bluuebunny/crossref_metadata_2025 huggingface dataset:
Using 9-Axis Sensor for Precise Cardiosurgical Robot Master Angular Position Determination
Authors: Żak Paweł
Published: March 2013

The article will focus on the presentation of the possibility of practical application of integrated 9-axis sensor, in which magnetic field, acceleration and angular velocity 3-axis sensors were used. Particular emphasis will be placed to describe the mentioned sensors data fusion algorithm, which is necessary for precise and unequivocal determination of the angular position of the tested device. Another presented issue is a selection of an appropriate data filtering algorithm with selected filtering parameters. Additionally, the possibility of implementing described solutions in the angular positions measurement system of cardiosurgical Robin Heart robot master will be shown. Also, a design concept of mentioned robot master along with its working principle will be mentioned.
Wear Model in Milling Compacted Graphite Iron with Different Lead Angle Using Ceramic Cutting Tools
Authors: Karabulut Şener , Güllü Abdulkadir
Published: March 2013

The objective of this study is to reveal the influence of the lead angle variation on tool wear in the process of face milling of compacted graphite iron with ceramic cutting tools. To achieve this goal, 36 milling experiments were carried out with different lead angles, cutting speeds and feed rates at the 2.5 mm constant depth of cut. The tool flank wear was strongly affected by the lead angle variations. SEM analyses of the cutting inserts were performed and experimental results have been modelled with artificial neural networks (ANN) and regression analysis. A comparison of ANN model with regression model is also carried out. The R2 values for testing data were calculated as 0.992 for ANN and 0.998 for regression respectively. This study is considered to be helpful in predicting the wear mechanism of the ceramic cutting tool in the machining of compacted graphite iron. A quicker method for the estimation of tool life is proposed, which requires less consumption of workpiece material and tools.
Corrosion of Ni-Al and Ni-Al-Al2O3 Plasma Sprayed Coatings in 0.01 M H2SO4 and 3.5% NaCl Solutions
Authors: Starosta Robert
Published: March 2013

In the paper researches results of corrosion properties of Ni-Al alloy and Ni-Al-Al2O3 composite coatings were presented. Coatings were obtained by plasma torch. The studies in 0.01 M H2SO4 and 3.5 NaCl environments were realized. Measurements were made following methods: polarization and impedance spectroscopy. Rated coatings are more resistant to the 3.5% NaCl environment than the 0.01 M H2SO4. Corrosion current density for alloy coatings in artificial seawater was 19 μΑ/cm2 and 28 μA/cm2 environment acidic. Impedance spectroscopy studies showed that the alloy and composite coatings are characterized by greater charge transfer resistance in sodium chloride solution than in sulfuric acid solution. The value of corrosion potential in an environment of 3.5% NaCl is about 300 mV lower than 0.01 M H2SO4. Composite coatings Ni-Al-Al2O3 were characterized by a higher corrosion current densities and increased resistance than Ni-Al coatings in 0.01 M H2SO4 solution. It is related to the porosity of composite coatings. It was found little effect of oxide phase participation on corrosion current density and corrosion potential in 3.5% NaCl environment.
Effect of Cutting Parameters on Surface Texture of Flame Sprayed Coatings
Authors: Starosta Robert
Published: March 2013

Coatings were turned by two tools: a) ISO 2R 2525K10, geometry and cutting parameters recommended by Messner Eutectic Castolin Company (tool angle β = 90o, approach angle κr = 45o, nose radius rε =0,8 mm, clearance angle α = 6o, rake angle γ = -5o) b) bit tool with CBN WNGA080408S01030A insert mounted in DWLNRL-2525M08 holder (cutting inserts β = 80o, approach angle κr = 95o, nose radius 0,8 mm, clearance angle α = 6o, rake angle γ = -6o). The influence of cutting speed, feed rate, depth of turning on the coating surface roughness was estimated. The following cutting parameters: cutting speed Vc = 45 214 m/min, feed rate f = 0,04 0,196 mm/rev, depth of cut ap = 0,05 0,3 mm. The lowest value of the roughness Ra = 0,5μm of the coatings were obtained by using cutting tools and parameters and bit tool: Vc = 214 m/min, f = 0,06 mm/rev, ap = 0,3 mm.
Effect of Magnetohydrodynamical Stirring Method on Deformation Resistance of AlSi7Mg Aluminium Alloy
Authors: Krakowiak Marlena , Bajor Teresa , Rydz Dariusz
Published: March 2013

Most of the industry oriented research and development is based on conventional casting alloys Al-Si. This paper presents the results of deformation the hypoeutectic AlSi7Mg alloy used to manufacturing pistons for combustion engines. This is the material about high plasticity and corrosion resistance. For the research it was produced by semi-continuous casting process with magnetohydrodynamic stirring in crystalliser (MHD) and in conventional casting way. The results of deformation resistance of both materials have been described.
Effect of Thermo-Mechanical Treatment on Mechanical Properties of AlCuMg Alloys
Authors: Bajor Teresa , Krakowiak Marlena , Rydz Dariusz
Published: March 2013

