bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst
Authors: Saidina Amin Nor Aishah , Istadi Istadi , Yee New Pei 
Published: July 2014

A one-dimensional mathematical model was developed to simulate the performance of catalytic fixed bed reactor for carbon dioxide reforming of methane over Rh/Al2O3 catalyst at atmospheric pressure. The reactions involved in the system are carbon dioxide reforming of methane (CORM) and reverse water gas shift reaction (RWGS). The profiles of CH4 and CO2 conversions, CO and H2 yields, molar flow rate and mole raction of all species as well as reactor temperature along the axial bed of catalyst were simulated. In addition, the effects of different reactor temperature on the reactor performance were also studied. The models can also be applied to analyze the performances of lab-scale micro reactor as well as pilot-plant scale reactor with certain modifications and model verification with experimental data. © 2008 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Mathematical Model of Ion Transport in Electrodialysis Process
Authors: Rohman F. S. , Aziz N. 
Published: July 2014

Mathematical models of ion transport in electrodialysis process is reviewed and their basics concept is discussed. Three scales of ion transport reviewed are: 1) ion transport in the membrane, where two approaches are used, the irreversible thermodynamics and modeling of the membrane material; 2) ion transport in a three-layer system composed of a membrane with two adjoining diffusion layers; and 3) coupling with hydraulic flow system in an electrodialysis 2D and 3D cell, where the differential equation of convectivediffusion is used. Most of the work carried out in the past implemented NP equations since relatively easily coupled with other equations describing hydrodynamic conditions and ion transport in the surrounding solutions, chemical reactions in the solutions and the membrane, boundary and other conditions. However, it is limited to point ionic transport in homogenous and uniformly - grainy phases of structure. © 2008 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Design of a Simple and Cheap Water Electrolyser for the Production of Solar Hydrogen
Authors: Prasad Ram 
Published: July 2014

Commercially available conventional alkaline electrolyser and advanced polymer membrane electrolysers for water electrolysis are quite expensive. Taking into account this aspect, a very simple and cheap water electrolyser has been designed and fabricated utilising easily available economical materials for small scale production of hydrogen using renewable energy from photovoltaic panel. The construction details of the electrolyser with a schematic drawing of the experimental set-up for PV production of H2 are given. In order to fabricate the compact electrolyser, two coaxial tubular PVC pipes were used. The lower part of the inner pipe has fine perforations for the transport of ions through electrolyte between the electrodes. Two cylindrical electrodes, cathode and anode are kept in inner and outer pipes respectively. The performance of hydrogen production was measured using a photovoltaic panel directly connected to the electrolyser under atmospheric pressure and in 27wt% KOH solution. Flow rates of hydrogen and oxygen were measured using a digital flow meter. High purity fuel cell grade hydrogen (99.98%) and oxygen (99.85%) have been produced. The experimental results confirm that the present electrolyser has eligible properties for hydrogen production in remote areas. No such electrolyser has been reported prior to this work. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Catalytic Hydrolysis of Ethyl Acetate using Cation Exchange Resin (Amberlyst - 15) : A Kinetic Study
Authors: Ayyappan K. R. , Toor Amrit Pal , Gupta Ri , Bansal Ajay , Wanchoo R. K. 
Published: July 2014

The kinetic behavior of the heterogeneous hydrolysis of aqueous ethyl acetate over an acidic cation exchange resin, Amberlyst 15, was investigated. The experiments were carried out in a fixed bed reactor at temperatures from 313.15 to 343.15 K and feed molar ratios ,θBo (water to ethyl acetate) from 62.4 to 265.88. The conversion of ethyl acetate was found to increase with increasing reaction temperature. Gas bubble formation was observed at reaction temperature ≥ 343.15K. Absence of mass transfer resistance was verified by conducting the experiments at different catalyst loadings (20 g, 40 g, 64 g) under varied feed flow rates (1 to 25 cm3/min ). The kinetic data was correlated with pseudo first order model and model parameters were determined using Nelder-Mead algorithm for minimizing the objective function. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology
Authors: Istadi Istadi , Anggoro Didi Dwi , Marwoto Putut , Suherman Suherman , Nugroho Bambang Tri 
Published: July 2014

Biodiesel production has received considerable attention in the recent past as a renewable fuel. The production of biodiesel by conventional transesterification process employs alkali or acid catalyst and has been industrially accepted for its high conversion and reaction rates. However for alkali catalyst, there may be risk of free acid or water contamination and soap formation is likely to take place which makes the separation process difficult. Although yield is high, the acids, being corrosive, may cause damage to the equipment and the reaction rate was also observed to be low. This research focuses on empirical modeling and optimization for the biodiesel production over plasma reactor. The plasma reactor technology is more promising than the conventional catalytic processes due to the reducing reaction time and easy in product separation. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Advanced Mathematical Model to Describe the Production of Biodiesel Process
Authors: Ibrehem Ahmmed S. , Al-Salim Hikmat S. 
Published: July 2014

