Small-scale Apparatus Research Articles

The Fate of Mycotoxins during the Distillation Process of Barley Shochu, a Distilled Alcoholic Beverage

Mycotoxins are frequent contaminants of grains and critical risk substances for brewers. Fermented barley mash contaminated artificially with 13 representative mycotoxins was distilled with small-scale apparatuses to elucidate the possibility of mycotoxin transfer from mash to distillates. None of these were detected in the distillates. The distillation process can effectively reduce the contamination risk posed by mycotoxins in distilled alcoholic beverages.

9학년 과학교과서 물질변화에서의 규칙성 단원 실험 분석과 Small-Scale Chemistry를 적용한 실험 개발

이 연구는 9학년 과학교과서 물질변화에서의 규칙성 단원에 제시되어 있는 실험의 분석과 small-scale chemistry (SSC)를 적용한 실험을 개발하고자 하는 것이다. 연구를 위하여 9학년 9종 과학교과서의 물질변화에서의 규칙성 단원에 제시되어 있는 앙금생성, 물의 전기분해, 과산화수소수의 분해 실험들을 분석하고, 13명의 과학교사들에게 과학교과서의 실험들을 수행하게 하여 문제점과 개선해야할 사항들을 추출하였다. 개선해야할 사항들을 바탕으로 SSC를 적용하여 개발한 실험들을 19명의 예비교사들에게 과학교과서의 실험과 함께 수행하게 한 후 SSC를 적용한 실험의 장점과 단점을 조사하였다. 연구 결과, 요오드화납 앙금생성 실험과 Hoffman식 물의 전기분해 실험, 그리고 이산화망간을 촉매로 사용하는 과산화수소수의 분해 실험이 9학년 과학교과서에 가장 많이 제시되어 있었다. 과학교과서의 실험들에서 개선해야할 사항들로는 시약의 소모량, 실험시간, 실험장치 규모 등이었다. SSC를 적용하여 개발한 실험들의 장점은 적은 양의 시약 사용으로 폐액 처리의 용이성과 실험의 안전성을 높여주며, 실험시간의 단축과 재현성이 있는 실험결과들을 얻을 수 있는 것 등이었다. 반면에 단점은 적은 양의 시약 사용으로 실험관찰에서 다소간의 어려움과 성취감의 감소, 작은 규모의 실험 기구 사용의 미숙함 등이었다. 그러나 SSC를 적용하여 개발한 실험들을 9학년 과학실험으로 활용한다면, 적은 양의 시약을 사용하여 간편하게 재현성이 있는 실험을 이론수업과 병행하여 실시할 수 있어, 학생들이 물질변화에서의 규칙성에 대한 과학적인 개념을 형성하는데 도움을 줄 것으로 기대된다. The purpose of this study was to analyze experiments for the rules of material change unit in 9th grade science textbooks and develop experiments applying small-scale chemistry (SSC). For this study, experimental methods for the precipitation experiment, water electrolysis experiment, decomposition of hydrogen peroxide experiment presented in the 9 science textbooks were analyzed. Problems and improvements that were needed were extracted by 13 science teachers performing the experiments. Experiments applying SSC were developed based on the improvements needed. Afterwards, 19 pre-service science teachers performed both the developed SSC experiments and the science textbooks' experiments. A questionnaire about merits and demerits of the experiments applying SSC was performed. According to the results of this study, most of the 9th grade science textbooks included the lead iodide precipitation experiment, water electrolysis experiment by Hoffman voltameter, and decomposition of hydrogen peroxide experiment using catalytic manganese dioxide. Improvements were needed on the quantity of reagents, time for performing experiments, and scale of experimental apparatus. Merits of the developed experiments applying SSC which used small amount of reagents were safety, easy waste material disposal, short reaction time, and reproducible experimental results. Demerits of the experiments applying SSC were difficulty in observing, decreased achievement, and lack of skill in handling small-scale apparatus. Therefore, if the experiments developed applying SSC were to be utilized in 9th grade science experiments, it will be possible to use less reagent and be able to teach and carry out reproducible experiments at the same time. Also, the reproducible experiments based on SSC will help students under stand the scientific concepts for the rules of material change unit.

