bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of the alum-amine process for the recovery of alumina from shale
Authors: Thomas G , Ingraham T R
Published: March 2018

Based on a review of the extensive published literature on the recovery of alumina from clays and shale, sufficient experimental work was done on a bench scale to establish a flow sheet whereby these materials might he treated for the recovery of cell-grade
alumina. The significant step in the processing is the recovery of potassium alum, and its purification by either recrystallization or liquid-liquid extraction
The influence of combined additions of tin, cadmium, antimony and copper on the structure and properties of galvanized coatings
Authors: Sebisty J J , Palmer H
Published: March 2018

The structure and properties of laboratory-prepared galvanized coatings on steel sheet, as affected by combined additions of tin, cadmium, antimony and copper to iron-saturated zinc baths, have been investigated in a statistically- designed series of tests. It
was found that the most important single factor affecting the thickness, metallographic structure, forming properties, surface appearance and storage-stain corrosion of the coatings was the aluminum content of the bath. The bath temperature and the time of immersion modified the behaviour of
aluminum and were thus prominent secondary factors. Statistically, the influence of tin, cadmium, antimony and copper was minor to negligible, except with respect to surface appearance and storage-stain corrosion of the coatings.
The metallography of creep-rupture fracture in aluminum
Authors: Bleakney H H
Published: March 2018

The evidence presented in this report is interpreted as showing that there is no sharp change from ductile to brittle behaviour in creep-rupture tests of commercially pure aluminum; that all ruptures at less than 100% reduction in area originate in
intercrystalline fissures; and that the degree of embrittlement depends upon the extent and number of the fissures.
A study of the Athabasca bitumen from the Abasand quarry, Alberta, Canada
Authors: Boyd M L , Montgomery D S
Published: March 2018

The pentane-soluble portion, which constitutes 77% of the Abasand bitumen, was chromatographed on activated fullers earth by the elution technique. This procedure resulted in a separation of the resinous and oil components. The resins were fractionated into
four groups by the use of a succession of increasingly polar solvents. The following properties are given for each resin fraction: ash content, emission spectra of the ash, elementary analysis, molecular weight, density at 20°C, refractive index at 20°C, infra-red spectrum, ultraviolet
spectrum, and visible spectrum. One resin fraction, CC14 (i), was further chromatographed on silica gel, to determine the amount of saturated material. Quantitative estimates of the number of methyl and methylene groups, and also the number of aromatic carbon atoms have been made from the infra-red
spectrum. Each resin fraction has been characterized by the application of van Krevelen's structural analysis system, arid also by two new methods devised by the authors. The chemical structure of each fraction has been expressed in terms of five structural groups, and a quantitative estimate has
been made of the degree of condensation of the aromatic rings.
Anionic adsorption on three sulphide minerals
Authors: Dibbs H P
Published: March 2018

A study has been made of anionic adsorption on. pyrite, sphalerite and galena from solutions of sodium sulphide, labelled with sulphur-35, and phosphoric acid, labelled with phosphorus-32. It was found that the three minerals exhibited similar behaviour in each
solution. The dependence of this behaviour on pH and on the concentration of the test solution has been examined. Senior
Metal inert-gas welding of tin bronze castings
Authors: Nolan M J , Winterton K
Published: March 2018

Considerable experimental work has been done to determine a suitable welding method for the repair of tin bronze castings. Preliminary investigations with the metal-arc, carbon-arc tungsten inert-gas and metal inert-gas processes indicated that best welds were
produced with metal inert-gas welding. With other processes, there was a greater tendency for generally poor mechanical properties associated with cracking and porosity. Metallurgical investigations indicate that weld porosity may derive from hydrogen in the sand-cast base metal. Steam-reaction
porosity is inhibited by a higher degree of deoxidation in the weld metal. Some of the cracking problems are associated with the brittle tin-rich delta constituent, which is precipitated in increased amounts in the weld metal and in the heat-affected zone. Lead, often blamed for , cracking troubles,
does not appear to be harmful in small amounts. An experimental procedure has been developed for metal inert-gas welding using a modified bronze composition of filler wire with enhanced silicon and phosphorus content, which will produce joints with good mechanical properties, comparable with those
of the base material, and substantially free of welding defects.
Electromechanical properties of three experimental lead zirconate-lead titanate ceramic compositions
Authors: Weston T B
Published: March 2018

Three experimental piezoelectric compositions in the lead titanate-lead zirconate series have been produced, using conventional ceramic fabrication techniques. Long-period grinding of the constituents in ball mills made it possible to employ sintering
temperatures lower than those previously reported, but there was some loss of lead oxide during« fabrication and impurity pickup during grinding was substantial. The finished ceramic samples proved difficult to pole, but development of a suitable poling technique yielded piezoelectric
properties only slightly poorer than the best values reported in the literature for similar compositions, generally produced by more elaborate methods. Although some unexpected changes of composition during fabrication were observed, it was possible to draw some conclusions regarding the effect of
minor chemical modification, including the addition of niobia, on the electromechanical properties.
Radiation effects on p- - and n- - type catalysts used in the thermal dissociation of ethyl alcohol
Authors: Donato M
Published: March 2018

The dissociation of anhydrous ethyl alcohol has been studied over the temperature range 330 °-430°C with the employment of catalysts that had been exposed to a range of estimated "integrated" neutron doses of up to 96.6 x 10 18 n/cm Z . The catalysts
are ZnO, an n-type semiconductor, prepared by decomposition of the carbonate, and CrZ 0 3' a p-type semiconductor, prepared by dehydration of the hydroxide. Measurable changes in yield and decomposition mechanism have been observed as compared with the unirradiated catalysts. The variation in the
behaviour of the catalysts has been related to the various neutron doses received and the results are discussed in the framework of the electronic theory of catalysis on semiconductors.
Gamma-ray analysis of atmospheric dust samples
Authors: Horwood J L
Published: March 2018

