically, the higher the pool concentration and/or wind velocity, the higher the evaporation rate. The surrounding turbulence effect was also taken into consideration and was proven to have a lower influence on the evaporation rate. In light of these experiments, we present below a physical model named EVAP-Tox used to estimate the time variation of the evaporation rate of an ammonia solution.

Observations of Small-Scale Turbulence and Energy Dissipation Rates in the Cloudy Boundary Layer

2006 ◽  
Vol 63 (5) ◽  
pp. 1451-1466 ◽  
Author(s):  
Holger Siebert ◽  
Katrin Lehmann ◽  
Manfred Wendisch
Keyword(s):  
Boundary Layer ◽  
Energy Dissipation ◽  
Wind Velocity ◽  
Turbulence Theory ◽  
Horizontal Wind ◽  
Inertial Subrange ◽  
Intermittent Flow ◽  
Small Scale ◽  
Dissipation Rates ◽  
Wide Range

Abstract Tethered balloon–borne measurements with a resolution in the order of 10 cm in a cloudy boundary layer are presented. Two examples sampled under different conditions concerning the clouds' stage of life are discussed. The hypothesis tested here is that basic ideas of classical turbulence theory in boundary layer clouds are valid even to the decimeter scale. Power spectral densities S( f ) of air temperature, liquid water content, and wind velocity components show an inertial subrange behavior down to ≈20 cm. The mean energy dissipation rates are ∼10−3 m2 s−3 for both datasets. Estimated Taylor Reynolds numbers (Reλ) are ∼104, which indicates the turbulence is fully developed. The ratios between longitudinal and transversal S( f ) converge to a value close to 4/3, which is predicted by classical turbulence theory for local isotropic conditions. Probability density functions (PDFs) of wind velocity increments Δu are derived. The PDFs show significant deviations from a Gaussian distribution with longer tails typical for an intermittent flow. Local energy dissipation rates ɛτ are derived from subsequences with a duration of τ = 1 s. With a mean horizontal wind velocity of 8 m s−1, τ corresponds to a spatial scale of 8 m. The PDFs of ɛτ can be well approximated with a lognormal distribution that agrees with classical theory. Maximum values of ɛτ ≈ 10−1 m2 s−3 are found in the analyzed clouds. The consequences of this wide range of ɛτ values for particle–turbulence interaction are discussed.

TurkStream Collapse Test Program

2018 ◽  
Author(s):  
Chris Timms ◽  
Doug Swanek ◽  
Duane DeGeer ◽  
Arjen Meijer ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thermal Ageing ◽  
Full Scale ◽  
The Black Sea ◽  
Small Scale ◽  
Test Program ◽  
Line Pipe ◽  
Medium Scale ◽  
Collapse Resistance ◽  
Full Scale Tests ◽  
The Impact

The TurkStream pipeline project is designed to transport approximately 32 billion cubic meters of natural gas annually from Russia to Turkey under the Black Sea, with more than 85% of the deep-water route being deeper than 2000 m. The offshore section is intended to consist of two parallel lines, each approximately 900 km long. The preliminary stages of the front end engineering design (pre-FEED) phase was managed by INTECSEA. To support the analyses and design of the deepest portions, a full scale collapse test program was performed by C-FER Technologies (C-FER). This collapse test program, which included 62 full-scale collapse and pressure+bend tests, 54 medium-scale ring collapse tests, and hundreds of small-scale tests, was primarily aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance resulting from the thermal induction heat treatment effect (thermal ageing) that arises during the pipe coating process. Two grades of 32-inch (813 mm) outside diameter (OD) line-pipe, SAWL450 and SAWL485 with wall thicknesses of 39.0 mm or 37.4 mm, respectively, were supplied from various mills for testing. The collapse test program objectives were as follows: • Determine the collapse resistance of line pipes originating from various pipe mills; • Determine the pressure+bend performance of line pipes originating from various pipe mills; • Measure the effect of thermal ageing on material and collapse testing results, including the impact of multiple thermal cycles; and • Evaluate the results of medium-scale ring collapse tests as compared to full-scale tests. This paper presents selected results of this work, along with some comparisons to predictive equations.

scholarly journals ANALYSIS OF THE FUCTIONAL ROLE OF RICE MILLING COMPANY ON THE WELFARE OF RICE FARMERS IN THE SUB-DISTRICT BUAY MADANG TIMUR DISTRICT OKU TIMUR

Jurnal AKTUAL ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 47
Author(s):  
Aisah Aisah
Keyword(s):  
Large Scale ◽  
Raw Materials ◽  
Small Scale ◽  
Functional Roles ◽  
Medium Scale ◽  
Rice Farmers ◽  
Result Show ◽  
Rice Milling ◽  
Processing And Storage

