Determination of foreign materials of plant origin in cotton linters

The present article describes a test procedure which can be used for determination of foreign materials of plant origin in raw cotton linters. Laboratories that perform the cellulose yield test require very little additional equipment to carry out this test. A portion of the dry cellulose sample, remaining after the completion of the AOCS Official Cellulose Yield Method Bb 3–47 is bleached, formed into a hand sheet and the total projected area of the visible dirts is determined on both sides of the hand sheet. The determination of the dirts is patterned according to principles used in Technical Association of Pulp and Paper Industries Standard Procedures T213 M-43 and T437 M-43. There are three main groups of foreign materials encountered: stalks, cockle burs and cotton seed hulls. The numbers and distribution of these particles vary with the general geographic locality and individual shipments of cotton linters. The test procedure described considers only those dirt particles which survive the major purification steps in the manufacturing of pulp from linters, and are undesirable from the quality point of view of the finished product. Prior to the development of the test only visual grading estimations have been used for this purpose. Presented at the AOCS Meeting, Minneapolis, 1963.     

THE MODULUS OF ELASTICITY AS AN INDICATION OF THE UNIFORMITY OF ELECTRICAL PORCELAIN1

An electrical porcelain body of the composition 30% H and G A1 china clay, 20% Dorset English ball clay, 20% Ottawa flint, and 30% Buckingham feldspar, fired to cone 11. showed a modulus of elasticity of 9.54 ± 0.02 × 10⁶ 1b. per sq. in. (mean of 164 measurements). A similar body with Kentucky special ball clay substituted for Dorset hall clay gave a value of 10.01 ± 0.02 × 10⁶ 1b. per sq. in. (mean of 69 measurements) The accuracy of the measurements was ± 1.5%. The use of the modulus as a measure on. the uniformity of electrical porcelain gave excellent results The variations were expressed in terms of statistical constants such ac: the standard deviation and the coefficient of variability.     

含磺酸基和羧基的纤维素衍生物型减水剂的合成与性能研究

以新疆棉短绒为原料,氨基磺酸、丁二酸酐为酯化剂,采用一锅法合成了磺酸基/羧基纤维素酯(简称：CLCSC)。通过IR、NMR表征了产品结构,GPC测量了产品的重均分子量在2.29× 103 ~1.94× 104范围内。考察了pH对CLCSC溶液黏度性能的影响,并对其用作减水剂的性能和机理进行了初步研究。结果表明：CLCSC取代度最高达到0.92;pH为2~12对不同取代度、不同浓度的CLCSC溶液的黏度影响较小,并且其黏度维持在较低状态,而且当CLCSC掺量为水泥量的1%时,混凝土减水率为28.5%,泌水率为80%,混凝土抗压实验结果表明, CLCSC能在保持相同工作性的条件下起到减水增强作用。因此,CLCSC有望成为具有实际应用价值的混凝土高效减水剂。     

Coke yield and heat transfer in reaction of liquid–solid agglomerates of Athabasca vacuum residue

The ultimate coke yield was determined for agglomerates of Athabasca vacuum residue and coke particles by heating on Curie‐point alloy strips in an induction furnace at 503 and 530°C until all toluene‐soluble material was converted. Coke yield results from agglomerates were compared to the coke yield results from reacting thin films of vacuum residue. The average coke yield from the agglomerates was 23%, while the coke yield from thin films of 20 µm thickness was 11%, which supports the role of mass transfer in coke formation reactions. The ultimate coke yield was insensitive to vacuum residue concentration, agglomerate size, and reaction temperature. The temperature profile within agglomerates was measured by implanting a thermocouple, and a simple heat transfer model was used to describe the temperature variation with time. The effective thermal diffusivity of the agglomerates was 0.20 × 10^?6 m²/s. Control experiments on reaction in thin liquid films confirmed that heating rates in the range of 14.8–148 K/s had no effect on the ultimate yield of coke yield.     