Gamma-ray spectra of dust samples from the atmosphere were plotted from measurements with a five-channel analyser. Peaks from fission products Zr-95, Nb-95, Ru-103, Ce-141, Ce-144 and Cs-137, with half-lives of several days and longer were identified. The same
peaks were found in a sample of house dust. Very long-lived fission products such as caesium-1 37 were not of sufficient activity to permit identification until the samples had decayed for several months.
Determination of kerosene entrainment losses in the solvent extraction of a leach liquor
Authors: Lapointe C M
Published: March 2018

The entrainment losses of kerosene in the barren raffinate, in the course of the solvent extraction of uranium from, a leach liquor, have been determined by the addition of C14- labelled decane to the circuit. The toluene extract of the raffinate was made the
main constituent of a liquid scintillator in which the carbon activity was measured by means of a single channel beta-ray spectrometer. An average value of 33 ppm kerosene was found in the raffinate.
Low pressure hydrogenation of coker distillate from Athabasca bitumen
Authors: Booth F L , Carson R E , Bowles K W , Montgomery D S
Published: March 2018

The desulphurization of coker distillates from separated Athabasca bitumen was investigated by hydrogenation over a cobalt molybdate-alumina catalyst. Five process variablestemperature, pressure, liquid hourly space velocity, hydrogen-to-liquid feed ratio, and
sulphur content of the liquid feedwere examined. With one particular -feed, a yield of over 100% of oil product having a sulphur content of 0.2% was obtained under the f011owing conditions: 420°C (788°F), 1000 psi, 1.8 volumes of feed per volume of catalyst per hour, and 4500 cu ft
of hydrogen per barrel of feed With the same feed at a constant hydrogen-to-liquid feed ratio and a pressure of 1000 psi, a relation was established between temperature, space velocity, and the sulphur content of the oil product. The rate of decline of catalyst activity due to coke deposition was
also studied and it was found that at a pressure of 1000 psi little coking occurred at temperatures below 430°C (806°F). Above this temperature the coke deposition increased exponentially with the temperature. The quality of the motor gasolines produced was a little below that of
commercial regular grade gasoline, the gas oils were on the borderline of acceptability as diesel fuel, and the heavier distillates were usable as numbers 4 and 5 fuel oils or cracking and recycle stocks.
Hot workability of alpha brasses
Authors: Thomson R , Edwards J O
Published: March 2018

Both lead and bismuth have a deleterious effect on the hot working properties of alpha brasses. The work reported in this article shows that the element uranium, when present in the alloy in such proportions as to form stable high melting point intermetallic
compounds with all of the bismuth or lead, is a highly effective agent in removing the characteristic hot shortness in hot-rolled contaminated alpha brass. It is suggested that melt treatment by uranium may thus afford considerable production economies in terms of scrap utilization, casting shop
practice, hot fabrication, etc. The principle may be extended to other alloys susceptible to impurity effects during hot working, and, indeed, to other problems where the fixation of one constituent is desirable for any reason. This is a condensed version of a report issued by the Departrnent of
Mines and Technical Surveys, Ottawa, Canada. The authors are, respectively, at the Canadian Uranium Research Foundation and the Non-Ferrous Section of the Department of Mines and Technical Surveys
A study of sed1mented organic matter and its natural derivatives
Authors: King L H , Goodspeed F E , Montgomery D S
Published: March 2018

The need for a classification covering the entire spectrum of organic matter in geological formations has been recognized for some time, but owing to. the lack of sufficient data the formulation of such a classification has been held back. In this report,
techniques are described for the preparation of samples of organic matter from geological formations whereby ash contents can be lowered to a level where reliable property measurements can usually be obtained. Property measurements were made on a wide variety of samples which vary in structure from
aliphatic to graphitic types. The properties measured include: elemental analysis, volatile matter content, refractive index, density, solubility in carbon disulphide, and infrared spectra. Structural parameters derived from these properties include aromaticity, reduced molar volume, ring
condensation index, an estimate of aromatic cluster size, and quantitative structural group data obtained from the infrared spectra of solid materials mounted in KBr. The correlation of these parameters, as well as of the measured properties, with atom percent carbon delineated structural trends and
development tracks for the materials under consideration. These results are compared with the structural and metamorphic trends in coal. The problem of classification is discussed in terms of genesis and chemical structure. The samples are divided into two major groups on the basis of their origin:
sedimented organic matter (syngenetic), and natural derivatives of sedimented organic matter (epigenetic). It appears that further geological qualification is required before the material of syngenetic origin can be properly classified according to its inherent chemical properties, but the study
shows that the epigenetic material can be effectively classified in terms of atom percent carbon, volatile matter content, and solubility.
Origin of the Albert mines oil shale (New Brunswick) and its associated albertite
Authors: King L H
Published: March 2018

The Albert Mines oil shale is part of the Albert formation of the Moncton basin of New Brunswick, and is of Mississippian age. The deposit is a varved dolomitic, organic marlstone, and is probably of planktonic algal origin. It bears a striking resemblance to
certain facies of the Green River formation. The oil shale is associated with the type vein of albertite, and the unique occurrence is considered as evidence that the albertite had its origin in the organic matter of the shale. However, the albertite properties are different from those of the
organic matter of the shale; the former is more highly aromatic in structure. It is suggested that the albertite developed as a chemical fraction of the shale, possibly from a fraction of degraded aquatic humus. It probably migrated in aqueous solution, assisted by dissociating functional groups
that are still in evidence in the infrared spectra. Precipitation of the albertite from the migrating solutions probably resulted from a change in environmental pH. Various other origins for albertite are discussed.
Electrical resistivity measurements on western Canadian coals
Authors: King L H
Published: March 2018