Analytical Approach for Predicting Effects of Vitiated Air on the Mass Loss Rate of Large Pool Fire in Confined Compartments

The aim of this study is to determine the vaporization rate of an under-ventilated pool fire in a closed environment. A theoretical model that allows the determination of the burning rate of fuels for compartment fires under vitiated conditions is presented. In this formulation, the radiative and convective components of the heat flux from the flame to the pool surface are both evaluated and related to the ambient oxygen mass fraction. The model was first compared with the empirical correlation determined by Peatross and Beyler before being applied to pool fires using heptane and PMMA as fuels in a small-scale apparatus. The global model presented here was then implemented in the CFD code ISIS and was validated against experiments involving a Hydrogenated Tetra-Propylene pool fire test in a confined and mechanically ventilated compartment. It is shown that the model is able to correctly predict the fuel mass loss rate and provides a reasonable assessment of the heat flux from the flame to the pool surface.

Analytical Approach for Predicting Effects of Vitiated Air on the Mass Loss Rate of Large Pool Fire in Confined Compartments

The aim of this study is to determine the vaporization rate of an under-ventilated pool fire in a closed environment. A theoretical model that allows the burning rate of fuels to be determined for compartment fires under vitiated conditions is presented. The radiative and convective components of the heat flux from the flame to the pool surface are both evaluated and related to the ambient oxygen mass fraction. The model was first compared with the empirical correlation determined by Peatross and Beyler [1] before being applied to pool fires using heptane and PMMA as fuels in a small-scale apparatus. The global model presented here was then implemented in the CFD code ISIS and was validated against experiments involving a hydrogenated tetra-propylene pool fire test in a confined and mechanically ventilated compartment. It is shown that the model is able to correctly predict the fuel mass loss rate and provides a reasonable assessment of the heat flux from the flame to the pool surface.

Precision of the Cone Calorimeter and ICAL Test Methods

Repeatability and reproducibility are typically determined for standard fire test methods on the basis of an interlaboratory test program (round-robin) to define their precision. Significant differences in precision were found in the past between the repeatability and reproducibility of small-scale and intermediate- and large-scale fire test methods that all utilize oxygen calorimetry to measure heat release rate. Repeatability of heat release rate related measurements with small-scale apparatus has been found to be significantly better than the repeatability of the intermediate and large-scale apparatuses. In this paper, the results of two round-robins are compared on the basis of relative repeatability standard deviations and relative reproducibility standard deviations calculated for individual materials for individual test parameters. The first one was a cone calorimeter round-robin and the second was an intermediate-scale calorimeter (ICAL) round-robin. The objective and subjective factors that might have contributed to the differences between the two test methods in both repeatability and reproducibility were analyzed. The most important factors that caused the differences in the ICAL round-robin were higher theoretical uncertainty of the ICAL, inadequate pre-round-robin calibrations, the small numbers of participating laboratories and samples tested, prevalence of fire-retardant-treated materials, and possible failure of some of the laboratories to fully comply with the standard. These factors, especially the fact that the testing procedures and apparatuses in the participating laboratories may not have been in complete accordance with the standards, indicate that the results of the round-robins did not reflect the real precision of the test methods. However, the terminology using the two components of precision, repeatability and reproducibility, is maintained in this paper except where a specific distinction is noted. Recommendations are made on how to improve the results of future fire test round-robins.

