bluuebunny/crossref_metadata_2025 huggingface dataset:
Monolayer-directed Assembly and Magnetic Properties of FePt Nanoparticles on Patterned Aluminum Oxide
Authors: Yildirim Oktay , Gang Tian , Kinge Sachin , Reinhoudt David , Blank Dave , Van der Wiel Wilfred , Rijnders Guus , Huskens Jurriaan
Published: March 2010

FePt nanoparticles (NPs) were assembled on aluminum oxide substrates, and their ferromagnetic properties were studied before and after thermal annealing. For the first time, phosph(on)ates were used as an adsorbate to form self-assembled monolayers (SAMs) on alumina to direct the assembly of NPs onto the surface. The Al2O3 substrates were functionalized with aminobutylphosphonic acid (ABP) or phosphonoundecanoic acid (PNDA) SAMs or with poly(ethyleneimine) (PEI) as a reference. FePt NPs assembled on all of these monolayers, but much less on unmodified Al2O3, which shows that ligand exchange at the NPs is the most likely mechanism of attachment. Proper modification of the Al2O3 surface and controlling the immersion time of the modified Al2O3 substrates into the FePt NP solution resulted in FePt NPs assembly with controlled NP density. Alumina substrates were patterned by microcontact printing using aminobutylphosphonic acid as the ink, allowing local NP assembly. Thermal annealing under reducing conditions (96%N2/4%H2) led to a phase change of the FePt NPs from the disordered FCC phase to the ordered FCT phase. This resulted in ferromagnetic behavior at room temperature. Such a process can potentially be applied in the fabrication of spintronic devices.
Preparation and Characterization of Rare Earth Doped Fluoride Nanoparticles
Authors: Jacobsohn Luiz G. , Kucera Courtney , James Tiffany , Sprinkle Kevin , DiMaio Jeffrey R. , Kokuoz Baris , Yazgan-Kukouz Basak , DeVol Timothy A. , Ballato John
Published: March 2010

This paper reviews the synthesis, structure and applications of metal fluoride nanoparticles, with particular focus on rare earth (RE) doped fluoride nanoparticles obtained by our research group. Nanoparticles were produced by precipitation methods using the ligand ammonium di-n-octadecyldithiophosphate (ADDP) that allows the growth of shells around a core particle while simultaneously avoiding particle aggregation. Nanoparticles were characterized on their structure, morphology, and luminescent properties. We discuss the synthesis, properties, and application of heavy metal fluorides; specifically LaF3:RE and PbF2, and group IIA fluorides. Particular attention is given to the synthesis of core/shell nanoparticles, including selectively RE-doped LaF3/LaF3, and CaF2/CaF2 core/(multi-)shell nanoparticles, and the CaF2-LaF3 system.
Thermal and Optical Properties of CdS Nanoparticles in Thermotropic Liquid Crystal Monomers
Authors: Lee Hooi Ling , Mohammed Issam Ahmed , Belmahi Mohammed , Assouar Mohamed Badreddine , Rinnert Hervé , Alnot Marc
Published: March 2010

Two new mesogenic monomers, namely 3,3’-dimethoxy-4,4’-di(hydroxyhexoxy)-N-benzylidene-o-Tolidine (Ia) and 4,4’-di(6-hydroxyhexoxy)-N-benzylidene-o-Tolidine (IIa), were reacted with cadmium sulfide (CdS) via an in situ chemical precipitation method in ethanol to produce CdS nanocomposites. A series of different mass compositions of CdS with Ia and IIa ranging from 0.1:1.0 to 1.0:1.0 (w/w) were prepared and characterized using X-ray Diffraction (XRD), Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Polarizing Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC), X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence Spectroscopy (PL). XRD showed that the broad peaks are ascribed to the formation of cubic CdS nanoparticles in both Ia and IIa. The average particle size for both nanocomposites was less than 5 nm with a narrower size distribution when compared with pure CdS nanoparticles. The analyses from POM and DSC demonstrated that mass composition from 0.1:1.0 up to 0.5:1.0 of CdS:Ia nanocomposites showed their enantiotropic nematic phase. On the other hand, polarizing optical microscopy (POM) for IIa nanocomposites showed that the liquid crystal property vanished completely when the mass composition was at 0.2:1.0. PL emissions for CdS: Ia or IIa nanocomposites indicated deep trap defects occurred in these both samples. The PL results revealed that addition of CdS to Ia monomers suppressed the photoluminescence intensity of Ia. However, the introduction of CdS to IIa monomers increased the photoluminescence and was at a maximum when the mass composition was 0.3:1.0, then decreased in intensity as more CdS was added. The XPS results also showed that the stoichiometric ratios of S/Cd were close to 1.0:1.0 for both types of nanocomposites for a mass composition of 1.0:1.0 (CdS:matrix).
Effects of Tetrodotoxin on the Mammalian Cardiovascular System
Authors: Zimmer Thomas
Published: March 2010

The human genome encodes nine functional voltage-gated Na+ channels. Three of them, namely Nav1.5, Nav1.8, and Nav1.9, are resistant to nanomolar concentrations of tetrodotoxin (TTX; IC50 ≥ 1 μM). The other isoforms, which are predominantly expressed in the skeletal muscle and nervous system, are highly sensitive to TTX (IC50 ~ 10 nM). During the last two decades, it has become evident that in addition to the major cardiac isoform Nav1.5, several of those TTX sensitive isoforms are expressed in the mammalian heart. Whereas immunohistochemical and electrophysiological methods demonstrated functional expression in various heart regions, the physiological importance of those isoforms for cardiac excitation in higher mammals is still debated. This review summarizes our knowledge on the systemic cardiovascular effects of TTX in animals and humans, with a special focus on cardiac excitation and performance at lower concentrations of this marine drug. Altogether, these data strongly suggest that TTX sensitive Na+ channels, detected more recently in various heart tissues, are not involved in excitation phenomena in the healthy adult heart of higher mammals.
Synthesis of Marine Polycyclic Polyethers via Endo-Selective Epoxide-Opening Cascades
Authors: Vilotijevic Ivan , Jamison Timothy
Published: March 2010

