bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoindentation-Induced Phase Transformation in Silicon Thin Films
Authors: Čtvrtlík Radim , Tomaštík Jan , Ranc Vaclav
Published: September 2013

Nanoindentation-induced phase transformation of amorphous, annealed amorphous and microcrystalline hydrogen-free silicon thin films were studied. Series of nanoindentation experiments were performed with a sharp Berkovich indenter at various unloading rates. The structural changes in indentation deformed regions were examined using Raman spectroscopy. Analyses of indentation curves and Raman spectra suggest that high pressure phases appear more easily in annealed amorphous Si thin films than in microcrystalline ones.
Micro-Mechanical Testing of Metal Foam Cell Walls Using Miniature Three-Point Bending
Authors: Fíla Tomáš , Kytýř Daniel , Koudelka Petr , Doktor Tomáš , Zlámal Petr , Jiroušek Ondřej
Published: September 2013

This paper is focused on determination of micro-mechanical material properties of aluminium metal foam at level of single cell wall. For the purpose of homogenization, complex and heterogenous inner structure of metal foams requires deep understanding of its deformation mechanisms and local mechanical properties. Therefore, a series of micro-scale bending tests of specimens prepared from foam's cells wall were performed. Initially, a technique of specimen preparation was developed. Dimensions and geometry of the specimens were inspected using scanning electron microscopy (SEM). Custom-designed three-point bending device suitable for testing at micro-scale was used for loading. Thin pure aluminium metal sheets were used for calibration of the described method. Six single cell wall specimens were tested. It can be concluded that the developed specimen preparation technique and loading method are suitable to determine local mechanical properties of thin walled metal foams.
The Variation of Mechanical Properties of WC-Based HVOF Sprayed Coatings with Respect to the Co Content
Authors: Houdková Šárka , Bláhová Olga , Kašparová Michaela
Published: September 2013

The indentation methods (HR15N, HV0.3, HIT, EIT) were used to evaluate differences between the WC-based coatings with 12, 17 and 25% of Co binder. The two sets of WC-12%Co coatings with two different sets of parameters were sprayed to evaluate the influence of spraying parameters. The measured mechanical characteristic were correlated to the to the wear resistance of the coatings evaluated by dry sand/rubber wheel test according to ASTM G-65 and pin-on disc according to ASTM G-99. The measured results showed that there is almost no difference between the abrasive wear resistance of WC-Co coating with 12 and 17% of Co binder, while the wear of coating with 25% of Co binder is significantly higher. The importance of the spraying parameters on the WC-12%Co coatings properties has been found to be comparable to the importance of binder content influence.
Microstructural and Vickers Microhardness Evolution of Heat Treated Secondary Aluminium Cast Alloy
Authors: Hurtalová Lenka , Tillová Eva , Chalupová Mária
Published: September 2013

Secondary aluminium alloys are made out of aluminium scrap and aluminium-processable waste by recycling. These alloys contain different alloying elements such as Al, Cu, Fe, Si and Mg that form intermetallic phases in aluminium matrix and influence on the microstructure, basic mechanical properties and microhardness evolution in aluminium cast alloy. As experimental material was used secondary aluminium cast alloy AlSi9Cu3. Material was subjected to heat treatment (age-hardening) consisting of a solution treatment at temperature 515 °C with holding time 4 hours, than water quenching at 40 °C and artificial aging by different temperature 130 °C, 150 °C and 170 °C with different holding time (2, 4, 8, 16 and 32 hours). The age-hardening led to changes in the morphology of structural components, but also leads to precipitation of finer hardening phases in the material substructure. As optimal age-hardening mode for secondary aluminium cast alloy AlSi9Cu3 was determined mode consisting of solution treatment at temperature 515 °C with holding time 4 hours and artificial aging at temperature 170 °C with holding time 16 hours. After this heat treatment cast alloy shows the best changes in microstructure and mechanical properties. These changes are comparable with changes by primary AlSi9Cu3 cast alloy.
Stability of Superalloys Doped with Rare Earth Elements
Authors: Jasinski Walenty , Zawada Paweł
Published: September 2013

The stability of the microstructure and properties of the iron superalloys of the secondgeneration IN 519 (24% Cr, 24% Ni, 1.5% Nb) modified with 0.1 and 0.2 [wt.%] rare earthelements was investigated. The alloys underwent annealing at 825 oC for 10, 100 and 1000 h. Thefollowing techniques were used to evaluate the phase transformation: X-ray diffraction on crosssectionand isolates extracted from the as-cast and annealed alloys, microstructure analysis byoptical microscopy, hardness measurements by Brinell and nanoindentation with a Berkovich tipmethod. The analysis of changes in hardness distribution due to thermal processing of superalloyswas conducted with respect to the average hardness of matrix and phase precipitates.
Evaluation of Local Mechanical Properties of Thin Coatings Prepared by PVD Evaporation
Authors: Jakubéczyová Dagmar , Zubko Pavol , Hagarová Mária , Zubko Juraj
Published: September 2013