Technology development and new grades of alloys creation put before construction materials the number of requirements in range of durability and reliability of created constructions. Receivers expect materials with high strength properties, low production cost of the finished product, availability, corrosion resistance and low specific gravity. So the specific needs of customers mean that studies are constantly associated with the exploration of new materials and technologies that could meet made requirements [1,2,. In large scale this demand is met through the use of non-ferrous metals and their alloys. Selection of appropriate manufacturing techniques and the use of heat treatment procedures allow to obtain materials with better mechanical properties. Here the leading role has the aluminium and its alloys. Due to specific mechanical properties aluminium based materials are used in almost each field of industry. In aircraft industry they are used for the manufacture of fuselage elements in automobile industry the light alloys are used to make cylinder blocks, and other elements of internal combustion engines. In the construction industry they are used to manufacture windows and doors, as well as beautiful self-supporting lightweight facades. While the aluminium alloy products such as films or cans are also used in the food industry. The combination of physico-chemical and mechanical properties of aluminium alloys makes them the optimal solution for innovative design, thanks to them engineers can provide high strength associated with very low gravity. This allows to minimize the costs of subsequent use of the product, and while achieving good strength parameters. As part of this work the analysis of strain rate and temperature impact on mechanical properties of the tested alloy will be carried out. The experimental studies conducted in the temperature range of recrystallization (test temperature: 400°C, 450°C, 480°C, 500°C) using two strain rates 1 s-1and 0,1 s-1. This paper present the analysis of the application of high-temperature deformation changes in structure mainly caused by the dynamic recrystallization processes, which determine the optimal parameters of AlCuMg deformation process [. The proposed methodology of the research work made it possible to determine the effect of temperature-velocity parameters to changes in mechanical properties (inter alia: microhardness measurements) and changes in the structure of the material, which are closely related to the level achieved in mechanical properties.
EIS Research of AW-7020 Alloy Joints Welded by FSW
Authors: Dudzik Krzysztof , Charchalis Adam
Published: March 2013

The results of corrosion properties research of aluminum alloy AW 7020 (AlZn5Mg1) welded by friction stir welding FSW were presented. Friction Stir Welding (FSW) a new technology can be successfully used for butt welding of different types of aluminum alloy sheets. In the article the parameters for friction stir welding of sheets made of AlZn5Mg1 (7020) alloy was presented. The study was carried out in accordance with the requirements of the ASTM G 106. EIS measurement was performed in three electrode system in an artificial seawater (3.5% NaCl). Impedance studies were carried out at the corrosion potential. Changed voltage signal amplitude in the range ± 10 mV and frequency range of changes was as follows: 100 kHz - 0.1 Hz. Atlas 0531 EU & IA potentiostat was used for studies. The results of electrochemical impedance spectroscopy are presented in the form of parameters characterizing the corrosion process. Obtained results were statistically analyzed. The electrochemical impedance spectroscopy studies have shown that the joint welded by FSW has better electrochemical corrosion resistance than the native material - AW-7020 alloy. Original value are received results of the corrosion properties of new method friction stir welded AlZn5Mg1 alloy compared with the native material.
Knowledge Acquisition and Management for Marine Diesel Engine Diagnosis
Authors: Charchalis Adam , Pawletko Rafał
Published: March 2013

The paper presents the research relevant to knowledge acquisition for marine diesel engine diagnosis. Basic sources of knowledge which can be used for construction of diagnostics knowledge base are identified. The basic knowledge related to the diesel diagnostic was undertaken from experts and from diagnostic database. The paper questionnaire was used to the knowledge acquisition from experts [. With the paper questionnaire the basic knowledge related to the marine diesel exploitation was undertaken. The rule induction algorithms was used to knowledge acquisition from diagnostic database [. Training and test data were acquired from experiment on marine engine Sulzer 3AL 25/30. The paper proposes the original system of knowledge management for the marine diesel engine diagnosis. The system allows the collection of knowledge from different sources, its evaluation and update.
Influence of Rolling Reduction, Strip Shape and Asymmetry Factor on the Strip Curvature
Authors: Kawałek Anna , Dyja Henryk , Knapiński Marcin , Kwapisz Marcin , Laber Konrad Błażej
Published: March 2013

In order to improve the quality of plates, an asymmetric rolling process can be introduced, which will help reduce the total roll separating force and increase plate flatness and decrease thickness deviations along the width and length of rolled strip [1÷.
Investigation of Wear of Ceramic Coating on Tool Steel 105WCr6
Authors: Kuliavas Liudas Albinas
Published: March 2013

Lifetime of details directly influences lifetime of machines and equipments. Details in most cases wear out, instead of collapse. Raise of their wear resistance is a perspective problem. The most economic way is drawing hard-wearing coverings on a surface of the details made of steel. In our work coverings from oxide ceramics (Al2O3 and Al2O3+TiO2) coatings, covered by gas-flame spraying on a surface of the specimens made from tool steels 105WCr6 were investigated. Before a conversion coating specimens were hardened and tempered, the surface was exposed to sandblasting, and the special sub layer for raise of an adhesion of a covering with a basis was put. After drawing a ceramic covering micro hardness of a covering and a basis was measured. Then it was tested contact and abrasive wear resistance of surfaces on original installations. It is resulted and circuits a technique of research of wear resistance. Agency on wear resistance of an aspect oxide ceramics, type of wear contact and abrasive, heating of the superficial layer arising because of a friction of two surfaces is investigated. At the end of work leading-outs and are presented to the recommendation on application oxide ceramics to increase of wear resistance of steel details.
Investigation of W-Re-Ni Heavy Alloys Produced from Plasma Spheroidized Powders
Authors: Majewski Tomasz
Published: March 2013