A correlation of Young's modulus with yield stress in oriented poly(vinyl chloride)

The variations of tensile and compressive yield stresses and of Young's modulus of oriented poly(vinyl chloride) sheet with direction and with degree of orientation, represented by birefringence, are shown. Young's modulus was calculated from elastic stiffness constants measured by an ultrasonic pulse method at 5MHz with estimated strain and strain rate amplitudes of 2 × 10^?5 and 100s^?1. Yield strains were about 5 × 10^?2 measured at strain rates of about 2 × 10^?2s^?1. Although the measuring conditions were so different there was found to be a close correlation between tensile yield stress and Young's modulus, the two quantities being connected by a simple linear relationship, as direction of measurement and degree of orientation were varied. Compressive yield stress did not correlate with Young's modulus, and changed little with direction or degree of orientation by comparison with tensile yield stress. The empirical linear relationship between tensile yield stress and Young's modulus, difficult to account for theoretically, might form the basis of a method for determining tensile yield stress ultrasonically.     

Extraction of Lipids from Municipal Wastewater Plant Microorganisms for Production of Biodiesel

Municipal wastewater treatment plants in the USA produce over 6.2 × 10⁶ t of dried sewage sludge every year. This microorganism-rich sludge is often landfilled or used as fertilizer. Recent restrictions on the use of sewage sludge, however, have resulted in increased disposal problems. Extraction of lipids from sludge yields an untapped source of cheap feedstock for biodiesel production. Solvents used for extraction in this study include n-hexane, methanol, acetone, and supercritical CO₂. The gravimetric yield of oil was low for nonpolar solvents, but use of polar solvents gave a considerably increased yield; however, the percentage of saponifiable material was less. Extraction of lipids with a mixture of n-hexane, methanol, and acetone gave the largest conversion to biodiesel compared with other solvent systems, 4.41% based on total dry weight of sludge. In situ transesterification of dried sludge resulted in a yield of 6.23%. If a 10% dry weight yield of fatty acid methyl esters is assumed, the amount of biodiesel available for production in the USA is 1.4 × 10⁶ m³/year. Outfitting 50% of municipal wastewater plants for lipid extraction and transesterification could result in enough biodiesel production to replace 0.5% of the national petroleum diesel demand (0.7 × 10⁶ m³).     

A Novel Approach for Determination of Free Fatty Acids in Vegetable Oils by a Flow Injection System with Manual Injection

A non-aqueous flow injection method for determining free fatty acid (FFA) content in corn and sunflower oil samples was developed. A single-line manifold system was built by modification of an HPLC for flow injection analysis (FIA). Without pre-treatment, oil samples were injected into a n-propanol solution containing KOH and phenolphthalein (PHP). The main parameters, such as flow rate of carrier phase, length, geometry, inner diameters of the coils and reagent concentration were all optimized. The proposed FIA method was validated for precision, accuracy, linear region, limit of detection (LOD) and limit of quantification (LOQ). The intra- and inter-day measurements of the precision of the method were found to be within the limits of acceptance criteria (RSD < 1%), and were rugged when the method was performed by a different analyst. The linear concentration range was calculated as 0.09–1.50 and 0.07–1.40 FFA% for corn and sunflower oils, correspondingly. The LOD and LOQ were found to be 7.53 × 10⁻⁴–2.28 × 10⁻³ oleic acid % and 7.11 × 10⁻⁴–2.23 × 10⁻³ oleic acid % for corn and sunflower oils, respectively. The results were compared with those obtained by the AOCS (Ca-5a-40) method using statistical t and F tests, and a significant difference was not observed between the methods at a 95% confidence level. The proposed method is suitable for quality control of routine applications due to its simplicity, high sample throughput, and economy of solvents and sample, offering considerable promise as a low cost analytical system that needs minimum human intervention over long periods of time.     

Comparison of FTIR and capillary gas chromatographic methods for quantitation oftrans unsaturation in fatty acid methyl esters

A computer-assisted method has been developed for estimation of isolatedtrans unsaturation using the peak area of thetrans absorbance band at 966 cm-1from FTIR spectra of fatty acid methyl esters. Peak areas were used to determine thetrans content of weighed standards containing from 0 to 100% methyl elaidate and of hydrogenated soybean oil samples containing up to 36%trans unsaturation. These data for percenttrans by FTIR were compared to corresponding data obtained by capillary gas chromatography and the AOCS Official Method 14-61. Determination of isolatedtrans composition in oils using peak areas gave values with the smallest standard deviation for weighed standards and values within 4% of those obtained by capillary gas chromatography and the AOCS Official Method for hydrogenated samples. Presented at the AOCS meeting in Phoenix, AZ in May 1988. To whom correspondence should be addressed.     

