A Method to Measure Emissions from Dryers with Diffuse Leakages,Using Evaporated Water as a Tracer

Abstract

This paper describes a novel method to measure emission from dryers. The method resolves the known difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapor to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted VOCs and to determine the moisture content of the drying medium.     

A Method to Measure Emissions from Dryers with Diffuse Leakages 2—Sensitivity Studies

Measurements of VOC emissions from dryers have several known difficulties. An earlier published method to measure emissions of VOC from dryers deals with problems associated with diffuse emissions and high moisture content of the drying medium.^[1] In this article, a different calculation path are used and the influence of the main parameters are studied in more depth. For one experiment, confidence intervals for all of the parameters are calculated. Experimentally induced uncertainties are found to be more important than a theoretically important parameter. Suggestions are made on how to increase accuracy.     

A Procedure to Measure the Diffusion Coefficient of Water in Brick as a Function of the Water Concentration

A procedure to measure the diffusion coefficient of water in brick as a function of the water concentration has been proposed, based on a method of measuring the mass of a drying brick at both outer ends. In this method, the brick is subjected to one-dimensional drying. The procedure was tested using a simulation with realistic parameter values and experimental inaccuracies. An experiment consisted of 120 s of drying and measuring the masses every 10 s with an accuracy of 10^?6 kg. The sample was first dried to a lower water content and the drying was stopped for some time to allow the concentration profile to approximate a known equilibrium concentration profile, after which another measurement was performed at that lower water content. Minimizing the differences between the masses, as measured and as it follows from the model, gave the value of the diffusion coefficient. The method failed for low water concentrations.     

分光光度法测定循环水中微量甲醇

采用高锰酸钾在酸性介质中将甲醇氧化为甲醛,甲醛与变色酸生成紫红色化合物进行比色测定,试验了介质酸度、保持时间、保持温度和波长对测定结果的影响,优化选择了最佳的测定条件,建立了分光光度法测定循环水中微量甲醇的方法。方法测定下限介于0.005~0.008 mg之间,加标回收率在95%~103%之间,相对标准偏差小于2%。     

用热水示踪技术测量蒸馏塔板上液体返混的微机温度测量装置

对测量塔板上液体返混的温度测量仪进行了调试研究,仪器的测量精度为1.5级,时间常数为4.0～4.8s,相对滞后时间为0.05～0.3s。仪器有良好的重复性和分辨能力,采用激励一响应技术用热水做示踪．通过对涡流扩散系数测试值和计算值的比较,仪器的测量结果准确可靠。     

A New Method to Measure Aerosol Particle Bounce Using a Cascade Electrical Low Pressure Impactor

The phase state of secondary organic aerosol (SOA) in the atmosphere is of scientific interest as it can impact SOA growth and reactivity. For this purpose, a simplified method is described herein to estimate SOA bounce factor to gain an improved understanding of the phase state of atmospheric aerosols. This new method involves the use of a multistage electrical low pressure cascade impactor operating with either smooth or sintered impaction plates. Measurement of the raw current on smooth and sintered plates allows one to calculate the bounce factor, eliminating the need for a scanning mobility particle sizer to independently measure the SOA aerodynamic size distribution. The proposed method provides the temporal resolution necessary to measure phase changes in a continuously evolving SOA parcel.

We validate our method by measuring the bounce factor of solid and liquid aerosols, namely ammonium sulfate (AS), dioctyl sebacate (DOS), oleic acid (OA) and ozonized OA, and also present bounce factor evolution of aging α-pinene-derived aerosols. The results suggest that the new method can be used to understand the phase state of amorphous and crystalline substances, as well as distinguish between liquid and nonliquid particles.

Copyright 2015 American Association for Aerosol Research     

Investigation of Diamond Synthesis from a Mixture of an Explosive with a Carbon Additive Using a Tracer Technique

The synthesis of detonation diamonds from a mixture of RDX labeled by C¹⁴ isotope with soot was studied experimentally. It was shown that a considerable portion of the diamonds (24.7 ± 3.4)% are formed from the carbon of RDX molecules. The degree of conversion of the carbon atoms of soot to the diamond phase is (16.0 ± 1.6)%. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 117–118, September–October, 2005.     