The contribution deals with evaluation of mechanical properties of thin hard coatings prepared by ARC evaporation on steel substrate K110. In this paper TiN and AlTiCrN are comparatively studied. The thickness of TiN and AlTiCrN coatings was evaluated using the calotest, GDOES and nanohardness was also measured. The results show that AlTiCrN coatings posses higher hardness and Young´s modulus than simple monolayer TiN coatings. The substrate-coating interface was without failures, which confirmed excellent adhesion properties of the system. Due to their specific properties, the coatings appear suitable for use in practical operations.
Influence of the Filler Root Surface Treatment on Bending Fatigue Test Results of the Hardened Gears
Authors: Jonšta Petr , Maršálek Petr , Havlík Jiří , Jonšta Zdenĕk
Published: September 2013

This article deals with testing of fatigue properties of hardened gears at bending. These tests are defined by the standard ISO 6336 - method B, when testing is carried out under reference conditions close to the real operation. This type of testing may be helpful to evaluate the influence of new materials, design parameters, production technology, or the effects of surface finishing. The first part of this article deals with the theory of fatigue testing methodology using modified stair-case method and characteristics of the testing machine. The second part of the paper is devoted to the characteristics of the experimental material and the results achieved. The case hardened steel gears alloyed by Cr-Ni-Mo were selected for the experiment. Hardened gears were subjected to local hardness measurement and subsequently the bending fatigue tests were performed. Ruptured samples were analyzed using a scanning electron microscope. The local bending stress was determined using the modified computational model based on the ISO 6336 standard methodology. The focus of this work consisted in evaluation of the influence of the filler root surface treatment on fatigue limit at bending on the basis of the realized experiments and their confrontation with the equivalents specified in the standards ISO 6336 and ČSN 01 4686.
Local Mechanical Properties of Borides in Fe-B Steels
Authors: Kolaříková Marie , Chotěborský Rostislav , Savková Jarmila , Bryksí Stunová Barbora
Published: September 2013

One of the ways to increase service life of the abrasive wear parts are new developed as-cast steels with ceramic phase. Expensive wear resistant high chromium cast iron can be exchanged by Fe – B alloys. The mechanical properties of the borides in the Fe – B cast iron depend on alloying elements like chromium or nickel. A set of sample with different content of carbon, chromium, nickel and boron has been prepared. Chemical composition (GDOES) and microstructure of the as-cast alloys have been investigated as well as the hardness and Young modulus of the borides. Our results shown that mechanical properties of borides depends both on chromium and carbon content.
Determination of Mechanical Properties of Active Solder Alloys Using the Measuring Method “Small Punch Test”
Authors: Koleňák Roman , Martinkovič Maroš
Published: September 2013

The paper deals with determination of mechanical properties of active solders type Sn3.5Ag4Ti(Ce,Ga), Sn2Ti, Bi25In18Sn and Sn2La by use of “Small Punch Test” (SPT). Reference curves were plotted for determination of mechanical properties of the mentioned solders, which allowed mutual comparison of measured results from SPT test with the results obtained from standard tests. On comparison of SPT results with the results of standard methods agreement of both results is obvious. It may be thus concluded that SPT technique can be used for assessment of mechanical properties for a wide scope of soldering materials.
Influence of Interphase Imperfection on Micro-Crack Behavior in Polymer Composites Filled by Rigid Particles
Authors: Majer Zdeněk , Náhlík Luboš
Published: September 2013

In this paper a particulate composites with polypropylene matrix and rigid mineral fillers are studied. The polymer particulate composites are frequently used in many engineering applications. Due to the physical and chemical interaction between matrix and particles a third phase (generally called interphase) is formed. The composite is modeled as a three-phase continuum. The properties of particles and interphase have a significant effect on the global behavior of the composite. On the basis of fracture mechanics methodology the interaction of micro-crack propagation in the matrix filled by rigid particles covered by the very soft interphase is analyzed. The effect of the composite structure on their mechanical properties is studied here from the theoretical point of view. The properties of particles and matrix were determined experimentally. Conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in polymer particulate composites with respect to interphase.
Local Strain and Stress Analysis of Globe Valve Housing Subjected to External Axial Loading
Authors: Mitrovic Nenad , Milosevic Milos , Momčilović Nikola , Petrovic Aleksandar , Miskovic Zarko , Sedmak Aleksandar , Popovic Predrag
Published: September 2013

Globe valves have widespread application in various industrial sectors. Due to this variety, valve is subjected to different working loads (static, dynamic, thermal etc.) that can cause valve failures. In this paper, the analysis is performed on globe valve subjected to external axial loading caused by pipeline dilatations. Experimental analysis was focused on determining local mechanical properties of critical areas, i.e. on local areas of globe valve housing with high geometrical discontinuities. Experimental analysis and numerical model verification were performed using system Aramis based on Digital Image Correlation method. Using full-field experimental results, numerical model behavior was improved and enabled acquiring more accurate results in transition areas that cannot be found in currently available literature. Determining local mechanical properties of critical areas enables better understanding of complex structures such as valve housing and provides an opportunity for further development and improvement for practical industrial application.
Effect of Beta Irradiation on Microhardness of Polyamide 6
Authors: Ovsik Martin , Manas David , Manas Miroslav , Stanek Michal , Bednarik Martin , Kratky Petr
Published: September 2013

