Cotton dust particle size distribution in oil mills

Analytical procedures have been developed for characterizing the size and shape of cotton dust particulates collected by the vertical elutriator (VE) sampler. Data are reported for dust distributions on VE filters collected from different processing areas (cleaning, delintering, hulling, and baling) in cottonseed oil mills. Results of particle volume distributions obtained with a Coulter counter are compared with data obtained from an image-analysis system designed to classify cotton dust into fibrous and nonfibrous (particulate) components. The image-analysis data include distributions of the lengths and widths of fibers and the areas and diameters of particles present on the VE filters. In many of the locations studied, a considerable amount of the total dust sampled can be attributed to lint, lint fragments, and also to particles significantly larger than 15 μm diameter. Southern Region, SEA, USDA.     

Foliar boron application affects lint and seed yield and improves seed quality of cotton grown on calcareous soils

Cotton (Gossypium hirsutum L.) is one of the most important fiber crops worldwide because of the good fiber quality, high yield, and high adaptability. Cotton has high requirements for B and many times B is applied to correct B deficiency. Despite the fact that B is important for cotton the effect of foliar applications on seed yield and seed quality was not adequately determined and especially when cotton is grown on calcareous soils. A field study was conducted to determine if foliar B application during anthesis increases seed set, lint yield, seed yield, yield components and improves seed quality of cotton grown on calcareous soils. Boron solutions were applied at four rates (0, 400, 800 and 1,200 mg l⁻¹ of B) to field plots exhibiting no vegetative symptoms of B deficiency. Foliar B application increased the number of bolls per plant, the number of bolls per square meter, the mean boll weight, the lint and the seed yield. Cotton yield was increased by an average of 40% over the two locations with B application compared with the control. However, there was no significant difference between the three rates of B. The number of bolls per plant increased by an average of 29% and the number of bolls per square meter increased by an average of 29% with B application in both locations compared with the control treatment. Also foliar application of B improved seed germination by an average of 17% and increased seed vigor determined as accelerated aging (AA) by an average of 25% compared with the control treatment in both locations. The results obtained here suggest that foliar B application can improve the lint and seed yield and seed quality of cotton grown on calcareous soils.     

宣钢除尘系统优化升级改造

宣钢焦化厂对该厂5#、6#焦炉的除尘系统进行了优化升级,即对除尘控制系统、除尘风机控制系统、泄爆阀进行了改造,并对除尘排灰系统进行了优化,不仅延长了设备的使用寿命,简化了操作,还提高了除尘效果。     

Plant–herbivore–carnivore Interactions in Cotton, <Emphasis Type="Italic">Gossypium hirsutum</Emphasis>: Linking Belowground and Aboveground

Most studies on plant–herbivore interactions focus on either root or shoot herbivory in isolation, but above- and belowground herbivores may interact on a shared host plant. Cotton (Gossypium spp.) produces gossypol and a variety of other gossypol-like terpenoids that exhibit toxicity to a wide range of herbivores and pathogens. Cotton plants also can emit herbivore-induced volatile compounds at the site of damage and systemically on all tissues above the site of damage. As these volatile compounds attract natural enemy species of the herbivore, they are thought to represent an indirect plant defense. Our study quantified gossypol and gossypol-like compounds in cotton plants with foliage feeding (Heliocoverpa zea), root feeding (Meloidogyne incognita), or their combination. Cotton plants with these treatments were studied also with respect to induced local and systemic volatile production and the attraction of the parasitic wasp Microplitis croceipes to those plants. We also evaluated whether foliage or root feeding affected foliar nitrogen levels in cotton. After 48 hr of leaf feeding and 5 wk of root feeding, local and systemic induction of volatiles (known to attract parasitoids such as M. croceipes) occurred with herbivore damage to leaves, and it increased in levels when root herbivory was added. Nevertheless, M. croceipes were equally attracted to plants with both leaf and root damage and leaf damage only. In contrast to previous studies in cotton, production of gossypol and gossypol-like compounds was not induced in leaf and root tissue following foliage or root herbivory, or their combination. We conclude that root feeding by M. incognita has little influence on direct and indirect defenses of Gossypium hirsutum against insect herbivory.     

