bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Determination of Sound Absorption Coefficients of Four Types of Malaysian Wood
Authors: Jayamani Elammaran , Hamdan Sinin , Suid Nurizahusna Binti
Published: April 2013

Currently, one of the important topics in acoustic science is noise control. It is important to control the noise in order to minimize extraneous noise in rooms, buildings, and our environment. Noise control can be achieved by reducing the intensity of sound to the level that is not harmful to human ear. There are four basic principles employed to reduce noise which is absorption, isolation, vibration isolation, and vibration damping. In fact, the most recognized technique to reduce noise is sound absorption on the materials itself. Sound absorption on material such as wood and porous material have been developed and studied by few researchers. Materials that reduce the sound intensity as the sound wave passes through it by the phenomenon of absorption are called sound absorptive materials. There are lot of methods can be used on determining the sound absorption coefficient of materials. In this paper, a preliminary work has been carried out experimentally to determine the sound absorption coefficient of four types of Malaysian wood. They are Tapang (Koompassia excels), Pulai (Alstonai angustiloba), Selunsor merah (Tristianiopsis beccariana) and Jelutong (Dyera polyphylla). The test was performed using the ASTM E1050-98/ISO 10534-2 (American Society for Testing and Material) standards for the sound absorption coefficient testing. This method is known as impedance tube method (Two-Microphone Method). The absorption coefficient depends on the frequencies. In this study the values of the frequencies used was in the range from 350 Hz to 1000 Hz.
Evaluation of Different Internal Structure and Build Orientation for Multijet Modeling Process
Authors: Hafsa M.N. , Ibrahim M. , Sharif S. , Omar M.F.M. , Zainol M.A.
Published: April 2013

Rapid Prototyping (RP) technology has proven its capability to produce complex parts with shorter lead time. This advantage could benefit tremendously in application such as the Investment Casting (IC) process. The focus of the study is the production of sacrificial IC patterns produced using Multijet Modeling (MJM) RP technology. It includes the evaluation of dimensional accuracy and the surface roughness of part with a hollow and quasi hollow inner support patterns. Different internal structure's pattern were developed using CAD software, and the part were fabricated using MJM technique in two different build orientations. Analyses were done using Coordinate Measuring Machine (CMM) and the surface roughness tester. Results show that part built with 90º orientation is better than part built with 0º orientation both in terms of accuracies and roughness. Different internal structure similarly affects the final part quality, though the post processing steps also have their influence, thus making it no clear different among the parts. However, it demonstrated parts with square structure produced the best dimensional accuracy and the part with hatch structure produced the best surface roughness.
Acid Pretreatment of WC-Co for Surface Roughening and Cobalt Removal Prior to CVD Diamond Coating
Authors: Norafifah H. , Noordin M.Y. , Izman S. , Kurniawan D.
Published: April 2013

Chemical vapor deposition (CVD) diamond coatings are being developed to be applied on carbide cutting tools to enhance wear resistance and increase tool life. As a prerequisite, for ensuring adhesion of CVD diamond on tungsten carbide substrate, it is necessary to prepare high surface roughness and to remove the cobalt on tungsten carbide surface during the pretreatment. In this study, a two step acid pretreatment was examined for those purposes. Etching using modified Murakamis reagent was initially performed to roughen the surface. Subsequently, the carbide was immersed in nitric acid to remove cobalt. Concentration of the acid solutions and reaction time were varied. Results showed that the initial step by modified Murakamis reagent etching resulted in a surface roughness of Ry = 6.95 µm, which is a 15% increase from the average initial surface roughness. The second step by nitric acid immersion on modified Murakamis reagent etched carbide samples resulted in carbide surfaces with zero cobalt content, confirming the effectiveness of the pretreatment.
Active Force Control Applied to Spray Boom Structure
Authors: Tahmasebi Mona , Rahman Roslan Abdul , Mailah Musa , Gohari Mohammad
Published: April 2013

Distribution pattern of spray boom in fields is affected by several parameters which one of the important reasons is horizontal and vertical vibrations because of unevenness surfaces. Spray boom movements lead to decrease of spread efficiency and crop yield. Generally, active suspension is employed to control and attenuate the vibration of sprayer booms because these suspensions reduce the high frequency vibration of spray booms thanks to irregularities soil. In this research, a proportional-integral-derivative controller with active force control is used to remove undesired rolling of spray boom. Simulation results depict that the proposed scheme is more effective and accurate than PID control only scheme. The AFC based scheme shows the robustness and accuracy compared to the PID controller.
Probabilistic Analysis of Surface Crack in Round Bars under Tension Loading
Authors: Ismail Al Emran
Published: April 2013

This paper presents the probabilistic analysis of surface crack in round bars subjected to tension stress using Monte Carlo Simulation (MCS). A probabilistic model based on an elastic finite element analysis (FEA) was developed to evaluate the failure probability obtained using a K-estimation method. This method is based on the stress intensity factor (SIF) where the failure occurred when the SIF was assumed to exceed the critical SIF. It was found that, the K-estimation method was adequate to evaluate the failure probability of the bars when compared with the results obtained using the probabilistic FEA approach. The advantage of K-estimation methods was the reduction of the computational time and cost significantly.
Improving Engine Performance and Low Temperature Properties of Blended Palm Biodiesel Using Additives. A Review
Authors: Ali Obed M. , Mamat Rizalman
Published: April 2013