The thermodynamics of micelle formation by a polystyrene-b-polyisoprene block copolymer in N,N′-dimethylacetamide

The thermodynamics of micelle formation by a polystyrene-b-polyisoprene block copolymer in N,N′-dimethylacetamide, which is a selectively bad solvent for polyisoprene, has been investigated. The micelles have a very narrow size distribution enabling the association process to be treated as a single-stage equilibrium. The temperature dependence of the critical micelle concentration was determined from measurements of scattering intensity against temperature carried out at six concentrations within the range 2.3 × 10⁻⁷ to 1.2 × 10⁻⁴ mol dm⁻³. A plot of 1n (c.m.c.) against T⁻¹ gave a value for the standard enthalpy of micellisation (per mole of copolymer chains in the micelle) of − 153 ± 6 kJ mol⁻¹. The standard entropy contribution (-TΔS^Θ) to the standard free energy of micellisation was found to be positive. These results are in strong contrast to those reported for synthetic surfactants in aqueous media for which a favourable standard entropy change is the factor mainly responsible for micelle formation.     

Comparative study of methods of determining oil content of sunflower seed

An extraction-gravimetric method (AOCS Official Method Ai 3-75) was compared with 2 instrumental techniques, near-infrared reflec-tance (NIR) spectroscopy and wide-line nuclear magnetic resonance (NMR), for the determination of the oil content of oilseed-type hybrid sunflower seed. Eight sunflower seed samples of varying oil contents, replicated 5 times, were analyzed by the 3 procedures. The overall mean oil contents and standard deviations for the 8 samples were: AOCS method, 44.5% ± 0.33%; NMR, 44.8% ± 0.27%; and NIR, 44.2% ± 0.81%. Analysis of variance of the means of the 3 methods of analysis indicated no difference (p>0.05) in oil content due to the method. However, there was a difference (p>0.001) in total oil content due to replicated analyses of the same sample with the NIR method. With the AOCS and NMR methods, no effect (p>0.05) of replicated analyses of the same sample was found. The NMR method was more precise and repro-ducible than the other 2 methods. Although the NIR mean oil contents were not significantly different from the means of the other 2 methods, the coefficient of variations for all samples were consistently higher for the NIR analyses than for the AOCS and NMR analyses.     

Automatic karl fischer titration of moisture in sunflower seed

An automatic Karl Fischer (KF) titrator of the motor-driven buret type was applied to the determination of moisture in sunflower seed. A study of the effect of sample size on KF moisture analysis showed a significant decrease in moisture content with increase in sample size from 1 to 5 g. In the moisture range of 5.5–10.5%, a sample size of 3–4 g gave moisture values closest to those obtained by the AOCS official oven method for sunflower seed. Comparison of KF moisture analysis with oven methods on 6 samples with moisture contents ranging from 5.4 to 12.7% showed that KF moisture values were not significantly different from air oven and vacuum oven methods. The mean standard deviation of KF determinations of whole sunflower seed was 0.11% moisture content, whereas for forced draft oven moistures, the mean standard deviation was 0.05%. KF moisture values generally were slightly lower than the air oven moisture values. Using KF and vacuum oven methods to measure moisture contents, sunflower seed were found to lose 0.6% moisture from a sample containing 8.9% moisture when grinding the sample with Hyflo Super Cel as in the AOCS official method.     

Indium-free large area Nb-doped SnO2 thin film as an alternative transparent conducting electrode

Niobium doped tin oxide (NTO) thin film deposited via facile chemical spray pyrolysis technique on to a large area (10 × 10 cm²) glass substrate exhibits better optical and electrical properties. The structural, surface, optical and electrical properties were analyzed by means of XRD, XPS, AFM, SEM-EDS, Hall Effect, and four-point probe techniques. The deposited NTO thin film was found to possess a maximum average transmittance value around 75% due to enhanced optical bandgap (3.77 eV) by Nb-dopant effect. The variation of sheet resistance of the large area (10 × 10 cm²) coated thin film over the entire region was studied at every 1 × 1 cm² area. The film doped with 1.5 wt% of Nb content showed improved carrier concentration (9.33 × 10¹⁹ cm^-3), higher free carrier mobility (39.4 cm²/V·s), improved electrical resistivity (1.69 × 10^-3 Ω cm) and low sheet resistance (26.5 Ω/□). The temperature dependent electrical measurement was carried out from 200 to 450 °C in steps of 50 °C to understand the resistance stability of the film. In addition to these studies, we report the surface work function of NTO thin film to identify its suitability in optoelectronic devices. The estimated electrical properties confirm the substitution of Nb⁵⁺ in Sn site of SnO₂ lattice. Our results indicate the optimized NTO thin film to possess promising optical and electrical transport properties to serve as a better indium-free alternate transparent conducting electrode in various optoelectronic devices.     