Field resistivity measurements were made in advance of a coal face to determine the probability of encountering outbursts as the coal was mined. This field work led to the measuring of resistivity on laboratory specimens in order to ascertain the influence of
adsorbed methane, carbon dioxide, and moisture. The laboratory work shows that moisture, but not adsorbed gases, can account for the large resistivity fluctuations encountered in the field. The field measurements apparently detect fracturing in the coal ahead of an advancing face when the fractures
are saturated with moisture, but outbursts cannot be predicted from the measurements.
Dense lithium fluoride for gamma-ray-free neutron shielding
Authors: Svikis V D
Published: March 2018

A simple method of processing powdered LiF into dense and strong LiF, suitable for self-supporting neutron shielding, was developed. The processing was carried out in two stages. In the first stage, chemically pure LiF powder was slip-cast and sintered for
periods of from 1 to 5 hours at temperatures ranging from 500 0 to 840 °C, in order to establish the best conditions for making dense 'and volume-stable LiF aggregate. Aggregates were prepared with densities in the range 52 to 92% of theoretical, depending on sintering temperature and time.
Maximum density was achieved by sintering at 700°C for 3 hours. In the second stage, dense and stabilized LiF aggregate was graded, pressed into shapes at 4000, 6000 and 8000 psi, and heated at 600° and 800°C, to find the best conditions for making dense compacts. LiF compacts, as
large as 8-3/4 by 4-1/2 by 3 in., with densities in the range 78 to 85% of theoretical were prepared. Maximum density and good mechanical strength were attained when the graded aggregate was pressed into shapes at a pressure of 8000 psi and the shapes were heated for five hours at 800°C.
The material can be cut and machined to close dimensional tolerances.
Ageing behaviour of A1-10% Mg casting alloys at room temperature and up to 150°C (300°F)
Authors: Pollard W A
Published: March 2018

The ageing and related phenomena of the A1-10% Mg casting alloy, at room temperature and up to 150°C (300°F), have been studied by tensile testing and metallographic examination over periods of up to six years. In alloys containing more than about
10.2% Mg aged at room temperature, a slow but continuous increase in strength occurs at least up to five years. However, at 50°C (122°F) and above, this age-hardening does not occur, but precipitation is observed first at grain boundaries, with no change in properties, and then in
Widmanstaetten form within grains, accompanied by rapid embrittlement. Reversion of the room temperature aged material occurs above 50 °C . (122 °F). The results are discussed in terms of recent work on the Al-Mg alloys and of recent theories of age-hardening.
Uranium in alloy steel
Authors: Makepeace C E
Published: March 2018

The effect on the mechanical properties at room temperature and at elevated temperatures, of adding uranium to alloy steel in plate and sheet form, was investigated in thirty-two factorial experiments n Statistically significant results indicate that uranium
form8 a stable compound, probably uranium monocarbide, which is not affected by prior heat treatment. Adding less than one-half per cent uranium was observed to result in an increase in the time to reach 0.1% creep strain and a decrease in the susceptibility to hot cracking in alloy steel
sheet.
Activation energy calculation from a linearly-increasing-temperature experiment
Authors: Ingraham T R , Marier P
Published: March 2018

A simplified method ha. been developed for the determination of the activation energy of a heterogeneous reaction having linear kinetics. The thermal decomposition of calcium carbonate has been used as an example and it has been shown that when the logarithm of
the weight loss per unit area of powder compacts is plotted against the reciprocal of absolute temperature, for a run done with a linear heating rate, a linear relationship is obtained. When the logarithms of the heating rate and the absolute temperature are included, results for a variety of
heating rates can be completely correlated. Heating rates of less than 5 degrees per minute are recommended. An activation energy of 48.4 ± 2 kilocalories per mole has been estimated for the decomposition reaction and 7 ± 3 kilocalories per mole for the formation
reaction.
Properties of sand-cast magnesium alloys part viii: foundry characteristics of magnesium-zinc-silver-zirconium casting alloys
Authors: Lagowski B , Meier J W
Published: March 2018

In continuation of earlier work, additional casting alloys were developed in the magnesium-zinc-silver-zirconium system to achieve the optimum combination of mechanical properties and foundry characteristics. In particular, some work was directed to the
production of thin-walled premium-quality castings. The effects of section thickness, heavy chilling, and hot water quenching after solution treatment on the mechanical properties of high-strength magnesium casting alloys were investigated. Results of a study of foundry characteristics, including
hot tearing, fluidity (castability), susceptibility to microshrinkage, linear shrinkage and density, are reported. It was found that alloy ZQ91-T6 shows great promise for applications in more complex, and especially in thin-walled castings.
Fe-Ta oxides: phase relations at 1200 °C
Authors: Turnock A C
Published: March 2018

Subsolidus phase relations of the oxides in the system Fe-Ta-0 were experimentally determined at 1200°C, 1 atm total pressure, and variable partial pressures of oxygen. Tantalum pentoxide reacts readily with either ferrous or ferric oxide at subsolidus
temperatures and the following ternary compounds have been synthesized: Fe4Ta206, Fe3Ta208 .1, FeTa0 4, FeTa206, solid solutions between the latter two compounds, and tantalian magnetites. The compositions of solid solutions between FeTa04 and FeTa206 were very sensitive to variation of oxygen
pressure. This sensitivity explains the oxidation behavior of tapiolite. The incorporation into magnetite of up to 7 at % Ta was demonstrated, with a resulting increase in the size of the unit cell and decrease in magnetic permeability.
Production of high-purity magnesia
Authors: Kent G A
Published: March 2018