The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic pathways display biological effects ranging from potentially therapeutic properties to extreme lethality. Much of the structural complexity of ladder polyether and oxasqualenoid natural products can be traced to these hypothesized cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of ladder polyethers and oxasqualenoid natural products.
Preparation of the Pyridinium Salts Differing in the Length of the N-Alkyl Substituent
Authors: Marek Jan , Stodulka Petr , Cabal Jiri , Soukup Ondrej , Pohanka Miroslav , Korabecny Jan , Musilek Kamil , Kuca Kamil
Published: March 2010

Quaternary pyridinium salts with chains ranging from C8 to C20 belong in the large group of cationic surfactants. In this paper, the preparation of such cationic surface active agents based on the pyridinium moiety and differing in the length of the N-alkyl chain is described. Additionally, HPLC technique was established to distinguish each prepared pyridinium analogue. This study represents universal method for preparation and identification of quaternary pyridinium detergents.
Conjugate Addition of Nucleophiles to the Vinyl Function of 2-Chloro-4-vinylpyrimidine Derivatives
Authors: Raux Elizabeth , Klenc Jeffrey , Blake Ava , Sączewski Jarosław , Strekowski Lucjan
Published: March 2010

Conjugate addition reaction of various nucleophiles across the vinyl group of 2-chloro-4-vinylpyrimidine, 2-chloro-4-(1-phenylvinyl)pyrimidine and 2-chloro-4-vinylquinazoline provides the corresponding 2-chloro-4-(2-substituted ethyl)pyrimidines and 2-chloro-4-(2-substituted ethyl)quinazolines. Treatment of these products, without isolation, with N-methylpiperazine results in nucleophilic displacement of chloride and yields the corresponding 2,4-disubstituted pyrimidines and quinazolines.
Ultrasound-Assisted Synthesis of Novel 4-(2-Phenyl-1,2,3-Triazol-4-yl)-3,4-Dihydropyrimidin-2(1H)-(Thio)ones Catalyzed by Sm(ClO4)3
Authors: Liu Chen-Jiang , Wang Ji-De
Published: March 2010

An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydro-pyrimidin-2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4-carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter reaction times and higher yields.
Introduction and Assessment of Measures for Quantitative Model-Data Comparison Using Satellite Images
Authors: Mattern Jann Paul , Fennel Katja , Dowd Michael
Published: March 2010

Satellite observations of the oceans have great potential to improve the quality and predictive power of numerical ocean models and are frequently used in model skill assessment as well as data assimilation. In this study we introduce and compare various measures for the quantitative comparison of satellite images and model output that have not been used in this context before. We devised a series of test to compare their performance, including their sensitivity to noise and missing values, which are ubiquitous in satellite images. Our results show that two of our adapted measures, the Adapted Gray Block distance and the entropic distance D2, perform better than the commonly used root mean square error and image correlation.
Organic ISFET Based on Poly (3-hexylthiophene)
Authors: Scarpa Giuseppe , Idzko Anna-Lena , Yadav Anandi , Thalhammer Stefan
Published: March 2010

We have fabricated organic field-effect transistors (OFETs) with regioregular poly(3-hexylthiophene) (P3HT) operable at low-voltages in liquid solutions, suitable for in vitro biosensing applications. Measurements in electrolytes have shown that the performance of the transistors did not deteriorate and they can be directly used as ionsensitive transducers. Furthermore, more complex media have been tested, with the perspective of cell analysis. Degradation effects acting on the device operating in liquid could be partly compensated by adopting an alternate current measuring mode.
Fluorescent Silicate Materials for the Detection of Paraoxon
Authors: Johnson Brandy , Melde Brian , Thomas Cassandra , Malanoski Anthony , Leska Iwona , Charles Paul , Parrish Damon , Deschamps Jeffrey
Published: March 2010

Porphyrins are a family of highly conjugated molecules that strongly absorb visible light and fluoresce intensely. These molecules are sensitive to changes in their immediate environment and have been widely described for optical detection applications. Surfactant-templated organosilicate materials have been described for the semi-selective adsorption of small molecule contaminants. These structures offer high surface areas and large pore volumes within an organized framework. The organic bridging groups in the materials can be altered to provide varied binding characteristics. This effort seeks to utilize the tunable binding selectivity, high surface area, and low materials density of these highly ordered pore networks and to combine them with the unique spectrophotometric properties of porphyrins. In the porphyrin-embedded materials (PEMs), the organosilicate scaffold stabilizes the porphyrin and facilitates optimal orientation of porphyrin and target. The materials can be stored under ambient conditions and offer exceptional shelf-life. Here, we report on the design of PEMs with specificity for organophosphates and compounds of similar structure.
An Adaptive Fault-Tolerant Event Detection Scheme for Wireless Sensor Networks
Authors: Yim Sung-Jib , Choi Yoon-Hwa
Published: March 2010