Advanced mathematical model was used to capture the batch reactor characteristics of reacting compounds. The model was applied to batch reactor for the production of bio-diesel from palm and kapok oils. Results of the model were compared with experimental data in terms of conversion of transesterification reaction for the production of bio-diesel under unsteady state. A good agreement was obtained between our model predictions and the experimental data. Both experimental and modeling results showed that the conversion of triglycerides to methyl ester was affected by the process conditions. The transesterification process with temperature of about 70 oC, and methanol ratio to the triglyceride of about 5 times its stoichiometry, and the NAOH catalyst of wt 0.4%, appear to be acceptable process conditions for bio diesel process production from palm oil and kapok oil. The model can be applied for endothermic batch process. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Variability of Energy Dissipation and Shear Rate with Geometry in Unbaffled Surface Aerator
Authors: Kumar Bimlesh 
Published: July 2014

The dissipation rate of turbulent kinetic energy () and shear rate (γ) are the key process parameters for mixing in surface aerators. At constant dynamic variables (rotational speed), both  and γ are greatly affected by the geometric parameters (impeller diameter, cross-sectional area of the tank, liquid height, rotor blade length and immersion height). By doing numerical computation by VISIMIX ®, present work analyzes the effect of non-dimensional (which is non-dimensionalized through rotor diameter) geometric parameters on e and g. With an increase in liquid height, there is an increase in the case of energy dissipation and shear rate values. In the case of tank area and blade length, it is vice versa. Energy dissipation and shear rate are not affected by the variation in immersion height of the impeller.
New Dynamic Analysis and System Identification of Biodiesel Production Process from Palm Oil
Authors: Ibrehem Ahmmed S. , Al-Salim Hikmat S. 
Published: July 2014

In this study we present advanced mathematical model was used to capture the batch reactor characteristics of reacting compounds new parameters and new a prerequisite average slope analysis (PASA) method for the system dynamic behaviour under different operational conditions is a prerequisite to the good selection for these parameters. The model was applied to batch reactor for the production of bio-diesel from palm and kapok oils. Results of the model were compared with experimental data in terms of conversion of transesterification reaction for the production of bio-diesel under unsteady state. A good agreement was obtained between our model predictions and the experimental data. Both experimental and modeling results showed that the conversion of triglycerides to methyl ester was affected by the process conditions and by using PASA that could be achieved by making some deterministic tests either in real data plant or in the physical model that properly and adequately fits the actual process. The input-output relationships are studied using the open-loop dynamic response of the process, which can be determined from the process model by stepping different inputs and recording output responses. Starting from steady state conditions, each input is perturbed with certain magnitude that is enough to show the effect on the system dynamics. The transesterficition process with temperature of about 70 oC, and methanol ratio to the triglyceride of about 5 times its stoichiometry and the NAOH catalyst of wt 0.4%, appear to be acceptable process conditions. PASA shows methanol ratio to the triglyceride has big effect on the system. PASA method can be applied for different processes. © 2009 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Production of Biodiesel from Oleic Acid and Methanol by Reactive Distillation
Authors: Kusmiyati Kusmiyati , Sugiharto Agung 
Published: July 2014

Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats. Generally, it is formed by transesterification reaction of triglycerides in the vegetable oil or animal fat with an alcohol. In this work, esterification reaction was carried out using oleic acid, methanol and sulphuric acid as a catalyst by reactive distillation method. In order to determine the best conditions for biodiesel production by reactive distillation, the experiments were carried out at different temperature (100 0C, 120 0C, 150 0C and 180 0C) using methanol/oleic acid molar ratios (1:1, 5:1, 6:1, 7:1, 8:1), catalyst/ oleic acid molar ratios (0.5%wt, 1%wt, 1.5%wt and 2%wt) and reaction times (15, 30, 45, 60, 75 and 90 minutes). Results at temperature 180 0C, methanol/ oleic acid molar ratio of 8:1, amount of catalyst 1% for 90 minute reaction time gives the highest conversion of oleic acid above 0.9571. Biodiesel product from oleic acid was analysed by ASTM (American Standard for Testing Material). The results show that the biodiesel produced has the quality required to be a diesel substitute. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Preparation Methods and Applications of CuO-CeO2 Catalysts: A Short Review
Authors: Prasad Ram , Rattan Gaurav 
Published: July 2014