This investigation was carried out to produce magnesite, or magnesia with low iron content. Flotation and magnetic separation of uncalcined magnesite ore yielded concentrates in the order of 2% Fe (as Fe203)and 0.5% SiOz. Calcination of the concentrates
followed by flotation and magnetic separation further reduced the iron to about 1 % Fez03 and the silica to about 0.4%. Leaching calcined ore or concentrate with dilute acetic acid produced magnesia containing less than 0.01% Fe203 and low silica. A procedure for producing high-grade
magnesia is suggested.
Effect of 0.12% chlorhexidine and zinc nanoparticles on the microshear bond strength of dentin with a fifth-generation adhesive
Authors: Alaghehmad Homayoon , Mansouri Elham , Esmaili Behnaz , Bijani Ali , Nejadkarimi Sogol , Rahchamani Mohsen
Published: March 2018

Objective: In this study, we compared the effects of 0.12% chlorhexidine (CHX) and nano zinc oxide (NZO) on the microshear bond strength of dentin with a fifth-generation adhesive after acid etching. Materials and Methods: Forty molar teeth were randomly divided into four main groups based on dentin surface treatment technique (a) control (single bond 2); (b) NZO; (c) CHX; and (d) NZO + CHX. In each group, half of the samples underwent thermocycling, with no thermocycling in the other half. Then, failure mode was evaluated under a stereomicroscope. Statistical analysis was performed using t-test, two-way ANOVA, and Chi-squared test. Results: The mean microshear bond strength of the groups without thermocycling was more than that of the groups with thermocycling, but there were no statistically significant differences between the groups with and without thermocycling in pair-wise comparisons. Conclusion: Pretreatment with NZO and CHX separately and simultaneously had no effect on the microshear bond strength of a fifth-generation adhesive.
Effect of heat polymerization conditions and microwave on the flexural strength of polymethyl methacrylate
Authors: Ozkir Serhat Emre , Yilmaz Burak , Unal Server Mutluay , Culhaoglu Ahmet , Kurkcuoglu Isin
Published: March 2018

Objective: The objective of this study is the effect of different heat polymerization conditions on the strength of polymethyl methacrylate (PMMA) resin base is unknown. Distinguishing one method that provides improved mechanical properties may be beneficial to the clinical success of complete and partial dentures and overdentures. The purpose of this study was to evaluate the effect of different polymerization methods on the flexural strength of a dental PMMA resin. Materials and Methods: Forty PMMA specimens (64 mm × 10 mm × 4 mm) were prepared with 4 different polymerization methods (n = 10); heat polymerization at 74°C for 9 h, at 100°C for 40 min, and with 620 kPa pressure at 100°C for 20 min. The remaining group of specimens was microwave polymerized at 180 W for 6 min. All specimens were thermocycled at 5°C and 55°C for 5000 times. Three-point flexure test was used to measure the flexural strength of specimens. One-way ANOVA and Tukey Honestly Significant Difference were applied to analyze the differences in flexural strengths (⍺ = 0.05). Results: The flexural strength of heat-polymerized groups was similar. The flexural strength of microwave polymerized group was significantly different and lower than the other groups (P < 0.05). Conclusion: Polymerizing conventional heat-polymerizing PMMA resin with microwave energy resulted in a significant decrease in flexural strength. The results of this study suggest that clinicians may benefit from using heat polymerization when processing PMMA denture bases instead of microvawe polymerization when tested brand is used.
Increase the glyde path diameter improves the centering ability of F6 Skytaper
Authors: Troiano Giuseppe , Dioguardi Mario , Cocco Armando , Zhurakivska Khrystyna , Ciavarella Domenico , Muzio Lorenzo Lo
Published: March 2018

Objective: The aim of this study was to assess the impact of glide path preparation, performed with PathGlider 0.15 (Komet Brasseler GmbH & Co., Lemgo, Germany) and PathGlider 0.20 (Komet Brasseler GmbH & Co., Lemgo, Germany), on the centering ability of 25-size F6 Skytaper in J-shape simulated root canals, compared with no glide path executed. Materials and Methods: Sixty J-shaped ISO 15 0.02 taper endo training blocks (Dentsply Maillefer) were assigned to three groups (n = 20 for each group). Photographic images were taken on endoblocks before and after shaping procedures. After superimposition, the software AutoCAD 2013 (Autodesk Inc., San Rafael, USA) was used for record the centering and shaping ability at 9 different levels from the apex. Results: Shaping procedures including the using of PathGlider 0.20 resulted in a lower amount of resin removed and in a clear improvement of centering ability of the Skytaper 0.25 at almost all reference point levels. Conclusions: Within the limitations of this study, it could be concluded that the glide path procedure, performed with the PathGlider 0.20 before the shaping with 25-size F6 Skytaper, might determine a lower amount of resin removed and a better centering ability compared with the groups without glide path procedure and those treated with PathGlider 0.15.
Volumetric analysis of hand, reciprocating and rotary instrumentation techniques in primary molars using spiral computed tomography: An in vitro comparative study
Authors: Jeevanandan Ganesh , Thomas Eapen
Published: March 2018