In this paper, we present an adaptive fault-tolerant event detection scheme for wireless sensor networks. Each sensor node detects an event locally in a distributed manner by using the sensor readings of its neighboring nodes. Confidence levels of sensor nodes are used to dynamically adjust the threshold for decision making, resulting in consistent performance even with increasing number of faulty nodes. In addition, the scheme employs a moving average filter to tolerate most transient faults in sensor readings, reducing the effective fault probability. Only three bits of data are exchanged to reduce the communication overhead in detecting events. Simulation results show that event detection accuracy and false alarm rate are kept very high and low, respectively, even in the case where 50% of the sensor nodes are faulty.
Development of a Low-Cost Attitude and Heading Reference System Using a Three-Axis Rotating Platform
Authors: Lai Ying-Chih , Jan Shau-Shiun , Hsiao Fei-Bin
Published: March 2010

A development procedure for a low-cost attitude and heading reference system (AHRS) with a self-developed three-axis rotating platform has been proposed. The AHRS consists of one 3-axis accelerometer, three single-axis gyroscopes, and one 3-axis digital compass. Both the accelerometer and gyroscope triads are based on micro electro-mechanical system (MEMS) technology, and the digital compass is based on anisotropic-magnetoresistive (AMR) technology. The calibrations for each sensor triad are readily accomplished by using the scalar calibration and the least squares methods. The platform is suitable for the calibration and validation of the low-cost AHRS and it is affordable for most laboratories. With the calibrated parameters and data fusion algorithm for the orientation estimation, the self-developed AHRS demonstrates the capabilities of compensating for the sensor errors and outputting the estimated orientation in real-time. The validation results show that the estimated orientations of the developed AHRS are within the acceptable region. This verifies the practicability of the proposed development procedure.
DFB Lasers Between 760 nm and 16 µm for Sensing Applications
Authors: Zeller Wolfgang , Naehle Lars , Fuchs Peter , Gerschuetz Florian , Hildebrandt Lars , Koeth Johannes
Published: March 2010

Recent years have shown the importance of tunable semiconductor lasers in optical sensing. We describe the status quo concerning DFB laser diodes between 760 nm and 3,000 nm as well as new developments aiming for up to 80 nm tuning range in this spectral region. Furthermore we report on QCL between 3 µm and 16 µm and present new developments. An overview of the most interesting applications using such devices is given at the end of this paper.
The Comparison of Environmental Effects on Michelson and Fabry-Perot Interferometers Utilized for the Displacement Measurement
Authors: Wang Yung-Cheng , Shyu Lih-Horng , Chang Chung-Ping
Published: March 2010

The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.
Symmetry in Generating Functions
Authors: Watanabe Shigeru
Published: March 2010

Generating functions play important roles in theory of orthogonal polynomials. In particular, it is important to consider generating functions that have symmetry. This paper is a survey on generating functions that define unitary operators. First, classical generating functions that define unitary operators are discussed. Next, group theoretical approach to generating functions that have unitarity are discussed.
A Classification System to Detect Congestive Heart Failure Using Second-Order Difference Plot of RR Intervals
Authors: Thuraisingham R. A.
Published: March 2010

A classification system to detect congestive heart failure (CHF) patients from normal (N) patients is described. The classification procedure uses thek-nearest neighbor algorithm and uses features from the second-order difference plot (SODP) obtained from Holter monitor cardiac RR intervals. The classification system which employs a statistical procedure to obtain the final result gave a success rate of 100% to distinguish CHF patients from normal patients. For this study the Holter monitor data of 36 normal and 36 CHF patients were used. The classification system using standard deviation of RR intervals also performed well, although it did not match the 100% success rate using the features from SODP. However, the success rate for classification using this procedure for SDRR was many fold higher compared to using a threshold. The classification system in this paper will be a valuable asset to the clinician, in the detection congestive heart failure.
UPTAKE OF CADMIUM BY LETTUCE (Lactuca sativa) AS INFLUENCED BY ITS ADDITION TO A SOIL AS INORGANIC FORMS OR IN SEWAGE SLUDGE
Authors: SINGH S. SHAH
Published: March 2010

The effect of forms of added Cd in a soil on the uptake of Cd by lettuce (Lactuca sativa) was studied in the greenhouse. For two levels of added Cd (2.5 ppm and 5.0 ppm) and for two successive crops grown on the same soil, the average Cd concentration of plants grown in soil treated with inorganic forms was five times greater than that of plants from soils treated with sewage sludged containing Cd at the same concentrations. Forms of inorganic Cd had some effect on Cd uptake; lower amounts were taken up from soils treated with Mn oxide-Cd precipitates than from Cd precipitates with Fe and Al hydroxides and with lime. The dry matter weight of the first lettuce crop was higher at 2.5 ppm levels of Cd additions than at 5.0 ppm levels of Cd. The differences were significant for one inorganic treatment and for both sludge treatments. In the second crop of lettuce, the differences were smaller between the two levels of Cd for inorganic treatments; however, for two sludge treatments the yields were greater and statistically significant at 5.0 ppm Cd as compared to 2.5 ppm Cd. A significant correlation coefficient (r) was obtained between the DTPA-extractable Cd and the Cd content of lettuce plants for the six inorganic treatments. However, when sludge treatments were included along with inorganic treatments, the value of the correlation coefficient (r) was reduced. Caution is advised in employing the DTPA extraction of soils as a measure of Cd uptake by plants when Cd is incorporated from heterogeneous sources.
SOIL CHEMICAL PROPERTIES AND REMOVAL OF NUTRIENTS BY CORN RESULTING FROM DIFFERENT RATES AND TIMING OF LIQUID DAIRY MANURE APPLICATIONS
Authors: CULLEY J. L. B. , PHILLIPS P. A. , HORE F. R. , PATNI N. K.
Published: March 2010