Design and testing of a small-scale sublimation apparatus

In many areas of scientific research and development, for example in the pharmaceutical industry, it is important to prepare and to characterize crystals of pure organic compounds which are thermodynamically stable. The formation of crystals from the gas phase is technically less straightforward than crystallisation from solution, but sublimation techniques can have several important features. In the present paper we report the design and testing of a novel apparatus for small scale sublimation and fractional deposition of crystals. The instrument has been developed with special reference to the needs in the pharmaceutical industry. A few mg of the samples are enclosed, under reduced pressure, in thin-walled glass tubes, along which a well defined temperature gradient can be formed. During an experiment the substance will sublime from the hot end of the glass tube and crystals will be deposited along the temperature gradient. The applicability of the instrument has been verified by experiments with several test compounds. Results from experiments with carbamazepine, are reported in some detail. Carbamazepine single crystals of high quality were obtained and the transition temperature between the triclinic (Form I) and the monoclinic (Form III) crystal modifications agreed with literature values.

Mixing of Horizontally Injected High-Density Solution in Vertically Upward Low-Velocity Water Flow

Basic experiments on the mixing of horizontally injected high-density calcium chloride water solution in vertically upward low-velocity water flow have been performed in a small-scale apparatus. Mixing patterns observed in the experiments have been classified into complete mixing and incomplete mixing, or complete entrainment and incomplete entrainment. In complete mixing, the injected high-density solution is completely mixed with or entrained into the vertically upward water flow. On the other hand, in incomplete mixing, the high-density solution is partly mixed with or entrained into the vertically upward water flow and partly falls down or stays there even in the upward water flow. Numerical calculations have been conducted by solving the continuity equation and the momentum equations for the total fluid together with the mass transfer equation for the solute, taking density change into account. The numerical calculations have predicted approximately the increase in mixing efficiency, which is defined as the fraction of the injected solute mass that actually leaves the test section, and the calculations also have estimated approximately the boundary flow rates between the complete and incomplete mixing processes observed in the experiments.

Mixing of Horizontally Injected High-Density Solution in Vertically Upward Low-Velocity Water Flow

Basic experiments on the mixing of horizontally injected high-density calcium chloride water solution in vertically upward low-velocity water flow have been performed in a small-scale apparatus. Mixing patterns observed in the experiments have been classified into complete mixing and incomplete mixing, or complete entrainment and incomplete entrainment. In complete mixing, the injected high-density solution is completely mixed with or entrained into the vertically upward water flow. On the other hand, in incomplete mixing, the high-density solution is partly mixed with or entrained into the vertically upward water flow and partly falls down or stays there even in the upward water flow. Numerical calculations have been conducted by solving the continuity equation and the momentum equations for the total fluid together with the mass transfer equation for the solute, taking density change into account. The numerical calculations have predicted approximately the increase in mixing efficiency, which is defined as the fraction of the injected solute mass that actually leaves the test section, and the calculations also have estimated approximately the boundary flow rates between the complete and incomplete mixing processes observed in the experiments.

Small-scale forward smouldering experiments for remediation of coal tar in inert media

This paper presents a series of experiments conducted to assess the potential of smouldering combustion as a novel technology for remediation of contaminated land by water-immiscible organic compounds. The results from a detailed study of the conditions under which a smouldering reaction propagates in sand embedded with coal tar are presented. The objective of the study is to provide further understanding of the governing mechanisms of smouldering combustion of liquids in porous media. A small-scale apparatus consisting of a 100-mm in diameter quartz cylinder arranged in an upward configuration was used for the experiments. Thermocouple measurements and visible digital imaging served to track and characterize the ignition and propagation of the smouldering reaction. These two diagnostics are combined here to provide valuable information on the development of the reaction front. Post-treatment analyses of the sand were used to assess the amount of coal tar remaining in the soil. Experiments explored a range of inlet airflows and fuel concentrations. The smouldering ignition of coal tar was achieved for all the conditions presented here and self-sustained propagation was established after the igniter was turned off. It was found that the combustion is oxygen limited and peak temperatures in the range 800–1080 °C were observed. The peak temperature increased with the airflow at the lower range of flows but decreased with airflow at the higher range of flows. Higher airflows were found to produce faster propagation. Higher fuel concentrations were found to produce higher peak temperatures and slower propagation. The measured mass removal of coal tar was above 99% for sand obtained from the core and 98% for sand in the periphery of the apparatus.