Measurement results of 92W-5Re-3Ni and 77W-20Re-3Ni sinters produced from powders spheroidized in a plasma jet are presented in the paper. The production process is described, typical microstructures are presented, and the analysis of chemical composition in selected microregions of the samples have been performed. Additionally, a comparison of selected properties of materials produced from powders spheroidized in plasma and from non-modified powders is shown.
Modelling of Titanium-Steel Bimetallic Composite Behaviour under Mechanical Cyclic Loading
Authors: Karolczuk Aleksander , Kowalski Mateusz , Robak Grzegorz
Published: March 2013

The aim of the paper is to analyse how different mechanical properties of bonded metals influence the cyclic behaviour of bimetallic components. The simulations also include different initial state of stress since one of the methods for manufacturing bimetals is explosive welding which introduces residual stresses into bonded materials. The analysed cyclic behaviour concerns cyclic stress-strain relation in elastic-plastic strain state. The multi-surface plasticity model of Mróz-Garud was applied. Results shows that depend on residual stresses the ratchetting phenomena could occur.
Modelling the Magnetic Characteristics and Temperature Influence on Construction Steels
Authors: Jackiewicz Dorota , Szewczyk Roman , Salach Jacek
Published: March 2013

This paper concerns the possibility of use of the Jiles-Atherton-Sablik extended model to describe the magnetic characteristics for construction steel ST3. Result of the modelling utilizing extended Jiles-Atherton-Sablik model are in good agreement with results of experimental measurements for magnetic hysteresis loops B(H). However experimental results indicated, that the influence of temperature on B(H) characteristics is relatively small and can be neglected from the point of view of modelling for technical applications, such as stress estimation for non-destructive testing.
Research of Spheroidization Processes of W-Re Powders
Authors: Majewski Tomasz
Published: March 2013

Measurement results of the research aimed at plasma spheroidization of a mixture of W-re powders are presented in the paper. Such powders may be a good prefabricated unit for production of W-Re sinters or materials comprising, besides W-Re, also other metals like Fe, Ni, Co, and so on. The influence of plasma spheroidization parameters on the powder oxidization level, and the process effectiveness are shown. Moreover, measurement results of powders oxides reduction after plasma modification are presented.
Surfaces Modification of Al-Cu Alloys by Plasma-Assisted CVD
Authors: Kyzioł Karol , Kaczmarek Łukasz , Jonas Stanisława
Published: March 2013

Aluminum-copper alloys (Al-Cu) are nowadays widely used in various applications, mainly in automotive and aviation industry, because of their unique properties such as high strength, low density and good corrosion resistance. However, usages of aluminum alloys are partially limited due to their reduced hardness, wear resistance and poor tribological parameters. Desired useful parameters can be improved by application of PA CVD technology. This work presents the results concerning determination and analysis of the structure and the selected properties of the modified surfaces of Al-Cu alloys (2xxx series) that were prepared using plasma assisted MW CVD (Micro-Wave Chemical Vapour Deposition) method. To ensure effectiveness of the substrate modification process, the covered surface was subjected to pre-treatment with argon plasma and/or nitriding process. In conclusion, the research has confirmed that the wear resistance of the Al-Cu alloy can be successfully modified by application of MW CVD technique. The obtained results can serve as a basis in the design of the technology of a-Si:C:N:H layers for diverse applications.
Fretting-Corrosion of 316L Steel Metallic Biomaterial Methodological Aspects
Authors: Kulesza Ewa
Published: March 2013

Methodological aspects of fretting and fretting-corrosion research of metallic biomaterials are presented in this article. At the Faculty of Mechanical Engineering Technical University of Bialystok tribometer device was constructed to test the fretting phenomenon with flat-on-flat contact configuration [. Based on the results of published research the fretting regimes were established. Values of the amplitude of reversible movement were 80-120 µm, the frequency was 1 Hz [2] and the value of the pressure was 20 MPa. Fretting-corrosion tests in simulated biological fluids should be performed in the three-electrode system in presence of the reference electrode and counter electrode along with the working electrode to the potentiostat. It is important to leave the system loaded and immersed for about 30 minutes prior to testing the potential of the system. During that time system potentials are stabilized. After that, acquiring data for fretting corrosion should be started with measurement potential/time changes [. A better understanding of the fretting processes will largely eliminate its effects at the construction design stage.
Multiscale Modelling Method for Chosen Functionally Graded Material
Authors: Miedzińska Danuta , Panowicz Robert , Jóźwicki Przemysław
Published: March 2013