The CuO-CeO2 catalytic systems are getting popular for catalyzing very actively the various reactions of environmental, commercial and other importance. In recent years, many methods have been in use for the preparation of versatile CuO-CeO2 catalysts. Reviewing the useful preparation methods of such catalysts is thus the need of the time in view of the globally increasing interest towards all the low temperature redox reactions. This article presents a short review on seventeen different preparation methods of the copperceria catalysts, followed by critical discussions on the related redox properties and advancements accomplished with respect to their application aspect, including a systematic compilation of the concerned newer literature in a well-concievable tabular form. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Mixed Oxide Supported MoO3 Catalyst: Preparation, Characterization and Activities in Nitration of o-xylene
Authors: Kemdeo S. M. , Sapkal V. S. , Chaudhari G. N. 
Published: July 2014

TiO2-ZrO2 mixed oxide support was prepared and impregnated with 12 wt % MoO3 and calcined at various temperatures. The resultant catalyst systems were characterized by XRD, FT-IR, BET, SEM, NH3-TPD and pyridine adsorbed FT-IR methods to know the physico-chemical changes occurred in course of thermal treatment. Activities of these catalysts were tested by employing them in the nitration of o-xylene. Mostly, 500 oC calcined catalyst sample was found to be most active for nitration reaction. Catalyst calcined at higher temperatures showed the negative influence on o-xylene conversion and 4-nitro-o-xylene selectivity. Conversion can be correlated with the presence of strong Brönsted acid sites over the catalyst surface whereas change in selectivity was found attributed to the pore diameter of the catalyst. These catalysts also performed satisfactorily, when used for nitration of other aromatics. No use of corrosive sulfuric acid and efficient reusability of the catalyst make the process environmentally friendly and economic. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids
Authors: Gupta Renu , Bansal Ajay 
Published: July 2014

Hydrodynamic studies of trickle bed reactors (TBRs) are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic liquid saturation are greatly affected by the physical properties of the liquids. In the present study experiments have been carried out in a concurrent downflow air - liquid trickle bed reactor to investigate the dynamic liquid saturation and pressure drop for the water (non-foaming) and 3% polyethylene glycol and 4% polyethylene glycol foaming liquids in the gas continuous regime (GCF) and foaming pulsing regime (FP). In the GCF regime the dynamic liquid saturation was found to increase with increase in liquid flow rate for non-foaming and foaming liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP) regime. The decrease in dynamic liquid saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic liquid saturation was observed. The pressure drop for foaming liquids is observed to be manifolds higher compared to non-foaming liquid in the GCF regime. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Potential of LiNO3/Al2O3 Catalyst for Heterogeneous Transesterification of Palm Oil to Biodiesel
Authors: Istadi Istadi , Pramudono Bambang , Suherman Suherman , Priyanto Slamet 
Published: July 2014

Production of biodiesel through transesterification process using heterogenous catalysts in order to avoid the saponification problem was studied. In this process, palm oil reacted with methanol to form a mixture of glycerol and biodiese over a solid basic catalyst. One type of the catalysts used in this research is basic catalyst of LiNO3/Al2O3. The parameters studied in this research are concentration of LiNO3 loading on Al2O3 and effect of different reaction time. The products was analyzed using Gas Chromatography to determine composition and yield of resulted methyl esters as well as conversion of palm oil to biodiesel. The major products in this transesterification reaction were biodiesel and glycerol. It can be concluded that the 20 wt% LiNO3/Al2O3 catalyst is potential for producing biodiesel from palm oil over transesterification reaction. Advantages of the usage of this catalyst is that the soap formation was not observed in this research. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
ENU Mutagenesis in the Mouse
Authors: Stottmann Rolf , Beier David 
Published: July 2014

ABSTRACTThis unit describes the treatment of laboratory mice with the mutagen N‐ethyl‐N‐nitrosourea (ENU) to induce very highly increased rates of mutation throughout the genome. Further, it describes several popular mating schemes designed to produce animals displaying phenotypes associated with the induced mutations. Curr. Protoc. Hum. Genet. 82:15.4.1‐15.4.10 © 2014 by John Wiley & Sons, Inc.
Getting Started with Microbiome Analysis: Sample Acquisition to Bioinformatics
Authors: Kumar Ranjit , Eipers Peter , Little Rebecca B. , Crowley Michael , Crossman David K. , Lefkowitz Elliot J. , Morrow Casey D. 
Published: July 2014