The polymer additional cross-linking influences the surface nano and micro layers in the way comparable to metals during the thermal and chemical-thermal treatments (e.g. surface hardening, cementation). Our research confirms the comparable properties of surface irradiated polyamide 6 (PA6) with high performance polymers. The surface layer of polymer material such as polyamide 6 is modified by β – radiation. Material properties of the surface layer created are measured by microhardness test using the DSI method (Depth Sensing Indentation). The influence of irradiation dose on mechanical properties (materials parameter) of PA6 is a subject of this research.
Using the Multi-Parameter Fracture Mechanics for more Accurate Description of Stress/Displacement Crack Tip Fields
Authors: Šestáková Lucie
Published: September 2013

Most of fracture analyses often require an accurate knowledge of the stress/displacement field over the investigated body. However, this can be sometimes problematic when only one (singular) term of the Williams expansion is considered. Therefore, also other terms should be taken into account. Such an approach, referred to as multi-parameter fracture mechanics is used and investigated in this paper. Its importance for short/long cracks and the influence of different boundary conditions are studied. It has been found out that higher-order terms of the Williams expansion can contribute to more precise description of the stress distribution near the crack tip especially for long cracks. Unfortunately, the dependences obtained from the analyses presented are not unambiguous and it cannot be strictly derived how many of the higher-order terms are sufficient.
Evaluation of Local Plastic Flow in the Vicinity of Indentation by the Means of DIC Applied on SEM Micrographs
Authors: Valach Jaroslav , Kytýř Daniel , Fenclová Nela , Koudelka Petr , Doktor Tomáš , Fíla Tomáš
Published: September 2013

The paper presents application on digital image correlation (DIC) and microindentation for investigation of plastic flow under Brinell ball indenter applied on steel specimen made of two parts screwed together. Specimens in two different material states (a) as delivered (b) annealed were investigated. This approach enables internal surface to act as the external one and to be examined by aforementioned methods. Results obtained by application of DIC on scanning electron microscope (SEM) images are compared to microhardness maps and agreement is demonstrated.
Influence of Loading Conditions on the Deformation Behavior of Human Enamel Studied by Instrumented Indentation
Authors: Halgaš Radoslav , Dusza Ján , Kaiferova Jana , Kovácsova Lucia , Markovská Neda
Published: September 2013

As the hardest and one of the most durable load bearing tissues of the body, enamel has attracted considerable interest from both material scientists and clinical practitioners due to its excellent mechanical properties. The aim of this investigation is to determine the influence of different loading conditions on the deformation behavior of human enamel using instrumented indentation and Berkovich indenter. The used samples were fresh intact human premolars, extracted due to orthodontic reasons. Hardness tests were performed with different loading regimes. To study the influence of loading rates tree different loading rates have been used with 10, 100 and 1000 mN/min. at maximum applied load of 200 mN. The indentation size effect (ISE) was studied using loads from 5 mN to 400 mN without holding time. The indents have been studied using atomoc force microscopy and scanning electron microscopy.
Characterization of Polypropylene Staple Yarns by Acoustic Dynamic Modulus
Authors: Kremenakova Dana , Militky Jiri , Huang Juan
Published: September 2013

The acoustic or sonic pulse-propagation technique for the measurement of dynamic elastic modulus has the advantage of not being dependent on the sample cross-sectional characteristics. This technique also gives a direct measure of modulus rather than the indirect measure in the form of load versus extension. The sonic tests are relatively simple to apply and are nondestructive. The values of sonic modulus of fibrous structures are dependent on the orientation of components and packing density as well. The main aim of this work is to quantify effect of yarn twist on the sonic modulus of staple yarns from polypropylene fibers. The results are compared with selected models of yarn twist influence on the mechanical properties of staple yarns. The correlation between yarn orientation factor defined by Pan and sonic modulus are shown. The sonic modulus is compared with tensile modulus of yarns.
Nanohardness vs. Friction Behavior in Magnetron Sputtered and PECVD W-C Coatings
Authors: Lofaj František , Ferdinandy Milan , Hornak Peter
Published: September 2013

The nanoindentation and tribological measurements were performed on DC and RF magnetron sputtered W-C coatings to optimize the deposition conditions to obtain maximum nanohardness and to compare their properties and behavior with earlier studied PECVD W-C coatings. Despite number of similarities, some consequences of a tribo-chemical transfer film formation are inconsistent with the existing wear model for W-C coatings with controlled carbon content. Transfer films in the friction contact consist from iron- and tungsten oxides and carbon generated during carbide oxidation. The role of carbon in the transfer films leading to high coefficients of friction has to be principally different from the expected lubricative role of carbon in W-C coatings and needs further study.
Nanoindentation Applied to Materials with an Inner Structure
Authors: Němeček Jiří
Published: September 2013

