1,890 research outputs found
The functionalization of carbon nanotubes using a batch oscillatory flow reactor
This paper describes an efficient method for the functionalizing of multi-walled carbon nanotubes (MWCNT) using oscillatory flow mixing (OFM). A 3. l batch oscillatory flow reactor (OFR) was designed and constructed for pilot scale functionalization of MWCNT in order to potentially improve their compatibility within a thermoplastic polyphenylene sulphide (PPS) matrix. The OFM batch reactor consisted of a jacketed cylindrical vessel with a vertical axial oscillator that contained a series of baffled mixing plates. MWCNTs dispersed in dimethylformamide (DMF) were introduced into the reactor and a two stage reaction for functionalizing MWCNTs with PPS compatible groups was carried out under oscillation of baffles at elevated temperatures. Fluid mixing observations in the reactor showed that MWCNTs formed a uniform dispersion of aggregated flocs before and during the functionalization reaction. On completion of the reaction and cessation of the oscillation, the aggregated flocs of MWCNT rapidly sedimented at the bottom of the reactor; hence could be collected as a concentrated mass thereby facilitating the separation of functionalized MWCNTs from the solvent. The functionalized MWCNTs were dried and then characterized by transmission electron microscopy, infrared spectroscopy as well as thermal gravimetric analysis in order to investigate the extent of MWCNT functionalization. The characterization results confirmed the effective and relatively uniform functionalization of the MWCNTs despite formation of aggregates, indicating that OFM provides a viable approach for functionalizing MWCNTs
A low-viscosity family of ionic liquids based on the tetracyanoborate anion for CO2 capture
The extraordinary properties of ionic liquids (ILs) such as their negligible vapor pressure have placed them in the spotlight of researchers as alternative solvents for separation processes. The large number of anion/cation combinations allows the possibility of "designing" ILs according to the specifications required for the process. ILs should be chemically and thermally stable. When used for gas purification and carbon dioxide (CO2) capture, ILs are required to have a high CO2 absorption capacity and low viscosity. The newly task-specific ILs achieve higher CO2 loadings at moderate pressures, also at supercritical conditions. However, the relatively high viscosity of some ILs is a drawback for their practical application, in spite of their high gas solubility. The aim of this work is to study the feasibility of using tetracyanoborate-based ionic liquid for CO2 capture. The main characteristic of this family of ILs is their low viscosity compared to "traditional" ionic liquids, such as tetrafluoroborate or hexafluoroborate. We will present some pure component properties such as viscosity, density and surface tension, as well as solubility measurements of the binary systems IL+ CO2. The solubility of CO2 in 1-ethyl-3-methylimidazolium tetracyanoborate [emim][TCB] and 1-hexyl-3-methylimidazolium tetracyanoborate [hmim][TCB] was measured using the Cailletet apparatus where the bubble point was visually determined. The encouraging results show that the tetracyanoborate ionic liquids have a large potential for CO2 absorption applications
A low-viscosity family of ionic liquids based on the tetracyanoborate anion for CO2 capture
The extraordinary properties of ionic liquids (ILs) such as their negligible vapor pressure have placed them in the spotlight of researchers as alternative solvents for separation processes. The large number of anion/cation combinations allows the possibility of "designing" ILs according to the specifications required for the process. ILs should be chemically and thermally stable. When used for gas purification and carbon dioxide (CO2) capture, ILs are required to have a high CO2 absorption capacity and low viscosity. The newly task-specific ILs achieve higher CO2 loadings at moderate pressures, also at supercritical conditions. However, the relatively high viscosity of some ILs is a drawback for their practical application, in spite of their high gas solubility. The aim of this work is to study the feasibility of using tetracyanoborate-based ionic liquid for CO2 capture. The main characteristic of this family of ILs is their low viscosity compared to "traditional" ionic liquids, such as tetrafluoroborate or hexafluoroborate. We will present some pure component properties such as viscosity, density and surface tension, as well as solubility measurements of the binary systems IL+ CO2. The solubility of CO2 in 1-ethyl-3-methylimidazolium tetracyanoborate [emim][TCB] and 1-hexyl-3-methylimidazolium tetracyanoborate [hmim][TCB] was measured using the Cailletet apparatus where the bubble point was visually determined. The encouraging results show that the tetracyanoborate ionic liquids have a large potential for CO2 absorption applications