The paper deals with the numerical and experimental analyses of functionally graded material structures which are represented by a surface layer of the steel sample hardened during the laser treatment process. A functionally graded parameter of the researched structure was assumed as the hardness value experimentally measured with the use of a Vickers hardness test method. The microstructure of the tested layer was also analyzed for the Vickers test verification. Two homogenization methods were used for the purpose of layer substitute properties for numerical calculations. The first one was to divide the FGM domain into a number of layers in the direction of material gradation and then apply a numerical homogenization method within each layer. The resulting material model describes the FGM as a composite of homogeneous layers. The second method was based on the Mori-Tanaka homogenization theory and was carried out with the use of Digimat software, which is the nonlinear multi-scale materials and structures modelling platform. Both methods were compared and showed good correspondence.
Influence of Flat Lapping Kinematics on Machinability of Ceramics
Authors: Barylski Adam , Deja Mariusz
Published: March 2013

New tools for flat grinding of ceramics (Al2O3) are presented in the paper. Electroplated CBN tools (B64 and B107) were used in a modified single-disc lapping machine configuration. The results from experiments, such as the material removal rate and surface roughness parameters are presented and analyzed. Numerical simulations, based on the model for the shape error and tool wear estimation in machining with flat lapping kinematics, are also presented. The tool life of electroplated tools can be extended by choosing appropriate parameter K related to the process kinematics.
Spectral and Statistical Analysis for Ceramic Plate Specimens Subjected to Impact
Authors: Akinci Tahir Cetin , Seker Serhat , Gürbüz Riza , Guseinovienė Eleonora
Published: March 2013

In this study, ceramic plate behaviour was elaborated on the basis at sound signal variations caused by the impact. All tests were performed using plate specimens and pendulum testing station; with date acquisition and analysis systems. Two various methodologies such as; spectral and statistical were used. In the spectral analysis, power spectral densities were calculated for both virgin and cracked specimens with rage of frequency 0-33kHz. In the case of this frequency range was separated in to two repairs i.e. 0-28 kHz and 28-33 kHz. Differences in sound signals of virgin and cracked plate specimens were significant. The effect none related with cracked specimen spectral behaviour and it property can be interpreted as absorption of the vibrational effects in the cracked regions. An analysis of statistical results has shown a smaller value of skewness for virgin specimen than cracked one, case show smallest skewness value than the healthy cases skewness value.
Technological Problems in Lapping on Flat Surfaces of Ceramic Parts
Authors: Barylski Adam
Published: March 2013

This paper will present the results of research on single-disc lapping of flat surfaces of small ceramic elements. Machining with the use of different tools such as metallic, two-metallic and abrasive-metallic will be analyzed. The basics and techniques of reinforcement of laps will be discussed. The results of the influence of parameters on the surface quality of ceramic conponents (sealing0 for three treatments on lapping machines will be presented on the paper.
Control of the Hydrostatic Load Unit with the Electronic Control System
Authors: Banaś Michal
Published: March 2013

The paper presents a hydrostatic load unit, its design and the operation principle. The load unit has been integrated with an electronic control system. The components of the control system as well as its advantages have been discussed. The benefits of the integration have been illustrated with the outline of work programs for the microcontroller.
Didactic Models Used on Mechatronic Courses
Authors: Kelemen Michal , Gmiterko Alexander , Kelemenová Tatiana , Trebuňa František , Miková Ľubica , Bobovský Zdenko
Published: March 2013

The paper deals with one-chip controller Basic Atom, which is often used as control unit in mechatronics systems designed via students. Students can use our building units for training of control subsystem developing for mechatronic products. Also several theses have been done on this topic. Mechatronic systems and robots from these theses are available for other students as training models for practical exercises.
Diagnosing Propulsion Systems of a Vessels in Varying Marine Conditions
Authors: Charchalis Adam
Published: March 2013

The paper presents some problems of carrying out measurements of energetic characteristics and vessels performance in the conditions of sea examinations. We present the influence of external conditions in the change of vessels hull resistance and propeller characteristics as well as the influence of weather conditions in the results of examinations and characteristics of gas turbine engine. We also discuss the manner of reducing the results of measurements to the standard conditions. We present the way of preparing propulsion characteristics and the analysis of examination uncertainty for the measurement of torque.
Evaluation of Fatigue Life of Cylindrical Geared Wheels
Authors: Drewniak Józef , Rysiński Jacek
Published: March 2013

The main aim of the work is determination of numerical and numerical-analytical methods of evaluation of fatigue strength and life of geared tooth considering tooth breakage phenomenon. The discussed tasks were performed using the following tools: dual boundary element method, BEASY package as well as fracture mechanics
Is chlorhexidine mouth rinse, used as a mono-therapy or adjunct with oral hygiene, effective at reducing plaque growth and gingival inflammation?
Authors: Van Zy Andre W. , Hartshorne Johan , Carrasco-Labra Alonso
Published: March 2013