Nowadays, nanoindentation is commonly applied to various materials to assess micromechanical properties. Often, exact microstructure of the material building blocks is not properly analyzed which may introduce large discrepancies in the data obtained from different tests. It is shown in the paper, that different deformation mechanisms in tension and compression take place for the tested materials which is demonstrated by large differences between the measured nanoindentation moduli and macroscopic tensile elastic moduli. The situation is illustrated on several types of biological and man-made fibers. Differences ~44-57% in elastic moduli evaluated from the two tests appear in case of biological fibers, ~68% difference was found for high strength PVA fibers and 767% (!) for carbon fibers.
Recognition of Devonian hydrocarbon source rocks in Beluga O-23 well, Hudson Bay Basin
Authors: Zhang S , Hu K
Published: September 2013

The Hudson Bay Basin is a Phanerozoic sedimentary basin in the eastern Canadian Arctic, whose succession is dominated by Ordovician to Devonian sediments and for which the hydrocarbon potential remains poorly understood. In the recent years, the Hudson Bay-Foxe
basins project under the Geological Mapping for Energy and Mineral (GEM) Program has paid a great attention to the lower part of the Paleozoic succession comprising the Upper Ordovician and Lower Silurian. This present report focuses on the study of petroleum potential source rocks of the Devonian
succession (Stooping River, Kwataboahegan, Moose River, Murray Island and William Island formations).
A total of 50 well cutting samples were collected from 875 to 630 meter (Devonian succession) in the Beluga O-23 well, of which 28 contain dark, organic-rich fragments preferentially picked from the cuttings. The 28 samples were analyzed using Rock-Eval6 Pyrolysis technique. The Rock-Eval6 data show
that the Devonian succession in the Beluga O-23 well contains immature high yield hydrocarbon potential source rocks with TOC ranging from 1.6 to17.64% (average 9.07%) and with a Type II kerogen signature. These hydrocarbon potential source rocks are mainly concentrated in five narrow zones
within the selected interval from the upper part of the Stooping River Formation to the lower part of the Williams Island Formation as identified by the well log interpretation.
Chemical analysis in the field by x-ray fluorescence spectroscopy, an example from the Lac Dasserat study, Quebec
Authors: Grenier A , McNeil R , Alpay S
Published: September 2013

Two types of X-ray fluorescence (XRF) spectrometers were deployed on site to analyse stream and lake surface waters as well as lake sediment chemistry. Water and sediment samples were collected downstream of the abandoned Aldermac VMS mine, 15 km west of
Rouyn-Noranda, Quebec. The goals of the study are to identify the spatial and temporal extent of metal contamination as a result of decades of acid mine drainage from the Aldermac site and to evaluate and compare rapid data collection in the field by XRF with laboratory-based inductively coupled
plasma mass spectrometry (ICP-MS) for Cu, Zn and Mn.
Water chemistry was determined by a Bruker S2 PICOFOX total reflection X-ray fluorescence (TXRF) spectrometer from filtered and acidified samples spiked with Ga as an internal standard. The instrument demonstrated high accuracy for the certified reference material (CRM), TMDA-51.3. Data obtained for
Cu, Zn and Mn concentrations were within acceptable limits of the certified values. Analytical results by ICP-MS of lake and stream samples showed excellent correlation (r2 > 0.99) with field analysis by TXRF for the three metals.
Lake sediment geochemistry was determined by a handheld Olympus Innov-X Delta Premium DP-4000 X-ray fluorescence spectrometer. Sample preparation in the field included drying and reducing samples to a powder. High accuracy of analytical results was obtained using CRM LKSD-1 for Cu, Zn and Mn.
Comparison of Cu, Zn and Mn concentrations determined by handheld XRF with ICP-MS analyses of aqua-regia and four-acid digestions of sediment samples also yielded excellent correlations (r2 > 0.98).
Results suggest that TXRF analysis of surface waters and handheld XRF analysis of lake sediments provide practical and accurate diagnostic tools for rapid field analysis of Cu, Zn and Mn concentrations. Overnight results allowed quick testing of scientific hypotheses (e.g., contaminant flowpaths,
locations of potential control sites) without waiting for laboratory results (e.g., by ICP). Rapid data acquisition
also provided guidance for and optimization of daily sampling strategies during field work. Rapid field-based analytical results from XRF spectrometry have the potential to provide efficiencies for environmental risk assessments conducted by industrial project proponents and environmental
consultants.
Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops
Authors: Deora A. , Gossen B. D. , Hwang S. F. , Pageau D. , Howard R. J. , Walley F. , McDonald M. R.
Published: September 2013