Liquid dairy cattle manure was applied at three rates (224, 560 and 879 kg/(ha∙yr) of manure nitrogen (N)) and four different times: in the fall after harvest of silage corn, before seeding, half in the fall and half before seeding, or in winter to continous corn grown on sandy clay loam for 5 yr. Two other plots were included: one received chemical N-P-K fertilizer at recommended rates, and one received neither fertilizer nor manure. Over the 5-yr study, soil organic carbon increased in the surface layer of the high-rate plots, but decreased in the chemically fertilized plot. Soil inorganic N contents measured at harvest in the 0- to 120-cm layer of the manured plots were related to both cumulative and annual N inputs. Bicarbonate extractable phosphorus in the 0- to 15-cm layer increased each year in the medium- and high-rate plots and exceeded 90 μg/g in the high-rate plots after 5 yr. Exchangeable potassium levels increased singificantly in the plow layer of the medium- and high-rate plots. Smaller accumulations occurred in the winter-applied plots than in the fall- and spring-applied plots. Uptake of nutrients by the corn crop increased with manure rate, but generally was not affected by time of application.
MINERAL DISTRIBUTION AND WEATHERING IN CHERNOZEMIC AND LUVISOLIC SOILS FROM CENTRAL SASKATCHEWAN
Authors: ST. ARNAUD R.J. , SUDOM M.D.
Published: March 2010

The quartz, feldspar and mica contents of various fractions from soils developed from both glacial till and lacustrine deposits are compared. Similar mineral compositions are noted for both types of deposits. Using quartz as a resistant index mineral, the degree of weathering of micas, K-feldspars, Na-feldspars, Ca-feldspars, dolomite and calcite are evaluated for an Orthic Black Chernozemic soil and an Orthic Gray Luvisol. The latter soil has been more severely weathered than the Chernozemic soil, showing approximately double the losses of mineral components. Mineral losses from the entire solum of the Gray Luvisol include 40% of the Ca-feldspars, 22% of the Na-feldspars, and 17% of the K-feldspars. Although there is evidence of mica loss within upper horizons of both profiles, the K-depletion in upper layers is balanced by mica increases (K sorption) in lower solum horizons. Possible mechansims of K sorption and desorption among different size fractions are proposed.
THE OCCURENCE OF BASIC FERRIC SULFATES IN SOME CANADIAN SOILS
Authors: ROSS G.J. , IVARSON K.C.
Published: March 2010

Acid sulfate conditions were found in six soils from various areas in Canada by the presence of basic ferric sulfates, the prominence of the iron oxidizing bacterium Thiobacillus ferrooxidans, and the low pH values from 2.9 to 4.2. The content of natrojarosite [NaFe3(SO4)2(OH)6] was greater than, or equal to, jarosite [KFe3(SO4)2(OH)6] in the majority of the soils. The Boundary, Keld and Nicomekl soils from western areas and the Kanguk soil from an arctic area contained relatively large proportions of natrojarosite whereas the de l’Anse and Acadia soils contained larger proportions of jarosite. The recognition of acid sulfate conditions in soils and underlying materials is important not only in relation to agriculture but also with respect to construction projects, as strong acidification and corrosion may be expected, even in permafrost areas, upon exposure of pyrite-containing shales to air.
CHLORTETRACYCLINE IN SOIL AMENDED WITH POULTRY MANURE
Authors: WARMAN P.R. , THOMAS R.L.
Published: March 2010

Poultry manure from birds fed a ration containing 11 μg chlortetracycline (CTC)/g feed contained 22.5 μg CTC/g. Recovery rates of CTC added to manure were low (22–28%), so 22.5 μg/g must be considered a low estimate. When manure containing CTC was added to soil, no CTC was recovered at manure to soil ratios greater than 1:10. CTC in manure added to soil at practical levels did not affect the respiration pattern of the soil.
A STUDY OF MACROCRYSTALLINE PEDOGENIC CARBONATES USING SUBMICROSCOPIC TECHNIQUES
Authors: MERMUT A. R. , ST. ARNAUD R. J.
Published: March 2010

Calcitic plasmic fabric, grain calcans, neocalcitans and carbonatic glaebules with diffuse boundary were studied in situ, in soils by electron probe and SEM analyses. The occurrence of pedogenic magnesium-bearing calcite, previously detected by a shift of X-ray diffraction spacing on bulk samples, was verified by electron probes analyses on purely pedogenic carbonatic sites. This made it possible to understand further the nature of carbonates and to differentiate pure calcite from magnesium-bearing calcite. Common types of microcrystalline pedogenic carbonates included elongated, equidimensional, rod-shaped, and layered crystals. Equidimensional crystals were common in calcite, whereas elongated and rod types occurring sometimes as bundles of coalescing fibres were found to be magnesium calcite. Most visible pedogenic carbonate crystals in the soils studies had a diameter of 0.3–1.0 μm. This size range may be important in establishing relative levels of secondary carbonates in soils. Phosphorus values for studied features were higher than in the entire soil and arc evidence of precipitation of this element with pedogenic carbonates.
LEACHING OF FOUR ORCHARD HERBICIDES IN SOIL COLUMNS
Authors: HOGUE E. J. , GAUNCE A. , KHAN S. U.
Published: March 2010

