Thermal effects occurring in ultrahigh-pressure liquid chromatography (UHPLC) and low-density supercritical fluid chromatography (SFC) have a negative impact on chromatographic performance, because peaks broaden and get distorted. A... more
Thermal effects occurring in ultrahigh-pressure liquid chromatography (UHPLC) and low-density supercritical fluid chromatography (SFC) have a negative impact on chromatographic performance, because peaks broaden and get distorted. A solution to this problem is to thermally insulate the chromatographic column. A strict adiabatic environment can be achieved by embedding the whole chromatographic column in a large vacuum chamber, itself connected to a turbomolecular pump that delivers a high vacuum. From a practical viewpoint, this prototype research apparatus is costly, its assembly is time-consuming, and it is complex. Consequently, it is not adapted to routine analyses in standard analytical laboratories. Therefore, a new approach, using vacuum-jacketed column technology, has been developed to cope with these practical limitations. The applications and advantages of this new technology relative to standard columns are presented and discussed for both UHPLC and SFC separations operated under extreme conditions.
Whereas the retention rules of achiral compounds are well defined in high-performance liquid chromatography, on the basis of the nature of the stationary phase, some difficulties appear in super/subcritical fluid chromatography on packed... more
Whereas the retention rules of achiral compounds are well defined in high-performance liquid chromatography, on the basis of the nature of the stationary phase, some difficulties appear in super/subcritical fluid chromatography on packed columns. This is mainly due to the supposed effect of volatility on retention behaviours in supercritical fluid chromatography (SFC) and to the nature of carbon dioxide, which
This book presents an in-depth analysis of key recommendations of the consecutive state finance commissions (SFCs) across states of India in the local and national perspective. It reviews the working of SFCs and their critical role in... more
This book presents an in-depth analysis of key recommendations of the consecutive state finance commissions (SFCs) across states of India in the local and national perspective. It reviews the working of SFCs and their critical role in strengthening local governments, both Panchayats and municipalities in the various states. The volume attempts to identify some of the emerging issues related to the efficacy of SFC in fiscal decentralization. It appraises nearly eighty SFC reports and actions taken thereon by the respective State Governments with contextual analysis. Please see the link https://www.palgrave.com/gp/book/9789811622021#
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement... more
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.
Normal phase liquid chromatography (LC) methods often have long run times and involve environmentally toxic/costly solvents. Supercritical fluid chromatography (SFC) methods on the other hand are faster, inexpensive, and eco-friendly.... more
Normal phase liquid chromatography (LC) methods often have long run times and involve environmentally toxic/costly solvents. Supercritical fluid chromatography (SFC) methods on the other hand are faster, inexpensive, and eco-friendly. SFC involves the use of low viscosity supercritical carbon dioxide that can be operated at flow rates up to 3x higher than LC without losing separation efficiency and thereby leading to faster analysis. In this Application Note, we describe a method to transfer a United States Pharmacopeia (USP) prednisolone assay normal phase HPLC method to SFC. The Agilent 1260 Infinity Hybrid SFC/UHPLC System was used to perform both normal phase as well as the SFC methods. The results show that the SFC method meets the system suitability criteria, is 4x faster, and results in 17x lower solvent expenses. Robustness tests on the SFC method demonstrate excellent robustness for routine analysis.
Díaz, José Gregorio;Peraza, César;Arteaga, Francisco;Jiménez, Carlos Implantación del lenguaje GRAFCET en controladores lógicos programables de gama baja utilizando el lenguaje escalera Ingeniería UC, Vol. 14, Núm. 2, agosto-sin mes,... more
Díaz, José Gregorio;Peraza, César;Arteaga, Francisco;Jiménez, Carlos Implantación del lenguaje GRAFCET en controladores lógicos programables de gama baja utilizando el lenguaje escalera Ingeniería UC, Vol. 14, Núm. 2, agosto-sin mes, 2007, pp. 50-57 Universidad de ...
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement... more
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.
A blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch-wise (B-EIE) and in continuous (C-EIE). Better oil quality, mainly in terms... more
A blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch-wise (B-EIE) and in continuous (C-EIE). Better oil quality, mainly in terms of acidity, free tocopherol and partial acylglycerol content, was obtained after EIE. The clear melting point after any interesterification process was similar and about 9 °C lower as result of the modification in the TAG profile, which approaches the calculated random distribution. Interesterification changed the SFC profile significantly. For the fully refined interesterified blends, the SFC profile was similar and clearly different from the starting blend. Interesterification decreased the content of solids at temperatures >15 °C and increased the content of solids at temperatures
Nowadays, a large portion of synthetic products (active cosmetic and therapeutic ingredients) have their origin in natural products. Kniphofia uvaria is a plant from Africa which has proved in the past by in-vivo tests an antioxidant... more
Nowadays, a large portion of synthetic products (active cosmetic and therapeutic ingredients) have their origin in natural products. Kniphofia uvaria is a plant from Africa which has proved in the past by in-vivo tests an antioxidant activity due to compounds present in roots. Recently, we have observed anthraquinones in K. uvaria seeds extracts. These derivatives are natural colorants which could have interesting bioactive potential. The aim of this study was to obtain an extract enriched in anthraquinones from K. uvaria seeds which mainly contains glycerides. First, the separation of the seed compounds was studied by using supercritical fluid chromatography (SFC) in the goal to provide a rapid quantification method of these bioactive compounds. A screening of numerous polar stationary phases was achieved for selecting the most suited phase to the separation of the four anthraquinones founded in the seeds. A gradient elution was optimized for improving the separation of the bioactive compounds from the numerous other families of major compounds of the extracts (fatty acids, di-and triglycerides). Besides, a non-selective and green Supercritical Fluid Extraction (SFE) with pure CO 2 was applied to seeds followed by a Centrifugal Partition Chromatography (CPC). The CPC system was optimized by using the Arizona phase system, to enrich the extract in anthraquinones. Two systems were selected to isolate the bioactive compounds from the oily extract with varied purity target. The effect of the injection mode for these very viscous samples was also studied. Finally, in order to directly apply a selective process of extraction to the seeds, the super/subcritical fluid extraction was optimized to increase the anthraquinone yield in the final extract, by studying varied modifier compositions and nature, as well as different temperatures and backpressures. Conditions suited to favour an enrichment factor bases on the ratio of anthraquinone and triglycerides extracted are described.
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement... more
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.
An analytical method based on Ultra-High-Performance Supercritical Fluid Chromatography (UHPSFC) coupled with Atmospheric Pressure Chemical Ionization − High-resolution mass spectrometry (APCI-Q-TOF-HRMS) was developed for compounds... more
An analytical method based on Ultra-High-Performance Supercritical Fluid Chromatography (UHPSFC) coupled with Atmospheric Pressure Chemical Ionization − High-resolution mass spectrometry (APCI-Q-TOF-HRMS) was developed for compounds screening from oily samples. The hyphenation was made using a commercial UHPLC device coupled to a CO 2 pump in order to perform the chromatographic analysis. An adaptation of the injection system for compressible fluids was accomplished for this coupling: this modification of the injection sequence was achieved to prevent unusual variations of the injected volume related to the use of a compressible fluid. UHPSFC-HRMS hyphenation was optimized to enhance the response of the varied compounds from a seed extract (anthraquinones, free fatty acids, diacylglycerols, hydroxylated triacylglycerols and triacylglycerols). No split was used prior to the APCI ionization source, allowing introducing all the compounds in the spectrometer, ensuring a better sensitivity for minor compounds. The effects of a mechanical make-up (T-piece) added before this ionization source was discussed in terms of standard deviation of response, response intensity and fragmentation percentage. The location of the T-piece with regards to the backpressure regulator (BPR), the flow rate and the nature of the make-up solvent were studied. Results show that the effects of the studied parameters depend on the nature of the compounds, whereas the make-up addition favours the robustness of the mass response (quantitative aspect).
In the present study, two cancer therapeutic drugs (docetaxel and bortezomib) were separated from their potential impurities on a chromatographic platform by utilizing CO 2 gas (supercritical state) and quantified. The chromatographic... more
In the present study, two cancer therapeutic drugs (docetaxel and bortezomib) were separated from their potential impurities on a chromatographic platform by utilizing CO 2 gas (supercritical state) and quantified. The chromatographic separations were achieved on two short columns BEH-2EP (100 mm  3 mm, 1.7 mm) and CHIRALPAK AD-3 (100 mm  4.6 mm, 3 mm) for docetaxel and bortezomib, respectively. The present work describes the role of organic modifiers in the separation of polar compounds by supercritical fluid chromatography. The two new methods were fully validated in accordance with the current ICH (International Council for Harmonization of technical requirements for pharmaceuticals for human use) guidelines. The stability indicating power of the methods was demonstrated from the stress studies conducted on the injection formulations of the two compounds. The methods are precise with % RSD of 0.4, linear with the correlation coefficient of r 2 $ 0.999 and accurate in the range of 50–150% of the target assay concentration. The two methods can be equally employed for the assay determination of docetaxel and bortezomib APIs as well.