Rice Milling Company is rice industry’s oldest and largest classified in Indonesia, which is able to absorb more than 10 million workers, handles more than 40 million tons of grain.  Rice Milling Company agro-industy is the central point, because this is where the main product is obtained in the form of rice and raw materials for advanced processing of food and industrial products.  Rice Miling Unit in the district of OKU Timur there is some skala, ranging form small-scale, medium-scale to large-scale.  Fuctional benefits of each different scale milling is also different.  The average rice farmers often sell gabahnya to the rice milling unit closest to the place residence, whether it is large-scale, medium and small.  Rice produced by the milling-grinding different quality.  Usually when a large-scale millimg yield of rice is cleaner than the other scale.  But it does not become a reference for milling grain milling usually depends on consumer demand.  The purpose of the study are : 1.  To determine levels of volume (tonnage) and the retention time of each service fuctional rice storage (barns) wich carried a different scale rice milling unit.  2.  To determine differences in the bebefits of economic transactions received by farmers and rice millers of different scale of business, especially when seen from the level of the milling costs, the purchase price of rice by rice milling unit, and the quality of milling services and service scale.  The result show that : the fuctional role of each is different milling.  Large-scale milling has three fuctional roles are : Processing, storage and distribution.  Medium-scale miling functional has two roles, namely : processing and distribution.  While small-scale rice milling unit has only two functional roles are : processing and storage.

scholarly journals KAJIAN PERAN RISET DAN PENGEMBANGAN DALAM MENDUKUNG INDUSTRI KAKAO NASIONAL = STUDY ON THE ROLE OF RESEARCH AND DEVELOPMENT IN SUPPORTING INDONESIAN COCOA INDUSTRY

2016 ◽  
Vol 10 (1) ◽  
pp. 19-26
Author(s):  
Lamhot P. Manalu
Keyword(s):  
Research And Development ◽  
Foreign Exchange ◽  
Oil Palm ◽  
Small Scale ◽  
Processing Industry ◽  
Average Growth ◽  
Medium Scale ◽  
Intermediate Products ◽  
Quality Policy

Cocoa is commodities third largest foreign exchange earner after oil palm and rubber. In 2012 production totaled 833 310 tonnes of cocoa with an average growth of 1.56%. There are two major challenges in the development of the national cocoa industry, the increase in quantity (production and productivity) and quality. To support these efforts the role of research and development is needed to ensure that the procedures adopted are appropriate and fit. This study aims to study the role of research and development and other supporting factors in addressing the problems of the national cocoa. The study is in the form of survey respondents which are R&D institutes, universities and cocoa processing industry. The results show that there is a problem of national cocoa industry in all aspects, here the cultivation aspect is the biggest problem. The next aspects are mentoring, institutional, business scale, quality, policy, processing of intermediate products and processing of downstream products. The study also shows that there is still a lot of research results that can not be utilized by the cocoa industry, the rest has to be applied even if but only for a small scale so that the less significant. In the small and medium scale of cocoa enterprises, the equipment used is generally low capacity so inefficient. ABSTRAKKakao merupakan komoditas perkebunan penghasil devisa terbesar ketiga setelah kelapa sawit dan karet. Pada tahun 2012 produksi kakao tercatat sebesar 833.310 ton dengan rata-rata pertumbuhan sebesar 1,56%. Ada dua tantangan utama dalam pengembangan industri kakao nasional yaitu peningkatan kuantitas (produksi dan produktifitas) dan kualitas. Untuk mendukung usaha tersebut peran riset dan pengembangan (risetbang) sangat dibutuhkan untuk memastikan prosedur yang diterapkan sudah tepat dan sesuai.Studi ini bertujuan untuk mempelajari peran risetbang serta faktor pendukung lainnya dalam menjawab permasalahan kakao nasional. Studi ini berupa hasil survey terhadap responden (pelaku risetbang kakao) yaitu lembaga penelitian dan pengembangan, universitas serta industri pengolahan kakao. Hasil kajian menunjukkan bahwa permasalahan industri kakao nasional terdapat pada semua aspek, dimana aspek budidaya merupakan permasalahan terbesar. Aspek berikutnya adalah penyuluhan, kelembagaan, skala usaha, mutu, kebijakan, pengolahan produk antara dan pengolahan produk hilir. Studi juga menunjukkan bahwa masih banyak hasil riset yang tidak dapat dimanfaatkan oleh industri kakao skala besar, sisanya walaupun telah bersifat aplikatif tetapi hanya untuk skala kecil sehingga kurang signifikan. Pada industri usaha skala kecil dan menengah umumnya peralatan yang digunakan berkapasitas rendah sehingga tidak efisien.

scholarly journals Effect of the scale of production on the cost-effectiveness of milk production systems belonging to the “Balde Cheio” program