This study describes a systematic review of the best available evidence on the effectiveness of a chlorhexidine mouth rinse as a mono-therapy or as an adjunct to mechanical oral hygiene against plaque growth and gingival inflammation. Medline, EMBASE and the Cochrane Central register of Controlled Trials were searched up to April 2011. Randomised controlled clinical trials that compared chlorhexidine to placebo or controlled mouth rinses or regular oral hygiene for a minimum duration of at least four weeks amongst gingivitis patients (≥ 18 years of age) were included. A total of 30 publications fulfilled the selection criteria. Clinical parameters measured at baseline and end of trial were plaque, gingival inflammation, bleeding and staining. Chlorhexidine reduced plaque by 33% and gingivitis by 26% compared to a placebo or a control mouth rinse. The investigators concluded that when used together with oral hygiene, chlorhexidine mouth rinses provide significant reductions in plaque and gingivitis scores in gingivitis patients, but a significant increase in staining compared to placebo or control mouth rinses.
Acinic Cell Carcinoma of the Minor Salivary Glands of the Tongue: A Case Study with Review of Literature
Authors: Kudpaje Akshay , Gupta Sumit , Naik Sudhir , Halkud Rajshekar , Prashanth V , Nanjundappa A , Biswas Siddharth
Published: March 2013

Background

Acinic cell carcinoma (ACC) is a relatively rare and slowly growing tumor of the major salivary glands, usually arising from the parotid and rarely from the submandibular and sublingual salivary glands. ACC accounts for 3 to 4% of parotid tumors, 2 to 6% of all salivary gland tumors and 10 to 17% of all malignant salivary gland tumors.

Case report

A 40-year-old woman reported a slow growing mass in the oral cavity. The transoral aspiration biopsy was reported as pleomorphic adenoma arising from the minor salivary glands of the junctional zone of base of tongue. Rest of the neck examination was normal and magnetic resonance imaging (MRI) revealed the mass confined to the superficial layers of the tongue without invasion.

Intervention

The tumor was resected transorally with adequate margins. The tumor histology was typical of ACC with the margins free and wide on all the sides. The patient was kept on monthly follow-up where palpable nodes developed during the course of 6 months. The neck was addressed with supraomohyoid dissection and followed up without irradiation.

Conclusion

ACC is a low-grade malignant salivary neoplasm rarely diagnosed in minor salivary glands of the oral cavity. The overall prognosis after surgical resection depends on the extent of lesion and the adequacy of the initial resection. Hence, keeping in mind the malignant potential of the disease careful long-term follow-up is advised.

How to cite this article

Naik SM, Kudpaje A, Gupta S, Nanjundappa A, Halkud R, Prashanth V, Biswas S. Acinic Cell Carcinoma of the Minor Salivary Glands of the Tongue: A Case Study with Review of Literature. Int J Head and Neck Surg 2013; 4(1):24-28.
Classic Lipoma of the Palatine Tonsil: Case Report and Review of the Literature
Authors: Abu-Ghanem Sara , Zilker Vladimir , Trejo Leonor , Fliss Dan M
Published: March 2013

Lipomas in the oral cavity are rare benign soft tissue mesenchymal neoplasms, representing1% of all benign oral tumors. Very few cases of tonsillar lipoma have been reported in the English literature. The diagnosis and differentiation of lipoma with clinically similar lesions, such as squamous papilloma, adenomas, chondromas, hamartomas and teratomas, is essential for correct treatment management and follow-up. We describe a rare case of palatine tonsil lipoma in a 67-year-old female and an updated review of the sparse English literature.

How to cite this article

Abu-Ghanem S, Zilker V, Trejo L, Fliss DM. Classic Lipoma of the Palatine Tonsil: Case Report and Review of the Literature. Int J Head and Neck Surg 2013;4(1):41-43.
A Comparative Study of Distribution of Protein and Cholesterol in Various Fractions of Human Semen from Infertile and Fertile Subjects
Authors: Srinivas MS , Sundaram Vickram , Pathy M Ramesh , Sridharan TB
Published: March 2013

Aim

To elucidate the concentration of the protein and cholesterol in different fractions of human semen from different infertile categories and comparing them with the fertile group.

Materials and methods

The human semen was collected from different infertile categories including oligoasthenospermia, asthenospermia, azoospermia, normospermia, oligospermia and fertile group. Immediately after collection, the semen analysis was done as per WHO standard protocols. After that, the semen was centrifuged to get the different fractions. Four main fractions were obtained, (1) spermatozoa, (2) debris or material that precipitates at 12 K rpm for 10 minutes, (3) prostasomes which was precipitated at 20K rpm for 120 minutes, (4) seminal plasma. The protein concentration was done by Lowry's method and cholesterol was estimated by diagnostic kit.

Results

Sodium dodecyl sulfate—polyacrylamide gel electrophoresis (SDS PAGE) was run for all the categories of semen samples for their seminal plasma and the fertility associated protein was identified. A significant difference was found in the concentration of proteins in all subfractions when compared between control and infertile categories. Almost 86% of the protein was recovered from soluble fraction. In case of azoospermia, the protein content was very low when compared with fertile group. Seminal plasma proteins were visualized by silver staining. The molecular weight of the protein bands were ranging from 6.5 to 205 kDa. The band with molecular weight around 55 kDa was found to be missing in case of oligoasthenospermia. This particular protein is said to be fertility associated protein. The content of cholesterol for different subfraction of the human semen samples from infertile and fertile samples was compared. A wide range of cholesterol was recovered from prostasomes, that too purified.