After the oil crisis in 1973, renewable sources of energy are gianing more interest due to multiplicity feedstocks and lower pollution compared with fossil fuels. Wide agricultural lands through the world are not fully benefited. Therefore, farming should include the production of non-food products which are suitable to weather conditions of these lands. This leads to the production of biodiesels as renewable fuel for the domestic energy market, to reduce the dependence on fossil fuels. Biodiesel have gained a large interest of researches during the last few decades, the major reason to find an alternative fuel, is the increasing worry about the greenhouse gas effects and environmental regulations. Blended palm biodiesel with ordinary diesel fuel have been approved as a fuel for compression ignition engines without any modification. Palm biodiesel application is relatively limited to its poor cold flow properties characteristics. Many experimental studies are conducted to evaluate the influence of using different additives with Palm Oil Methyl Ester (POME) biodiesel/diesel blends on fuel properties (viscosity, cold properties, anticorrosiveness, cetane number, heat content, volatility) and engine performance. This article provides a literature survey on the effect of different additives to improve the fuel properties of palm biodiesel and engine performance. The review shows that the additive usage in palm biodiesel is accompanying for improving the cold flow properties and better engine performance as well emission regulation.
Effect of Operating Temperature on Direct Recycling Aluminium Chips (AA6061) in Hot Press Forging Process
Authors: Yusuf N.K. , Lajis Mohd Amri , Daud M.I. , Noh Mohamad Zaky
Published: April 2013

A method of solid-state recycling aluminum alloy using hot press forging process was studied as well as the possibility of the recycled chip to be used as secondary resources. This paper presents the results of recycled AA6061 aluminium alloy chip using different operating temperature for hot press forging process. Mechanical properties and microstructure of the recycled specimens and as-received (reference) specimen were investigated. The recycled specimens exhibit a good potential in the strength properties. The result for yield strength (YS) and ultimate tensile strength (UTS) at the minimum temperature 430°C is 25.8 MPa and 27.13 MPa. For the maximum operating temperature 520°C YS and UTS are 107.0MPa and 117.53 MPa. Analysis for different operating temperatures shows that the higher temperatures giving better result on mechanical properties and finer microstructure. The strength of recycled specimen increases due to the grain refinement strengthening whereas particle dispersion strengthening has minor effects. In this study, the recycled AA6061 chip shows the good potential in strengthening as the comparison of using only 17.5% of suggested pressure (70.0/400.0) MPa, the UTS exhibit 35.8% (117.58/327.69) MPa. This shows a remarkable potential of direct recycling by using hot press forging process.
An EOQ Based Multi-Storage Location of Spare Part Inventories: A Case Study
Authors: Mohd-Lair Noor Ajian , Pang Chuan Kian , Liew Willey Y.H. , Semui Hardy , Yew Loh Zhia
Published: April 2013

Spare parts inventory management is very important to ensure smooth operation of maintenance department. The main objectives of inventory management of spare parts are to ensure the availability of spares and materials for the maintenance tasks and increase the productivity of the maintenance department. This research centred on the development of the Computerised Inventory Management System (CIMS) for the maintenance team at Weida Integrated Industries Sdn. Bhd. The inventory management technique used to control the spare parts inventory in this research was the basic Economic Order Quantity models (EOQ). However, the CIMS developed is unique as it has the ability in handling inventories in multiple-storage locations. The CIMS was written using the Visual Basic 2010 software. This CIMS has the abilities to keep records and process the spare parts information effectively and faster besides helping the user to perform spare parts ordering tasks compared to the current manual recording. In addition, the ordering quantity and frequency for the CIMS is determined through the EOQ technique. However, observation indicates that the overall average inventory level currently at the factory is lower than the expected overall average inventory level produced by the CIMS. This is due to the fact that the CIMS was unable to consider the opening stock in ordering the inventories. Therefore, further improvements are needed to optimize the performance of the system such as using the EOQ with the reorder point technique, the periodic or continuous review system.
The Effect of Laser Focal Point Distance on Carbon Fiber Reinforced Plastics (CFRP) Cutting Performance
Authors: Rahman Norzaina Abdul , Saidin Wahab , Rahim Erween Abdul , Mohid Z.
Published: April 2013

Carbon fiber reinforced plastics (CFRP) composites as high performance material in aerospace industry. The application of laser technology to cut the CFRP shows promising advantages. The present study focuses the effect of focal point distance on the kerf width, HAZ, taper angle and morphology surfaces when cutting CFRP using laser process. Experiments have been conducted on CFRP and microstructure of the cross-section of the HAZ during cutting was analyzed. The results showed that focal position gave a significant effect on the cutting characteristic.
Simulation Analysis of Rabbit Chase Models on a Cellular Manufacturing System
Authors: Bin Che Ani Mohd Norzaimi , Ismail Aimuni Binti , Mustafa Shaliza Azreen , Feng Chin Jeng
Published: April 2013