Machine vision based particle size and size distribution determination of airborne dust particles of wood and bark pellets

Dust management strategies in industrial environment, especially of airborne dust, require quantification and measurement of size and size distribution of the particles. Advanced specialized instruments that measure airborne particle size and size distribution apply indirect methods that involve light scattering, acoustic spectroscopy, and laser diffraction. In this research, we propose a simple and direct method of airborne dust particle dimensional measurement and size distribution analysis using machine vision. The method involves development of a user-coded ImageJ plugin that measures particle length and width and analyzes size distribution of particles based on particle length from high resolution scan images. Test materials were airborne dust from soft pine wood sawdust pellets and ground pine tree bark pellets. Subsamples prepared by dividing the original dust using 230 mesh (63 μm) sieve were analyzed as well. A flatbed document scanner acquired the digital images of the dust particles. Proper sampling, layout of dust particles in singulated arrangement, good contrast smooth background, high resolution images, and accurate algorithm are essential for reliable analysis. A “halo effect” around grey-scale images ensured correct threshold limits. The measurement algorithm used Feret's diameter for particle length and “pixel-march” technique for particle width. Particle size distribution was analyzed in a sieveless manner after grouping particles according to their distinct lengths, and several significant dimensions and parameters of particle size distribution were evaluated. Results of the measurement and analysis were presented in textual and graphical formats. The developed plugin was evaluated to have a dimension measurement accuracy in excess of 98.9% and a computer speed of analysis of < 8 s/image. Arithmetic mean length of original wood and bark pellets airborne dust particles were 0.1138 ± 0.0123 and 0.1181 ± 0.0149 mm, respectively. The airborne dust particles of wood and bark pellets can be described as non-uniform, finer particles dominated, very finely skewed with positive skewness, leptokurtic, and very well sorted category. Experimental mechanical sieving and machine vision methods produced comparable particle size distribution. The limitations and merits of using the machine vision technique for the measurement of size and size distribution of fine particles such as airborne dust were discussed.     

A lab-scale study on the humidity conditioning of flue gas for improving fabric filter performance

A centrifugal separator was constructed to examine the effect of flue gas humidity on the adhesional force between fabric and collected dust. A lab-scale fabric filter sampling system (FFSS) was also manufactured by using a piece of flat fabric as a sample of bag material. In addition, an automatic control system for gas humidity was devised and installed in the FFSS, and, then, the following effects were studied: (i) the influence of gas humidity on the adhesional force between fabric and dust particles; (ii) the influence of gas humidity on the performance of fabric filter in terms of pressure drop, ΔP, dust removal efficiency, η, and specific cake resistance, K′₂; (iii) the variations in the composite-performance indices with gas humidity; and (iv) the influence of gas humidity on cleaning of dust-cake in terms of effective residual pressure drop. The main objectives were to determine the minimum and maximum values for the gas humidity range and to find the appropriate conditions for dust cleaning in terms of the critical value of effective residual pressure drop.     

Effect of nitrogen and zinc fertilization and plant growth retardants on cottonseed, protein, oil yields, and oil properties

The increase in the population in Egypt makes it imperative to explore promising approaches to increase food supply, including protein and oil, to meet the needs of the Egyptian people. Cotton is the principal crop of Egyptian agriculture. It is grown mainly for its fiber, but cottonseed products are also of economic importance. Cottonseed is presently the main source of edible oil and meal for livestock in Egypt. Field experiments were conducted in two successive seasons at the Agricultural Research Center (Giza, Egypt) on cotton (Gossypium barbadense L. cv. Giza 75) to determine the effect of nitrogen (N) fertilizer rate (107 and 161 kg of N/ha applied as ammonium nitrate containing 33.5% N in two equal doses at 6 and 8 wk after sowing), together with foliar applications of plant growth retardants (mepiquat chloride “Pix”, chloromequat chloride “Cycocel”, and daminozide “Alar”, each applied once at 288 g active ingredient/ha, after 75 d from sowing) and zinc (Zn) (applied in chelated form after 80 and 95 d from sowing at 48 g of Zn/ha) on seed, protein and oil yields and oil properties of cotton. The higher N-rate, as well as the application of all growth retardants and Zn, resulted in an increase in cottonseed yield, seed protein content, oil and protein yields/ha, seed oil refractive index, unsaponifiable matter, and total unsaturated fatty acids (oleic and linoleic). These treatments tended to decrease oil acid value, saponification value, and total saturated fatty acids. The seed oil content tended to decrease as N-rate increased and increased with the application of all growth retardants and Zn. There were some differences between Pix, Cycocel, and Alar regarding their effects on the studied characters. The highest increase in seed, oil, and protein yields/ha was found with Pix, followed by Cycocel. The Cycocel treatment gave the lowest total saturated fatty acids oil content, followed by Alar.     