Conclusion

A thrive study have to be done in all the subfractions of the semen irrespective of the category of samples to know the exact function of the each subfractions in terms of protein and cholesterol distribution.

How to cite this article

Sundaram V, Srinivas MS, Rao KA, Pathy MR, Sridharan TB. A Comparative Study of Distribution of Protein and Cholesterol in Various Fractions of Human Semen from Infertile and Fertile Subjects. Int J Infertility Fetal Med 2012;3(3):78-82.
An Analysis of Factors Affecting the Duration of Latency Period and Its Impact on Neonatal Outcome in Patients with PPROM
Authors: Gami Neha , Singhal Seema
Published: March 2013

Introduction

Preterm premature rupture of membranes (PPROM) complicates approximately 3% of all births, but accounts for 30% of neonatal morbidity and mortality among premature gestations. Prediction of latency period for women with PPROM is imprecise and therefore consulting women with PPROM about their predicted latency period is a difficult task. The studies are limited, thus more information is required to support clinical decisions and to provide prognostic information in cases of expectant management following PPROM.

Materials and methods

We conducted a prospective observational study of women with singleton pregnancies presenting with rupture of membranes. A total of 120 women presenting with PPROM from 26 to 36 weeks with rupture of membrane were included in this study.

Results

Advanced maternal age >30 years was found to be associated with prolongation of latency period (p = 0.000). Nulliparity was found to be associated with shortening of latency period (p = 0.012). An inverse association between gestational age at the time of presentation and latency period was established. The average gain in duration of latency period by not doing a digital examination was found to be statistically significant (p = 0.000). Gestational age and duration of latency period were found to be the important predictors of neonatal outcome.

Conclusion

In the current study, several predictive factors were identified which affect the duration of the latency period in cases of PPROM. This information may assist clinician in risk stratification and in providing consultation regarding the natural course of expectant management for women presenting with PPROM.

How to cite this article

Singhal S, Puri M, Gami N. An Analysis of Factors Affecting the Duration of Latency Period and Its Impact on Neonatal Outcome in Patients with PPROM. Int J Infertility Fetal Med 2012;3(3):87-91.
The global 3-D distribution of tropospheric aerosols as characterized by CALIOP
Authors: Winker D. M. , Tackett J. L. , Getzewich B. J. , Liu Z. , Vaughan M. A. , Rogers R. R.
Published: March 2013

Abstract. The CALIOP lidar, carried on the CALIPSO satellite, has been acquiring global atmospheric profiles since June 2006. This dataset now offers the opportunity to characterize the global 3-D distribution of aerosol as well as seasonal and interannual variations, and confront aerosol models with observations in a way that has not been possible before. With that goal in mind, a monthly global gridded dataset of daytime and nighttime aerosol extinction profiles has been constructed, available as a Level 3 aerosol product. Averaged aerosol profiles for cloud-free and all-sky conditions are reported separately. This 6-yr dataset characterizes the global 3-dimensional distribution of tropospheric aerosol. Vertical distributions are seen to vary with season, as both source strengths and transport mechanisms vary. In most regions, clear-sky and all-sky mean aerosol profiles are found to be quite similar, implying a lack of correlation between high semi-transparent cloud and aerosol in the lower troposphere. An initial evaluation of the accuracy of the aerosol extinction profiles is presented. Detection limitations and the representivity of aerosol profiles in the upper troposphere are of particular concern. While results are preliminary, we present evidence that the monthly-mean CALIOP aerosol profiles provide quantitative characterization of elevated aerosol layers in major transport pathways. Aerosol extinction in the free troposphere in clean conditions, where the true aerosol extinction is typically 0.001 km−1 or less, is generally underestimated, however. The work described here forms an initial global 3-D aerosol climatology which we plan to extend and improve over time.
On the consistency between global and regional methane emissions inferred from SCIAMACHY, TANSO-FTS, IASI and surface measurements
Authors: Cressot C. , Chevallier F. , Bousquet P. , Crevoisier C. , Dlugokencky E. J. , Fortems-Cheiney A. , Frankenberg C. , Parker R. , Pison I. , Scheepmaker R. A. , Montzka S. A. , Krummel P. B. , Steele L. P. , Langenfelds R. L.
Published: March 2013

Abstract. Satellite retrievals of methane weighted atmospheric columns are studied within a Bayesian inversion system to infer the global and regional methane emissions and sinks. 19-month inversions from June 2009 to December 2010 are independently computed from three different space-borne observing systems under various hypotheses for prior-flux and observation errors. Posterior methane emissions are inter-compared and evaluated with surface mole fraction measurements, via a chemistry-transport model. Sensitivity tests show that refining the assigned error statistics has a larger impact on the quality of the inverted fluxes than correcting for residual airmass-factor-dependent biases in the satellite retrievals. Improved configurations using TANSO-FTS, SCIAMACHY, IASI and surface measurements induce posterior methane global budgets of respectively, 568 ± 17 Tg yr−1, 603 ± 28 yr−1, 524 ± 16 yr−1 and 538 ± 20 yr−1 over the one-year period August 2009–July 2010. This consistency between some of these satellite retrievals and surface measurements is promising for future improvement of CH4 emission estimates by inversions.
Measurements on pointing error and field of view of Cimel-318 Sun photometers in the scope of AERONET-Europe
Authors: Torres B. , Toledano C. , Berjón A. , Fuertes D. , Molina V. , Gonzalez R. , Canini M. , Cachorro V. E. , Goloub P. , Podvin T. , Blarel L. , Dubovik O. , Bennouna Y. , de Frutos A. M.
Published: March 2013