Cellular manufacturing system facilitates lean manufacturing in terms of production flexibility and control simplification. The paper presents a case study on a newly constructed cellular manufacturing system adopted by an electronic assembly factory as the back end process. The original rabbit chase is infeasible in this case because products handled are multi-types and multi-paths. Further, the cycle times are largely imbalance. The application of two proposed rabbit chase models was investigated through computer simulations enhanced with ANOVA and surface response methodology. The allocation of operators and the impact of changing lot size to the performances of the cell are investigated. For the findings, there are clear indications of the effects of the number of operators and the lot size for the performances of the system, regardless which rabbit chase model used.
Improvement of Mechanical Properties of Polycaprolactone (PCL) by Addition of Nano-Montmorillonite (MMT) and Hydroxyapatite (HA)
Authors: Abdul Haq Reazul Haq , Saidin Wahab , Mat Uzir Wahit
Published: April 2013

For many years, researcher have focused on developing a medical part of human body from polymer as to replace metal. This report described the mechanical characteristic of biodegradable Polycaprolactone (PCL) blend with nanoMontmorillonite (MMT) and Hydroxyapatite (HA). The amount of nanoMMT is varies from 2 to 4 by weight % meanwhile the amount of HA is fixed to 10 by weight percentage (wt %). The addition of nanoMMT and HA filler is to tune and indirectly improve the mechanical properties of PCL. These are proven by carrying out the tensile, and also flexural test for samples which is injected from injection molding machine. Both the tensile and flexural test are conducted using Shimadzu AG-I Unversal Testing Machine with 10kN capacity. From the analysis it is found that overall PCL/MMT/HA composites gives better result in both tensile and flexural analysis compare to PCL/MMT composite. PCL/MMT/HA composite with 2 wt% of MMT and 10 wt% of HA have indicated the highest tensile modulus, meanwhile PCL/MMT/HA composite with 4 wt% MMT and 10 wt% HA have plotted the highest flexural strength and modulus value.
Melt Flow and Mechanical Properties of Polypropylene/Recycled Plaster of Paris
Authors: Jikan S.S. , Arshat I. Mat , Badarulzaman Nur Azam
Published: April 2013

Polypropylene (PP) composites have better material properties such as good strength, better stiffness, improve of ductility; good stability and thermal expansion; and low cost of production. Nevertheless, these properties depend on the matrix phase, the phase dispersion of fillers and strengthening mechanism, shapes and arrangements of filler particles and the bonding interface between filler and matrix [1]. Plaster of paris (POP) has been chosen as filler in this composite system because it is used in many ceramic manufacturing and construction sectors which produce lots of POP wastes. It becomes one of the environmental issues due to the amount of used POP that has been disposed without recycling. Therefore, it is crucial to develop new composite material which consists of recycled POP as filler in order to assist the government in addressing the environmental issue.
Friction Characteristics of RBD Palm Olein Using Four-Ball Tribotester
Authors: Syahrullail Samion , Wira Jazair Yahya , Wan Nik W.B. , Fawwaz W.N.
Published: April 2013

In this study, the effect of load on the tribological performance of RBD palm olein is investigated using a four-ball wear tester according to the standard test of ASTM D4172. Tests were conducted with 40, 60, 80, 100 and 120 kg normal loads. The experimental temperature and rotational speed were held constant at 75 °C and 1200 rpm, respectively. The test duration was 60 minutes in all cases. For each load, the tribological properties of RBD palm olein were compared with the properties of additive-free paraffinic mineral oil. The results focused on the frictional torque, wear scar diameter, friction coefficient and the flash temperature. Following the completion of the wear test experiments, the ball wear condition and lubricant properties were observed. These results show that RBD palm olein has a lower coefficient of friction than paraffinic mineral oil; however showed a high oxidation effect under high temperature work conditions.
Optimisation of Circular Sawing Conditions to Maximize Tool Productivity for each Class of Material
Authors: Carlos José C. , Amaral Pedro M. , Coelho Adriano , Tavares Andre , Fernandes Jorge C. , Rosa Luís G.
Published: April 2013

The research disclosed in the present paper reports a new computer algorithm to maximize tool productivity in circular sawing processes, as a function of the stone characteristics and the quality required for the product. This algorithm is currently applied in tool testing at the company FrontWave and will be used in a new type of numeric machine to cut stone, called LeanMachine®. This optimization algorithm essentially depends on three variables: cutting depth, forward speed and rotational speed (identified as the main variables quantifying the sawing process), and how the variables are related with the forces acting on the tool. The algorithm uses the data provided by the relationships between each of the variables and the force acting on the tool (the so-called “force plots”) to determine the optimum working conditions for each tool, aiming to maximize productivity and minimize wear and energy consumption. The algorithm works with different production strategies, involving quality versus productivity, a key factor in the stone industry. A rating is subsequently attributed to each tool, allowing the establishment of tool rankings that can be used as selection criteria by machine operators or automatically in modern cutting stone machines such as LeanMachine®.
Considerations on Granite Dimension Stone Porosity and Modifications from Quarry to Slabs
Authors: Frascá Maria H.B.O.
Published: April 2013