2018 ◽  
Vol 39 (3) ◽  
pp. 1211
Author(s):  
Flávio De Moraes ◽  
Marcos Aurélio Lopes ◽  
Francisval De Melo Carvalho ◽  
Afonso Aurélio de Carvalho Peres ◽  
Fábio Raphael Pascoti Bruhn ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Labor Force ◽  
Milk Production ◽  
Large Scale ◽  
Unit Cost ◽  
Small Scale ◽  
Total Cost ◽  
Medium Scale ◽  
Return On Capital ◽  
The Cost

This study investigates the cost-effectiveness of 20 demonstration units (DUs) belonging to the "Balde Cheio" program. The units in question are from the state of Rio de Janeiro, Brazil, dating from January to December 2011, and are sorted according to the scale of production (small, medium and large). The data were analyzed using Predictive Analytical software (PASW) 18.0. The scale of production influenced the total cost of milk production, and therefore profitability and cost-effectiveness. The large-scale stratum showed the lowest total unit cost. The positive results in medium and large scales in milk production lead to optimal conditions for long-term production, with the capitalization of cowmen. The items regarding the effective operating cost (EOC) with the biggest influence on the costs of dairy activity in the small scale stratum were food, energy and miscellaneous expenses. In the medium scale, these were food, labor force, and miscellaneous expenses. Finally, in the large scale, they were food, labor force and energy. In the small and large scale, the items regarding the total cost with the biggest influence on the costs of dairy activity were food, labor force, and return on capital, while in the medium scale, they were food, return on capital, and labor force. The average break-even point of 14 of the DUs was higher than the average daily production.

Time variation in transfer amounts of mercury by a river system near an artisanal and small-scale gold mining area in West Java, Indonesia

2019 ◽  
Vol 78 (24) ◽  
Author(s):  
Takashi Tomiyasu ◽  
Yuriko Kono Hamada ◽  
Christine Baransano ◽  
Nuril Hidayati ◽  
Joeni Setijo Rahajoe
Keyword(s):  
Time Variation ◽  
Gold Mining ◽  
River System ◽  
Mining Area ◽  
Small Scale ◽  
West Java

scholarly journals Laboratory Evaluation and Construction of Fully Recycled Low-Temperature Asphalt for Low-Volume Roads

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Christiane Raab ◽  
Manfred N. Partl
Keyword(s):  
Ambient Temperature ◽  
Laboratory Experiments ◽  
Traffic Simulation ◽  
Traffic Load ◽  
Laboratory Evaluation ◽  
Small Scale ◽  
Medium Scale ◽  
Low Volume Roads ◽  
Low Volume

Growing economy and increasing pollution evoke the need for more environmentally friendly road construction techniques and the saving of natural resources. In this context, cold recycling plays an important role since, on the one hand, it allows to reduce CO2 emissions drastically and, on the other hand, it offers a variety of opportunities for high percentages of recycling. Inspired by experience in Sweden, the international project “Optimal Recycling of Reclaimed Asphalts for low-traffic Pavement” (ORRAP) for low-volume roads in the Upper Rhine region aims to develop and establish a new strategy for 100% reclaimed asphalt pavement (RAP) at ambient temperature (20°C) without adding virgin bituminous binders or rejuvenators. The still ongoing research project involves laboratory experiments as well as in situ test sections. The link between small-scale laboratory experiments and in situ testing is provided by medium-scale traffic simulation in the laboratory. This paper describes results from medium-scale compaction in the laboratory using different methods as well as traffic simulation with a medium-scale mobile traffic load simulator. The results show that compaction in the laboratory at ambient temperature (20°) is very difficult to achieve. Nevertheless, it was found that compaction at a temperature of 60°C appears possible and provides promising results regarding stability and rutting enabling the in situ construction. The in situ pavement construction at ambient temperature on a low-volume road in Switzerland resulted in a visibly well-compacted and stable base course which was covered by a hot mix asphalt surface course the day after. The test section will be monitored closely over the next 12 months.

scholarly journals Hydrologic-environmental effects of sponge city under different spatial scales

2019 ◽  
Vol 10 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Jiake Li ◽  
Cong Mu ◽  
Chenning Deng ◽  
Menghua Ma
Keyword(s):  
Environmental Effects ◽  
Large Scale ◽  
Peak Flow ◽  
Spatial Scales ◽  
Small Scale ◽  
Pollution Load ◽  
Sponge City ◽  
Medium Scale ◽  
Total Runoff ◽  
Runoff Reduction

