Thanh Huong Phung - Academia.edu (original) (raw)
Papers by Thanh Huong Phung
Extraction of curcumin from turmeric residue (Curcuma longa L.) using deep eutectic solvents and surfactant solvents
Analytical Methods, 2022
An efficient choline chloride-based DES method is used to extract curcumin in turmeric residue fo... more An efficient choline chloride-based DES method is used to extract curcumin in turmeric residue for the first time.
The association between HLA-B*15:02 and phenytoin-induced severe cutaneous adverse reactions: a meta-analysis
Pharmacogenomics, 2021
Aim: Phenytoin (PHT) is a common anticonvulsant agent known for inducing severe cutaneous adverse... more Aim: Phenytoin (PHT) is a common anticonvulsant agent known for inducing severe cutaneous adverse reactions (SCARs). HLA-B*15:02 as a risk factor of PHT-induced SCARs was reported in numerous studies with inconsistent results. This meta-analysis aimed to establish pooling evidence of this association. Materials & methods: Pooled odds ratios (ORs) with 95% CIs were estimated using a random-effects model. Results: A total of 11 studies on 1389 patients, were included for the analyses. There was a significant association between HLA-B*15:02 and PHT-induced SCAR (pooled OR = 2.29, 95% CI: 1.25–4.19, p = 0.008). Furthermore, there was a significant association regarding Stevens–Johnson syndrome/toxic epidermal necrolysis (OR = 3.63, 95% CI: 2.15–6.13, p
The Application of Clinical Genetics, 2021
Background: Allopurinol, a common anti-hyperuricemia drug, is well known as an inducer of severe ... more Background: Allopurinol, a common anti-hyperuricemia drug, is well known as an inducer of severe cutaneous adverse drug reactions (SCARs). One of the most well-defined risk factors of allopurinol-induced SCARs is the presence of polymorphic alleles of human leukocyte antigen (HLA) genes, such as HLA-B*58:01 and HLA-C*03:02 alleles. There is no commercial test or published in-house protocol for the specific detection of the HLA-C*03 :02 allele. In this article, we established for the first time a simple allele-specific (AS) PCR method to identify HLA-C*03:02 allele carriers, and at the same time, determine their zygosities. Methods: A two-step AS-PCR protocol, using four primer sets, was designed to specifically amplify and differentiate the HLA-C*03:02 allele from 17 other HLA-C alleles found in Vietnamese people. The protocol was validated with PCR-sequencing-based typing (SBT) of 100 samples of unknown genotypes. Results: The PCR protocol can detect the HLA-C*03:02 allele and determine the zygosity. The results of this protocol were highly consistent with those of the SBT (ĸ = 0.98, p < 0.001). Regarding the specific detection of the HLA-C*03:02 allele, the PCR protocol had a sensitivity of 100% (95% CI: 91.61-100%) and specificity of 98.3% (95% CI: 90.9-99.7%). The protocol was used to determine the distribution of the HLA-C*03:02 allele in 810 unrelated Vietnamese Kinh people, 14.2% of which were HLA-C*03:02 carriers, the allele frequency was 7.5%. Conclusion: A novel AS-PCR protocol with a sensitivity of 100% for the detection of the HLA-C*03:02 allele was established. The protocol can be used for personalized treatment with allopurinol in order to minimize the risk of SCARs in Vietnamese people as well as in other Asian populations with similar genetic characteristics.
Asian Pacific journal of allergy and immunology, 2021
BACKGROUND Severe cutaneous adverse drug reactions (SCARs) are rare but deadly drug reactions wit... more BACKGROUND Severe cutaneous adverse drug reactions (SCARs) are rare but deadly drug reactions with severe damages to patients. One of the most well-known SCARs risk factors is the human leukocyte antigen (HLA) genes polymorphism. Among the HLA polymorphic alleles, the HLA-A*33:03 allele has been found in association with SCARs induced by various drugs, especially in Asian people. There has not been any report on the specific detection protocol of the HLA-A*33:03 allele. OBJECTIVE This study aimed to design a nested AS-PCR protocol for detecting and distinguishing diplotype genotype of the HLA-A*33:03 allele. METHODS A nested allele-specific (AS)-PCR protocol with four primer sets was designed. The method was compared with the Sanger sequencing method on 100 samples of unknown genotypes of unrelated Vietnamese people. RESULTS The nested AS-PCR method could identify the HLA-A*33:03 allele and the HLA-A*33:03 diplotype genotypes. Comparison with the Sanger sequencing method showed an a...