This paper presents the physical and petrographic characterization of selected granitic rock types from several quarries in Brazil and aims to contribute to a better knowledge of the engineering properties of granite dimension stone, focusing on laboratory physical determinations and the possible changes that would occur along processing operations, i.e., from the quarried rock to the polished slabs or tiles. The tests – petrography and porosity determinations – led to the collection of parameters of in natura and processed rock material, respectively from specimens obtained from small cubic blocks and polished slabs, situations considered representative of the stresses to which the rock is submitted to during the several processing stages. The results indicated that porosity tends to be higher for “tiles” than for “blocks”, and that “S-type granites” have higher porosity/open-pores values than “ordinary granites”, mainly due to their conspicuous microcracking. Moreover, in spite porous configuration may be modified during stone processing, it was found that such changes are not homogeneous and intrinsically associated to the petrographic characteristics, as previous microcracking and alteration states. Finally, as the new physical conditions, acquired after processing, may influence the stone durability, it is strongly suggested that they should be taken into account, as an additional criterion, to the cladding or flooring natural stone selection and specification.
A New Laboratory Methodology for Assessing the Cutting Behaviour of Gangsawing Blades
Authors: Anjinho Carlos A. , Amaral Pedro M. , Fernandes Jorge Cruz , Rosa Luis G.
Published: April 2013

The objective of this work is to present a new laboratory testing methodology suitable for estimate the forces generated during multiple blade gangsawing employed on marble and limestone. This methodology allows analysing the tool behaviour aiming to contribute for developing new products and/or optimize the working conditions for processing different classes of stones. In the present research, 3 different diamond linear blades were tested against 2 types of stones (limestone and marble), studying the effect of two working parameters. The linear blades differ in the characteristics of the segments: size of diamond grit and type of metallic binders used to embed the diamond. The classification equipment used in this work consists in a special bridge cutting machine incorporating a tailored instrumentation / sensing system to control the working conditions while all the necessary cutting outputs are monitored and stored by special software. Taking into account the output parameters measured to evaluate the tool behaviour (vertical and horizontal forces, electric energy consumption, vibrations measured by accelerometers and tool wear); it is possible to classify and select tools with relation to the efficacy of the cut.
Comparison between Cobalt and Niobium as a Matrix Component for Diamond Impregnated Tools Used for Stone Cutting
Authors: de Oliveira Hellen C.P. , Coelho Adriano , Amaral Pedro M. , Fernandes Jorge C. , Rosa Luís Guerra
Published: April 2013

This investigation examines the possibility of adding niobium (Nb) to the Fe-Cu system in order to obtain, after powder compaction and sintering, a binder material (bonding matrix) with the adequate wear properties needed for the fabrication of diamond impregnated tools for stone cutting. The main objective is the replacement of cobalt (Co) by Nb in the Fe-Cu-Co alloys that are currently used in diamond tools. For this purpose, a comparative study has been conducted on some selected compositions of matrices integrated in cutting discs. Results of diamond impregnated 25wt%Fe-50wt%Cu-25wt%Nb and 25wt%Fe-50wt%Cu-25wt%Co matrices are directly compared because all tests were conducted under similar conditions. Two types of diamonds were used: without coating and Ti-coated. After the hot-pressing cycles, the main mechanical properties of the sintered bodies were evaluated. Cutting tests under real conditions, in Porriño granite, were carried out to compare the performance of the tools. Although the mechanical properties of the matrices with Nb were different from those found in the matrices with Co, the results obtained from the cutting tests have revealed that the tools made of 25wt%Fe-50wt%Cu-25wt%Nb and 25wt%Fe-50wt%Cu-25wt%Co matrices, both with 50/60 mesh diamonds, show quite similar behaviour during the cutting operations, thus indicating that replacement of Co by Nb is a promising route to be followed in the near future.
Optical and Electrical Properties of ZnO Thin Films Grown by Sol-Gel Method
Authors: Bala Waclaw , Zorenko Yurij , Savchyn Volodymyr , Voznyak Taras , Paprocki Kazimierz , Popielarski Pawel , Szybowicz Miroslaw
Published: April 2013

The ZnO thin films have been produced on p-type Si and quartz substrates by the spin-coating method and after deposition were heated at different temperatures in the range from 650K to 850K. The photoluminescence (PL) and cathodoluminescence (CL) measurements were carried out at temperature range 12K-350K. I-V, C-V measurements were performed on the Al/ZnO/Si/Al structures at different temperatures. The structural properties of the ZnO thin films were carried out using x-ray and SEM method. The effects of the thickness variation and annealing temperature on the crystallinity parameters were observed. The electrical response of grains, grain boundaries, and contacts of the ZnO film was obtained.
The Study of Radiation-Induced Instability in the Glassy Arsenic Sulphides by Optical Spectroscopy
Authors: Shpotyuk Yaroslav , Polovynko Ihor
Published: April 2013

Optical changes caused by 60Co γ-irradiation are studied in glassy-like As40S60. The observed long-wave shift in the range of fundamental optical absorption edge accompanied by increase in transmittance is explained as a manifestation of complicated nature of radiation-induced structural transformations associated with coordination topological defects and additional shrinkage input from natural physical ageing.
Peculiarities of the GGG:Nd-Microlaser Performance under Various Pulse Pumping Conditions
Authors: Sugak Dmytro Yu. , Kopko B.M. , Haiduchok V.G. , Syvorotka I.I. , Solskii I.M. , Luchechko A.P. , Vakiv M.M. , Buryy O.A.
Published: April 2013