The most recent developments in graph partitioning research often considerscale-free graphs. Instead we focus on partitioning geometric graphsusing a lessusual strategy: Inverse Space-filling Partitioning (ISP). ISP... more
The most recent developments in graph partitioning research often considerscale-free graphs. Instead we focus on partitioning geometric graphsusing a lessusual strategy: Inverse Space-filling Partitioning (ISP). ISP relies onaspace filling curve to partition a graph and was previously applied to graphsessentially generated from Meshes. We extend ISP to apply it to a new context where the targets are nowWide Area Graphs.Weprovideanextended comparisonwith twostate-of-the-art graph partitioning streaming strategies, namelyLDG and FENNEL. We also proposecustomized metrics to better understand and identify theuse cases for which theISPpartitioning solutionis best suited. Experimentations show that in favourable contexts, edge-cuts can be drastically reduced, going frommore34% using FENNEL to less than 1% using ISP.
a b s t r a c t Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of... more
a b s t r a c t Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of resources from the municipal solid waste stream. In São Paulo, Brazil, recycling cooperatives play a crucial role in providing recycling services including collection, separation, cleaning, stocking, and sale of recyclable resources. The present research attempts to measure the greenhouse gas emission reductions achieved by the recycling cooperative Cooperpires, as well as highlight its socioeconomic benefits. Methods include participant observation, structured interviews, questionnaire application, and greenhouse gas accounting of recycling using a Clean Development Mechanism methodology. The results show that recycling cooperatives can achieve important energy savings and reductions in greenhouse gas emissions, and suggest there is an opportunity fo...
Supermultiplier models have been recently brought to the post-Keynesian debate. Yet these models still rely on quite simple economic assumptions, being mostly flow models which omit the financial determinants of autonomous expenditures.... more
Supermultiplier models have been recently brought to the post-Keynesian debate. Yet these models still rely on quite simple economic assumptions, being mostly flow models which omit the financial determinants of autonomous expenditures. Since the output growth rate converges in the long run to the exogenously given growth rate of the " non-capacity creating " autonomous expenditure and the utilization rate moves towards the normal utilization rate, the paradoxes of thrift and costs remain valid only in terms of level effects (average growth rates). The aim of this paper is to investigate whether the core conclusions of supermultiplier models hold in a more complex economic framework. It thus presents a supermultiplier SFC model, in which private business investment is assumed to be completely induced by income while the autonomous expenditure component-in this case consumption out of wealth-becomes endogenous. The results of the numerical simulation experiments suggest tha...
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement... more
PLC, the core element of modern automation systems, due to serial execution, exhibits limitations like slow speed and poor scan time. Improved PLC design using FPGA has been proposed based on parallel execution mechanism for enhancement of performance and flexibility. Modelsim as simulation platform and VHDL used to translate, integrate and implement the logic circuit in FPGA. Xilinx's Spartan kit for implementation-testing and VB has been used for GUI development. Salient merits of the design include cost-effectiveness, miniaturization, user-friendliness, simplicity, along with lower power consumption, smaller scan time and higher speed. Various functionalities and applications like typical PLC and industrial alarm annunciator have been developed and successfully tested. Results of simulation, design and implementation have been reported.
A blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch-wise (B-EIE) and in continuous (C-EIE). Better oil quality, mainly in terms... more
A blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch-wise (B-EIE) and in continuous (C-EIE). Better oil quality, mainly in terms of acidity, free tocopherol and partial acylglycerol content, was obtained after EIE. The clear melting point after any interesterification process was similar and about 9 °C lower as result of the modification in the TAG profile, which approaches the calculated random distribution. Interesterification changed the SFC profile significantly. For the fully refined interesterified blends, the SFC profile was similar and clearly different from the starting blend. Interesterification decreased the content of solids at temperatures >15 °C and increased the content of solids at temperatures
Gasoline is a complex mixture that possesses a quasi-continuous spectrum of hydrocarbon constituents. Surrogate fuels that decrease the chemical and/or physical complexity of gasoline are used to enhance the understanding of fundamental... more
Gasoline is a complex mixture that possesses a quasi-continuous spectrum of hydrocarbon constituents. Surrogate fuels that decrease the chemical and/or physical complexity of gasoline are used to enhance the understanding of fundamental processes involved in internal combustion engines (ICEs). Computational tools are largely used in ICE development and in performance optimization; however, it is not possible to model full gasoline in kinetic studies because the interactions among the chemical constituents are not fully understood and the kinetics of all gasoline components are not known. Modeling full gasoline with computer simulations is also cost prohibitive. Thus, surrogate mixtures are studied to produce improved models that represent fuel combustion in practical devices such as homogeneous charge compression ignition (HCCI) and spark ignition (SI) engines. Simplified mixtures that represent gasoline performance in commercial engines can be used in investigations on the behavior of fuel components, as well as in fuel development studies. In this study, experimental design was used to investigate surrogate fuels. To this end, SI engine dynamometer tests were conducted, and the performance of a high-octane, oxygenated gasoline was reproduced. This study revealed that mixtures of iso-octane, toluene, n-heptane and ethanol could be used as surrogate fuels for oxygenated gasolines. These mixtures can be used to investigate the effect of individual components on fuel properties and commercial engines performance.
Significant quantities of food are being wasted by people in day to day life which cause real environmental problems. These food wastes can be used as a potential feedstock for ethanol production and this could also be an alternate for... more
Significant quantities of food are being wasted by people in day to day life which cause real environmental problems. These food wastes can be used as a potential feedstock for ethanol production and this could also be an alternate for disposal of the polluting residues, which is the primary aim of the project. Secondly, diesel fuel and ethanol were blended for this investigation and injection was done through continuous manifold injection. It reduces exhaust emissions and shows better lube oil quality as compared together tested fuels. This is mainly due to the effect of fuel additive in the blended fuel. The specific objective of this investigation is to develop the performance of fuel by using as in-house-formulated fuel additive. Rice ranks first among the most significant food followed by corn, banana and Mango and milk. It is a stable food among south India. The rice is more prone to wastage at place like marriage halls, hostels, restaurants. To determine the performance, combustion and emission analysis are performed on the single cylinder diesel engine, diesel, ethanol 10, ethanol 20 and ethanol 30.
The genius Kniphofia is a plant from Africa with tubular red flowers. In Europe, Kniphofia uvaria is used for ornamental gardening whereas in Africa, this one is more used for medicinal application. Extracts from Kniphofia uvaria seeds... more
The genius Kniphofia is a plant from Africa with tubular red flowers. In Europe, Kniphofia uvaria is used for ornamental gardening whereas in Africa, this one is more used for medicinal application. Extracts from Kniphofia uvaria seeds have proved themselves, through ex-vivo testing's, a biological activity for a cosmetic use. However, the anthraquinone amount is low with regards to the one of lipids. Methods to obtain concentrated fractions in bioactive compounds should be developed.
Network Function Virtualization (NFV) can support customized on-demand network services with flexibility and cost-efficiency. Virtual Network Function (VNF) instances need to be scaled out, scaled in, and reallocated across the NFV... more
Network Function Virtualization (NFV) can support customized on-demand network services with flexibility and cost-efficiency. Virtual Network Function (VNF) instances need to be scaled out, scaled in, and reallocated across the NFV infrastructure (NFVI) to avoid a violation of service agreements when the demand traffic changes. However, selecting the new placement of VNFs for migrating a service function chain (SFC) is an issue of efficient NFV control. We propose two novel integer linear programming (ILP) models and two approximation algorithms for SFC placement and migration to maximize the cost-efficiency of an NFV network regarding the changes of service demands and dynamic routing. The ILP models allow us to obtain the optimal solutions of SFC placement and migration with explicit dynamic paths. The approximation migration results provided by our proposed heuristic and reinforcement learning algorithms are close to the optimal solution. Evaluation results carried out with real datasets and synthetic network topologies provide a helpful suggestion of a migration strategy for an NFV service provider to optimize the operating cost of an NFV network in the long term.