Color Research & Application, 2019
Image color appearance models (Image CAMs) have been developed to predict the perception of compl... more Image color appearance models (Image CAMs) have been developed to predict the perception of complex scenes and are mainly used for image rendering and video reproduction applications. Among these Image CAMs, iCAM is an Image CAM that takes an image as the input and provides the perceptual attributes for each pixel. On the other hand, nonimaging CAMs are widely used and validated, but they always assume a simple test scene of a uniform flat stimulus, a quasi-neutral background, and a surround. This study presents an evaluation of the performance of iCAM when applied to these simple self-luminous scenes in predicting the influence of background luminance, background size, saturation, and stimulus size on stimulus brightness. The results show that iCAM is capable of predicting the effect of background luminance and some background size scenarios. However, for unrelated self-luminous stimuli (dark background), the model predictions do not match the reference data. An evaluation of the effect of the filter kernel size and its relation to the physiological mechanism of image processing inside the visual system has been investigated. Furthermore, the impact of saturation and stimulus size on brightness seems to be underestimated by the model, because the Helmholtz-Kohlrausch and stimulus size effects are not included. Hence, these findings call for an enhanced Image CAM.
Http Www Theses Fr, Dec 20, 2013
Http Www Theses Fr, Jul 6, 2012
R : the set of all real numbers Z : the set of all integer numbers N : the set of all natural num... more R : the set of all real numbers Z : the set of all integer numbers N : the set of all natural numbers L : system size k : wave number l c : typical length scale h(t) : mean high of surface w(L, t), W (L, t) : interface width h(x, t) : the height of interface at position x and time t u(x, t) : the velocity field ρ(x, t) : density field ρ in (x) : initial density u in (x) : initial velocity m i (t) : mass of i-th particle x i (t) : position of i-th particle u i (t), v i (t) : velocity of i-th particle p i (t) : momentum of i-th particle ξ i (t) : distance between two particles N : number of time steps I : number of particles f (x, t), g(X, τ) : scaling function
Microstructured fluids: Structure, diffusion and rheology of colloidal dispersions
AIP Conference Proceedings, 1992
The behavior of concentrated Brownian suspensions in a linear shear flow is studied numerically. ... more The behavior of concentrated Brownian suspensions in a linear shear flow is studied numerically. Particle trajectories are calculated by Stokesian dynamics, a molecular-dynamics-like method that accurately represents the suspension ...
Thermal proximity effects in lithography
Catalysis Communications, 2015
Commercial silica-alumina catalysts prepared by different procedures have been characterized. Bot... more Commercial silica-alumina catalysts prepared by different procedures have been characterized. Both present strong Lewis acidity together with Brønsted sites able to protonate pyridine. No evidence of "zeolitic" bridging OH's but significant heterogeneity of terminal silanol groups, part of which are likely "pseudobridging", was found. Similar high activity in ethanol conversion but markedly different selectivities to ethylene and diethyl ether were found. They are less active than both zeolites and -Al 2 O 3. Lewis sites with alumina-like acidobasic neighbour are more selective for ethylene production while Lewis sites with silica-like covalent neighbour are more selective for diethyl ether.
