Comprehensive Study on the Chemical Structure of Dioxane Lignin from PlantationEucalyptus globulusWood

2001 ◽  
Vol 49 (9) ◽  
pp. 4252-4261 ◽  
Author(s):  
Dmitry V. Evtuguin ◽  
Carlos Pascoal Neto ◽  
Artur M. S. Silva ◽  
Pedro M. Domingues ◽  
Francisco M. L. Amado ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Dioxane Lignin ◽  
Comprehensive Study

Effects of Organic Additives on Calcium Sulfate Scaling in Pipes

2009 ◽  
Vol 62 (8) ◽  
pp. 927 ◽  
Author(s):  
Tung A. Hoang ◽  
H. Ming Ang ◽  
Andrew L. Rohl
Keyword(s):  
Pipe Flow ◽  
Calcium Sulfate ◽  
Chemical Structure ◽  
Flow System ◽  
Organic Additives ◽  
Pipe System ◽  
Calcium Sulfate Scale ◽  
First Time ◽  
Over Time ◽  
Comprehensive Study

A comprehensive study of the effects of nine organic additives on the formation of calcium sulfate scale in a pipe system was conducted using a multiple pipe flow system. Several factors that influence the inhibitory capability of phosphonic and carboxylic additives such as their chemical structure, their concentration, and the run time were closely scrutinized. Results showed that the organic additives influence the deposition of calcium sulfate on the walls of a pipe flow system at various levels. The superiority of the phosphonic additives, especially N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTP) and nitrilotrimethylenephosphonic acid (NTMP), to other organic compounds with respect to scale prevention is discussed thoroughly. For the first time, it was demonstrated that a solution with a given concentration of inhibitor that is continuously refreshed in a pipe reactor becomes less effective over time. The morphology of the scales formed in the presence of different additives is also studied, using scanning electron microscopy.

scholarly journals Properties of extracted Eucalyptus globulus kraft pulps

TAPPI Journal ◽  
2012 ◽  
Vol 11 (4) ◽  
pp. 47-55 ◽  
Author(s):  
G.V. DUARTE ◽  
J.A.F. GAMELAS ◽  
B.V. RAMARAO ◽  
T.E. AMIDON ◽  
P.J. FERREIRA
Keyword(s):  
Surface Energy ◽  
Eucalyptus Globulus ◽  
Chemical Structure ◽  
Hot Water ◽  
Water Extraction ◽  
Kraft Pulps ◽  
Hot Water Extraction ◽  
Extraction Step ◽  
Kraft Cooking ◽  
Comprehensive Study

This work was a comprehensive study of the properties of extracted Eucalyptus globulus kraft pulps. Five levels of hot water extraction were performed, each followed by kraft cooking to three different kappa numbers. As extraction took place, the hemicelluloses content of the kraft pulps was reduced from 21%-22% to 3%-4% and, conversely, the cellulose fraction increased from 73%-75% to 85%-90%. Fiber length decreased for all pulps and kink index increased greatly with extraction. The dispersive components of the surface energy for the control (unextracted) and extracted (120 min) kappa no. 15 kraft pulps, as determined by inverse gas chromatography, were found to be 30.8 and 34.9 mJ/m2, respectively. The acid-base properties of the pulp surface seemed to be enhanced by the inclusion of the hot-water extraction step. We discuss the surface energy properties in terms of the chemical structure of the pulps. In addition, we report on two models able to predict the mass removal and kappa number of pulps prepared from preextracted chips.

Removal of Trihalomethane Precursors from River and Lake Water by Activated Carbon Adsorption

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1687-1694 ◽  
Author(s):  
Y. Takeuchi ◽  
Y. Suzuki ◽  
A. Koizumi ◽  
N. Soeda
Keyword(s):  
Activated Carbon ◽  
Lake Water ◽  
Biological Treatment ◽  
Chemical Structure ◽  
Activated Carbon Adsorption ◽  
Carbon Adsorption ◽  
Strong Relation ◽  
Drinking Water Purification ◽  
Eastern Japan ◽  
Comprehensive Study

A comprehensive study was undertaken to clarify the method of reducing trihalomethane and its precursors from river and lake water in view of drinking water purification. Sources of water were chosen among lakes and rivers in Eastern Japan and biological treatment and coagulative precipitation of the water samples were carried out prior to activated carbon adsorption. A strong relation was shown between TOC and THMFP of raw and treated samples, and the relation changed due to the extent of biological treatment. Though the chemical structure of substances which may cause trihalomethane formation is not clear, the content of ammoniacal nitrogen is responsible for the reduction of trihalomethane formation produced by the addition of chlorine. However, this does not mean that the reduction of chlorine dose can be achieved simply by the process of biological treatment.

Inelastic Electron-Matter Interactions

1978 ◽  
Vol 36 (3) ◽  
pp. 259-267
Author(s):  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Chemical Structure ◽  
Inelastic Electron ◽  
Primary Concern ◽  
Unique Probe ◽  
Introductory Paper ◽  
Elastic Processes ◽  
Experimental Level ◽  
Inelastic Processes

In this introductory paper, my primary concern will be in identifying and outlining the various types of inelastic processes resulting from the interaction of electrons with matter. Elastic processes are understood reasonably well at the present experimental level and can be regarded as giving information on spatial arrangements. We need not consider them here. Inelastic processes do contain information of considerable value which reflect the electronic and chemical structure of the sample. In combination with the spatial resolution of the electron microscope, a unique probe of materials is finally emerging (Hillier 1943, Watanabe 1955, Castaing and Henri 1962, Crewe 1966, Wittry, Ferrier and Cosslett 1969, Isaacson and Johnson 1975, Egerton, Rossouw and Whelan 1976, Kokubo and Iwatsuki 1976, Colliex, Cosslett, Leapman and Trebbia 1977). We first review some scattering terminology by way of background and to identify some of the more interesting and significant features of energy loss electrons and then go on to discuss examples of studies of the type of phenomena encountered. Finally we will comment on some of the experimental factors encountered.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Hexachlorobenzene toxicity in the monkey ovary: III. Ultrastructure induced by high (10 mg/kg) dose exposure