Deora, A., Gossen, B. D., Hwang, S. F., Pageau, D., Howard, R. J., Walley, F. and McDonald, M. R. 2014. Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops. Can. J. Pant Sci. 94: 109–118. Application of boron (B) has been reported to reduce clubroot severity in various Brassica spp., but residual B can have phytotoxic effects on other crops in the rotation. The objective of this study was to test the efficacy of broadcast application of B for clubroot suppression in canola (B. napus) and the effect of residual B on wheat, barley, field pea and canola. Field trials to assess clubroot suppression by B at various rates (1 to 64 kg B ha−1) were conducted in organic (Ontario) and mineral soils (Alberta, Quebec) heavily infested with Plasmodiophora brassicae in 2011 and 2012. Phytotoxicity was not observed in canola until applications rates exceeded 48 kg B ha−1. Boron did not reduce clubroot incidence at any site, irrespective of rate, and only reduced severity at the organic soil site at 6 wk after seeding. There was a small increase in shoot weight and yield of canola with increasing B application rates at the organic soil site. The potential phytotoxicity of residual B (4 to 16 kg B ha−1) was assessed in mineral soils in Ontario and Saskatchewan in 2012. Toxicity symptoms were noted initially in most of the crops, but seedlings recovered quickly and there was no significant reduction in fresh weight at harvest or seed yield of most of the cultivars. The present study indicates that pre-plant broadcast application of B delays clubroot development and increases vegetative growth and yield compared with non-treated plants in organic soil. Also, even high residual rates (16 kg ha−1) of application are unlikely to have a negative effect on crops in rotation in mineral soil. However, the effect of B application on canola yield found in this study was not sufficient to justify application for commercial canola production, even where clubroot is prevalent.
Oral Health-related Quality of Life and Associated Factors in National Cadets Corps of Udupi District, India
Authors: Pentapati Kalyana Chakravarthy , Acharya Shashidhar , Bhat Meghashyam , Rao Sree Vidya Krishna
Published: September 2013

Objective

To assess the oral impact on daily performances (OIDP) and to study the inter-relationship between OIDP, dental attendance, socioeconomic status and caries experience among children enrolled in the National Cadets Corps (NCC).

Materials and methods

A cross-sectional survey of 389 male NCC cadets in the age group of 13 to 15 years was done. Child version of Oral Impacts on Daily Performances questionnaire (Child-OIDP) was used to assess the quality of life. Information on demographic correlates and oral health behavior was obtained through self-administered questionnaire. The cadets were clinically examined for caries using decayed, missing and filled tooth index (DMFT).

Results

A total of 359 children completed all the stages of the survey. The mean age of children was 13.96 ± 0.6 years. Fiftyfive percent of the participants experienced at least one impact in the last 3 months. The mean OIDP score for the population was 12.13 ± 5.85. The most prevalent impact was ‘difficulty in eating’ (37%) and the least affected daily performance was social contact (17%). Dental attendance and caries experience showed significant positive correlation with all the impacts and the overall OIDP score. Hierarchical multiple regression analysis showed significant influence of dental attendance and caries experience on OIDP.

Conclusion

The study revealed that oral health has significant impact on quality of life of Indian children.

How to cite this article

Pentapati KC, Acharya S, Bhat M, Rao SVK, Singh S. Oral Health-related Quality of Life and Associated Factors in National Cadets Corps of Udupi District, India. World J Dent 2013;4(2):81-85.
Intraoral Local Anesthesia and Ocular Complications
Authors: Patil Kavitha , Munoli Karishma , Kumar Vinod , Venkataraghavan Kartik
Published: September 2013

Background

Ocular complications due to intraoral local anesthesia are rare but most distressing to the dentist and patient. Ocular complications after local anesthetic injections are rarely reported in the literature and these complications include strabismus, ptosis, diplopia, blindness, ophthalmoplegia, loss of accommodation.

The dentist must be vigilant and beware of ocular complications when performing local anesthetic nerve blocks.

Aim

The aim and objective of this review is to help the dental surgeons to understand about the causes, mechanisms and symptoms of ocular complications to enable them to diagnose, manage and prevent those complications.

Materials and methods

The revision included a systematic literature search of past 10 years with keywords dental anesthesia, ocular complications, blindness after dental anesthesia, diplopia following dental anesthesia.

Papers for review were chosen from the selected articles. When data did not appear sufficient or were inconclusive; recommendations were based upon expert or consensus opinion by experienced researchers and clinicians.

Conclusion

The various ocular complications, its causes, mechanisms and management are emphasized in this review paper. As per literature review ocular complications are rare to occur but they are most distressing, clinicians should be aware of complications and should be able to diagnose and understand the complications for timely prevention and effective management.

How to cite this article

Patil K, Munoli K, Kumar V, Venkataraghavan K. Intraoral Local Anesthesia and Ocular Complications. World J Dent 2013;4(2):108-112.
Diminished Ovarian Reserve, Causes, Assessment and Management
Authors: Arora Mala , Kaur Mandeep
Published: September 2013

Diminished ovarian reserve predicts diminished ovarian response to stimulation but does not predict cycle fecundity. It has been recently defined by ESHRE, the Bologna's criteria, according to which at least two of the following three features should be present: (1) Age >40 years/any other risk factor for DOR, (2) abnormal ovarian reserve test, i.e. antral follicle count, AMH, (3) poor ovarian response in a previous stimulated cycle, i.e. less than three follicles after standard gonadotropin stimulation. Poor response to maximal stimulation on two previous occasions also defines DOR.