The mobility of four residual orchard herbicides, diuron, dichlobenil, simazine and terbacil was compared in soil columns using a sandy loam and loam soil common to the Okanagan Valley. Mobility for all herbicides was greater in the sandy loam than loam soil. Dichlobenil was least mobile in the soil columns followed by diuron, simazine then terbacil. No dichlobenil was leached through the 30-cm sandy loam soil column with 120 cm of water but 40 cm of water leached more than half of the terbacil. More dichlobenil was converted to the water-soluble 2,6-dichlorobenzamide in the loam soil than in the sandy soil. This metabolite is water-soluble and was partially leached through the loam soil column with the highest level of irrigation.
SOURCES OF SULFUR FOR RAPESEED
Authors: NOELLEMEYER E. J. , BETTANY J. R. , HENRY J. L.
Published: March 2010

Rapeseed grown in pots on a S-deficient soil showed little response to elemental S fertilizers applied at rates of up to 150 ppm S. The dry matter yields, percent S and N/S ratios of the aboveground material indicated severe S deficiency in the crop. A readily available S source (ammonium sulfate) at rates of 75 and 30 ppm S increased yield by three to five times over that produced by the highest rates of elemental S.
CHANGES AND SIGNIFICANCE IN NATURAL 15N ABUNDANCE IN RESIDUAL NITROGEN FERTILIZER STUDIES
Authors: KARAMANOS R. E. , RENNIE D. A.
Published: March 2010

The systematic decline in δa15N (per mill 15N excess) of plant material with application of fertilizer under field conditions was verified in a growth chamber experiment with soil columns. The δa15N of NO3−-N in the zones of the high NO3−-N accululation was lower than that of the soil-derived NO3−-N but not necessarily lower than the δa15N of the fertilizer material as was the case in previously reported field experiments. Calculation of the fate of the fertilizer N based on the principle of isotopic dilution provided semi-quantitative estimates of the added N found in the plant, the soil, and the leachate.
ORIGIN OF SILT/SESQUIOXIDE COATINGS ON SAND GRAINS IN SOME PODZOLIC SOILS OF EASTERN ONTARIO
Authors: KEMP R. A. , RUTHERFORD G. K.
Published: March 2010

A micromorphological feature, termed a grain sesquosiltan, was identified in the Bf and BC horizons of some podzols in Eastern Ontario. It is suggested that the inherited or cryogenically-derived dense silasepic fabric has been gradually modified over time by weathering, illuviation and pedoturbation. This has resulted in the formation of silt/sesquioxide coatings around sand grains.
COMPARATIVE RESPONSES OF PEANUTS, ALFALFA, AND SOYBEANS TO VARYING RATES OF BORON AND MANGANESE ON TWO CALCAREOUS ONTARIO SOILS
Authors: LOMBIN G. L. , BATES T. E.
Published: March 2010

This study evaluated the relative responses of alfalfa (Medicago sativa L.), peanuts (Arachis hypogaea L.), and soybeans [Glycine max (Merr.)] on two calcareous Ontario soils. The B-horizon of a Pontypool sand (Typic Psammentic Hapludalf) and the Ap-horizon of a Plainfield Fine Sand (Typic Udipsamment) were each cropped to all three species in the greenhouse. Thirty-six treatments comprised factorial combinations of three rates (0, 0.25 and 1.00 μg/g) of B, two rates (0 and 25 μg/g) of Mn, the two soils, and the three crops with three replications. Plants were clipped at soil level at flowering stage, oven-dried to constant weight, and analyzed for nutrient content. Boron and Mn additions significantly increased concentrations of these elements in plant tissue. Boron uptake was significantly higher on the coarser-textured Pontypool soil and toxicity significantly reduced soybean yields on this soil, but alfalfa and peanut yields were unaffected. Peanuts appeared least sensitive to B toxicity and Mn deficiency. Soybeans were most sensitive to B toxicity and alfalfa most sensitive to Mn deficiency. The differences in tolerance to B seem attributable to the relative abilities of the three species to withstand high B concentrations in plant tissue rather than to differences in uptake. Differential susceptibility to Mn deficiency on the other hand seems attributable to relative efficiencies of the crops to extract Mn from Mn-deficient soils. Soil organic matter may have had some ameliorative effect on B toxicity. Yield and nutrient uptake were not significantly affected by B × Mn interactions.
PEDOLOGICAL INVESTIGATION OF A GRAY LUVISOL DEVELOPED FROM EOLIAN SAND
Authors: PAWLUK S. , DUDAS M. J.
Published: March 2010

Dark Gray Luvisols developed from dune sand parent material near Devon, Alberta, have Ae horizons of unusually high chromas and dark values when moist, and B horizons with very hard massive structure when dry. Micromorphological examination shows the high chromas in the Ae reflect the presence of organic, and to a lesser extent, matrix coatings on f-members. Hardening results from development of chlamydic and plectic fabrics in the B, where clay bridges bind f-members together. The illuvial clays contributing to the fabric organization are, in part, derived from accretionary eolian deposits (containing minerals such as beidellite), in part from calcitic residua (largely non-expandable components), and in part from dislodgement of clay domains (rich in montmorillonite) inherent within the Ae horizon as a constituent of the original parent material. All are actively translocated down the solum.
QUANTITATIVE RELATIONSHIP BETWEEN NET NITROGEN MINERALIZATION AND MOISTURE CONTENT OF SOILS
Authors: MYERS R. J. K. , WEIER K. L. , CAMPBELL C. A.
Published: March 2010