Genetic Transformation of Quercus ilex Somatic Embryos with a Gnk2-like Protein That Reveals a Putative Anti-Oomycete Action
Holm oak is a key tree species in Mediterranean ecosystems, whose populations have
been increasingly threatened by oak decline syndrome, a disease caused by the combined action of
Phytophthora cinnamomi and abiotic stresses. The aim of the present study was to produce holm oak
plants that overexpress the Ginkbilobin-2 homologous domain gene (Cast_Gnk2-like) that it is known
to possess antifungal properties. Proembryogenic masses (PEMs) isolated from four embryogenic
lines (Q8, E2, Q10-16 and E00) were used as target explants. PEMs were co-cultured for 5 days with
Agrobacterium EHA105pGnk2 and then cultured on selective medium containing kanamycin (kan)
and carbenicillin. After 14 weeks on selective medium, the transformation events were observed in
somatic embryos of lines Q8 and E2 and a total of 4 transgenic lines were achieved. The presence of the
Cast_Gnk2-like gene on transgenic embryos was verified by PCR, and the number of transgene copies
and gene expression was estimated by qPCR. Transgenic plants were obtained from all transgenic
lines after cold storage of the somatic embryos for 2 months and subsequent transfer to germination
medium. In an in vitro tolerance assay with the pathogen P. cinnamomi, we observed that transgenic
plants were able to survive longer than wild typeinfo:eu-repo/semantics/publishedVersio
Service Performance Assessment: A PI Toolset Methodology for VEs
Part 2: Knowledge-Based ServicesInternational audienceNowadays service sector is becoming more and more relevant in building successful collaborative economies. In this environment Virtual Enterprises (VEs) are forcing a change in the way traditional manufacturing systems are managed. Therefore measuring service performances plays an important role in turning company strategic goals into reality. Performance Indicators (PIs) consist in a supporting tool to assess service efficiency and effectiveness. Consequently, determining the most significant activities which need to be controlled and measured through proper PIs becomes essential. Within this paper, a PI Toolset is going to be presented and tested through industrial use case. The PI Toolset has been developed to support VEs in selecting significant activities, to manage governance processes and to support the design and implementation of specific PIs related to the precise use case objectives. Finally, a lesson learnt approach has been adopted so to stress strengths and weaknesses of both proposed methodology and tools
Synchronous neoplastic lesions in colorectal cancer. An analysis of possible risk factors favouring presentation
Aim: few data have been published regarding the causes of
synchronous lesions in patients with colorectal cancer. The aim of
our study was to identify potential factors that might be implicated
in the development of multicentric lesions, since this knowledge
could be useful for tailored follow-up once initial synchronous lesions
have been removed.
Methods: we retrospectively reviewed 382 colorectal cancer
cases diagnosed by total colonoscopy and histological study of
surgical specimens. We divided our population into 2 groups,
based on whether they had synchronous lesions or otherwise.
Several data related to personal and family history, habits, symptoms,
and tumor characteristics were assessed. Univariate and
multivariate statistical analyses were performed.
Results: 208 (54.5%) patients had synchronous adenomas
and 28 (7.3%) had synchronous cancer. A multivariate analysis
showed that the following parameters were consistently related
to the presence of multicentric lesions –male gender: OR = 1.97;
CI = 1.13-3.45; p = 0.017; age ≥ 59 years: OR = 2.57;
CI = 1.54-4.29; p < 0.001; personal history of colonic adenomas:
OR = 3.04; CI = 1.04-8.85; p = 0.042; and obstructive tumors:
OR = 0.48; CI = 0.27-0.85; p = 0.012.
Conclusion: our results show that several parameters that are
easy to measure could be considered risk factors for the development
of multicentric lesions. These factors need to be confirmed
with follow-up studies analyzing their role in patients with and
without metachronic lesions once all synchronous lesions have
been removed
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