Abstract The storm water management models were established at three spatial scales (large, medium, and small) based on a sponge city pilot area in China to explore the hydrological and environmental effects of rainfall conditions and development modes. Results showed the following. (1) Total runoff reduction rates increased from 26.7% to 53.9% for the rainfall event of a 2-year recurrence period as the scale increased. For 5-year and above recurrence periods, total runoff reduction rates were 19.5–49.4%. These rates increased from the small to medium scale and slightly decreased from the medium to large scale. (2) The runoff coefficients were 0.87–0.29, which decreased from the small to medium scale and were basically constant from the medium to large scale. (3) The peak flow reduction rates decreased with increased recurrence periods. The rates increased initially and then decreased at the small scale, whereas the opposite trend occurred at the medium scale. (4) The reduction rates of pollutants were negatively correlated with recurrence periods under the three spatial scales. The pollution load reduction rates were 19.5–54.7%, which increased from the small to medium scale and were basically constant from the medium to large scale.

scholarly journals Cartographic Remote-Sensing Monitoring of Glaciological Systems (Example, Mount El‛ Brus, U.S.S.R.) (Abstract)

1987 ◽  
Vol 9 ◽  
pp. 247-248
Author(s):  
Yu. F. Knizhnikov ◽  
V.I. Kravtsova ◽  
I.A. Labutina
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Large Scale ◽  
Quantitative Information ◽  
Snow Accumulation ◽  
Aerial Photographs ◽  
Small Scale ◽  
Medium Scale ◽  
Remote Sensing Monitoring ◽  
Periglacial Zone

Remote-sensing methods in monitoring the glacierization of Mount EI‛ brus are used to produce base and dynamic maps, and to obtain quantitative information (dynamic indices) about the rate, intensity, and variations of the process. The monitoring system is divided, according to scope and territory covered, into small-scale for total glacierization and the periglacial zone, medium-scale for separate glaciers, and large-scale (detailed) for part of the glaciers or sectors of the adjoining slopes. The approximate relationship of even scales is 1 : 4. Small-scale monitoring remote-sensing systems are important for making maps showing the complex characteristics of the glaciological system. A series of maps was produced including geographical, those of high-altitude zones, slope and exposure angles, geological, glaciomorphological, climatic (temperature, precipitation, and winds), distribution of direct solar radiation, hydrological (source of streams), seats of avalanches, and landslides. All these data serve as a cartographical basis in monitoring the glacierization of Mount EI‛ brus. They are compiled from remotely sensed and Earth-based data. Current monitoring on a small scale includes observations of the conditions which determine the existence of the glacial system - this includes data on winter snowfall and the period of snow cover. These observations were obtained from meteorological and resource satellites, and from scanner data of medium and high resolution. Also important are observations of changes in the outline of glaciers, times of snowfall and character of the distribution of snow, and its redistribution due to avalanches and snowstorms. High-resolution space photographs, small-scale aerial photographs, and aerovisual observations provide the data for these observations. It has been determined that the area of the glaciers of Mount El‛ brus has been reduced by 1 % in the last 25 years, i.e. the rate of its deglacierization dropped sharply as compared to preceding decades. The role of quantitative information gains importance in the medium-scale level of monitoring. Topographical maps of separate glaciers compiled from aerial photographs or data from ground stereo-photogrammetric surveys constitute the base maps at this level. The main method used in monitoring were large-scale surveys from aircraft, perspective surveys from helicopters, and phototheodolite surveys. Multi-date surveys of the glaciers provide data about the changes in their outlines and height, the character of their relief, their moraines, the amount of snow accumulation and ablation in separate years, the surface rates of ice flow and their fluctuations. The techniques by which quantitative information is obtained about changes in the glaciers are derived from processing the data of multi-date surveys. The organization and techniques of phototheodolite surveys have been improved. A theory evolved for determining the surface-ice movement by stereo-photogrammetric means and the technique for it has also improved; algorithms and programs for machine processing of the data of multi-date surveys (ground and from aircraft) have been produced At this level of monitoring, it has been found that the retreat rate of most glaciers has slowed down and several glaciers are now in equilibrium. Several glaciers became active at the beginning of the 1970s and 1980s; this was accompanied by an increase in their height and forward movement. For example, activation of Kyukyurtlyu Glacier has been recorded (higher surface and increasing flow rate) which has caused the glacier to move forward 100 m. Surveys at an interval of 2 years recorded the beginning of the process of retreat of this glacier. Detailed monitoring is used to detect the mechanism of the dynamic processes and to study it on local representative sectors. On a glacier it may take the form of annual surveys of its tongue, which makes it possible to observe the processes of formation of moraines and glacio-fluvial relief. Studies may also be made of the mechanism of the movement of avalanches and landslides, deducing their quantitative characteristics and appraising the results of avalanches and landslides. Multi-date surveys of sectors of the slopes provide information about processes in the periglacial zone. At this level, regularly repeated ground stereo-photogrammetric surveys are the main means of observation. Glaciological remote-sensing monitoring provides a wealth of data for theoretical development in the field of glaciology. It makes it possible to forecast and produce warnings about hazardous processes and phenomena.

Sign in / Sign up

Export Citation Format

Share Document