The 0- to 15- and 15- to 30-cm depths of five cultivated Queensland soils and 32 virgin and cultivated western Canadian soils were incubated at a range of moisture contents for 14 days at 35 °C. In most soils, net nitrogen mineralization was linearly related to moisture content in the available range (−0.03 to −4.0 MPa). Optimum moisture for net nitrogen mineralization corresponded to a soil pore water potential of between −0.01 and −0.03 MPa, while that at which no net nitrogen mineralization occurred was close to −4.0 MPa. Initially, the regression for each soil was normalized by the method of Stanford and co-workers, but this technique proved unsatisfactory. However, by normalizing against available moisture (between −0.03 and −4.0 MPa) we succeeded in grouping the soils. The response of all soils could be described by a model of the form: y = bx + (1 − b)x2 constrained to pass through x0, y0 and x1, y1when both axes were scaled between 0 and 1. In the equation, y is net nitrogen mineralized expressed as a proportion of the maximum rate; x is normalized moisture content; and the subscripts max and 0 refer to soil pore water potentials of −0.03 and −4.0 MPa, respectively. Almost all data conformed to this model. Most soils had a linear response (i.e., b = 1.0), but nine Canadian and one Queensland soil showed a curvilinear response. The expression worked well for the nine Canadian soils and b was estimated statistically to range between 1.22 and 2.18.
ACETYLENE AS A POSSIBLE SUBSTRATE IN THE DENITRIFICATION PROCESS
Authors: YEOMANS JANE C. , BEAUCHAMP E. G.
Published: March 2010

The possible involvement of acetylene (C2H2) as a carbon substrate in the denitrification process was studied in the laboratory with Brookston silty clay. Two experiments of 360 and 600 h durations, respectively, were conducted with saturated soil with or without C substrate (1% wt/wt ground alfalfa) and C2H2 (1.0 kPa) in an He environment. Incomplete reduction of NO3− to N2O and N2 occurred in the absence of both C substrate and C2H2. With C substrate but without C2H2, complete reduction of NO3− to N2 was observed. In the absence of C substrate and in the presence of C2H2, N2O production was higher than in the absence of both C substrate and C2H2 and complete reduction of NO3− to N2O and N2 was observed. With both C substrate and C2H2 added, there was complete conversion of NO3− to N2. A decrease in C2H2 concentration was observed in the absence of C substrate. Production of C2H4 or CO2 did not account for this decrease in C2H2 concentration. When N2O and C2H2 were introduced together into preincubated flasks, N2O concentration showed an initial increase and then a decrease. A decrease in C2H2 concentration was also observed. Again, this decrease was not accounted for by either C2H4 or CO2 production. Increases in the production of N2O and N2 gases and decrease in C2H2 concentration in the absence of C substrate suggested that C2H2 enhanced denitrification. No conclusive data were obtained to suggest that C2H2 acts as a carbon source during denitrification.
SOIL ACIDIFICATION BY FERTILIZERS AND LONGEVITY OF LIME APPLICATIONS IN THE PEACE RIVER REGION
Authors: HOYT P. B. , HENNIG A. M. F.
Published: March 2010

Acidification of two soils was measured in an experiment in which fertilizer and CaCO3 treatments were applied in various combinations. The highest rate of fertilizer used, which included N at 139 kg/ha, decreased the pH in 4–5 yr in unlimed Donnelly (Gray Luvisol) and Josephine (Eluviated Gleysol) soils by 0.43 and 0.18 units, respectively. The fertilizer increased the soluble Al content in both soils. Yields of barley (Hordeum vulgare L.) were greatly increased by the fertilizer and lime treatments. However, by the fourth crop on the Josephine soil, fertilizer failed to give a yield increase in the absence of lime; this was apparently due to declining soil pH and increasing soluble Al. In another experiment, loss of lime was measured over an 8-yr period in six soils that had been limed with Ca(OH)2 to pH 6.5–7.0. The average loss of lime from the soils was equivalent to 495 kg of CaCO3/ha annually. This was accompanied by a decline in pH of 0.48 unit in the 8 yr. Liming caused substantial increases to subsoil pH for three of the soils. Despite the decline in surface soil pH, increases in yields of barley from liming were sustained over the 8-yr period. The implication of these findings to soil fertility practices in the Peace River region are discussed.
EFFECT OF TOTAL CATION CONCENTRATION AND SODIUM ADSORPTION RATIO ON EXCHANGEABLE SODIUM RATIO
Authors: DOERING E. J. , MERRILL S. D. , WILLIS W. O.
Published: March 2010

Replicated analyses for each of five levels of total cation concentration showed that exchangeable sodium ratio (ESR) and sodium adsorption ratio (SAR) were linearly related by equations of the form ESR = a + b (SAR). The coefficient, b, decreased from 0.0163 to 0.0085 as total cation concentration increased from 39 to 1057 meq/L, showing that the equilibrium of exchange, as measured by ESR and SAR, is strongly affected by total cation concentration of the soil solution. A regression line, previously published by the U.S. Salinity Laboratory Staff, lies between the regression lines for 39 and 110 meq/L. Exchangeable sodium ratio can be inferred from SAR alone as long as SAR is not larger than about 20. However, the error of estimate for ESR is shown to increase with increasing SAR and total cation concentration unless the effect of total cation concentration is taken into account. This is an important factor to be considered when high-salt solutions are used to reclaim sodic soils.
CHARACTERISTICS OF SOME LOAMY-TEXTURED PODZOLS IN NORTHEASTERN ONTARIO
Authors: EVANS L. J.
Published: March 2010