1991 ◽  
Vol 49 ◽  
pp. 130-131
Author(s):  
A. Singh ◽  
A. Dykeman ◽  
J. Jarrelf ◽  
D. C. Villeneuve
Keyword(s):  
Present Report ◽  
Reproductive Toxicity ◽  
Control Group ◽  
Primate Model ◽  
Human Follicular Fluid ◽  
Thin Sections ◽  
Cynomolgus Monkeys ◽  
Cacodylate Buffer ◽  
Induction Cycle ◽  
Comprehensive Study

Hexachlorobenzene (HCB), a persistent and mobile organochlorine pesticide, occurs in environment. HCB has been shown to be present in human follicular fluid. An objective of the present report, which is part of a comprehensive study on reproductive toxicity of HCB, was to determine the cytologic effects of the compound on ovarian follicles in a primate model.Materials and Methods. Eight Cynomolgus monkeys were housed under controlled conditions at Animal facility of Health and Welfare, Ottawa. Animals were orally administered gelatin capsules containing HCB mixed with glucose in daily dosages of 0.0 or 10 mg/kg b.w. for 90 days; the former was the control group. On the menstrual period following completion of dosing, the monkeys underwent an induction cycle of superovulation. At necropsy, one-half of an ovary from each animal was diced into ca. 2- to 3-mm cubed specimens that were fixed by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3). Subsequent procedures followed to obtain thin sections that were examined in a Hitachi H-7000 electron microscope have been described earlier.

Comparison of Substructures Between Uniaxial and Biaxial Deformation in 1100-0 Aluminum

1981 ◽  
Vol 39 ◽  
pp. 52-53
Author(s):  
D. L. Rohr ◽  
S. S. Hecker
Keyword(s):  
Plastic Strain ◽  
Cell Walls ◽  
Room Temperature ◽  
Mechanical Response ◽  
Biaxial Tension ◽  
Initial Deformation ◽  
Uniaxial Deformation ◽  
Biaxial Deformation ◽  
Stress States ◽  
Comprehensive Study

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.

Microvasculature and structure of hemal lymph nodes in the wall of the rabbit bladder: a vascular corrosion casting and EM study

1995 ◽  
Vol 53 ◽  
pp. 1074-1075
Author(s):  
F.E. Hossler ◽  
M.I. McKamey ◽  
F.C. Monson
Keyword(s):  
Lymph Nodes ◽  
Light Microscopy ◽  
Corrosion Casting ◽  
Fixed Tissue ◽  
Infusion Pressure ◽  
India Ink ◽  
Cacodylate Buffer ◽  
Rabbit Bladder ◽  
Lateral Walls ◽  
Comprehensive Study

A comprehensive study of the microvasculature of the normal rabbit bladder, revealed unusual "capillary glomeruli" along the lateral walls. Here they are characterized as hemal lymph nodes using light microscopy, SEM, TEM, ink injection, and vascular casting.Bladders were perfused via a cannula placed in the abdominal aorta with either 2% glutaraldehyde in 0.1M cacodylate buffer (pH 7.4) for fixation, 10% India ink in 0.9% saline and 0.1M phosphate (pH 7.4) for vessel tracing, or resin (Mercoximethylmethacrylate: catalyst, 4:1:0.3; Ladd Research Industries) for vascular corrosion casting. Infusion pressure was 100mm Hg. Fixed tissue was sectioned from epon-araldyte resin, and stained with toluidine blue for light microscopy, and lead and uranium for TEM. Ink injected tissue was photographed directly from saline-filled bladders illuminated from below. Resin-filled tissue was macerated in 5% KOH and distilled water. Casts were critical point dried, sputter coated with goldpalladium, and examined by routine SEM at 10 KV.

Chemical structure of diamond-like carbon thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 710-711
Author(s):  
N.-H. Cho ◽  
K.M. Krishnan ◽  
D.B. Bogy
Keyword(s):  
Electrical Resistivity ◽  
Chemical Structure ◽  
Diamond Like Carbon ◽  
Chemical Structures ◽  
Sputtering Power ◽  
Data Aquisition ◽  
Equilibrium Phases ◽  
Electron Energy Loss ◽  
Power Densities ◽  
Preparation Techniques

Diamond-like carbon (DLC) films have attracted much attention due to their useful properties and applications. These properties are quite variable depending on film preparation techniques and conditions, DLC is a metastable state formed from highly non-equilibrium phases during the condensation of ionized particles. The nature of the films is therefore strongly dependent on their particular chemical structures. In this study, electron energy loss spectroscopy (EELS) was used to investigate how the chemical bonding configurations of DLC films vary as a function of sputtering power densities. The electrical resistivity of the films was determined, and related to their chemical structure.DLC films with a thickness of about 300Å were prepared at 0.1, 1.1, 2.1, and 10.0 watts/cm2, respectively, on NaCl substrates by d.c. magnetron sputtering. EEL spectra were obtained from diamond, graphite, and the films using a JEOL 200 CX electron microscope operating at 200 kV. A Gatan parallel EEL spectrometer and a Kevex data aquisition system were used to analyze the energy distribution of transmitted electrons. The electrical resistivity of the films was measured by the four point probe method.

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