Nutrient uptake and export from an Australian cotton field

Soil fertility may decline as a result of nutrient export from high-yielding cotton crops and this may limit the productivity of future crops unless these nutrients are replaced. Uptake of nutrients by cotton (Gossypium hirsutum L.) and nutrient export from the field in seed were measured within two cropping systems experiments from 1999 to 2005 in a flood-irrigated cotton field. Lint yields of the seven crops assessed ranged from 975 to 2725 kg lint/ha. Nutrient uptake was measured at mid to late boll-fill and nutrient removal determined from analysis of delinted seed. Cotton crops accumulated an average of 180 kg N/ha (range 67–403), 27 kg P/ha (range 18–43), 167 kg K/ha (range 88–264), 41 kg S/ha, 160 kg Ca/ha, 36 kg Mg/ha, 7 kg Na/ha, 890 gm Fe/ha, 370 gm Mn/ha, 340 gm B/ha, 130 gm Zn/ha and 51 gm Cu/ha. On average, the seed within harvested seed cotton removed 93 kg N/ha (range 38–189), 18 kg P/ha (range 8–34), 29 kg K/ha (range 13–51), 8 kg S/ha, 4 kg Ca/ha, 12 kg Mg/ha, 0.2 kg Na/ha, 136 g Fe/ha, 12 g Mn/ha, 41 g B/ha, 96 g Zn/ha and 20 g Cu/ha. Nutrients contained in the lint and trash were not included. For crops yielding about 1800 kg/ha, 70% of the Zn and P taken up was removed in the seed, also 52% of N, 38% of Cu, 34% of Mg, 21% of S, 17% of K and Fe, 12% of B and only 3% of Ca, Mn and Na. Predictive equations were developed to allow growers to estimate the removal of nutrients given the lint yield measured from their cotton crops.     

Effects of particulate matter on the pulmonary and vascular system: time course in spontaneously hypertensive rats

Background  

This study was performed within the scope of two multi-center European Commission-funded projects (HEPMEAP and PAMCHAR) concerning source-composition-toxicity relationship for particulate matter (PM) sampled in Europe. The present study aimed to optimize the design for PM in vivo toxicity screening studies in terms of dose and time between a single exposure and the determination of the biological responses in a rat model mimicking human disease resulting in susceptibility to ambient PM. Dust in thoracic PM size-range (aerodynamic diameter <10 μm) was sampled nearby a road tunnel (RTD) using a high volume cascade impactor. Spontaneously hypertensive rats were exposed to urban dust collected in Ottawa, Canada (EHC-93 10 mg/kg of body weight; reference PM) or different RTD doses (0.3, 1, 3, 10 mg/kg of body weight) by intratracheal instillation. Necropsy was performed at 4, 24, or 48 hr after exposure.     

Synthesis of cotton-bearing DEAE,carbamoyethyl, carboxyethyl,and poly(acrylamide) graft for utilization in dye removal

Cotton cellulose in the fabric form was subjected to etherification and grafting reactions with the purpose of obtaining cotton with ionic properties. Thus, cottons bearing DEAE, carbamoylethyl, and carboxyethyl groups, along with partially hydrolyzed poly(Aam) graft, were synthesized. The ability of these cotton substrates to function as ion exchangers, particularly for removal of direct, basic, acid, and reactive dyes from aqueous solution was examined. The obtained results reveal that such modifications increase the ability of cotton to remove these dyes to about 150 times. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1007–1014, 1999     

Generation of Submicron Arizona Test Dust Aerosol: Chemical and Hygroscopic Properties

This article describes a submicron dust aerosol generation system based on a commercially available dust disperser intended for use in laboratory studies of heterogeneous gas–aerosol interactions. Mineral dust particles are resuspended from Arizona Test Dust (ATD) powder as a case study. The system output in terms of number and surface area is adjustable and stable enough for aerosol flow reactor studies. Particles produced are in the 30–1000 nm size range with a lognormal shape of the number size distribution. The particles are characterized with respect to morphology, electrical properties, hygroscopic properties, and chemical composition. Submicron particle elemental composition is found to be similar for the particle surface and bulk as revealed by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectroscopy (ICP-OES), respectively. A significant difference in chemical composition is found between the submicron aerosol and the ATD bulk powder from which it was generated. The anionic composition of the water-soluble fraction of this dust sample is dominated by sulfate. Resuspended dust particles show, as expected, nonhygroscopic behavior in a humid environment. Small hygroscopic growth of about 1% (relative change in mobility diameter) was observed for 100 nm particles when the relative humidity (RH) was changed from 12 to 94%. Particles larger than 100–200 nm shrank about 1% once exposed to RH > 90%. This was interpreted as a restructuring of the larger agglomerates of dust to particles of smaller mobility diameter, under the influence of water vapor.     