Humo-Ferric Podzols (Typic Cryorthods) developed on glacial till or glaciolacustrine deposits were sampled in the Chapleau-Foleyet area of northeastern Ontario. pHs of Ae horizons ranged from 3.30 to 4.20 and of C horizons from 4.40 to 4.85. Cation exchange capacities (CEC) of mineral soil horizons averaged 1.7 meq/100 g, whilst those of the forest humus (fibrimors) averaged 166 meq/100 g. The CECs of the Bf and BC horizons were highly pH-dependent, averaging 3.2 meq/100 g at pH 4 and 16.8 meq/100 g at pH 8. The pH-dependency of CEC in these horizons was believed to be due to Al-complexes with organic matter. Calculated elemental loss using Zr as an internal standard showed significant losses of Mg, Fe, Ca and Al from Ae (albic) horizons and gains of Fe and, to a lesser extent, gains of Al in Bf (spodic) horizons. The clay mineralogy of Ae horizons was dominated by a high-charge smectite and that of Bf and BC horizons by chlorite.
A LABORATORY STUDY ON THE EFFECTS OF SOIL MOISTURE CONTENT, TEXTURE, AND TIMING OF LEACHING ON N LOSS FROM TWO SOUTHERN ALBERTA SOILS
Authors: SOMMERFELDT T. G. , CHANG C. , CAREFOOT J. M.
Published: March 2010

A column study was conducted to determine the effects of soil texture, initial soil moisture content and timing of leaching on N removal from two irrigated soils of southern Alberta. Pelleted NH4NO3 fertilizer (0.639 g N per column = 336 kg∙ha−1) was applied to Lethbridge loam (Leth L) and Cavendish fine sandy loam (CV FSL) at three initial levels of soil moisture: air dry (AD), 0.5 field capacity (0.5 FC), and wet (W, 25 cm suction). Leaching began immediately after the fertilizer application or was delayed 1 wk. Water was applied in 1400-mL (7.6 cm depth) increments every 2nd day for a total of 33 600 mL (175 cm depth). The leachate was collected, measured, and analyzed for NH4-N and NO3-N. The soil was analyzed for N content before and after leaching. More N was leached from CV FSL (0.600 g) than from Leth L (0.521 g). Responses to initial soil moisture were similar for both soils; the NO3-N concentration peak followed the advancing wetting front more closely in the AD than in the W systems and leaching losses were greatest from the 0.5 FC treatment. Delayed leaching did not significantly affect the amount of N leached. N losses, other than from leaching, were greatest in the W and AD treatments, in the AD treatment these losses were attributed to volatilization and, in the W soils, to denitrification.
THE ESTABLISHMENT OF SYNCHRONY BETWEEN SUBSURFACE LAYERS AND ESTIMATION OF OVERALL SUBSIDENCE OF CULTIVATED ORGANIC SOILS BY A PALYNOLOGICAL METHOD
Authors: MATHUR S. P. , LÉVESQUE M. P. , RICHARD P. J. H.
Published: March 2010

Pollen profiles of Tsuga canadensis in a virgin and two cultivated areas of a bog revealed the bimodal distribution characterized by easily recognizable minima, thus establishing synchrony between specific layers of the three organic soil profiles. This knowledge allowed estimation of overall subsidence of the cultivated soils, and would facilitate comparisons between subsurface layers now determinable as synchronous. Such comparisons should help determine the extent and depth of temporal biochemical and physical changes in subsurface layers of cultivated organic soils.
BORON CONCENTRATION IN THE SOIL SOLUTION UNDER IRRIGATION: A THEORETICAL ANALYSIS
Authors: JAME Y. W. , NICHOLAICHUK W. , LEYSHON A. J. , CAMPBELL C. A.
Published: March 2010

Current irrigation water criteria for boron (B) are based upon the B concentration of either the irrigation water or the soil saturation extract. The effects of the leaching fraction (LF) and the boron adsorption capacity (BAC) of the soil upon the soil solution concentration have not been considered. The objectives of this paper were (i) to develop a predictive model relating soil solution B concentration at equilibrium to the B concentration in irrigation water and the LF, and (ii) to show how the relationship between the B concentration of the soil solution under field conditions and the B concentration of the soil saturation extract can be modelled. The predictive model, derived from the mass balance concept, indicated that at equilibrium the value of the soil solution B in well-drained soil would be close to that of irrigation water, at the soil surface and will increase with depth with the highest value being near the bottom of the root zone where its magnitude is determined primarily on the degree of leaching. For irrigation water concentrations between 0.5 and 10 mg B/L, the weighted average B concentration of the soil solution in the profile of an alfalfa field would be about 1.9–2.7 times the irrigation water concentration at a LF of 0.1; it would be 1.4–1.9 times for a LF of 0.25; and 1.3–1.5 times for a LF of 0.4. The model of the relationship between soil solution B at field capacity and saturation extract B indicates the importance of the BAC of the soil. Without considering BAC, the ratio between the two would be 2. However, the model indicates that the ratio ranges from 1.0 to 1.8 depending upon the B concentration in the solution and the BAC of the soil. This suggests that the B concentration of the soil saturation extract does not provide a true representation of the soil solution B. In assessing B toxicity, the saturation extract concentration should be converted to the soil solution concentration at the actual water content of the soil.
EFFECT OF FERTILIZATION, ALTERED DRAINAGE AND VEHICLE TRACKS ON SOIL AERATION IN TUSSOCK TUNDRA
Authors: STUART LEE , MILLER PHILIP C.
Published: March 2010