Domestic Ukrainian optical materials have been used to manufacture a Gd3Ga5O12:Nd-microlaser having a generation wavelength of 1062,4 nm, and its generation properties have been investigated under various conditions of pulse-periodic pumping by a laser diode.
Luminescence of ZnO Nanocrystals in C21H38NCl and C23H14O11Na2 Matrixes
Authors: Omelchenko Myroslava M. , Panasyuk Myron R. , Kapustianyk Volodymyr B.
Published: April 2013

We report the data concerning investigations of photoluminescence spectra of ZnO nanoparticles in the matrixes of liquid crystal materials performed at T=290 K within a visible region. The mentuhflecioned spectra were obtained at polymeric state of Cetylpyridinium Chloride and Disodium Cromoglycate materials. The model of the radiation centers and mechanisms is discussed.
Plasma Frequency in Josephson Junctions with a Non-Sinusoidal Current-Phase Relation
Authors: Sergeyev Daulet
Published: April 2013

In this article we consider the modulation of the plasma frequency switching current-phase dependence of Josephson systems based on the CuO2 harmonic mode into the anharmonic one. It is established the increase of the plasma frequency in the cuprate high-temperature superconductors arising due to deviation of dependence current-phase between the oxide planes in high-temperature superconductors from the standard sine wave form.
Some Properties of Thin Film Structures on the Base of ZnO Obtained by MOCVD Method
Authors: Roshchina Nina M. , Smertenko Petro S. , Stepanov Volodymyr G. , Zavyalova Lyudmyla V. , Lytvyn Oksana
Published: April 2013

The ZnO thin film structures were obtained by MOCVD method under atmospheric pressure onto Si substrates heated up to 250-350 оС. The film thickness varied from 0.4 – 0.5 µm. The phase composition, structure and morphology of ZnO films as well as electrophysical properties of ZnO/Si heterojunction on their base were investigated. The possible charge flow mechanisms in ZnO/Si heterojunction are discussed.
The Role of Innate versus Adaptive Immune Responses in a Mouse Model of O'Nyong-Nyong Virus Infection
Authors: Seymour Robert L. , Rossi Shannan L. , Bergren Nicholas A. , Plante Kenneth S. , Weaver Scott C.
Published: April 2013

O'nyong-nyong virus (ONNV), an alphavirus closely related to chikungunya virus (CHIKV), has caused three major epidemics in Africa since 1959. Both ONNV and CHIKV produce similar syndromes with fever, rash, and debilitating arthralgia. To determine the roles of the innate and adaptive immune responses, we infected different knockout mice with two strains of ONNV (SG650 and MP30). Wild-type, RAG1 KO, and IFNγR KO mice showed no signs of illness or viremia. The STAT1 KO and A129 mice exhibited 50–55% mortality when infected with SG650. Strain SG650 was more virulent in the STAT1 KO and A129 than MP30. Deficiency in interferon α/β signaling (A129 and STAT1 KO) leaves mice susceptible to lethal disease; whereas a deficiency of interferon γ signaling alone had no effect on survival. Our findings highlight the importance of type I interferon in protection against ONNV infection, whereas the adaptive immune system is relatively unimportant in the acute infection.
CLARA-SAL: a global 28 yr timeseries of Earth's black-sky surface albedo
Authors: Riihelä A. , Manninen T. , Laine V. , Andersson K. , Kaspar F.
Published: April 2013

Abstract. We present a novel 28 yr dataset of Earth's black-sky surface albedo, derived from AVHRR instruments. The dataset is created using algorithms to separately derive the surface albedo for different land use areas globally. Snow, sea ice, open water and vegetation are all treated independently. The product features corrections for the atmospheric effect in satellite-observed surface radiances, a BRDF correction for the anisotropic reflectance properties of natural surfaces, and a novel topography correction of geolocation and radiometric accuracy of surface reflectance observations over mountainous areas. The dataset is based on a homogenized AVHRR radiance timeseries. The product is validated against quality-controlled in situ observations of clear-sky surface albedo at various BSRN sites around the world. Snow and ice albedo retrieval validation is given particular attention using BSRN sites over Antarctica, Greenland Climate Network stations on the Greenland Ice Sheet (GrIS), as well as sea ice albedo data from the SHEBA and Tara expeditions. The product quality is found to be comparable to other previous long-term surface albedo datasets from AVHRR.
Climatologies from satellite measurements: the impact of orbital sampling on the standard error of the mean
Authors: Toohey M. , von Clarmann T.
Published: April 2013