Design and performance evaluation of plasma air cleaning systems for removing yellow sand dust

Yellow sand dust (Asian dust storms) causes harmful damage indoors and outdoors during the springtime, and the removal of Yellow sand dust has become an issue for suitable indoor conditions. An air cleaner is required to remove Yellow sand dust efficiently to improve indoor air quality, and the removal characteristics of Yellow sand dust should be studied. The size distribution and mass concentration of Yellow sand dust observed in China and Korea are analyzed, and the removal efficiency of a plasma air cleaning system based on the principle of electrostatic precipitation is evaluated by using Yellow sand dust. Mass median diameter of Yellow sand dust sampled in Beijing and Seoul ranges from 7.0 to 8.0 μm with a mass concentration of 300-1,462 μg/m³. For a single-pass test, the efficiency of dust removal increases with increasing particle size and decreasing flow rate. The removal efficiency of Yellow sand dust in a plasma air cleaning system at a face velocity of 1.0 m/s is higher than 80%. For a multi-pass test in occupied spaces, the operation time required to reduce Yellow sand dust concentration from an initial concentration of 300 μg/m³ to 150 μg/m³ is 10 minutes for a test room of 27 m³.     

Entstaubung heißer Gase

Dust extraction from hot gases . The introduction of new, energy-saving, and low-pollution technologies required development of highly efficient systems for purifying dustloaden hot gases at temperatures between 500 and 1000°C and pressures between 1 and 20 bar. The present state of dust removal is described for separators utilizing gravitational forces, electrical effects, filtration, and wet techniques, and typical applications of present-day dust extraction from hot gases are presented. Possible developments with a view to extending the scope of dust extraction are indicated.     

Conditions of dust sampling in pneumatic conveying through the horizontal pipeline

The paper presents the results of examinations on the reciprocal relation between the isokinetic coefficient H of sampling, the quantity of measured mass concentration and the measuring usefulness of a dust sample aspired from the stream of solgas conveyed pneumatically in the horizontal pipeline. In gravimetric measurements of two-phase flows, the conditions under which aspiration is carried out, are extremely important. Available theoretical considerations and practical experiments usually concern aspiration in the vertical channels, where the manner of making measurements is universally known and it does not express any reservations. However, it is often necessary to conduct tests in the systems of horizontal conveying of solgas, where the conditions of taking a representative sample, even for the sake of the significant effect of the gravitational force, may vary from those suggested for measurements in the systems of vertical flow. The present paper also presents results of research on the selection of the isokinetic coefficient H in the case of aspiration in the horizontal channels. By means of a comparative experiment, one has found that the isokinetic coefficient, at which the results of the determined flow parameters are representative, has the optimal value of H = 1.05-1.09. The tests were conducted at the research station. In measurements the gravimetric method was applied to taking a representative sample. Dust samples were quantitatively analyzed by means of a grain-size laser analyzer. The tested dust was shale coal.     

Improvement of properties of natural polymers with organo–metallic complexes under ultraviolet radiation

Thin polymer films were prepared under ultraviolet radiation with a triacrylated aliphatic urethane oligomer that was diluted with reactive monomers such as N‐vinyl pyrrolidone and tripropylene glycol diacrylate. These films were characterized. The effect of incorporation of a minute amount (>0.15%) of a titanium–pyridine complex and its ligands on the characterization of these polymers was investigated. Cotton and jute yarns were treated with the solutions containing these materials under the UV radiation. The change in tensile properties of the treated natural polymers (cotton and jute) was evaluated, and it was found that the titanium–pyridine‐based complex substantially enhanced the tensile strengths (tenacity) for both cotton and jute. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1131–1138, 1999     

Fire hazard properties of viscose fibre dusts

Conclusions The fractional composition of viscose fibre dust formed in the packaging division has been investigated.A quantitative determination of the combustible dust accuulated in the manufacturing packaging site has been carried out.It has beem shown that the viscose fibre dust fraction with a particle size less than 0.800 mm presents an explosion hazard, but the content of explosive dust does not exceed 6.1% of the total amount of dust. Dust which has not been separated into fractions presents no explosion hazard.To ensure safety from fire in viscose fibre packaging locations, it is necessary to use a mechanized dust-collection system.Translated from Khimicheskie Volokna, No. 6, pp. 44–45, November–December, 1989.     