The treatment options are limited. Avoiding the GnRH agonist long protocol and stimulation with microdose flare or antagonist protocol yields better results. Adjuvant therapy with LH, DHEAS and growth hormone shows some benefit in improving the oocyte yield. It is advisable to perform ICSI for all obtained oocytes and some advocate assisted hatching. Pregnancy rates are, however, poor and often these patients require ovum donation. Developing tests that will diagnose DOR in a low-risk population will allow women to plan their reproductive careers early.

How to cite this article

Kaur M, Arora M. Diminished Ovarian Reserve, Causes, Assessment and Management. Int J Infertility Fetal Med 2013;4(2):45-55.
Effect of Submucosal Injection of Dexamethasone on Postoperative Discomfort after Third Molar Surgery: A Prospective Study
Authors: Ummar M , Nair Rakesh B , Rahman NM Mujeeb , Hafiz KA Abdul , Issac Johnson K , Sameer KM
Published: September 2013

Aim

To evaluate the relative ability of 4 mg dose of intraoperative dexamethasone, administered submucosally, to reduce the postoperative discomfort after third molar surgery.

Materials and methods

A total of 100 patients requiring surgical removal of a single mandibular third molar were included. The experimental group (50) received dexamethasone 4 mg as submucosal injection and control group (50) received no drugs. The maximum interincisal distance and facial contours were measured at baseline and at postsurgery days 2 and 7. The measurement of pain was done using visual analog scale (VAS).

Results

None of the patients developed wound infection or any serious postoperative complications. Postoperative edema tended to be less severe on the second postoperative day in the experimental group and the result was statistically significant. There were no significant differences in the reduction of pain and trismus between the two groups studied.

Conclusion

Submucosal administration of dexamethasone sodium phosphate (4 mg) results in reduction of postoperative edema, comparable with or greater than other routes of administration. Presumably, a higher effective drug concentration at the site of injury without loss due to distribution to other compartments may be achieved, and the submucosal route is convenient for both the surgeon and the patient.

Clinical significance

Submucosal route of administration of dexamethasone (4 mg) is effective in reducing postoperative discomfort after third molar surgeries.

How to cite this article

Nair RB, Rahman NMM, Ummar M, Hafiz KAA, Issac JK, Sameer KM. Effect of Submucosal Injection of Dexamethasone on Postoperative Discomfort after Third Molar Surgery: A Prospective Study. J Contemp Dent Pract 2013;14(3):401-404.
Flare-up Rate in Molars with Periapical Radiolucency in One-Visit vs Two-Visit Endodontic Treatment
Authors: AL-Omiri Mahmoud K , Iqbal Azhar , Akbar Iftikhar
Published: September 2013

Purpose

The objective of this study was to compare postobturation flare-ups following single and two-visit endodontic treatment of molar teeth with periapical radiolucency.

Materials and methods

A total of 100 patients with asymptomatic molar teeth with periapical radiolucency were selected. They were randomly allocated into two groups. Fifty patients received complete endodontic treatment in one-visit. Fifty patients received treatment by debridement and instrumentation at the first visit followed by obturation at the second visit.

Results

10% of patients had flare-ups in the single visit group and 8% of patients had flare-ups in the two-visit group. Number of visits did not affect the success of endodontic treatment (p > 0.05). Age, gender and tooth type had no effects on the occurrence of flare-ups regardless the number of visits (p > 0.05).

Conclusion

One-visit endodontic treatment was as successful as two-visit endodontic treatment as evaluated by rate of flareups in asymptomatic molar teeth with periapical radiolucency.

How to cite this article

Akbar I, Iqbal A, Al-Omiri MK. Flare-up Rate in Molars with Periapical Radiolucency in One-Visit vs Two- Visit Endodontic Treatment. J Contemp Dent Pract 2013; 14(3):414-418.
Surgical Elevation of Bilateral Maxillary Sinus Floor with a Combination of Autogenous Bone and Lyophilized Bovine Bone
Authors: Araujo Danilo Barral , de Jesus Campos Elisângela , Oliveira Marcos André Matos , Lima Max José Pimenta , Martins Gabriela Botelho , Araujo Roberto Paulo Correia
Published: September 2013

Aim

Realize the surgery of sinus lifting floor to allow the installation of osseointegrated implants for oral rehabilitation, with the combination of different biomaterials, autogenous bone and lyophilized bovine bone.

Background

Oral rehabilitation using the installation of osseointegrated implants is an alternative surgical approach that results in the satisfactory form, function and esthetics of the dental units.

Case report

After clinical, dental and laboratory assessment, a 47-year-old female patient underwent full maxillary oral rehabilitation involving the installation of osseointegrated implants to allow her to meet the physiological demands of occlusion and mastication. It was found that the patient had fully pneumatized maxillary sinuses with insufficient height to anchor implants, with a loss of the vertical dimension of the occlusal and masticatory functions due to general dental loss, compounded by the use of ill-fitting dentures; hence, the choice was made to take autogenous bone from the patient's chin area and supplement it with lyophilized bovine bone as collateral for larger areas to be grafted. It was also decided to avulse the remaining tooth units due to their impairment by periodontal disease.