Applied Catalysis A: General, 2015
Ethanol dehydration was investigated over commercial H-FER, H-MFI, H-MOR, H-BEA, H-Y and H-USY ze... more Ethanol dehydration was investigated over commercial H-FER, H-MFI, H-MOR, H-BEA, H-Y and H-USY zeolite samples, and alumina and silica alumina for comparison. The catalysts were characterized using FT-IR spectroscopy of the surface OH groups and of adsorbed CO and pyridine. UV-Vis, Raman and TG-DTA were applied to characterize coke, formed more on H-MOR and H-BEA. H-zeolites are definitely more active than silica alumina and alumina on catalyst weight base. The H-MOR sample is the most active but the H-MFI samples with Si/Al 2 ratios 280 and 50 show higher reaction rate per Al ion, H-FER and faujasites show highest ethylene yield (99.9% at 573 K). At lower temperature and higher space velocities, diethyl ether is formed with high yield (> 70 % at 453-473 K on H-BEA and H-MFI (50)). Overconversion of ethylene mainly to aromatics is observed on H-MFI (50). The different behaviour of protonic zeolites can predominantly be explained by confinement effects on the different zeolite cavities.
Applied Catalysis A: General, 2015
Ethanol dehydration was investigated (423-773 K, 1 atm, 1.43 h −1 WHSV in nitrogen) over titania,... more Ethanol dehydration was investigated (423-773 K, 1 atm, 1.43 h −1 WHSV in nitrogen) over titania, zirconia, as such and after impregnation with WO3. As for comparison, data on other WO3-free and WO3-containing catalysts will be also discussed, considered a strong Lewis acid (alumina), a covalent oxide (silica) and a basic material (calcined hydrotalcite). The catalysts were characterized using FT-IR of adsorbed pyridine and of wolframate species, and by UV-Vis spectroscopy. The results presented here show that WO3/ZrO2 and WO3/TiO2 are excellent catalysts for ethanol dehydration. Their performances may compete with those of zeolites and alumina both for conversion to diethyl ether and to ethylene. The addition of WO3 to both ZrO2 and TiO2 introduces strong Brønsted acid sites that are supposed to represent the active sites in the reaction, but also inhibits the formation of byproducts, i.e. acetaldehyde and higher hydrocarbons. This is attributed to the poisoning of basic sites and of reducible surface Ti and Zr centers, respectively.
Proximity correction and k1 performance for resists with nonoptical patterning response
SPIE Proceedings, 2004
Proximity correction and k1 performance for resists with nonoptical patterning response. [Proceed... more Proximity correction and k1 performance for resists with nonoptical patterning response. [Proceedings of SPIE 5376, 379 (2004)]. David S. Fryer, Vivek K. Singh, Thanh N. Phung, Peng Liu. Abstract. Model based OPC is critical for mask design employing current design rules. ...
2008 IEEE International Electron Devices Meeting, 2008
High-k/Ge interfaces are significantly improved through a new interface engineering scheme of usi... more High-k/Ge interfaces are significantly improved through a new interface engineering scheme of using both effective pre-gate surface GeO 2 passivation and post gate dielectric (post-gate) treatment incorporating fluorine (F) into high-k/Ge gate stack. Minimum density of interface states (D it) of 2 × 10 11 cm-2 eV-1 is obtained for Ge MOS capacitors. Hole mobility up to 396 cm 2 /Vs is achieved for Ge pMOSFETs with EOT ~10 Å and gate leakage current density less than 10-3 A/cm 2 at V t ± 1 V. Best drain current to date of 37.8 μA/μm at V g-V t = V d =-1.2V is presented for an L g of 10 µm. Variable rise and fall time charge pumping (CP) method is used to investigate Ge interface property and a significant D it reduction in both upper and lower half of bandgap is observed with F incorporation.
Applied Catalysis A: General, 2015
IR spectra of hydroxyl groups, adsorbed CO, pivalonitrile and pyridine on three H-MFI zeolite sam... more IR spectra of hydroxyl groups, adsorbed CO, pivalonitrile and pyridine on three H-MFI zeolite samples and on two H-Y faujasites are reported and discussed. Samples richer in Al (H-MFI (Si/Al2 = 30) and H-Y (Si/Al2 = 5.1)) show the presence of extraframework species and the presence of Lewis acidity together with Brønsted acidity. H-MFI with lowest Al content (Si/Al2 = 280) does not show any extraframework species (EF) and only presents Brønsted acidity. H-MFI with intermediate Al content (Si/Al2 = 50) possess very small amount of EF species and of Lewis acidity. H-Y with low Al content (Si/Al2 = 30) does not show extraframework species but shows the presence of Lewis acidity together with Brønsted acidity. The role of extraframework material as carrier of Lewis acidity is confirmed. It is proposed that Lewis acidity of low Al-content H-Y can arise from framework tetrahedral Al ions, which can enlarge their coordination to five without any previous dehydroxylation. A support for this hypothesis is given by the reversible shift of the LF OH stretching band, whose extent depends on the strength of the basic molecules: this is certainly not due to a direct interaction of the OH groups responsible for the LF band, which are located in cavities (sodalite cavity and hexagonal prisms) where the molecular probes cannot access.