Evaluation of the composition of the binder bridges in matrix granules prepared with a small-scale high-shear granulator

The aim of this work was to evaluate the binder bridges which can form in hydrophilic matrix granules prepared with a small-scale high-shear granulator. Matrices contained hydroxypropyl methylcellulose (HPMC) as a matrix-forming agent, together with lactose monohydrate and microcrystalline cellulose as filler. Water was used as granulating liquid. A 2 4 full factorial design was used to evaluate the effects of the operational parameters (impeller speed, chopper speed, dosing speed and wet massing time) on the granulation process. The temperature of the sample increased relevantly during the preparation in the small-scale apparatus. The same setup induced different temperature increases for different amounts of powder. This alteration enhances the solubility of lactose and decreases that of HPMC, and thus the quantities of the dissolved components can vary. Accordingly, changes in composition of the binder bridge can occur. Since exact determination of the dissolution of these materials during granulation is difficult, the consequences of the changes in solubility were examined. Differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and X-ray diffraction (XRD) measurements were made to evaluate the films prepared from liquids with different ratios of soluble materials. The DSC and XRD measurements confirmed that the lactose lost its crystalline state in the film. The TMA tests revealed that increase of the quantity of lactose in the film decreased the glass transition temperature of the film; this may be attributed to the interaction of the additives. At a lactose content of 37.5%, a second glass transition appeared. This phenomenon may be indicative of a separate amorphous lactose phase.

Modelling of steel scrap movement

Uneven movement of steel scrap during electric arc furnace melting causes operational problems, such as cave-ins. To understand the phenomenon, a small-scale apparatus has been built to simulate the flow of scrap that may be interlocked. It was found that flow starts at the point where the suspended length of the pile bottom reaches the average scrap size. The force balance in a suspended scrap pile has been analyzed to estimate the effective cohesion of interlocking. A numerical model has been developed to simulate the scrap flow.

Mechanisms for Stormwater Surges in Vertical Shafts

A num ber of large scale combined sewer systems have experienced events in which surges have resulted in the return of poor quality stormwater to grade in what are referred to as geysers. In spite of current concerns that these events be avoided by the proper design of new systems, there have been limited investigations to understand the conditions that lead to these surges or how to avoid them. In the course of an ongoing investigation into the dynamics of rapidly filling pipelines, two phenomena have been identified that may result in geyser-like phenomena. Both of these are associated with the movement of a large pocket of entrapped air along the crown of a nearly horizontal pipe. One case occurs when the leading edge of the air cavity arrives at a vertical riser at a location along the pipeline that is already in a surcharged state. A second case occurs as the trailing edge of the same air pocket arrives at the riser and the pipe is not in a surcharged condition. Experiments have been performed to reproduce both of these situations in a simplified fashion where several of the key variables can be controlled. The features of these experiments are described as well as some of the results obtained to date. These results are interpreted to identify aspects of a storage tunnel system that are under design control and how these affect the magnitude of the observed surges. Finally, since the experiments are performed in a relatively small-scale apparatus, speculation is presented on

1464 サイフォン吸引による堆積土砂・汚泥除去 : 小型試験と解析(S37-1 混相流動のダイナミックス(1),S37 混相流動のダイナミックス)

A new removal system of sediment on lake and/or reservoir bed by siphonage has been invented by Sadatomi, one of the present authors. The system seems useful to increase the capacity as well as to improve the water quality of lake and/or reservoir. In order to find an optimum design method of it in a practical application, experiments have been conducted using a small-scale apparatus having 1.2m long and 20mm I.D. siphon pipe. In addition, a mathematical model has been proposed to predict its hydraulic performance, and the model has been tested against the present experimental data to validate. The results of such experiments, analysis and validity tests are reported in this paper.