Abstract. Climatologies of atmospheric observations are often produced by binning measurements according to latitude and calculating zonal means. The uncertainty in these climatological means is characterised by the standard error of the mean (SEM). However, the usual estimator of the SEM, i.e., the sample standard deviation divided by the square root of the sample size, holds only for uncorrelated randomly sampled measurements. Measurements of the atmospheric state along a satellite orbit cannot always be considered as independent because (a) the time-space interval between two nearest observations is often smaller than the typical scale of variations in the atmospheric state, and (b) the regular time-space sampling pattern of a satellite instrument strongly deviates from random sampling. We have developed a numerical experiment where global chemical fields from a chemistry climate model are sampled according to real sampling patterns of satellite-borne instruments. As case studies, the model fields are sampled using sampling patterns of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and Atmospheric Chemistry Experiment Fourier-Transform Spectrometer (ACE-FTS) satellite instruments. Through an iterative subsampling technique, and by incorporating information on the random errors of the MIPAS and ACE-FTS measurements, we produce empirical estimates of the standard error of monthly mean zonal mean model O3 in 5° latitude bins. We find that generally the classic SEM estimator is a conservative estimate of the SEM, i.e., the empirical SEM is often less than or approximately equal to the classic estimate. Exceptions occur only when natural variability is larger than the random measurement error, and specifically in instances where the zonal sampling distribution shows non-uniformity with a similar zonal structure as variations in the sampled field, leading to maximum sensitivity to arbitrary phase shifts between the sample distribution and sampled field. The occurrence of such instances is thus very sensitive to slight changes in the sampling distribution, and to the variations in the measured field. This study highlights the need for caution in the interpretation of the oft-used classically computed SEM, and outlines a relatively simple methodology that can be used to assess one component of the uncertainty in monthly mean zonal mean climatologies produced from measurements from satellite-borne instruments.
Inclusion of ash and SO2 emissions from volcanic eruptions in WRF-Chem: development and some applications
Authors: Stuefer M. , Freitas S. R. , Grell G. , Webley P. , Peckham S. , McKeen S. A. , Egan S. D.
Published: April 2013

Abstract. We describe a new functionality within the Weather Research and Forecasting (WRF) model with coupled Chemistry (WRF-Chem) that allows simulating emission, transport, dispersion, transformation and sedimentation of pollutants released during volcanic activities. Emissions from both an explosive eruption case and a relatively calm degassing situation are considered using the most recent volcanic emission databases. A preprocessor tool provides emission fields and additional information needed to establish the initial three-dimensional cloud umbrella/vertical distribution within the transport model grid, as well as the timing and duration of an eruption. From this source condition, the transport, dispersion and sedimentation of the ash cloud can be realistically simulated by WRF-Chem using its own dynamics and physical parameterization as well as data assimilation. Examples of model applications include a comparison of tephra fall deposits from the 1989 eruption of Mount Redoubt (Alaska) and the dispersion of ash from the 2010 Eyjafjallajökull eruption in Iceland. Both model applications show good coincidence between WRF-Chem and observations.
Potential and limitations of risk scenario tools in volcanic areas through an example in Mount Cameroon
Authors: Gehl P. , Quinet C. , Le Cozannet G. , Kouokam E. , Thierry P.
Published: April 2013

Abstract. This paper presents an integrated approach to conduct a scenario-based volcanic risk assessment on a variety of exposed assets, such as residential buildings, cultivated areas, network infrastructures or individual strategic buildings. The focus is put on the simulation of scenarios, based on deterministic adverse events input, which are applied to the case-study of an effusive eruption on the Mount Cameroon volcano, resulting in the damage estimation of the assets located in the area. The work is based on the recent advances in the field of seismic risk. A software for systemic risk scenario analysis developed within the FP7 project SYNER-G has been adapted to address the issue of volcanic risk. Most significant improvements include the addition of vulnerability models adapted to each kind of exposed element and the possibility to quantify the successive potential damages inflicted by a sequence of adverse events (e.g. lava flows, tephra fall, etc.). The use of an object-oriented architecture gives the opportunity to model and compute the physical damage of very disparate types of infrastructures under the same framework. Finally, while the risk scenario approach is limited to the assessment of the physical impact of adverse events, a specific focus on strategic infrastructures and a dialogue with stakeholders helps in evaluating the potential wider indirect consequences of an eruption.
Supercooled interfacial water in fine grained soils probed by dielectric spectroscopy
Authors: Lorek A. , Wagner N.
Published: April 2013

Abstract. Water as thermodynamic state parameter affects nearly all physical, chemical and biological processes on the earth. Recent Mars observations as well as laboratory investigations suggest that water is also a key factor of current physical and chemical processes on the martian surface, e.g. rheological phenomena. Therefore it is of particular interest to get information about the liquid like state of water on martian analog soils in the temperature range below 0 °C. In this context, a parallel plate capacitor has been developed to obtain isothermal dielectric spectra of fine grained soils in the frequency range from 10 Hz to 1.1 MHz at martian like temperatures down to −70 °C. Two martian analogue soils have been investigated: a Ca-Bentonite (specific surface of 237 m2 g−1, up to 9.4% w/w gravimetric water content) and JSC Mars 1, a volcanic ash (specific surface of 146 m2 g−1, up to 7.4% w/w). Three soil-specific relaxation processes are observed in the investigated frequency-temperature range: two weak high frequency processes (bound or hydrated water as well as ice) and a strong low frequency process due to counter ion relaxation and the Maxwell–Wagner effect. To characterize the dielectric relaxation behavior, a generalized fractional dielectric relaxation model is applied assuming three active relaxation processes with relaxation time of the ith process according to an Eyring equation. The real part of effective complex soil permittivity at 350 kHz was used to determine ice and liquid like water content by means of the Birchak or CRIM equation. There are evidence that Bentonite down to −70 °C has a liquid like water content of 1.17 monolayers and JSC Mars 1 a liquid like water content of 1.96 mono layers.
Hemodialysis Patient Preference for Type of Vascular Access: Variation and Predictors across Countries in the DOPPS
Authors: Fissell Rachel B. , Fuller Douglas S. , Morgenstern Hal , Gillespie Brenda W. , Mendelssohn David C. , Rayner Hugh C. , Robinson Bruce M. , Schatell Dori , Kawanishi Hideki , Pisoni Ronald L.
Published: April 2013

Purpose

Catheters are associated with worse clinical outcomes than fistulas and grafts in hemodialysis (HD) patients. One potential modifier of patient vascular access (VA) use is patient preference for a particular VA type. The purpose of this study is to identify predictors of patient VA preference that could be used to improve patient care.