Voltage balancing converter network for series-connected battery stack
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
ABSTRACT Energy storage systems are critical elements in electric vehicle (EV) and hybrid electri... more ABSTRACT Energy storage systems are critical elements in electric vehicle (EV) and hybrid electric vehicle (HEV) applications. In these systems, lithium-ion batteries are preferred for their outstanding characteristics and advantages: high power density, long life cycles and high efficiency. For high voltage applications, batteries cells are connected in series, raising the issue of voltage balancing among cells. This paper presents a new structure of active voltage balancing of Li-ion cells associated in series in battery stack. It is based on the use of micro-converters network. The principle of the charge equalization is to derive energy from an overcharged cell and to transfer it to an undercharged cell no matter whether the battery is currently in charge or in use supplying a load. The highlight of this structure is not only its high efficiency and its ease of implement but moreover, its integration capacity in contrast to state of the art passive and active balancing topologies. A monitoring system is required to perform forced balancing. The results from simulations and experimental test bench validate the feasibility and the interest of the proposed balancing circuitry and operating principle.
Optimized structure for next-to-next balancing of series-connected lithium-ion cells
2011 Twenty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2011
Page 1. Optimized Structure for Next-to-Next Balancing of Series-Connected Lithium-ion Cells Than... more Page 1. Optimized Structure for Next-to-Next Balancing of Series-Connected Lithium-ion Cells Thanh Hai PHUNG, Jean-Christophe CREBIER, Alexandre CHUREAU, Alexandre COLLET,The Van NGUYEN Grenoble Electrical ...
Rheology and microstructure in colloidal suspensions
Physica Scripta, 1993
ABSTRACT The rheological behavior of a suspension of Brownian spheres at low Reynold numbers can ... more ABSTRACT The rheological behavior of a suspension of Brownian spheres at low Reynold numbers can be predicted with the help of Stokesian dynamics. In this approach the stress on each particle is calculated for a given configuration of the particles, then the configuration is changed according to the equations of motion based on Stokesian dynamics. The average stress follows from the time average over the configurations. The shear viscosity obtained by this method compares very well with the experimental results, both as function of the volume fraction and of the Peclet number. The origin of shear thinning and of shear thickening behaviors is respectively due to the saturation of the Brownian stress with the shear rate on one hand and to the formation of large aggregates on the other hand. At intermediate Peclet numbers a shear induced ordering is observed which is not directly linked to the behavior of the viscosity. Other kinds of transitions induced both in the presence of a shear flow and of an electric field will be presented.
Journal of Fluid Mechanics, 1996
The non-equilibrium behaviour of concentrated colloidal dispersions is studied by Stokesian Dynam... more The non-equilibrium behaviour of concentrated colloidal dispersions is studied by Stokesian Dynamics, a general molecular-dynamics-like technique for simulating particles suspended in a viscous fluid. The simulations are of a suspension of monodisperse Brownian hard spheres in simple shear flow as a function of the Péclet number, Pe, which measures the relative importance of shear and Brownian forces. Three clearly defined regions of behaviour are revealed. There is first a Brownian-motion-dominated regime (Pe ≤ 1) where departures from equilibrium in structure and diffusion are small, but the suspension viscosity shear thins dramatically. When the Brownian and hydrodynamic forces balance (Pe ≈ 10), the dispersion forms a new ‘phase’ with the particles aligned in ‘strings’ along the flow direction and the strings are arranged hexagonally. This flow-induced ordering persists over a range of Pe and, while the structure and diffusivity now vary considerably, the rheology remains unchan...