Abstract. Sensitivity studies indicate that among the different error sources of ground-based sky radiometer observations, the pointing error has an important role in the correct retrieving of aerosol properties, being specially critical for the characterization of desert dust aerosol. The present work analyzes the first results of two new measurements, cross and matrix, specifically designed for an evaluation of the pointing error in the standard instrument of the Aerosol Robotic Network, the Cimel CE-318 sun-photometer. The first part of the analysis contains a preliminary study whose results conclude on the need of a sun movement correction for the correct evaluation of the pointing error from both new measurements. Once this correction is applied, both measurements show an equivalent behavior with differences under 0.01° in the evaluation of the pointing error. The second part of the analysis includes the incorporation of the cross scenario in the AERONET routine measurement protocol in order to monitor the pointing error in field instruments. Using the data collected for more than a year, the pointing error is evaluated on 7 sun-photometers belonging to AERONET-Europe. The pointing error values registered are generally smaller than 0.01° though in some instruments values up to 0.03° have been observed. Moreover, the pointing error evaluation has shown that this measure can be used to detect mechanical problems in the robots or dirtiness in the quadrant detector due to the stable behavior of the values against time and solar zenith angle. At the same time, the matrix scenario can be used to derive the value of the field of view. The methodology implemented and the characterization of five sun-photometers is presented in the last part of the study. To validate the method, a comparison with field of view values obtained from the vicarious calibration method was developed. The differences between both techniques are under 3%.
Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles
Authors: Haverd V. , Raupach M. R. , Briggs P. R. , Canadell J. G. , Isaac P. , Pickett-Heaps C. , Roxburgh S. H. , van Gorsel E. , Viscarra Rossel R. A. , Wang Z.
Published: March 2013

Abstract. Information about the carbon cycle potentially constrains the water cycle, and vice versa. This paper explores the utility of multiple observation sets to constrain a land surface model of Australian terrestrial carbon and water cycles, and the resulting mean carbon pools and fluxes, as well as their temporal and spatial variability. Observations include streamflow from 416 gauged catchments, measurements of evapotranspiration (ET) and net ecosystem production (NEP) from 12 eddy-flux sites, litterfall data, and data on carbon pools. By projecting residuals between observations and corresponding predictions onto uncertainty in model predictions at the continental scale, we find that eddy flux measurements provide a significantly tighter constraint on continental net primary production (NPP) than the other data types. Nonetheless, simultaneous constraint by multiple data types is important for mitigating bias from any single type. Four significant results emerging from the multiply-constrained model are that, for the 1990–2011 period: (i) on the Australian continent, a predominantly semi-arid region, over half the water loss through ET (0.64 ± 0.05) occurs through soil evaporation and bypasses plants entirely; (ii) mean Australian NPP is quantified at 2.2 ± 0.4 (1σ) Pg C yr−1; (iii) annually cyclic ("grassy") vegetation and persistent ("woody") vegetation account for 0.67 ± 0.14 and 0.33 ± 0.14, respectively, of NPP across Australia; (iv) the average interannual variability of Australia's NEP (±0.18 Pg C yr−1, 1σ) is larger than Australia's total anthropogenic greenhouse gas emissions in 2011 (0.149 Pg C equivalent yr–1), and is dominated by variability in desert and savanna regions.
Modeling microbial exchanges between forms of soil nitrogen in contrasting ecosystems
Authors: Pansu M. , Machado D. , Bottner P. , Sarmiento L.
Published: March 2013

Abstract. Although nitrogen (N) is often linked to carbon (C) in organic molecules, C is carried from the atmosphere to the soil through plants while N is carried from the soil to plants by microbial transformations. Many schemes have been proposed to describe the microbial conversion between organic and inorganic forms of N but current models do not fully represent the microbial control over these conversions. This study followed the transfer of 15N between plant materials, microorganisms, humified compartments and inorganic forms in 6 very different ecosystems along an altitudinal transect. The microbial conversion of the 15N forms appeared to be strongly linked to that found previously for 14C forms since the parameters and relationships defined for C were appropriate for modeling the N cycle. The only difference was in the flows between microbial and inorganic forms. The CO2-C loss was modeled using the equation for microbial respiration. Inorganic N appears also closely associated with microorganisms, which, depending on their C : N ratio and those of the available substrates, regulate the N mineralization and immobilization processes. Applications at earth scale can use the approximation that the microbial C : N ratio does not vary with time, but for this study, microorganisms cannot be treated always as homeostatic as their C : N ratio can decrease during incubation and increase with altitude when C storage increases. The MOMOS model has been validated for the C cycle, and it also appears to be valid for microbial conversion of N forms. It uses a relatively small number of well-defined, climate-dependent parameters, and it should fill a gap in the range of current models based on a direct microbial control for describing C and N flows in ecosystems.
LGM permafrost distribution: how well can the latest PMIP multi-model ensembles reconstruct?
Authors: Saito K. , Sueyoshi T. , Marchenko S. , Romanovsky V. , Otto-Bliesner B. , Walsh J. , Bigelow N. , Hendricks A. , Yoshikawa K.
Published: March 2013