Objective fluorometric measurement of alfatoxins on TLC plates

Measurement of the solid state fluorescence of aflatoxins on silica gel-coated TLC plates on a densitometer equipped for fluorescence measurements showed a linear relationship between peak areas and concentration over a range of at least 2 to 105×10⁻⁴ μg of aflatoxins per spot. Response of individual aflatoxins was in order of B₂>G₂>B₁>G₁. Aflatoxins can be measured with a precision of ±2–4%. Presented at the AOCS Meeting, Los Angeles, April 1966. So. Utiliz. Res. Dev. Div., ARS, USDA.     

Urea-rubber matrices as slow-release fertilizers

The efficacy of a prototype slow-release fertilizer, urea-rubber matrix (URM) was assessed under flooded rice conditions. URM cuboids of size 0.5 × 1.0 × 0.4 cm were applied in comparison with prilled urea at levels of 50, 130 and 200 kg N ha^?1. URM was placed at the soil/solution interface in intimate association with rice seedlings whereas prilled urea was broadcast into the floodwater to simulate the normal application method of South East Asian farmers. URM cuboid sizes of 0.25 × 0.5 × 0.4 cm, 0.5 × 0.5 × 0.4 cm and 1.0 × 1.0 × 0.4 cm were similarly evaluated at a single rate of 130 kg N ha^?1; a broadcast URM treatment was also included. Different methods of prilled urea application including deep placement and split application were also studied at a single rate of 130 kg N ha^?1. It was found that the build-up of floodwater N (urea + NH ₄ ⁺ ) from URM during the 13 days following application was almost negligible irrespective of level or method of application. This was thought to result in low losses of N through ammonia volatilization as shown by higher rice grain yields in comparison with prilled urea at all levels of application. Deep-placed urea gave a comparable grain yield to that of broadcast URM. There was no significant difference in grain yield between URM applied by placement and by broadcast, suggesting that URM can be effectively applied either in intimate association with rice seedlings or by broadcasting to the rice field before, or after, planting. An attempt to predict the release of urea from URM was made using a diffusion-based simulation model. It was found that the model underestimated the actual release of urea from URM within the rhizosphere, probably due to the extensive penetration by rice roots of the URM cuboids.     

Improved synthesis of oxymethylene-linked poly(oxyethylene)

Polyethylene glycol 400 was reacted with CH₂Cl₂ in the presence of KOH to form oxymethylene-linked chains. The method gave a high yield of colourless high-molecular-weight elastomer. The ionic conductivity of a mixture of the polymer with LiCF₃SO₃ ([O]/[Li] = 25) was about 5 × 10^?5S cm^?1 at 25°C.     

Adhesion optimization for catalyst coating on silicon-based reformer

CMZ (ca. 30.0 wt.% Cu, 20 wt.% Mn, and 50 wt.% Zn) catalyst was chosen for the partial oxidation of methanol (POM) reaction. To enhance adhesion between a silicon-based reactor and catalysts, boehmite and bentonite were used as binders. Changes in conditions such as pH value, ratio of bentonite/boehmite, amount of solid contents per area of substrate, and aging time have crucial effects on adhesion and result in variable performance of catalyst in POM reaction. Regarding optimized adhesion conditions, 13 wt.% weight loss was observed and methanol conversion could be kept at ca. 80–90% of original catalyst performance in a packed-bed reactor. However, poor performance was observed in the micro-channel reactor. The methanol conversion (C_MeOH), H₂ selectivity (S_H2), and H₂ yield (Y_H2) achieved 58%, 67%, 5.7 × 10^?6 mol/min in micro-channel reformer at 250 °C, respectively.     