Extraction of curcumin from turmeric residue (Curcuma longa L.) using deep eutectic solvents and surfactant solvents
Analytical Methods, 2022
An efficient choline chloride-based DES method is used to extract curcumin in turmeric residue fo... more An efficient choline chloride-based DES method is used to extract curcumin in turmeric residue for the first time.
The association between HLA-B*15:02 and phenytoin-induced severe cutaneous adverse reactions: a meta-analysis
Pharmacogenomics, 2021
Aim: Phenytoin (PHT) is a common anticonvulsant agent known for inducing severe cutaneous adverse... more Aim: Phenytoin (PHT) is a common anticonvulsant agent known for inducing severe cutaneous adverse reactions (SCARs). HLA-B*15:02 as a risk factor of PHT-induced SCARs was reported in numerous studies with inconsistent results. This meta-analysis aimed to establish pooling evidence of this association. Materials & methods: Pooled odds ratios (ORs) with 95% CIs were estimated using a random-effects model. Results: A total of 11 studies on 1389 patients, were included for the analyses. There was a significant association between HLA-B*15:02 and PHT-induced SCAR (pooled OR = 2.29, 95% CI: 1.25–4.19, p = 0.008). Furthermore, there was a significant association regarding Stevens–Johnson syndrome/toxic epidermal necrolysis (OR = 3.63, 95% CI: 2.15–6.13, p
The Application of Clinical Genetics, 2021
Background: Allopurinol, a common anti-hyperuricemia drug, is well known as an inducer of severe ... more Background: Allopurinol, a common anti-hyperuricemia drug, is well known as an inducer of severe cutaneous adverse drug reactions (SCARs). One of the most well-defined risk factors of allopurinol-induced SCARs is the presence of polymorphic alleles of human leukocyte antigen (HLA) genes, such as HLA-B*58:01 and HLA-C*03:02 alleles. There is no commercial test or published in-house protocol for the specific detection of the HLA-C*03 :02 allele. In this article, we established for the first time a simple allele-specific (AS) PCR method to identify HLA-C*03:02 allele carriers, and at the same time, determine their zygosities. Methods: A two-step AS-PCR protocol, using four primer sets, was designed to specifically amplify and differentiate the HLA-C*03:02 allele from 17 other HLA-C alleles found in Vietnamese people. The protocol was validated with PCR-sequencing-based typing (SBT) of 100 samples of unknown genotypes. Results: The PCR protocol can detect the HLA-C*03:02 allele and determine the zygosity. The results of this protocol were highly consistent with those of the SBT (ĸ = 0.98, p < 0.001). Regarding the specific detection of the HLA-C*03:02 allele, the PCR protocol had a sensitivity of 100% (95% CI: 91.61-100%) and specificity of 98.3% (95% CI: 90.9-99.7%). The protocol was used to determine the distribution of the HLA-C*03:02 allele in 810 unrelated Vietnamese Kinh people, 14.2% of which were HLA-C*03:02 carriers, the allele frequency was 7.5%. Conclusion: A novel AS-PCR protocol with a sensitivity of 100% for the detection of the HLA-C*03:02 allele was established. The protocol can be used for personalized treatment with allopurinol in order to minimize the risk of SCARs in Vietnamese people as well as in other Asian populations with similar genetic characteristics.
Asian Pacific journal of allergy and immunology, 2021
BACKGROUND Severe cutaneous adverse drug reactions (SCARs) are rare but deadly drug reactions wit... more BACKGROUND Severe cutaneous adverse drug reactions (SCARs) are rare but deadly drug reactions with severe damages to patients. One of the most well-known SCARs risk factors is the human leukocyte antigen (HLA) genes polymorphism. Among the HLA polymorphic alleles, the HLA-A*33:03 allele has been found in association with SCARs induced by various drugs, especially in Asian people. There has not been any report on the specific detection protocol of the HLA-A*33:03 allele. OBJECTIVE This study aimed to design a nested AS-PCR protocol for detecting and distinguishing diplotype genotype of the HLA-A*33:03 allele. METHODS A nested allele-specific (AS)-PCR protocol with four primer sets was designed. The method was compared with the Sanger sequencing method on 100 samples of unknown genotypes of unrelated Vietnamese people. RESULTS The nested AS-PCR method could identify the HLA-A*33:03 allele and the HLA-A*33:03 diplotype genotypes. Comparison with the Sanger sequencing method showed an a...