Lipid distribution on cotton textiles in relation to washing with cellulase

Enzymes are used widely as effective additives to laundry detergents for improved detergency on soiled fabric. They have potential for cleaning of “dingy” soils in addition to the stain removal benefits. Cellulases contribute to the overall whiteness of cotton-containing textiles when worn and washed several times, meaning that their cleaning is not associated solely with the regions characterized by high amounts of fatty material, e.g., collars/cuffs. The focus of this research was to study further the performance of cellulases for whiteness maintenance of cotton textiles. Cotton garments soiled by multiple wearings and washed using a cellulase treatment were evaluated using scanning electron microscopy and X-ray microanalysis. Washing with cellulase significantly reduced residual soil concentrations at all morphological locations on the cotton fibers for each set of matched garments. The relative concentrations of residual soil on the fabrics agreed well with the color differences measured at 440 nm. Cellulase affected removal of oily soil from within the cotton fiber secondary wall, resulting in residual oil concentrations similar to those at morphological locations that were more accessible for detergency such as the fiber surface and crenulations. Since cellulase hydrolyzes cellulose, it was expected that the effect would be within the structure of the fiber, i.e., secondary wall. The cellulase effect on redeposition garments was similar to garments worn and washed. As with lipase, the enhanced removal of soil from the interior bulk structure of the cotton fiber with use of cellulase is unique, since most other detergent components have higher functionality at fabric, yarn, and fiber surfaces. We think that cellulase is functioning by hydrolyzing cellulose from the internal surfaces of fibrils within the secondary wall, opening up the pore structure for enhanced detergency and forming a new surface with each washing.     

Dust explosions in vented silos: Simulations and comparisons with current standards

Dust explosions represent a serious hazard to personnel and equipment in industries and silo facilities that handle combustible materials. Venting devices are the most common protective systems employed in silos, although their use may pose problems in large and low-strength silos. The main aim of the present work was to simulate dust explosions in silos using a commercial CFD program, the DESC code, to determine the pressures developed in vented explosions with vent areas of different sizes. Dust cloud characteristics were taken from studies carried out by the FSA (Research Centre for Applied System Safety and Industrial Medicine, Germany) in a 12 m³ silo with a mechanical feeding system. The pressures and associated vent areas in these simulations were compared to those contemplated in two venting standards. The simulated explosion pressures showed the expected trends for the associated vent areas and agreed reasonably well with the values contemplated in NFPA 68 (2007) [5]. However, when the reduced explosion overpressure was low, the vent area contemplated in EN 14491 (2006) [4] was much larger than in the present simulations.     

Flame‐retardant finishing of cotton fleece fabric: part I. The use of a hydroxy‐functional organophosphorus oligomer and dimethyloldihydroxylethyleneurea

Cotton fleece has become a popular fashion in recent years. However, most of the 100% cotton fleece fabric is not able to meet the federal flammability standard (‘16 CFR Part 1610: Standard for the Flammability of Clothing Textiles’) without chemical treatment. In this research, we investigated the use of the combination of a hydroxy‐functional organophosphorus oligomer (HFPO) as the flame‐retarding agent and dimethyloldihydroxylethyleneurea (DMDHEU) as the binder to reduce the flammability of cotton fleece. We found that HFPO is effective in reducing the flammability of the cotton fleece whereas DMDHEU enhances the effectiveness of HFPO due to phosphorus–nitrogen synergism. The flammability as well as other properties of the treated cotton fleece is affected by both the concentration of HFPO and that of DMDHEU. The cotton fleece treated with HFPO/DMDHEU passes the federal flammability standard and shows high strength retention with little change in fabric whiteness and hand. We also found that the flame‐retardant finishing system is durable to multiple home launderings. The combination of HFPO and DMDHEU has the potential to become a practical flame‐retardant finishing system to reduce the flammability of cotton fleeces. Copyright © 2006 John Wiley & Sons, Ltd.     

Application of a fibre-reactive chitosan derivative to cotton fabric as a zero-salt dyeing auxiliary

Cotton fabric has been treated with a fibre-reactive chitosan derivative containing quaternary ammonium groups, O -acrylamidomethyl- N -[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride (NMA-HTCC). Cotton treated with NMA-HTCC has been dyed with direct and reactive dyes without the addition of salt. The colour yield was higher than that on untreated cotton, despite the addition of a large amount salt in the latter case. After dyeing, cotton treated with NMA-HTCC gave better wash fastness than the untreated cotton. The light fastness was however inferior to that on untreated cotton. The antimicrobial activity of cotton treated with NMA-HTCC against Staphylococcus aureus was considerably lower after dyeing, probably due to the antimicrobial effect of the cationic group on NMA-HTCC being blocked by its combination with the anionic dye.