Objective: This present study was conducted to analyze the volumetric change in the root canal space and instrumentation time between hand files, hand files in reciprocating motion, and three rotary files in primary molars. Materials and Methods: One hundred primary mandibular molars were randomly allotted to one of the five groups. Instrumentation was done using Group I; nickel–titanium (Ni-Ti) hand file, Group II; Ni-Ti hand files in reciprocating motion, Group III; Race rotary files, Group IV; prodesign pediatric rotary files, and Group V; ProTaper rotary files. The mean volumetric changes were assessed using pre- and post-operative spiral computed tomography scans. Instrumentation time was recorded. Statistical analysis to access intergroup comparison for mean canal volume and instrumentation time was done using Bonferroni-adjusted Mann-Whitney test and Mann–Whitney test, respectively. Results: Intergroup comparison of mean canal volume showed statistically significant difference between Groups II versus IV, Groups III versus V, and Groups IV versus V. Intergroup comparison of mean instrumentation time showed statistically significant difference among all the groups except Groups IV versus V. Conclusion: Among the various instrumentation techniques available, rotary instrumentation is the considered to be the better instrumentation technique for canal preparation in primary teeth.
Impact of electro-neuro-feedback on postoperative outcome of impacted lower third molar surgery
Authors: Oteri Giacomo , Marcianò Antonia , Cervino Gabriele , Peditto Matteo
Published: March 2018

Objective: The purpose of this study was to evaluate the impact of a treatment with electro-neuro-feedback (ENF), a portable transcutaneous electrical nerve stimulation (TENS) device, on the clinical outcome and inflammatory biochemical parameters related to the impacted lower third molar surgery. Materials and Methods: A randomized, split-mouth, and single-blind study was conducted on 32 patients requiring lower third molars extractions and referred to the Oral Surgery Unit of the School of Dentistry of the University of Messina. Every patient underwent surgical removal of both lower third molars. The first extraction included a placebo (electrodes placement with turned-off device) treatment following the surgery, while the second had the ENF used next to the avulsion and the following days. Clinical parameters were collected 4 days before, immediately after, 2, 4, and 7 days after the surgical procedure. Biochemical parameters were obtained 1 day before the surgical removal and 7 days after. Data were processed using Wilcoxon–Mann–Whitney test, with significance being set at P < 0.05. Results: Clinical outcome parameters showed a significant improvement after the ENF treatment, while considered inflammatory markers expressed different patterns. Conclusions: ENF, a reliable portable TENS device, has demonstrated to be a useful tool in the managing of the postsurgical phases, reducing edema, pain, and consequent pain-killers consumption.
Comparative abrasive wear resistance and surface analysis of dental resin-based materials
Authors: Nayyer Maleeha , Zahid Shahreen , Hassan Syed Hammad , Mian Salman Aziz , Mehmood Sana , Khan Haroon Ahmed , Kaleem Muhammad , Zafar Muhammad Sohail , Khan Abdul Samad
Published: March 2018

Objective: The objective of this study was to assess the surface properties (microhardness and wear resistance) of various composites and compomer materials. In addition, the methodologies used for assessing wear resistance were compared. Materials and Methods: This study was conducted using restorative material (Filtek Z250, Filtek Z350, QuiXfil, SureFil SDR, and Dyract XP) to assess wear resistance. A custom-made toothbrush simulator was employed for wear testing. Before and after wear resistance, structural, surface, and physical properties were assessed using various techniques. Results: Structural changes and mass loss were observed after treatment, whereas no significant difference in terms of microhardness was observed. The correlation between atomic force microscopy (AFM) and profilometer and between wear resistance and filler volume was highly significant. The correlation between wear resistance and microhardness were insignificant. Conclusions: The AFM presented higher precision compared to optical profilometers at a nanoscale level, but both methods can be used in tandem for a more detailed and precise roughness analysis.
Comparison of osteoclastogenesis and local invasiveness of ameloblastoma and keratocystic odontogenic tumor
Authors: Al-Rawi Natheer H. , Al-Siraj Ammar K. , Majeed Ahlam H.
Published: March 2018

Objectives The aim of this study was to compare the expression of receptor-activated nuclear factor kappa B (RANK) with its ligand (RANKL) and matrix metalloproteinase-2 (MMP2) in solid/multicystic ameloblastomas (ABs) and keratocystic odontogenic tumors (KOTs). Materials and Methods: The expression of MMP2, RANK, and RANKL molecules was evaluated in 13 ABs and 14 KOTs by immunohistochemistry. The expressions were calculated in the odontogenic epithelial cells as well as the stromal cells. Results: Odontogenic epithelia of AB expressed MMP2, RANK, and RANKL significantly higher than that of KOTs (P < 0.05). The expression of MMP2, RANK, and RANKL was highest in plexiform subtype (79.9%, 81.08%, and 65.1%, respectively). KOTs without daughter epithelia nests expressed both MMP2 and RANK the least (56.06% and 47.5%, respectively). Stromal cells, on the other hand, expressed similar MMP2 pattern in odontogenic epithelia of both AB and KOT. RANKL was expressed weaker in the stromal cells of both lesions. Conclusion: Invasive biological and osteolytic behaviors of both lesions were evaluated in this study. It was found to be more in AB than keratocystic odontogenic. A significant expression of MMP2, RANK, and RANKL in both KOTs associated with microcyst and plexiform type AB as well.
Conceptual knowledge of oral health among school teachers in South India, India
Authors: Jagan P. , Fareed Nusrath , Battur Hemanth , Khanagar Sanjeev , Manohar Bhat
Published: March 2018