Color Research & Application, 2019
Image color appearance models (Image CAMs) have been developed to predict the perception of compl... more Image color appearance models (Image CAMs) have been developed to predict the perception of complex scenes and are mainly used for image rendering and video reproduction applications. Among these Image CAMs, iCAM is an Image CAM that takes an image as the input and provides the perceptual attributes for each pixel. On the other hand, nonimaging CAMs are widely used and validated, but they always assume a simple test scene of a uniform flat stimulus, a quasi-neutral background, and a surround. This study presents an evaluation of the performance of iCAM when applied to these simple self-luminous scenes in predicting the influence of background luminance, background size, saturation, and stimulus size on stimulus brightness. The results show that iCAM is capable of predicting the effect of background luminance and some background size scenarios. However, for unrelated self-luminous stimuli (dark background), the model predictions do not match the reference data. An evaluation of the effect of the filter kernel size and its relation to the physiological mechanism of image processing inside the visual system has been investigated. Furthermore, the impact of saturation and stimulus size on brightness seems to be underestimated by the model, because the Helmholtz-Kohlrausch and stimulus size effects are not included. Hence, these findings call for an enhanced Image CAM.
Http Www Theses Fr, Dec 20, 2013
Http Www Theses Fr, Jul 6, 2012
R : the set of all real numbers Z : the set of all integer numbers N : the set of all natural num... more R : the set of all real numbers Z : the set of all integer numbers N : the set of all natural numbers L : system size k : wave number l c : typical length scale h(t) : mean high of surface w(L, t), W (L, t) : interface width h(x, t) : the height of interface at position x and time t u(x, t) : the velocity field ρ(x, t) : density field ρ in (x) : initial density u in (x) : initial velocity m i (t) : mass of i-th particle x i (t) : position of i-th particle u i (t), v i (t) : velocity of i-th particle p i (t) : momentum of i-th particle ξ i (t) : distance between two particles N : number of time steps I : number of particles f (x, t), g(X, τ) : scaling function
Microstructured fluids: Structure, diffusion and rheology of colloidal dispersions
AIP Conference Proceedings, 1992
The behavior of concentrated Brownian suspensions in a linear shear flow is studied numerically. ... more The behavior of concentrated Brownian suspensions in a linear shear flow is studied numerically. Particle trajectories are calculated by Stokesian dynamics, a molecular-dynamics-like method that accurately represents the suspension ...
Thermal proximity effects in lithography
Catalysis Communications, 2015
Commercial silica-alumina catalysts prepared by different procedures have been characterized. Bot... more Commercial silica-alumina catalysts prepared by different procedures have been characterized. Both present strong Lewis acidity together with Brønsted sites able to protonate pyridine. No evidence of "zeolitic" bridging OH's but significant heterogeneity of terminal silanol groups, part of which are likely "pseudobridging", was found. Similar high activity in ethanol conversion but markedly different selectivities to ethylene and diethyl ether were found. They are less active than both zeolites and -Al 2 O 3. Lewis sites with alumina-like acidobasic neighbour are more selective for ethylene production while Lewis sites with silica-like covalent neighbour are more selective for diethyl ether.
Applied Catalysis A: General, 2015
Ethanol dehydration was investigated over commercial H-FER, H-MFI, H-MOR, H-BEA, H-Y and H-USY ze... more Ethanol dehydration was investigated over commercial H-FER, H-MFI, H-MOR, H-BEA, H-Y and H-USY zeolite samples, and alumina and silica alumina for comparison. The catalysts were characterized using FT-IR spectroscopy of the surface OH groups and of adsorbed CO and pyridine. UV-Vis, Raman and TG-DTA were applied to characterize coke, formed more on H-MOR and H-BEA. H-zeolites are definitely more active than silica alumina and alumina on catalyst weight base. The H-MOR sample is the most active but the H-MFI samples with Si/Al 2 ratios 280 and 50 show higher reaction rate per Al ion, H-FER and faujasites show highest ethylene yield (99.9% at 573 K). At lower temperature and higher space velocities, diethyl ether is formed with high yield (> 70 % at 453-473 K on H-BEA and H-MFI (50)). Overconversion of ethylene mainly to aromatics is observed on H-MFI (50). The different behaviour of protonic zeolites can predominantly be explained by confinement effects on the different zeolite cavities.