Methods

This study uses a cross-sectional sample of data from the Dialysis Outcomes and Practice Patterns Study (DOPPS 3, 2005-09), that includes 3815 HD patients from 224 facilities in 12 countries. Using multivariable models we measured associations between patient demographic and clinical characteristics, previous catheter use and patient preference for a catheter.

Results

Patient preference for a catheter varied across countries, ranging from 1% of HD patients in Japan and 18% in the United States, to 42% to 44% in Belgium and Canada. Preference for a catheter was positively associated with age (adjusted odds ratio per 10 years=1.14; 95% 0=1.02-1.26), female sex (OR 1.49; 95% 0=1.15-1.93), and former (OR=2.61; 95% 0=1.66-4.12) or current catheter use (OR=60.3; 95% 0=36.5-99.8); catheter preference was inversely associated with time on dialysis (OR per three years=0.90; 95% 0=0.82-0.97).

Conclusions

Considerable variation in patient VA preference was observed across countries, suggesting that patient VA preference may be influenced by sociocultural factors and thus could be modifiable. Catheter preference was greatest among current and former catheter users, suggesting that one way to influence patient VA preference may be to avoid catheter use whenever possible.
Direct and apparent residual effects of prohexadione - calcium applied to young cropping sweet cherry trees
Authors: Jacyna Tadeusz , Lipa Tomasz
Published: April 2013

The same young cropping 'Regina' sweet cherry trees were foliar treated with prohexadione-calcium (Pro- Ca) in two consecutive years at a concentration of [ 125, 125 x 2, 250 ]-(A) and [ 250, 375, 500 ]-(B) mg ProCa l-1, respectively. The following year some trees from A-treatments were left untreated to observe carry-over effects (C). None of A-treatments influenced tree trunk, shoot extension and internode growth, whereas B-treatments reduced shoot extension and internode length, simultaneously increasing flower bud density, particularly by 500 mg ProCa l-1. There were no carry-over effects produced by C-trees, except some retardation in shoot extension. None of the treatments influenced the tree cropping level. Fruit diameter was reduced by A-treatments, but fruit shape (L/D ratio) and mass were reduced by treatments B, and such reduction was also exhibited by C-trees (residual effects).
Des racines au ciel. Origines spirituelles du commentaire
Authors: Larangé Daniel S.
Published: April 2013

Le commentaire se déploie toujours dans le repère d’un texte élevé comme référence. Son identité se construit alors dans l’altérité (homme↔Dieu / / Je↔Tu) découlant justement du logocentrisme (théo)logique propre à l’autorité religieuse. La question générique du Texte qui enfante les commentaires ouvre la voie/x à toute une généalogie correspondant à la chute de l’Un dans le multiple (fini↔infini) tant spatiale et temporelle qu’identitaire où l’individu qui fait sens dans son unité s’avère être constitué, dans sa profondeur, de significations multiples et éclatées. Pourtant cette prolifération interne conduit à une homogénéité externe, car la somme des hérésies totalise l’« univers » tel qu’il est perçu et se perçoit à un moment donné en un lieu précis.
Les minorités francophones canadiennes face à l’immigration : particularismes et représentations de la diversité ethnoculturelle dans les milieux associatifs
Authors: Traisnel Christophe , Violette Isabelle , Gallant Nicole
Published: April 2013

Dans cet article, nous documentons la manière dont, au sein des minorités francophones canadiennes, les discours identitaires produits par les militants du milieu associatif articulent la notion de « diversité culturelle » et l’immigration. À travers une comparaison entre l’Acadie du Nouveau-Brunswick, la francophonie ontarienne et la francophonie de Colombie-Britannique, nous faisons ressortir les convergences et les divergences quant aux types de critères mobilisés pour définir et légitimer l’appartenance à la francophonie locale. Nous analysons en particulier la place occupée par la diversité culturelle dans la formalisation de discours identitaires marqués tout à la fois par leur dimension ethnique et civique.
Echo Graphic Evaluation of Retinoblastoma and its Management Modalities
Authors: Delhiwala Kushal S , Thakkar Hansa H
Published: April 2013

Aim:

To establish efficacy of echography in diagnosis of Retinoblastoma and study the outcome of different management options.

Material and Methods:

Retrospective evaluation of data of 100 Retinoblastoma patients for demographic data, clinical presentations, B scan (10MHz) ultrasonography (USG) findings, treatment outcome and follow up examination was carried out. Histopathology was correlated.

Results:

Out of 100 patients from 4 months to 6 years, 57 % were male and 43 % female. Fifty six percent patients were in age group of 1-3 years. Total 148 eyes of 200 had Retinoblastoma. Leucocoria (75, 51%) was the commonest presentation followed by ocular swelling/proptosis (29, 20 %). Histopathology confirmed the diagnosis in all enucleated eyes. Five patients had no calcification in either eye. Thirty three patients showing mass in 43 eyes could be followed up from 6 months to 4 years. Of 18 enucleated eyes, 2(11%) showed regrowth that responded to radiation therapy. Out of 28 eyes receiving laser and/or chemotherapy, (10.7 %) eyes had full regression, 10(35.7 %) partial regressions, 3(10.7 %) became atrophic, 3(10.7 %) showed progression, 1(3.6%) had regrowth in enucleated eye.