Cathodically pretreated poly(1-aminoanthraquinone)-modified electrode for determination of ascorbic acid, dopamine, and uric acid

This paper describes a rapid and reliable method for dopamine (DA), ascorbic acid (AA), and uric acid (UA) determination in human urine using a cathodically pretreated poly(1-aminoanthraquinone) (PAAQ)-modified electrode. By applying a simple cathodic pretreatment to the PAAQ electrode well-defined voltammetric peaks for AA, DA, and UA were obtained. The pretreated PAAQ showed good selectivity, sensitivity, and repeatability for measuring AA, DA, and UA with detection limits of 2.50 × 10^?5, 3.05 × 10^?6, and 1.15 × 10^?5 M, respectively. The practical applicability of the modified electrode is illustrated by selective measurements of AA and UA in human urine without any preliminary treatment. Recovery values between 94.8 and 102 % for AA and between 77.8 and 100 % for UA were obtained with a relative standard deviation of 2.74 and 2.98 %, respectively.     

Radiation-induced polymerization of ethylene in pilot plant. III. Heavy-phase recycling process

Radiation-induced polymerization of ethylene using aqueous tert-butyl alcohol as medium was carried out in a large-scale pilot plant with a 50-liter central source-type reactor at a pressure of 105 to 395 kg/cm², temperature of 30° to 80°C, mean dose rate of 4.5 × 10⁴ to 1.9 × 10⁵ rads/hr, ethylene feed rate of 5.5 to 23.5 kg/hr, and medium feed rate of 21 to 102 l./hr. The space–time yield and molecular weight of the polymer were in the range of 4.7 to 16.8 g/l.-hr and 1.3 × 10⁴ to 8.9 × 10⁴, respectively. The space–time yield and molecular weight increased with mean residence time at 30°C, whereas at 80°C they became almost independent of the time. The space–time yield increased with pressure and dose rate, slightly decreased with temperature, and was maximum at ethylene molar fraction of 0.5. The polymer molecular weight increased with pressure and ethylene molar fraction, and decreased with dose rate and temperature. The total amount of deposited polymer on the reactor wall, source case wall, and scraping blades was usually less than 1 kg, which was negligibly small for the analysis of polymerization. Continuous discharge of the polymer slurry and production of fine-powder polyethylene were successfully carried out. In the central source-type reactor, a dose rate of 1.9 × 10⁵ rads/hr was obtained with a ⁶⁰Co source of ca. 12 kCi.     

Compositional characterization of cottonseed soapstocks

Cottonseed soapstock samples, collected during the 1993–1994 crushing season from oilseed extraction mills throughout the United States Cotton Belt, were analyzed by chemical and chromatographic methods. Volatiles averaged 48.7±10.6% (mean±SD,n=39). On a dry basis, the samples averaged 33.3±7.3% fatty acids, 26.3±6.9% phospholipids, 8.4±6.4% triglycerides, and 7.5±3.0% gossypol. The analytical techniques accounted for 93.3±8.6% of the dry soapstock matter. The AOCS method for total fatty acids in soapstock yielded values in agreement with the chromatographic and phosphorus analyses. In contrast, the AOCS method for neutral oil in soapstock gave values that were significantly higher than those obtained by chromatography. The amount of nonlipid material in the samples correlated with the phosphorus content. Total gossypol and nitrogen levels were also related.     

Relationship of cotton nitrogen and yield with Normalized Difference Vegetation Index and plant height

The strength of the associations of cotton (Gossypium hirsutum L.) yield and N nutrition with integrated Normalized Difference Vegetation Index (NDVI) and plant height measurements has been scarcely documented. The objective of this investigation was to compare the strength in terms of determination coefficient (R²) among the associations of cotton yield and leaf N concentration with integrated and respective NDVI and plant height measurements taken at key growth stages. A field experiment was carried out on no-till cotton at Jackson and Milan in Tennessee during 2008–2010. Six N treatments of 0, 45, 90, 135, 179, and 224 kg N ha^?1 were implemented in a randomized complete block design with four replicates for all site years. Regressions of lint yield with NDVI × plant height and NDVI + plant height were sometimes stronger than those of lint yield with NDVI alone. Associations of leaf N concentration with NDVI × plant height and NDVI + plant height were similar to or variably stronger than those of leaf N with NDVI alone. Regressions of lint yield and leaf N with NDVI × plant height or NDVI + plant height were generally similar to those of lint yield and leaf N with plant height alone. Utilization of integrated NDVI and plant height measurements to predict cotton yield and/or assess N nutrition has variable advantages over the use of NDVI alone. Both integrated and respective NDVI and plant height measurements are more appropriate to be used to predict cotton yield than to assess N nutrition.