A Novel Atmospheric Freeze-Drying System Using a Vibro-Fluidized Bed with Adsorbent

Atmospheric freeze drying (AFD) in a vibro-fluidized bed dryer coupled with an adsorbent and multimode heat input is proposed for dehydration of food products at lower cost than the traditional freeze-drying process under vacuum. The aim of this project is to study the proposed AFD system using a vortex tube to produce low-temperature dry air, an alternative for producing dried food products of high quality. An experimental setup was designed and built to permit simultaneous application of convection, conduction, and radiation heat input to the drying material above its freezing point to ensure sublimation. A parametric evaluation over a broad range of possible parameter values was carried out using cubic-shaped potato and carrot as model heat-sensitive products. The influence of various system parameters on drying kinetics, quality, and functional properties of the dried products (color, rehydration properties, and morphology) were investigated. Comparison between physical quality and drying characteristics of the AFD system with AFD using fixed bed, fluidized bed dryer, and also with traditional vacuum freeze drying were carried out to investigate the viability of this new system. Results indicate that proposed system is an alternative to reduce the process time as well as to maintain the product quality at lower cost.     

A Novel Atmospheric Freeze-Drying System Using a Vibro-Fluidized Bed with Adsorbent

Atmospheric freeze drying (AFD) in a vibro-fluidized bed dryer coupled with an adsorbent and multimode heat input is proposed for dehydration of food products at lower cost than the traditional freeze-drying process under vacuum. The aim of this project is to study the proposed AFD system using a vortex tube to produce low-temperature dry air, an alternative for producing dried food products of high quality. An experimental setup was designed and built to permit simultaneous application of convection, conduction, and radiation heat input to the drying material above its freezing point to ensure sublimation. A parametric evaluation over a broad range of possible parameter values was carried out using cubic-shaped potato and carrot as model heat-sensitive products. The influence of various system parameters on drying kinetics, quality, and functional properties of the dried products (color, rehydration properties, and morphology) were investigated. Comparison between physical quality and drying characteristics of the AFD system with AFD using fixed bed, fluidized bed dryer, and also with traditional vacuum freeze drying were carried out to investigate the viability of this new system. Results indicate that proposed system is an alternative to reduce the process time as well as to maintain the product quality at lower cost.     

A Reliable Method to Measure the Adhesive Force with a Tiny Amount of Adhesive Material

A new method is proposed and developed to measure adhesive forces by use of the force-distance curve of a micro cantilever with an extremely small amount of testing material such as adhesive proteins. The contact area should be well-controlled at a reasonable value. Even though the area is desired to be as small as possible, a contact region of several micrometers by several micrometers is adopted in order to avoid obtaining meaningless measured values and uncertainty in the contact areas. An AFM cantilever is used after having been modified with a micro glass bead to enlarge the contact area for adhesion. A glass plate with micro-scale circular patterns is fabricated from a glass wafer by micro-machining processes in order to control precisely the contact area in adhesion tests. In the proposed method the adhesive materials are directly applied to the bead attached at the AFM cantilever before it is applied on the top area of the truncated cone on the fabricated glass plate. The developed method is applied to measure the adhesive forces of Cell-Tak® (which is a commercial extracted mussel adhesive) and recombinant Mgfp-5 (which is a recombinant mussel adhesive protein) and the statistical credibility of the measured adhesive force data is enormously improved as a result.     

A Reliable Method to Measure the Adhesive Force with a Tiny Amount of Adhesive Material

A new method is proposed and developed to measure adhesive forces by use of the force-distance curve of a micro cantilever with an extremely small amount of testing material such as adhesive proteins. The contact area should be well-controlled at a reasonable value. Even though the area is desired to be as small as possible, a contact region of several micrometers by several micrometers is adopted in order to avoid obtaining meaningless measured values and uncertainty in the contact areas. An AFM cantilever is used after having been modified with a micro glass bead to enlarge the contact area for adhesion. A glass plate with micro-scale circular patterns is fabricated from a glass wafer by micro-machining processes in order to control precisely the contact area in adhesion tests. In the proposed method the adhesive materials are directly applied to the bead attached at the AFM cantilever before it is applied on the top area of the truncated cone on the fabricated glass plate. The developed method is applied to measure the adhesive forces of Cell-Tak® (which is a commercial extracted mussel adhesive) and recombinant Mgfp-5 (which is a recombinant mussel adhesive protein) and the statistical credibility of the measured adhesive force data is enormously improved as a result.     