Concentrations of oxygen and carbon dioxide in the soil were measured periodically in disturbed and undisturbed Eriophorum vaginatum tussock tundra from 16 July to 21 Aug. 1979. The disturbed sites were in vehicle tracks, on plots cleared of vegetation, and on plots treated with urea, cornstarch, and artificially altered drainage. Vehicle tracks made in 1979 and the artificial impoundments did not significantly affect soil oxygen and carbon dioxide concentrations. The lowest soil oxygen concentration occurred in a 15-yr-old vehicle track and on the cleared plots. Urea and cornstarch temporarily reduced soil oxygen concentration and increased soil carbon dioxide levels. Tussocks were more poorly aerated than intertussock areas except in the old vehicle track. Soil oxygen concentration did not usually vary significantly between 5 and 15 cm, but dropped sharply at 25 cm. Oxygen diffusion coefficients calculated from an earlier study on soil oxygen flux and the current data on oxygen concentrations suggest that despite generally well-aerated conditions, anaerobic zones may occur frequently in tussock tundra soils.
EFFECT OF SEA CROP 16 AND ERGOSTIM ON CROP YIELDS AND PLANT COMPOSITION
Authors: GUPTA UMESH C. , MacLEOD J. A.
Published: March 2010

Experiments were conducted to determine the effect of Sea Crop (SC 16) and Ergostim on the yield and nutrient composition of a few crops. Studies conducted under greenhouse and field conditions showed that the yields of wheat (Triticum aestivum L.) and peas (Pisum sativum L.) were not affected by the addition of SC16. The nitrogen (N) and sulfur (S) concentrations of the two crops were not affected by SC 16, except in the control and SC 16 treatment only where the increases were likely due to a concentration effect, since these two treatments had lower yields. Boron (B) and molybdenum (Mo) concentrations in the plants were significantly affected by B and Mo applications, but not by SC 16. A greenhouse study showed that the yields of alfalfa (Medicago sativa L.) and wheat were not affected by the addition of Ergostim. The addition of Ergostim did not affect the N or S concentration of wheat or three cuts of alfalfa.
CONDITIONAL FORMATION CONSTANTS FOR ALUMINUM-ORGANIC MATTER COMPLEXES
Authors: HARGROVE W. L. , THOMAS G. W.
Published: March 2010

The objective of this study was to determine conditional formation constants which are dependent on pH for Al-organic matter complexes. Potentiometric titrations of H-organic matter in the presence of 0, 0.004 and 0.01 M AlCl3 were carried out by the batch method. The conditional formation constants were calculated by simply relating the amount of complex formed to the amounts of unreacted metal and ligand. The addition of Al3+ resulted in displacement of the titration curves, indicating complex formation. The formation constants (log K′f) increased as the pH increased, illustrating the strong dependence of Al adsorption on pH. Values for log K′f ranged from 1.78 to 3.90 in this study.
FACTORS AFFECTING FERTILIZER RESPONSE OF WHEAT IN SOUTHWESTERN SASKATCHEWAN
Authors: READ D. W. L. , WARDER F. G. , CAMERON D. R.
Published: March 2010

Fertilizer tests using hard red spring wheat (Triticum aestivum L.) were conducted in the field from 1967 to 1979 on stubble and fallow land on the major soil types throughout southwestern Saskatchewan. The yield, percent nitrogen and phosphorus in the grain, kernel and volume weights of the grain were measured, and the responses of each of these characteristics to N and P fertilizer were determined. These responses were related to soil measurements of available H2O, NO3-N, NH4-N and sodium-bicarbonate-extractable P, which were taken at seeding time, at depths to 120 cm, and to the monthly rainfall during the growing season. On fallow, nitrogen rates higher than 15 kg N/ha gave little significant increase. The yield increase per kilogram of P applied decreased as the rate of application increased. On stubble, the yield increase per kilogram of N applied decreased for each additional increment of N added, down to 3.1 kg/ha yield increase per kilogram of nitrogen per hectare when the rate of application was increased from 45 to 60 kg N/ha. Regression analysis showed that the soil and the weather variables used accounted for only 20% of the variability in yield on fallow crops and for 40% on stubble crops. Nitrogen content of the grain was only increased by rates of 45 kg N/ha or greater. The P content of grain was decreased by both N and P fertilizer.
CHANGES IN SOIL QUALITY UNDER ZERO TILLAGE FARMING SYSTEMS: DISTRIBUTION OF MICROBIAL BIOMASS AND MINERALIZABLE C AND N POTENTIALS
Authors: CARTER M. R. , RENNIE D. A.
Published: March 2010

The objectives of this study were to evaluate if zero tillage had significantly altered the distribution of certain soil properties formally developed under the shallow cultivation (conventional tillage) soil management systems used on the Canadian prairies. To this end, concentration gradients of available plant nutrients, microbial biomass and mineralizable C and N, were determined in the Ap soil horizon from four locations representing zero and conventional (shallow) tillage systems of 2-, 4-, 12- and 16-yr duration. No significant change coud be detected in total soil organic C and N between tillages systems. Concentrations of plant-available P and K were slightly increased in the surface 0- to 2-cm depth after 16 yr of zero tillage. Except for the 2-yr tillage site, concentration gradients of potential microbial biomass C and N, and potential net mineralizable C and N were significantly greater in the surface soil under zero tillage in comparison to conventional tillage. The reverse situation was observed at the lower depth. The percentage of soil organic C and N that was in the microbial biomass also reflected the above trends. Accumulation of mineral N and calculated N mineralization potentials were closely correlated to both the initial microbial biomass N and the decrease in size of the latter during mineralization. The possible relationships of tillage induced change and redistribution in potential biological activity to N availability were discussed.