AbstractHistorically, in order to study microbes, it was necessary to grow them in the laboratory. It was clear though that many microbe communities were refractory to study because none of the members could be grown outside of their native habitat. The development of culture‐independent methods to study microbiota using high‐throughput sequencing of the 16S ribosomal RNA gene variable regions present in all prokaryotic organisms has provided new opportunities to investigate complex microbial communities. In this unit, the process for a microbiome analysis is described. Many of the components required for this process may already exist. A pipeline is described for acquisition of samples from different sites on the human body, isolation of microbial DNA, and DNA sequencing using the Illumina MiSeq sequencing platform. Finally, a new analytical workflow for basic bioinformatics data analysis, QWRAP, is described, which can be used by clinical and basic science investigators. Curr. Protoc. Hum. Genet. 82:18.8.1‐18.8.29. © 2014 by John Wiley & Sons, Inc.
An intercomparison of Arctic ice drift products to deduce uncertainty estimates
Authors: Sumata Hiroshi , Lavergne Thomas , Girard‐Ardhuin Fanny , Kimura Noriaki , Tschudi Mark A. , Kauker Frank , Karcher Michael , Gerdes Rüdiger 
Published: July 2014

AbstractAn intercomparison of four low‐resolution remotely sensed ice‐drift products in the Arctic Ocean is presented. The purpose of the study is to examine the uncertainty in space and time of these different drift products. The comparison is based on monthly mean ice drifts from October 2002 to December 2006. The ice drifts were also compared with available buoy data. The result shows that the differences of the drift vectors are not spatially uniform, but are covariant with ice concentration and thickness. In high (low) ice‐concentration areas, the differences are small (large), and in thick (thin) ice‐thickness areas, the differences are small (large). A comparison with the drift deduced from buoys reveals that the error of the drift speed depends on the magnitude of the drift speed: larger drift speeds have larger errors. Based on the intercomparison of the products and comparison with buoy data, uncertainties of the monthly mean drift are estimated. The estimated uncertainty maps reasonably reflect the difference between the products in relation to ice concentration and the bias from the buoy drift in relation to drift speed. Examinations of distinctive features of Arctic sea ice motion demonstrate that the transpolar drift speed differs among the products by 13% (0.32 cm s−1) on average, and ice drift curl in the Amerasian Basin differs by up to 24% (3.3 × 104 m2 s−1). These uncertainties should be taken into account if these products are used, particularly for model validation and data assimilation within the Arctic.
The spatial scale dependence of water vapor variability inferred from observations from a very tall tower
Authors: Pressel Kyle G. , Collins William D. , Desai Ankur R. 
Published: July 2014

AbstractRecent studies have established that atmospheric water vapor fields exhibit spatial spectra that take the form of power laws and hence can be compactly characterized by scaling exponents. The power law scaling exponents have been shown to exhibit substantial vertical variability. In this work, Taylor's frozen turbulence hypothesis is used to infer the first‐order spatial structure function and generalized detrended fluctuation function scaling exponents for scales between 1 km and 100 km. Both methods are used to estimate the Hurst exponent (H) using 10 Hz time series of water vapor measured at 396 m altitude from an Ameriflux tower in Wisconsin. Due to the diurnal cycle in the boundary layer height at the 396 m observational level, H may be estimated for both the daytime convective mixed layer and the nocturnal residual layer. Values of are obtained for the convective mixed layer, while values of apply in the nocturnal residual layer. The results are shown to be remarkably consistent with a similar analysis from satellite‐based observations as reported in Pressel and Collins (2012).
Accelerated flooding along the U.S. East Coast: On the impact of sea‐level rise, tides, storms, the Gulf Stream, and the North Atlantic Oscillations
Authors: Ezer Tal , Atkinson Larry P. 
Published: July 2014

AbstractRecent studies identified the U.S. East Coast north of Cape Hatteras as a “hotspot” for accelerated sea‐level rise (SLR), and the analysis presented here shows that the area is also a “hotspot for accelerated flooding.” The duration of minor tidal flooding [defined as 0.3 m above MHHW (mean higher high water)] has accelerated in recent years for most coastal locations from the Gulf of Maine to Florida. The average increase in annual minor flooding duration was ∼20 h from the period before 1970 to 1971–1990, and ∼50 h from 1971–1990 to 1991–2013; spatial variations in acceleration of flooding resemble the spatial variations of acceleration in sea level. The increase in minor flooding can be predicted from SLR and tidal range, but the frequency of extreme storm surge flooding events (0.9 m above MHHW) is less predictable, and affected by the North Atlantic Oscillations (NAO). The number of extreme storm surge events since 1960 oscillates with a period of ∼15 year and interannual variations in the number of storms are anticorrelated with the NAO index. With higher seas, there are also more flooding events that are unrelated to storm surges. For example, it is demonstrated that week‐long flooding events in Norfolk, VA, are often related to periods of decrease in the Florida Current transport. The results indicate that previously reported connections between decadal variations in the Gulf Stream (GS) and coastal sea level may also apply to short‐term variations, so flood predictions may be improved if the GS influence is considered.