Abstract. Global-scale frozen ground distribution during the Last Glacial Maximum (LGM) was reconstructed using multi-model ensembles of global climate models, and then compared with evidence-based knowledge and earlier numerical results. Modeled soil temperatures, taken from Paleoclimate Modelling Intercomparison Project Phase III (PMIP3) simulations, were used to diagnose the subsurface thermal regime and determine underlying frozen ground types for the present-day (pre-industrial; 0 k) and the LGM (21 k). This direct method was then compared to the earlier indirect method, which categorizes the underlying frozen ground type from surface air temperature, applied to both the PMIP2 (phase II) and PMIP3 products. Both direct and indirect diagnoses for 0 k showed strong agreement with the present-day observation-based map, although the soil temperature ensemble showed a higher diversity among the models partly due to varying complexity of the implemented subsurface processes. The area of continuous permafrost estimated by the multi-model analysis was 25.6 million km2 for LGM, in contrast to 12.7 million km2 for the pre-industrial control, whereas seasonally, frozen ground increased from 22.5 million km2 to 32.6 million km2. These changes in area resulted mainly from a cooler climate at LGM, but other factors as well, such as the presence of huge land ice sheets and the consequent expansion of total land area due to sea-level change. LGM permafrost boundaries modeled by the PMIP3 ensemble-improved over those of the PMIP2 due to higher spatial resolutions and improved climatology-also compared better to previous knowledge derived from the geomorphological and geocryological evidences. Combinatorial applications of coupled climate models and detailed stand-alone physical-ecological models for the cold-region terrestrial, paleo-, and modern climates will advance our understanding of the functionality and variability of the frozen ground subsystem in the global eco-climate system.
Towards understanding the dynamic behaviour of floodplains as human-water systems
Authors: Di Baldassarre G. , Kooy M. , Kemerink J. S. , Brandimarte L.
Published: March 2013

Abstract. This paper offers a conceptual approach to explore the complex dynamics of floodplains as fully coupled human-water systems. A number of hydrologists have recently investigated the impact of human activities (such as flood control measures, land-use changes, and settlement patterns) on the frequency and severity of floods. Meanwhile, social scientists have shown how interactions between society and waters in floodplain areas, including the frequency and severity of floods, have an impact on the ways in which social relations unfold (in terms of governance processes, policies, and institutions) and societies are organised (spatially, politically, and socially). However, we argue that the interactions and associated feedback mechanisms between hydrological and social processes remain largely unexplored and poorly understood. Thus, there is a need to better understand how the institutions and governance processes interact with hydrological processes in floodplains to influence the frequency and severity of floods, while (in turn) hydrological processes co-constitute the social realm and make a difference for how social relations unfold to shape governance processes and institutions. Our research goal, therefore, is not in identifying one or the other side of the cycle (hydrological or social), but in explaining the relationship between them: how, when, where, and why they interact, and to what result for both social relations and hydrological processes? We argue that long time series of hydrological and social data, along with remote sensing data, can be used to observe floodplain dynamics from unconventional approaches, and understand the complex interactions between water and human systems taking place in floodplain areas, across scales and levels of human impacts, and within different hydro-climatic conditions, socio-cultural settings, and modes of governance.
Brief communication "A prototype forecasting chain for rainfall induced shallow landslides"
Authors: Mercogliano P. , Segoni S. , Rossi G. , Sikorsky B. , Tofani V. , Schiano P. , Catani F. , Casagli N.
Published: March 2013

Abstract. Although shallow landslides are a very widespread phenomenon, large area (e.g. thousands of square kilometres) early warning systems are commonly based on statistical rainfall thresholds, while physically based models are more commonly applied to smaller areas. This work provides a contribution towards the filling of this gap: a forecasting chain is designed assembling a numerical weather prediction model, a statistical rainfall downscaling tool and a geotechnical model for the distributed calculation of the factor of safety on a pixel-by-pixel basis. The forecasting chain can be used to forecast the triggering of shallow landslides with a 48 h lead time and was tested on a 3200 km2 wide area.
Investigation of superstorm Sandy 2012 in a multi-disciplinary approach
Authors: Kunz M. , Mühr B. , Kunz-Plapp T. , Daniell J.E. , Khazai B. , Wenzel F. , Vannieuwenhuyse M. , Comes T. , Elmer F. , Schröter K. , Fohringer J. , Münzberg T. , Lucas C. , Zschau J.
Published: March 2013

Abstract. At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation) and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about 4.2 billion US$ in the Caribbean and between 78 and 97 billion US$ for the US. Indirect economic losses from power outages is estimated in the order of 16.3 billion US$. Modelling sector-specific dependencies, quantifies total business interruption losses between 10.8 and 15.5 billion US$. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.