Emissions of N2O from Scottish agricultural soils, as a function of fertilizer N

Potato fields and cut (ungrazed) grassland in SE Scotland gave greater annual N₂O emissions per ha (1.0–3.2 kg N₂O–N ha^-1) than spring barley or winter wheat fields (0.3–0.8 kg N₂O–N ha^-1), but in terms of emission per unit of N applied the order was potatoes > barley > grass > wheat. On the arable land, especially the potato fields, a large part of the emissions occurred after harvest.When the grassland data were combined with those for 2 years' earlier work at the same site, the mean emission over 3 years, for fertilization with ammonium nitrate, was 2.24 kg N₂O–N ha^-1 (0.62% of the N applied). Also, a very strong relationship between N₂O emission and soil nitrate content was found for the grassland, provided the water-filled pore space was > 70%. Significant relationships were also found between the emissions from potato fields and the soil mineral N content, with the added feature that the emission per unit of soil mineral N was an order of magnitude larger after harvest than before, possibly due to the effect of labile organic residues on denitrification.Generally the emissions measured were lower, as a function of the N applied, than those used as the basis for the current value adopted by IPCC, possibly because spring/early summer temperatures in SE Scotland are lower than those where the other data were obtained. The role of other factors contributing to emissions, e.g. winter freeze–thaw events and green manure inputs, are discussed, together with the possible implications of future increases in nitrogen fertilizer use in the tropics.     

高压氨水-邻室抽吸消烟方法探讨

介绍了焦炉烟尘污染状况,捣固装煤时烟尘的特点及多种治理烟尘的方法,认为高压氨水-邻室抽吸消烟法是一种适用于小型机焦炉烟尘治理的有效方法,具有投资少、效果好、易操作、好维护等特点。     

Novel Method to Measure the Creep Strength of Adhesively Bonded Butt Joints Subjected to Constant Loading Using a Hydro-Pneumatic Testing Machine

This article proposes a new method to measure the creep strength of adhesively bonded joints using a hydro-pneumatic testing machine and a specimen holder, on which multi-specimens can be mounted in one testing machine. Creep tests were conducted on stainless steel butt joints bonded with epoxy adhesives. A hydro-pneumatic loading system was introduced to avoid successive failures of multi-specimens as well as to achieve a stable and constant loading through the experiments. Even after a failure occurs in one of the joints and thus generates an impact, the loading system is capable of absorbing the shock so that the other remaining joints do not fail simultaneously. It was experimentally verified that choke valves, which were introduced in the hydraulic circuit of the system, worked as a damper when failure occurred. Additionally, it was established that automatic reloading to the remaining specimens after the failure was short enough compared with the creep rupture time. As this new method relates to the efficiency of creep testing, the utility of the proposed approach with the multi-specimen setup has been verified.     

Exhaust emissions from a diesel powered vehicle fuelled by soybean biodiesel blends (B3-B20) with ethanol as an additive (B20E2-B20E5)

The effects of diesel oil-soybean biodiesel blends on a passenger vehicle exhaust pollutant emissions were investigated. Blends of diesel oil and soybean biodiesel with concentrations of 3% (B3), 5% (B5), 10% (B10) and 20% (B20) were used as fuels. Additionally, the effects of anhydrous ethanol as an additive to B20 fuel blend with concentrations of 2% (B20E2) and 5% (B20E5) were also studied. The emissions tests were carried out following the New European Driving Cycle (NEDC). The results showed that increasing biodiesel concentration in the fuel blend increases carbon dioxide (CO₂) and oxides of nitrogen (NO_X) emissions, while carbon monoxide (CO), hydrocarbons (HC) and particulate matter (PM) emissions are reduced. The addition of anhydrous ethanol to B20 fuel blend proved it can be a strategy to control exhaust NO_X and global warming effects through the reduction of CO₂ concentration. However, it may require fuel injection modifications, as it increases CO, HC and PM emissions.     