Objective: To measure conceptual oral health knowledge among school teachers using comprehensive measure of oral health knowledge (CMOHK) instrument. Materials and Methods: A total of 240 school teachers drawn through cluster random sampling from across Sullia taluk. Conceptual knowledge was assessed using Comprehensive measure of oral health knowledge questionnaire. Oral health status was recorded on a World Health Organization oral health assessment Proforma. Results: Overall distribution of CMOHK scores revealed that 106(44%) subjects had good conceptual oral health knowledge, 81(33.7%) subjects had fair and 53(22%) subjects were categorized under poor conceptual knowledge respectively. Statistically significant difference was observed for mean scores for conceptual knowledge in relation to gender (12.8v/s 15.3), in terms of type of school teachers (14.4 v/s 11.2) and in relation to age of the subjects. Primary school teachers exhibited a consistently better CMOHK scores 0.003(0.001-0.011) compared to their high school counterparts 0.003(0.001-0.012). Conclusion: The mean CMOHK score of this group was 12.5±1.3 and is considered to be fair. There is an inverse association between age, educational levels and income in relation to CMOHK scores.
Mobile Stress Interventions: Mechanisms and Implications
Authors: Jaimes Luis G , Steele Robert
Published: March 2018

According to the American Psychological Association, 49% of the U.S. population suers from chronic, daily stress. Chronic stress also has significant long-term behavioral and physical health consequences, including an increased risk of cardiovascular disease, cancer, anxiety and depression. In this work, we examine how smartphones and mobile sensing can help address the short and long-term consequences of stress. First, we define a conceptual framework for thinking about the interaction between real-time pervasive devices and the real-time physiology of stress. Second, using this framework, we propose a set of guidelines or requirements for pervasive just-in-time intervention (JITI) systems. Third, based on these guidelines, we specify a three-layer software/hardware architecture to support just-in-time interventions for stress. Several themes emerge from this discussion, including the need for robust and accurate context-sensitive forecasting of future stress. Fourthly we describe our experiments and results demonstrating the feasibility of forecasting future stress from current measurements and the eectiveness of the intervention management approach. Finally we discuss the broader implications of mobile-based stress interventions. Whilst this work focuses on chronic stress, we believe the ideas presented are generalizable to other types of just-in-time pervasive interventions.
La tuberculose à Mycobacterium bovis chez le cerf et le sanglier en France. Émergence et risque pour l’élevage bovin
Authors: Hars Jean , Boschiroli Maria-Laura , Duvauchelle Aurore , Garin-Bastuji Bruno
Published: March 2018

Depuis les années 1960, la tuberculose due à Mycobacterium bovis a été décrite dans la faune sauvage de plusieurs pays à travers le monde. Selon les cas, les différentes espèces de mammifères trouvées infectées par M. bovis peuvent être considérées comme réservoirs primaires, réservoirs secondaires ou culs-de-sac épidémiologiques. En 2000, la France a été déclarée officiellement indemne de tuberculose bovine et, jusqu’à cette date,

M. bovis n’avait jamais été isolé chez un animal sauvage en liberté. Cependant, depuis 2001, l''infection a été identifiée chez des ongulés sauvages dans quatre régions distinctes : tout d’abord en Normandie (2001), puis en Corse et en Bourgogne (2003), et dans les Pyrénées (2005). En 2001-2002, dans la forêt normande de Brotonne, une enquête épidémiologique a révélé des prévalences apparentes d''infection de 28% chez le sanglier et 14 % chez le cerf. La plupart des animaux ne présentaient pas de lésions visibles à l’inspection par les chasseurs. Des mesures de lutte (accroissement de la pression de chasse, interdiction d’affouragement, destruction des viscères des animaux tués…) ont été immédiatement prises pour tenter de contenir l’épizootie. Malgré cela, le phénomène s’est aggravé : en effet, en 2005-2006, la prévalence apparente a atteint plus de 30 % chez le sanglier et plus de 20 % chez le cerf, avec une augmentation du taux de lésions ouvertes dans les deux espèces Par contre, dans les autres régions, les cas semblent demeurer sporadiques (1 % < p< 5%). Les mêmes génotypes de M. bovis ont été retrouvés chez les ongulés sauvages et les bovins qui auraient pu être à leur contact. Ceci laisse supposer qu’il existe un réel lien épidémiologique entre les animaux sauvages et domestiques Ces résultats posent la question de l’émergence de la tuberculose dans la faune sauvage, de son origine, et du risque de transmission au bétail.
Étude sérologique de l’anémie infectieuse des équidés I. — Production des prédpitogènes G et C
Authors: Goret Pierre , Toma Bernard
Published: March 2018

Les modalités de la préparation des précipitogènes G et C à partir d’équidés infectés expérimentalement par le virus de l’anémie infectieuse des équidés sont présentées. Ces précipitogènes sont obtenus régulièrement à partir de la rate, de façon plus variable à partir d’autres organes (poumon, foie, rein, ganglion, thymus...). L’activité antigénique et la pureté des extraits produits à Alfort ou provenant d’autres Laboratoires ont été déterminées par immunodiffusion radiale. L’isolement des deux précipitogènes permet de suivre l’évolution des anticorps contre chacun d’eux chez les chevaux infectés par le virus A. I. E.
Réaction d’hypersensibilité cutanée chez le cobaye, consécutive à l’inoculation intra-dermique d’un antigène chlamydien («virus» de l’avortement de la brebis) purifié inactive
Authors: Faye P. , Charton André , Brugère J. , Le Layec Cl. , Solsona M. , Lefrançois C. , Gueslin M.
Published: March 2018