Conclusion

Bone grafts do not constitute suitable alternatives in the cosmetic and functional rehabilitation of the maxilla in patients requiring bilateral sinus elevation. The chin region provides bone tissue that, when complemented by lyophilized bovine bone grafts, ensures greater volume and less invasive surgery. In the case described here, a height gain of approximately 550% was obtained, making it possible to anchor seven implants.

Clinical significance

In this study, the surgical procedures used for grafting a combination of autogenous and lyophilized bovine bone, aimed to elevate the maxillary sinus floor to allow the installation of osseointegrated implants for oral rehabilitation.

How to cite this article

Araujo DB, de Jesus Campos E, Oliveira MAM, Lima MJP, Martins GB, Araujo RPC. Surgical Elevation of Bilateral Maxillary Sinus Floor with a Combination of Autogenous Bone and Lyophilized Bovine Bone. J Contemp Dent Pract 2013;14(3):445-450.
Tethered balloon-borne aerosol measurements: seasonal and vertical variations of aerosol constituents over Syowa Station, Antarctica
Authors: Hara K. , Osada K. , Yamanouchi T.
Published: September 2013

Abstract. Tethered balloon-borne aerosol measurements were conducted at Syowa Station, Antarctica, during the 46th Japanese Antarctic expedition (2005–2006). Direct aerosol sampling was operated from near the surface to the lower free troposphere (approximately 2500 m) using a balloon-borne aerosol impactor. Individual aerosol particles were analyzed using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. Seasonal and vertical features of aerosol constituents and their mixing states were investigated. Results show that sulfate particles were predominant in the boundary layer and lower free troposphere in summer, whereas sea-salt particles were predominant during winter through spring. Minerals, MgSO4, and sulfate containing K were identified as minor aerosol constituents in both boundary layer and free troposphere over Syowa Station. Although sea-salt particles were predominant during winter through spring, the relative abundance of sulfate particles increased in the boundary layer when air masses fell from the free troposphere over the Antarctic coast and continent. Sea-salt particles were modified considerably through heterogeneous reactions with SO42− CH3SO3− and their precursors during summer, and were modified slightly through heterogeneous reactions with NO3− and its precursors. During winter through spring, sea-salt modification was insignificant, particularly in the cases of high relative abundance of sea-salt particles and higher number concentrations. In August, NO3− and its precursors contributed greatly to sea-salt modification over Syowa Station. Because of the occurrence of sea-salt fractionation on sea ice, Mg-rich sea-salt particles were identified during the months of April through November. In contrast, Mg-free sea-salt particles and slightly Mg-rich sea-salt particles coexisted in the lower troposphere during summer. Thereby, Mg separation can proceed by sea-salt fractionation during summer in Antarctic regions.
Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station
Authors: Kasai Y. , Sagawa H. , Kreyling D. , Dupuy E. , Baron P. , Mendrok J. , Suzuki K. , Sato T. O. , Nishibori T. , Mizobuchi S. , Kikuchi K. , Manabe T. , Ozeki H. , Sugita T. , Fujiwara M. , Irimajiri Y. , Walker K. A. , Bernath P. F. , Boone C. , Stiller G. , von Clarmann T. , Orphal J. , Urban J. , Murtagh D. , Llewellyn E. J. , Degenstein D. , Bourassa A. E. , Lloyd N. D. , Froidevaux L. , Birk M. , Wagner G. , Schreier F. , Xu J. , Vogt P. , Trautmann T. , Yasui M.
Published: September 2013

Abstract. We observed ozone (O3) in the vertical region between 250 and 0.0005 hPa (~ 12–96 km) using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. The new 4 K superconducting heterodyne receiver technology of SMILES allowed us to obtain a one order of magnitude better signal-to-noise ratio for the O3 line observation compared to past spaceborne microwave instruments. The non-sun-synchronous orbit of the ISS allowed us to observe O3 at various local times. We assessed the quality of the vertical profiles of O3 in the 100–0.001 hPa (~ 16–90 km) region for the SMILES NICT Level 2 product version 2.1.5. The evaluation is based on four components: error analysis; internal comparisons of observations targeting three different instrumental setups for the same O3 625.371 GHz transition; internal comparisons of two different retrieval algorithms; and external comparisons for various local times with ozonesonde, satellite and balloon observations (ENVISAT/MIPAS, SCISAT/ACE-FTS, Odin/OSIRIS, Odin/SMR, Aura/MLS, TELIS). SMILES O3 data have an estimated absolute accuracy of better than 0.3 ppmv (3%) with a vertical resolution of 3–4 km over the 60 to 8 hPa range. The random error for a single measurement is better than the estimated systematic error, being less than 1, 2, and 7%, in the 40–1, 80–0.1, and 100–0.004 hPa pressure regions, respectively. SMILES O3 abundance was 10–20% lower than all other satellite measurements at 8–0.1 hPa due to an error arising from uncertainties of the tangent point information and the gain calibration for the intensity of the spectrum. SMILES O3 from observation frequency Band-B had better accuracy than that from Band-A. A two month period is required to accumulate measurements covering 24 h in local time of O3 profile. However such a dataset can also contain variation due to dynamical, seasonal, and latitudinal effects.
Calibration of the passive cavity aerosol spectrometer probe for airborne determination of the size distribution
Authors: Cai Y. , Snider J. R. , Wechsler P.
Published: September 2013