Applied Catalysis A: General, 2015
Ethanol dehydration was investigated (423-773 K, 1 atm, 1.43 h −1 WHSV in nitrogen) over titania,... more Ethanol dehydration was investigated (423-773 K, 1 atm, 1.43 h −1 WHSV in nitrogen) over titania, zirconia, as such and after impregnation with WO3. As for comparison, data on other WO3-free and WO3-containing catalysts will be also discussed, considered a strong Lewis acid (alumina), a covalent oxide (silica) and a basic material (calcined hydrotalcite). The catalysts were characterized using FT-IR of adsorbed pyridine and of wolframate species, and by UV-Vis spectroscopy. The results presented here show that WO3/ZrO2 and WO3/TiO2 are excellent catalysts for ethanol dehydration. Their performances may compete with those of zeolites and alumina both for conversion to diethyl ether and to ethylene. The addition of WO3 to both ZrO2 and TiO2 introduces strong Brønsted acid sites that are supposed to represent the active sites in the reaction, but also inhibits the formation of byproducts, i.e. acetaldehyde and higher hydrocarbons. This is attributed to the poisoning of basic sites and of reducible surface Ti and Zr centers, respectively.
Proximity correction and k1 performance for resists with nonoptical patterning response
SPIE Proceedings, 2004
Proximity correction and k1 performance for resists with nonoptical patterning response. [Proceed... more Proximity correction and k1 performance for resists with nonoptical patterning response. [Proceedings of SPIE 5376, 379 (2004)]. David S. Fryer, Vivek K. Singh, Thanh N. Phung, Peng Liu. Abstract. Model based OPC is critical for mask design employing current design rules. ...
2008 IEEE International Electron Devices Meeting, 2008
High-k/Ge interfaces are significantly improved through a new interface engineering scheme of usi... more High-k/Ge interfaces are significantly improved through a new interface engineering scheme of using both effective pre-gate surface GeO 2 passivation and post gate dielectric (post-gate) treatment incorporating fluorine (F) into high-k/Ge gate stack. Minimum density of interface states (D it) of 2 × 10 11 cm-2 eV-1 is obtained for Ge MOS capacitors. Hole mobility up to 396 cm 2 /Vs is achieved for Ge pMOSFETs with EOT ~10 Å and gate leakage current density less than 10-3 A/cm 2 at V t ± 1 V. Best drain current to date of 37.8 μA/μm at V g-V t = V d =-1.2V is presented for an L g of 10 µm. Variable rise and fall time charge pumping (CP) method is used to investigate Ge interface property and a significant D it reduction in both upper and lower half of bandgap is observed with F incorporation.
Applied Catalysis A: General, 2015
IR spectra of hydroxyl groups, adsorbed CO, pivalonitrile and pyridine on three H-MFI zeolite sam... more IR spectra of hydroxyl groups, adsorbed CO, pivalonitrile and pyridine on three H-MFI zeolite samples and on two H-Y faujasites are reported and discussed. Samples richer in Al (H-MFI (Si/Al2 = 30) and H-Y (Si/Al2 = 5.1)) show the presence of extraframework species and the presence of Lewis acidity together with Brønsted acidity. H-MFI with lowest Al content (Si/Al2 = 280) does not show any extraframework species (EF) and only presents Brønsted acidity. H-MFI with intermediate Al content (Si/Al2 = 50) possess very small amount of EF species and of Lewis acidity. H-Y with low Al content (Si/Al2 = 30) does not show extraframework species but shows the presence of Lewis acidity together with Brønsted acidity. The role of extraframework material as carrier of Lewis acidity is confirmed. It is proposed that Lewis acidity of low Al-content H-Y can arise from framework tetrahedral Al ions, which can enlarge their coordination to five without any previous dehydroxylation. A support for this hypothesis is given by the reversible shift of the LF OH stretching band, whose extent depends on the strength of the basic molecules: this is certainly not due to a direct interaction of the OH groups responsible for the LF band, which are located in cavities (sodalite cavity and hexagonal prisms) where the molecular probes cannot access.