MASS BALANCE AND DISPERSANT EFFECTIVENESS: ARE NEW TECHNIQUES AND METHODOLOGIES NEEDED?

ABSTRACT In order to obtain a scientifically-acceptable measurement of dispersant effectiveness, the oil mass balance must be demonstrated. While this is normal in small-scale laboratory apparatus, it has not been achieved in larger-scale wave basin and open ocean experiments despite the work of a large number of research groups. Five years ago, mass balance was either ignored or losses of up to fifty percent of the applied oil were accepted. In the larger wave basin experiments, recent work has reduced the unknown losses to between ten and fifteen percent. No such reduction has been achieved in the few open ocean tests that have been recently undertaken. This paper will discuss the limitation of current measuring technologies and experimental techniques. New experimental techniques will be suggested to improve mass balance calculations, such as changing the experimental plan for large wave basins from a Lagrangian description of motion to an Eulerian frame of reference. There are technologies, that can be applied to large wave basins, that are unique to this experimental situation, but are not widely used. These technologies will be discussed. For the open ocean situation, there are seldomly-used methods, which could be employed to improve the measurement of sub-surface plume characteristics and oil thickness on water. The current limitations of these technologies will be discussed.

Preliminary study on the suppression chemistry of water mists on poly(methyl methacrylate) flames

It is well-known that fire suppression by water mist is mainly based on physical effects such as heat extraction, oxygen displacement and attenuation of thermal radiation. However, the chemical effects of water mist on fire suppression are not yet clearly understood. As polymeric materials have been widely used in modern buildings, investigating the suppression chemistry of water mist on burning polymers is also important. The objective of this paper is to simulate the water sprays for fire extinction by a small-scale apparatus. Combustion products of poly(methyl methacrylate) (PMMA) in the surroundings with and without fine water mist were collected and analysed by gas chromatography (GC) and GC with mass spectrometry. The results showed that there exists a critical flow value of the water mist applied in the confined fire space. Complex products, such as aromatic compounds, were produced due to the interaction of water vapour with the PMMA flame.

Viscosity of ‘live’ water-in-crude-oil emulsions: experimental work and validation of correlations

A method for measuring emulsion viscosity under pressurized (1–100 bar) and temperature-controlled flow conditions is described. It makes use of a flow simulator shaped as a hollow wheel. As the wheel is rotating, the liquid inside will have a relative motion in the opposite direction of the rotation. The torque acting on the wheel shaft is measured and transformed, via a calibration model, into the viscosity of the fluid. The method has been applied to water-in-oil emulsions with several live North Sea crude oils with saturation pressures up to 100 bar and water cuts in the range 0–90%. The method is shown to be a useful way of obtaining estimates of emulsion viscosity for live oil systems in a relatively small scale apparatus. Even though the crude oils studied were rather different and had very different viscosities, the relative viscosities as a function of water cut up to at least 60% showed small variation and might be represented by a general ‘master curve’. The relative viscosities obtained experimentally have been compared to a temperature-dependent Richardson-type correlation [Rønningsen, H.P., 1995. Correlations for predicting viscosity of W/O-emulsions based on North Sea crude oils. Proc. SPE Int. Symp. Oil Field Chem., Houston, TX, USA, SPE 28968], and three other correlations proposed by Mooney [J. Colloid Sci. 6 (1951) 162], Pal and Rhodes [J. Rheol. 337 (1989) 1021] (P&R) and Pal [J. Colloid Interface Sci. 231 (2000) 168], respectively. Overall, when being tuned to measured data, the P&R correlation gives the best match, closely followed by the Mooney correlation, but for low and medium water cuts, the Rønningsen correlation is comparable. This correlation does not require any measurements for tuning. Although it may be slightly conservative at low to medium water cuts, and somewhat optimistic at very high water cuts, for practical purposes in design of flow lines, it provides a reasonably accurate first estimate of the effective liquid phase viscosity. The recent correlation of Pal [J. Colloid Interface Sci. 231 (2000) 168] was found to be extremely sensitive to the choice of tuning point and, thus, to be rather inaccurate either at low water cuts or high water cuts.