L’inoculation intra-dermique au cobaye syngénique d’un antigène chlamydien purifié, inactivé, mélangé à l’antigène complet de Freund, détermine un état d’hypersensibilité que révèle une deuxième injection intra-dermique pratiquée au sixième jour : La réaction obtenue ne fait pas intervenir d’anticorps circulants. L’état de sensibilité qu’elle traduit est transféré au cobaye neuf par injection intra-péritonéale d’une suspension en solution saline équilibrée d’un broyât de ganglions prélevés sur cobaye sensibilisé. L’intensité des réactions obtenues montre l’importance de la réaction cellulaire dans la réponse immunitaire du cobaye à l’injection de cet antigène.
Apparition d’anticorps anti-brucelliques après emploi d’une seringue ayant contenu du vaccin B 19
Authors: Trap Danièle , Gaumont R.
Published: March 2018

Dans cette expérimentation 6 jeunes bovins et 6 moutons indemnes de brucellose reçoivent du vaccin anti-aphteux à l’aide d’une seringue ayant contenu du vaccin B 19. On constate alors l'apparition d’agglutinines anti-brucelliques à des taux pouvant dépasser 240 UI/ml chez certains animaux dès le quinzième jour après l’injection et susceptibles de persister encore au trentième jour. Cette formation d’anticorps est liée à la présence de Brucella résiduelles dans la seringue. L’épreuve au mercaptoéthanol confirme leur origine vaccinale. Ces résultats sont en accord avec ceux de Ch. Pilet, G. Beck et G. A. Cullen. C’est pourquoi on ne saurait apporter trop de soins au nettoyage des seringues ayant contenu du vaccin B 19 lorsque l’on doit les employer pour un autre usage.
Enquête épidémiologique à propos d’un foyer de trichinose humaine dans la région parisienne
Authors: Motyka S.
Published: March 2018

L'épidémie de Trichinose humaine récemment constatée dans la région parisienne semble avoir été provoquée par la consommation de viande de cheval, crue ou insuffisamment cuite, en provenance de l'étranger.
La souris gestante, modèle de la chlamydiose abortive de la brebis
Authors: Rodolakis Anne
Published: March 2018

L’inoculation à la souris gestante, par voie intra-péritonéale, d’une suspension virulente de Chlamydia, à une dilution convenable, permet d'obtenir une infection abortive de la souris semblable à l’infection chlamydienne naturelle, de la Brebis.
Chlamydioses des ruminants (bovine, ovine, caprine) : étude expérimentale — I. Préparations d’antigènes chlamydiens purifiés concentrés
Authors: Faye P. , Charton André , Solsona M. , Le Layec Cl. , Gueslin M.
Published: March 2018

La méthode de concentration et de purification décrite dans cette note, appliquée à diverses variétés (ovine, caprine, bovine) de Chlamydia psittaci cultivées sur membrane vitelline d’œuf embryonné permet d'obtenir des suspensions dans lesquelles ni la microscopie (optique ou électronique), ni l'analyse chimique ne permettent de déceler d'élément autre que chlamydien.
De l’importance de la régulation artificielle du débit dans les cours d’eau de montagne, dont les eaux sont restituées, en aval des retenues de barrage
Authors: Fleckinger Robert
Published: March 2018

A partir d'observations sur le terrain, le caractère bénéfique de la régulation du débit pour l’équilibre naturel et la productivité d’un cours d’eau en salmonidés sont précisés. A cette occasion on remarque l’insuffisance de la législation sur la pollution qui ne vise que les qualités intrinsèques des eaux et néglige l'influence du débit sur les équilibres naturels.
Recherche des résidus d’antibiotiques dans les viandes
Authors: Billon Jean
Published: March 2018

Une méthode simple, sensible, rapide et peu onéreuse de dépistage est décrite pour la recherche des antibiotiques dans les viandes. Basée sur la technique des zones d'inhibition des cultures microbiennes, l'originalité de la méthode résulte de la technique d'obtention d’un exsudât musculaire stérile, de l’emploi de deux espèces microbiennes Bacillus subtilis cultivant sur gélose à pH 6ft et 8,0 et de Sarcina lutea cultivant sur gélose à pH 7,0.
De la survie de quelques Microccocaceae dans les miels du commerce
Authors: Tysset Camille , Durand C.
Published: March 2018

Après contamination expérimentale du miel, les staphylocoques pathogènes ne survivent, en moyenne, que 20 jours, constatation qui confirme la renommée du miel du point de vue de sa salubrité.
Les piroplasmes peuvent-ils se multiplier dans l’organisme de l’homme ?
Authors: Guilhon Jean , Morel P.
Published: March 2018

L'observation de deux cas de piroplasmose ou babésiose humaine observés, tout récemment, dans l’Ouest de la France, confirme la conviction profonde exprimée, dès 1956, par G. Logé de l’existence de cette protozoose humaine en Loire-Atlantique.
Le diagnostic sérologique de l’agalaxie contagieuse des petits ruminants : un test de fixation du complément
Authors: Perreau Pierre , Le Goff C. , Giauffret A.
Published: March 2018

Les auteurs rapportent la mise au point d’un test de fixation du complément destiné au sérodiagnostic de l’agalaxie contagieuse. Plusieurs types d’antigènes ont été essayés et les meilleurs résultats obtenus avec les mycoplasmes lysés par les ultra-sons ou le lauryl-sulfate de Na.