Voltage balancing converter network for series-connected battery stack
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
ABSTRACT Energy storage systems are critical elements in electric vehicle (EV) and hybrid electri... more ABSTRACT Energy storage systems are critical elements in electric vehicle (EV) and hybrid electric vehicle (HEV) applications. In these systems, lithium-ion batteries are preferred for their outstanding characteristics and advantages: high power density, long life cycles and high efficiency. For high voltage applications, batteries cells are connected in series, raising the issue of voltage balancing among cells. This paper presents a new structure of active voltage balancing of Li-ion cells associated in series in battery stack. It is based on the use of micro-converters network. The principle of the charge equalization is to derive energy from an overcharged cell and to transfer it to an undercharged cell no matter whether the battery is currently in charge or in use supplying a load. The highlight of this structure is not only its high efficiency and its ease of implement but moreover, its integration capacity in contrast to state of the art passive and active balancing topologies. A monitoring system is required to perform forced balancing. The results from simulations and experimental test bench validate the feasibility and the interest of the proposed balancing circuitry and operating principle.
Optimized structure for next-to-next balancing of series-connected lithium-ion cells
2011 Twenty-Sixth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2011
Page 1. Optimized Structure for Next-to-Next Balancing of Series-Connected Lithium-ion Cells Than... more Page 1. Optimized Structure for Next-to-Next Balancing of Series-Connected Lithium-ion Cells Thanh Hai PHUNG, Jean-Christophe CREBIER, Alexandre CHUREAU, Alexandre COLLET,The Van NGUYEN Grenoble Electrical ...
Rheology and microstructure in colloidal suspensions
Physica Scripta, 1993
ABSTRACT The rheological behavior of a suspension of Brownian spheres at low Reynold numbers can ... more ABSTRACT The rheological behavior of a suspension of Brownian spheres at low Reynold numbers can be predicted with the help of Stokesian dynamics. In this approach the stress on each particle is calculated for a given configuration of the particles, then the configuration is changed according to the equations of motion based on Stokesian dynamics. The average stress follows from the time average over the configurations. The shear viscosity obtained by this method compares very well with the experimental results, both as function of the volume fraction and of the Peclet number. The origin of shear thinning and of shear thickening behaviors is respectively due to the saturation of the Brownian stress with the shear rate on one hand and to the formation of large aggregates on the other hand. At intermediate Peclet numbers a shear induced ordering is observed which is not directly linked to the behavior of the viscosity. Other kinds of transitions induced both in the presence of a shear flow and of an electric field will be presented.
Journal of Fluid Mechanics, 1996
The non-equilibrium behaviour of concentrated colloidal dispersions is studied by Stokesian Dynam... more The non-equilibrium behaviour of concentrated colloidal dispersions is studied by Stokesian Dynamics, a general molecular-dynamics-like technique for simulating particles suspended in a viscous fluid. The simulations are of a suspension of monodisperse Brownian hard spheres in simple shear flow as a function of the Péclet number, Pe, which measures the relative importance of shear and Brownian forces. Three clearly defined regions of behaviour are revealed. There is first a Brownian-motion-dominated regime (Pe ≤ 1) where departures from equilibrium in structure and diffusion are small, but the suspension viscosity shear thins dramatically. When the Brownian and hydrodynamic forces balance (Pe ≈ 10), the dispersion forms a new ‘phase’ with the particles aligned in ‘strings’ along the flow direction and the strings are arranged hexagonally. This flow-induced ordering persists over a range of Pe and, while the structure and diffusivity now vary considerably, the rheology remains unchan...