Tertiary nitrification in a new dual-medium aerated filter

In an effort to develop an aerated filter with high nitrification capabilities, we formulated a new filter with 2 layers: the upper layer is filled with a plastic medium, and the lower with anthracite. We tested the filter in a pilot-scale apparatus on secondary-treated sewage, and in a small-scale apparatus on secondary-treated sewage and on artificial sewage. We evaluated the nitrification characteristics under various conditions of water velocity, air velocity, temperature, and pH. We designed a tertiary plant to treat 20,000 m3/day of secondary-treated sewage, using the new filter or a conventional filter. From these comparisons, it appeared that the dual-medium aerated filter had high nitrification capabilities and was an effective device for tertiary sewage treatment.

Experimental Verification of Vapor Insulation System And Its Application to LNG and LH2 Tank

For storage and transport of liquefied gas such as LNG or LH2 (liquefied hydrogen), it is of great importance to reduce the boil off gas to a minimum. The thermal insulation system is playing a significant roll here. Though the specification of tank insulation should be decided by the boil off figure of a desired total system from a view point of an economical and practical use of it, the reduction of evaporated quantity is being demanded stronger, and any achievements to enhance the reduction are appreciated. The authors have introduced a new concept for enhancement of insulation efficiency by indirectly using the cold boil off gas as a protective shield or a heat sink to limit transmission of heat to the tank/cargo. To verify this theory of “vapor insulation system”, an experiment based on cold gas flow was carried out in a small scale apparatus to analyze carefully the effect on the heat transmission with and without cold vapor flow. These results were implemented in a calculation model of a spherical tank for LNG and LH2, and combined with some parameters such as gas flow quantity, gas temperature and location of gas passage. Based on this work realistic examples of design were proposed for a new insulation system. The configuration takes into account the concept of the small leak protection system for MOSS spherical tank. The principle of this new insulation concept proposed is that cold nitrogen gas which is produced by heat-exchange with the boil off LNG or LH2 vapor flows through a small passage created in the insulation structure. The upward flow of cold gas through the annular space around the tank will absorb the heat from the hold space of the cargo tank before it reaches the valuable liquid cargo, and it will simultaneously work as a leak detection system of cargo.

Dioxin and NOx Control Using Pilot-Scale Pulsed Corona PlasmaTechnology

We carried out tests on certain incinerator plant for two years from 1993 through 1994, to assure the effect of pulsed corona discharge for removal of NOx and dioxin in flue gas in the small-scale experimental apparatus. The gas volume of the test plant is 50NM3/H. By the experiment, high performance of dioxin removal at the gas temperature of 150°C was achieved. Regarding NOx, the reduction efficiency of NO was about 60 percents, whereas that of NOx including NO2 was 30 percents at most.

水張格納容器方式の冷却材喪失事故時の圧力挙動に関する基礎実験

Japan Atomic Energy Research Institute has been conducting a design study of an advanced marine reactor MRX. MRX employs a water-filled containment vessel. In a case of loss of coolant accident (LOCA), the discharge of water from the reactor vessel almost stops when the pressures of reactor vessel and containment vessel become equal. The core flooding can be maintained passively. The MRX, therefore, does not adopt a safety injection system which the conventional reactors have.The purpose of this study is to investigate the thermal hydraulic behavior in the water-filled containment vessel during the LOCA. This report describes the fundamental experimental study focused on pressure increase of the containment vessel. The experiment was carried out by using a small scale apparatus. The pressures and temperatures in the vessels were measured. According to our observation, the vapor bubbles at nozzle exit contracted or expanded caused by flashing due to pressure reduction or condensation in the containment water. The pressure increase in the containment vessel was revealed to be the sum of compressed nitrogen gas pressure and saturated steam pressure. One-volume thermal equivalent model can predict well the pressure increase in the containment vessel in this experiment.