Un seuil significatif d'anticorps est proposé, à titre indicatif, pour assurer le diagnostic dans les conditions techniques décrites ; la spécificité du test est contrôlée et discutée.
Isolement de Chlamydia psittaci agent de l'Omithose, chez la Perdrix grise d’élevage (Perdrix perdix)
Authors: Louzis Claude
Published: March 2018

Chlamydia psittaci a été isolé sur des Perdrix grises d’élevage atteintes par ailleurs de Mycoplasmose à Mycoplasma gallisepticum.

L’agent étiologique de l’Ornithose a été mis en évidence après coloration de calques de rate, cultures sur œuf embryonné et système cellulaire et inoculation à la souris de laboratoire.
Enquête sur la Colibacillose du porcelet à l'occasion du sevrage
Authors: Renault Lucien , Le Bourhis Elizabeth , Maire Cl. , Vaissaire Josée
Published: March 2018

Les auteurs ont fait l'étude sérologique de 113 souches d’Escherichia coli isolées de porcelets atteints de colibacillose à l’occasion du sevrage.

Les résultats indiquent que la majorité appartient à des souches entéro-pathogènes et principalement aux sérogroupes 0149 : K 91, K 88 a, c et 0141 : K 85 a, c.
Méthode d'analyse microbiologique, en 24 heures, des denrées alimentaires. I. Principes et applications aux plats cuisinés
Authors: Catsaras Marc , Dorso Y.
Published: March 2018

L'analyse microbiologique de denrées alimentaires demandant habituellement un délai de 3 à 5 jours, il est apparu souhaitable d’établir, dans le cas des plats cuisinés, les principes d’une méthode qui permettrait d’obtenir, pour tous les germes recherchés, un résultat en 24 h. Les problèmes posés par la mise en évidence, dans ces conditions, des conformes, des E. coli, des anaérobies sulfito-réducteurs, des staphylocoques pathogènes, des Salmonella et des germes aérobies, sont pleinement discutés. Les premiers résultats obtenus sont signalés.
Thermorésistance du virus de la fièvre aphteuse dans le lait de vache infectée
Authors: Dhennin Léone , Labié Jacques
Published: March 2018

Les essais de destruction par la chaleur du virus aphteux contenu dans le lait écrémé de vaches expérimentalement infectées ont montré qu'un temps de chauffage de 20 secondes à 70° C abaisse le titre du virus au voisinage de 0 sans pour autant amener sa disparition complète.

A la température de 60° C une durée de chauffe de 320 secondes donne le même résultat.

Dans le lait virulent chauffé 20 secondes à 90° C il est encore possible de déceler la présence du virus aphteux.
Recherche des œstrogènes par radioimmunologie dans le plasma et les tissus des jeunes bovins
Authors: Richou-Bac Lucien , Mollet M. F. , Boursier Bernadette , Cumont G.
Published: March 2018

Par radioimmunologie, les teneurs en œstradiol 17 β et en DES ont été recherchées sur des prélèvements sanguins et tissulaires de veaux provenant de différents abattoirs français.

2 p. 100 des échantillons plasmatiques et 20 p. 100 des échantillons tissulaires présentent en œstradiol 17 0 des valeurs supérieures à 04 ppb. Le DES est détecté dans moins de 2 p. 100 des cas.
De la survie de quelques entérobactéries dans le miel stocké dans une enceinte réfrigérée à + 10° C
Authors: Tysset Camille , Durand C.
Published: March 2018

Le miel n’étant pas doué d’un pouvoir bactéricide mais bactériostatique les bactéries ne se multiplient pas lorsqu'il est entreposé dans une enceinte climatisée (10° C), mais leur élimination est longue, pouvant dépasser plus de 2 ans pour certains écotypes. Aussi la recherche de certains germes, notamment des Salmonelles est-elle indispensable.
La démodécie de la chèvre en France
Authors: Euzéby Jacques , Chermette René , Gevrey J.
Published: March 2018

La démodécie de la chèvre semble devenir de plus en plus fréquente en France, depuis une dizaine d’années ; elle contrarie sérieusement les élevages dans lesquels elle sévit sous forme endémique.

L’affection se manifeste par des symptômes et des lésions d’acné par rétention, sans caractères inflammatoires accusés. Elle se manifeste d’abord chez les chevreaux âgés de 10 à 15 mois et évolue lentement, en trois phases, pour se maintenir sous une forme très discrète chez les sujets adultes. Chez les individus jeunes très parasités l'état général peut être très sérieusement affecté.

Les auteurs exposent les caractères cliniques et anatomiques de l'infection démodécique de la chèvre, étudient les aspects de l’endémie et suggèrent des hypothèses étiologiques, dont les plus vraisemblables leur paraissent être : une contamination par contact avec les mangeoires souillées de Demodex et un transport par des poux anoploures.

Enfin, quelques mesures thérapeutiques et prophylactiques sont suggérées.
Un cas d’intoxication collective des bovins par les dérivés chlorés du naphtalène
Authors: Fleckinger Robert , Stevenin G. , Agnet M. , Richou-Bac Lucien
Published: March 2018

Nous avons observé, vraisemblablement pour la première fois en France, une intoxication collective de bovins dont les manifestations cliniques, nécropsiques et histopathologiques décrites dans la présente relation étaient comparables aux manifestations signalées par Wilson et Bell [1] aux U. S. A. dans la reproduction expérimentale de l'hyper kératose bovine (X -Disease) par les chloro-naphtalènes, puis dans plusieurs ouvrages [2] [3] [4],

Une source d’émission dans l’atmosphère d’aérosols de pentachloronaphtalènes sur support de poudre de silice colloïdale a pu être identifiée à proximité des bovins malades au moment de la manifestation de la maladie ; la suppression de l’utilisation du produit incriminé fit cesser toute manifestation ultérieure de la maladie.