Conclusion:

Outcome of chemotherapy and laser in retinoblastoma management is promising but not predictable in all patients. They need to be monitored regularly for a long time. Role of echography to diagnose and monitor such patients is indispensable. Enucleation has important role in retinoblastoma management.
A Cost Analysis Study of Squint Surgery in A Tertiary Care Ophthalmic Hospital for Development of Users Charges
Authors: Singh Sanju , Sinha Rajesh
Published: April 2013

Ten cases of Squint Surgery were studied to find actual cost incurred on patient care, so as to workout the modalities to develop package system for Squint Surgery. The cost analysis for the package had been divided into ‘primary cost’ in which cost of manpower, cost of consumable, cost of linen and laundering, cost of central sterile supply department (CSSD) and manifold was included. In “overhead cost”, building cost, cost of other fixed assets, electricity and water consumption, sanitation and air conditioning was included to find total cost for deriving the package cost.
Iron(III)‐Catalyzed Cascade Reaction between Nitroolefins and 2‐Aminopyridines: Synthesis of Imidazo[1,2‐a]pyridines and Easy Access towards Zolimidine
Authors: Santra Sougata , Bagdi Avik Kumar , Majee Adinath , Hajra Alakananda
Published: April 2013

The iron(III)‐catalyzed one‐pot cascade reaction between nitroolefins and 2‐aminopyridines has been demonstrated for the synthesis of imidazo[1,2‐a]pyridines by exploiting the bielectrophilic nature of nitroolefins. This methodology could be successfully applicable for the synthesis of zolimidine, a useful drug for the treatment of peptic ulcer. The reaction proceeds through Michael addition followed by intramolecular cyclization and in situ denitration.
Mechanical, morphological, and thermal properties of chemically treated pine needles reinforced thermosetting composites
Authors: Singh Singha Amar , Jyoti Khanna Aishwarya
Published: April 2013

In the recently published article cited above, the author's name Aishwarya Jyoti was incorrectly printed. The correct author's name is published above.
Mesoporous Gallosilicate with 3 D Architecture as a Robust Energy‐Efficient Heterogeneous Catalyst for Diphenylmethane Production
Authors: Anand Chokkalingam , Joseph Stalin , Lawrence Geoffrey , Dhawale Dattatray S. , Wahab Md. Abdul , Choy Jin‐Ho , Vinu Ajayan
Published: April 2013

Herein, we report the preparation of 3 D mesoporous gallosilicate with Ia3d symmetry (GaKIT‐6) and different gallium contents using Pluronic P123. The incorporation of gallium into the silica framework of KIT‐6 is difficult if the usual synthesis method of KIT‐6 is followed, because it requires a large amount of HCl in the synthesis mixture. Therefore, the amount of HCl in the synthesis mixture is reduced to suitably adjust the solution pH so as to incorporate a large amount of gallium into the silica framework of KIT‐6. The low‐angle powder XRD results confirm that all the samples demonstrate well‐ordered and a cubic 3 D structure with Ia3d symmetry. However, the wide‐angle XRD patterns show no peaks at the higher angle, which confirms the absence of gallium oxide nanoparticles in the nanochannels and the incorporation of gallium atoms into the silica framework. The nitrogen adsorption and electron microscopy studies reveal that the samples demonstrate excellent textural features with well‐ordered mesoporous structures having spherical morphology. The analysis of the solid‐state 29Si MAS NMR spectra confirms that the gallium atoms are bonded tetragonally with the silica framework of KIT‐6. Furthermore, the catalytic performance of the materials has been investigated in the benzylation of benzene, with benzyl chloride as a benzylating agent. The catalytic activity of GaKIT‐6 increases with an increase in gallium content in the catalyst. GaKIT‐6 with a Si/Ga molar ratio of 7 demonstrates much better catalytic activity than do several reported 1 D and 2 D heteroatom‐incorporated mesoporous materials. In addition, the GaKIT‐6 catalyst is found to be highly active even at reaction temperatures as low as 313 K, which demonstrates a high benzyl chloride conversion and diphenylmethane selectivity. The catalytic activity of the GaKIT‐6 catalyst is retained even after the recyclability test, which confirms that the GaKIT‐6 catalyst is highly stable and can be used thrice without affecting its structural order.
Arylboronic Acid Chemistry under Electrospray Conditions
Authors: Wang Lifang , Dai Chaofeng , Burroughs Sarah Kathryn , Wang Siming Liu , Wang Binghe
Published: April 2013

Boronic acids are important in the organic and biological arenas. Thus, their identification and characterization are important. ESI‐MS is a well‐known tool for such uses. Herein we report a systematic analysis of the chemical behavior of arylboronic acids under ESI‐MS conditions. Such information will be very critical to understanding the gas‐phase chemistry of boronic acids in an ESI mass spectrometer ion source in general and the MS analysis of boronic acids and their macromolecular conjugates in particular.