A Simple Method to Extract Essential Oils from Tissue Samples by Using Microwave Radiation

A microwave protocol to extract lipophilic substances from tissue was modified to extract essential oils (EOs) from plant tissue and insect feculae. The material, in a solvent transparent to microwave radiation, is exposed for a short time to steam in a microwave oven. EO extracts are analyzed directly by GC or GC-MS when plant material is fresh and terpenes contained in glandular structures on leaf surfaces are readily released into the solvent. For dried material or insect feculae, mechanical means are utilized first to break up tissue; however, the complete procedure is carried out inside the same vial to reduce losses. Statistical analysis shows that the reproducibility of the modified method is high. Several samples can be run within an hour with this method.     

Subcritical Water Treatment: A Simple Method to Prepare Porous Glass with a Core–Shell Structure

This paper presents a subcritical water treatment method for preparing porous glass with a core–shell structure from ordinary soda-lime glass beads in one step. In this method, reactive subcritical water rather than any other chemical additive was utilized to selectively corrode the glass and mainly leach the alkali ions from the glass. The core–shell structure has been characterized by scanning electron microscope observation. The mesoporous structure of the porous glass beads has been confirmed by a nitrogen adsorption–desorption measurement. The treated alkali–lime–silicate glass beads have mesopores with a narrow distribution ranging around 4 nm, and a uniform nanoflake array on the surface. The shell structure can be easily tailored by changing the treatment temperature and water flow rate. A possible mechanism of a corrosion-ion immigrating-recondensation pattern was hypothesized to explain the formation of the core–shell porous structure.     

Comparison of the Concentration Profiles of 12 Polycyclic Aromatic Hydrocarbons from Different Sources with Monitoring Data from Prague Using a Similarity Measure

A method not used yet for detection of similarity between polycyclic aromatic hydrocarbon (PAH) profiles was applied to selected air samples taken in three localities of Prague. Dissimilarities between PAHs profiles in the Prague atmosphere, solid fuel (coal or wood) combustion, vehicle exhaust, and vehicle exhaust in a traffic tunnel atmosphere indicates that there are other sources of PAHs in the atmosphere of Prague.     

草浆造纸废水处理的工艺研究

应用浸没燃烧浮选木质素、絮凝除硅、软填料和灰渣过滤工艺过程对草浆造纸废水进行处理研究,确定了最佳工艺条件为：浮选木质素的ｐＨ值为３、絮凝沉降的ｐＨ值为９～１０。各项指标均达到国家规定的排放标准。估算吨水成本为０．６５元,技术经济可行。     

Using a Crop/Soil Simulation Model and GIS Techniques to Assess Methane Emissions from Rice Fields in Asia. III. Databases

As part of a series of papers describing the use of a simulation model to extrapolate experimental measurements of methane (CH₄) emissions from rice fields in Asia and to evaluate the large-scale effect of various mitigation strategies, the collation and derivation of the spatial databases used are described. Daily weather data, including solar radiation, minimum and maximum temperatures, and rainfall were collated from 46 weather stations from the five countries in the study, namely China, India, Indonesia, Philippines, and Thailand. Quantitative soil data relevant to the input requirements of the model were derived by combining data from the World Inventory of Soil Emissions (WISE) database, the ISIS database, and the FAO Digital Soil Map of the World (FAO-DSMW). These data included soil pH; organic carbon content; sand, silt, and clay fractions; and iron content for top and subsoil layers, and average values of bulk density and available water capacity for the whole profile. Data on the areas allocated to irrigated, rainfed, upland, and deepwater rice at the province or district level were derived from the Huke & Huke (1997) database developed at IRRI. Using a geographical information system (GIS), a series of georeferenced data sets on climate, soils, and land use were derived for each country, at the province or district level. A summary of the soil-related derived databases is presented and their applicationn for use in global change modeling discussed.