Abstract. This work describes calibration methods for the particle sizing and particle concentration systems of the passive cavity aerosol spectrometer probe (PCASP). Laboratory calibrations conducted over six years, in support of the deployment of a PCASP on a cloud physics research aircraft, are analyzed. Instead of using the many calibration sizes recommended by the PCASP manufacturer, a relationship between particle diameter and scattered light intensity is established using three sizes of mobility-selected polystyrene latex particles, one for each amplifier gain stage. In addition, studies of two factors influencing the PCASP's determination of the particle size distribution – amplifier baseline and particle shape – are conducted. It is shown that the PCASP-derived size distribution is sensitive to adjustments of the sizing system's baseline voltage, and that for aggregates of spheres, a PCASP-derived particle size and a sphere-equivalent particle size agree within uncertainty dictated by the PCASP's sizing resolution. Robust determinations of aerosol concentration, and size distribution, also require calibration of the PCASP's aerosol flowrate sensor. Sensor calibrations, calibration drift, and the sensor's non-linear response are documented.
Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions
Authors: Girault M. , Arakawa H. , Barani A. , Ceccaldi H. J. , Hashihama F. , Kinouchi S. , Gregori G.
Published: September 2013

Abstract. The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG) during La Niña, a cold phase of El Niño Southern Oscillation (ENSO). Observations were conducted in a north-south transect (33.6–13.25° N) along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like) defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC) at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature) and La Niña (this study) conditions seems to demonstrate that La Niña conditions lead to higher concentrations of Synechococcus in the Subtropical gyre and a lower abundance of Synechococcus in the Kuroshio region. Our results suggest that the west part of NPSG is a complex area, where different water masses, salinity fronts and eddies lead to a heterogeneous distribution of ultraphytoplankton assemblages in the upper layer of the water column.
Technical Note: Controlled experimental aquarium system for multi-stressor investigation of carbonate chemistry, oxygen saturation, and temperature
Authors: Bockmon E. E. , Frieder C. A. , Navarro M. O. , White-Kershek L. A. , Dickson A. G.
Published: September 2013

Abstract. As the field of ocean acidification has grown, researchers have increasingly turned to laboratory experiments to understand the impacts of increased CO2 on marine organisms. However, other changes such as ocean warming and deoxygenation are occurring concurrently with the increasing CO2 concentrations, complicating the understanding of the impacts of anthropogenic changes on organisms. This experimental aquarium design allows for independent regulation of CO2 concentration, O2 levels, and temperature in a controlled environment to study the impacts of multiple stressors. The system has the flexibility for a wide range of treatment chemistry, seawater volumes, and study organisms. Control of the seawater chemistry is achieved by equilibration of a chosen gas mixture with seawater using a Liqui-Cel® membrane contactor. Included as examples, two experiments performed using the system have shown control of CO2 at values between approximately 500 and 1400 μatm and O2 at values from 80 to 240 μmol kg−1. Temperature has been maintained to 0.5 °C or better in the range of 10–17 °C. On a weeklong timescale, the system has achieved variability in pH of less than 0.007 pH units and in oxygen concentration of less than 3.5 μmol kg−1. Longer experiments, over a month in duration, have been completed with control to better than 0.08 pH units and 13 μmol kg−1 O2. The ability to study the impacts of multiple stressors in the laboratory simultaneously, as well as independently, will be an important part of understanding the response of marine organisms to a high-CO2 world.
Not all calcite ballast is created equal: differing effects of foraminiferan and coccolith calcite on the formation and sinking of aggregates
Authors: Schmidt K. , Rocha C. L. De La , Gallinari M. , Cortese G.
Published: September 2013

Abstract. Correlation between particulate organic carbon (POC) and calcium carbonate sinking through the deep ocean has led to the idea that ballast provided by calcium carbonate is important for the export of POC from the surface ocean. While this idea is certainly to some extent true, it is worth considering in more nuance, for example, examining the different effects on the aggregation and sinking of POC of small, non-sinking calcite particles like coccoliths and large, rapidly sinking calcite like planktonic foraminiferan tests. We have done that here in a simple experiment carried out in roller tanks that allow particles to sink continuously without being impeded by container walls. Coccoliths were efficiently incorporated into aggregates that formed during the experiment, increasing their sinking speed compared to similarly sized aggregates lacking added calcite ballast. The foraminiferan tests, which sank as fast as 700 m d−1, became associated with only very minor amounts of POC. In addition, when they collided with other, larger, foraminferan-less aggregates, they fragmented them into two smaller, more slowly sinking aggregates. While these effects were certainly exaggerated within the confines of the roller tanks, they clearly demonstrate that calcium carbonate ballast is not just calcium carbonate ballast- different forms of calcium carbonate ballast have notably different effects on POC aggregation, sinking, and export.