396 research outputs found
A statistical data-based approach to instability detection and wear prediction in radial turning processes
Radial turning forces for tool-life improvements are studied, with the emphasis on predictive rather than preventive maintenance. A tool for wear prediction in various experimental settings of instability is proposed through the application of two statistical approaches to process data on tool-wear during turning processes: three sigma edit rule analysis and Principal Component Analysis (PCA). A Linear Mixed Model (LMM) is applied for wear prediction. These statistical approaches to instability detection generate results of acceptable accuracy for delivering expert opinion. They may be used for on-line monitoring to improve the processing of different materials. The LMM predicted significant differences for tool wear when turning different alloys and with different lubrication systems. It also predicted the degree to which the turning process could be extended while conserving stability. Finally, it should be mentioned that tool force in contact with the material was not considered to be an important input variable for the model.The work was performed as a part of the HIMMOVAL (Grant Agreement Number: 620134) project within the CLEAN-SKY program, linked to the SAGE2 project for geared open-rotor development and the delivery of the demonstrator part. Funding through grant IT900-16 is also acknowledged from the Basque Government Department of Education, Universities and Research
Spectroscopic, thermodynamic, kinetic studies and oxidase/antioxidant biomimetic catalytic activities of tris(3,5-dimethylpyrazolyl)borate Cu(II) complexes
A series of copper(II) complexes, viz. [TpMeMeCu(Cl)(H2O)] (1), [TpMeMeCu(OAc)(H2O)] (2), [TpMeMeCu(NO3)] (3) and [TpMeMeCu(ClO4)] (4) containing tris(3,5-dimethylpyrazolyl)borate (KTpMeMe), have been synthesized and fully characterized. The substitution reaction of 1 with thiourea was studied under pseudo-first-order conditions as a function of concentration, temperature and pressure in methanol and acetonitrile as solvents. Two reaction steps that both depended on the nucleophile concentration were observed for both solvents. Substitution of coordinated methanol is about 40 times faster than the substitution of chloride. In acetonitrile, the rate constant for the displacement of coordinated acetonitrile was more than 20 times faster than the substitution of chloride. The reported activation parameters indicate that both reaction steps follow a dissociative mechanism in both solvents. On going from methanol to acetonitrile, the rate constant for the displacement of the solvent becomes more than 200 times faster due to the more labile acetonitrile, but the substitution mechanism remained to have a dissociative character. The antioxidant activities of 1–4 were evaluated for superoxide dismutase (SOD), glutathione-s-transferase (GST0 and glutathione reduced (GSH-Rd) activity. 1 and 2 were found to show (p < 0.05) the highest antioxidant activity in comparison to 3 and 4, which can be ascribed to the geometric configuration as well as the nature of the co-ligand. 1 showed catechol oxidase activity with turnover numbers of 20 min−1 and a coordination affinity for 3,5-DTBC of K1, = 31 mM−1. K1 is rather large and seems to be typical for faster biomimetic models, and also for the enzyme itself (25 mM−1). The reaction rate depended linearly on the complex concentration, indicating a first-order dependence on the catalyst concentration
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Factors Influencing Optical Coherence Tomography Peripapillary Choroidal Thickness: A Multicenter Study.
Purpose:To quantify peripapillary choroidal thickness (PCT) and the factors that influence it in healthy participants who represent the racial and ethnic composition of the U.S. population. Methods:A total of 362 healthy participants underwent optical coherence tomography (OCT) enhanced depth imaging of the optic nerve head with a 24 radial B-scan pattern aligned to the fovea to Bruch's membrane opening axis. Bruch's membrane, anterior scleral canal opening (ASCO), and the anterior scleral surface were manually segmented. PCT was measured at 100, 300, 500, 700, 900, and 1100 μm from the ASCO globally and within 12 clock-hour sectors. The effects of age, axial length, intraocular pressure, ethnicity, sex, sector, and ASCO area on PCT were assessed by ANOVA and univariable and multivariable regressions. Results:Globally, PCT was thicker further from the ASCO border and thinner with older age, longer axial length, larger ASCO area, European descent, and female sex. Among these effectors, age and axial length explained the greatest proportion of variance. The rate of age-related decline increased further from the ASCO border. Sectorally, the inferior-temporal sectors were thinnest (10.7%-20.0% thinner than the thickest sector) and demonstrated a higher rate of age-related loss (from 15.6% to 20.7% faster) at each ASCO distance. Conclusions:In healthy eyes, PCT was thinnest in the inferior temporal sectors and thinner PCT was associated with older age, European descent, longer axial length, larger ASCO area, and female sex. Among these associations, age had the strongest influence, and its effect was greatest within the inferior temporal sectors
Insights into seeds priming effects using a magnetic field and algal treatments on growth and productivity of faba bean under salinity stress conditions
Soil fertility and crop productivity in the Nile Delta are severely threatened by soil salinization. Hence, the development of reliable techniques to enhance the salinity tolerance of plants is an essential prerequisite for the desirable sustainable agricultural development in Egypt. In the present study, we evaluated the influence of seeds priming using a magnetic field (MF) at different exposure times (0, 15, 30, and 45 min), either alone or combined with seeds pre-soaking or foliar spraying with seaweed extracts of Hydroclathrus clathratus and Acanthophora spicifera. The effects on soil properties, growth, yield, and seed quality of Vicia faba grown in saline soil were assessed. Results indicated that MF-treated seeds (MFTS), either alone or coupled with seaweed treatments, distinctly improved soil characterization by decreasing EC and pH niches, and also increased the availability of soil macro- and micronutrient elements, particularly at MF long exposure time (≥30 min). MFTS and/or MFTS with seaweed treatments at 30 min improved soil fertility indices (CO2 evolution and nitrogenase activity) and induced the highest increases of macro- and micro-nutrient contents in seeds, plant growth and seed quality. Additionally, enhancement of chlorophyll a and b, carbohydrates and amino acids, and decreasing proline levels were the bases of salinity stress alleviation. Conclusively, seed priming in the MF coupled with foliar spraying of seaweed extracts could be a sustainable and affordable approach for cultivating V. faba plants under salinity stress conditions
Left-right symmetry at LHC and precise 1-loop low energy data
Despite many tests, even the Minimal Manifest Left-Right Symmetric Model
(MLRSM) has never been ultimately confirmed or falsified. LHC gives a new
possibility to test directly the most conservative version of left-right
symmetric models at so far not reachable energy scales. If we take into account
precise limits on the model which come from low energy processes, like the muon
decay, possible LHC signals are strongly limited through the correlations of
parameters among heavy neutrinos, heavy gauge bosons and heavy Higgs particles.
To illustrate the situation in the context of LHC, we consider the "golden"
process . For instance, in a case of degenerate heavy neutrinos
and heavy Higgs masses at 15 TeV (in agreement with FCNC bounds) we get
fb at TeV which is consistent with muon
decay data for a very limited masses in the range (3008 GeV, 3040 GeV).
Without restrictions coming from the muon data, masses would be in the
range (1.0 TeV, 3.5 TeV). Influence of heavy Higgs particles themselves on the
considered LHC process is negligible (the same is true for the light, SM
neutral Higgs scalar analog). In the paper decay modes of the right-handed
heavy gauge bosons and heavy neutrinos are also discussed. Both scenarios with
typical see-saw light-heavy neutrino mixings and the mixings which are
independent of heavy neutrino masses are considered. In the second case heavy
neutrino decays to the heavy charged gauge bosons not necessarily dominate over
decay modes which include only light, SM-like particles.Comment: 16 pages, 10 figs, KL-KS and new ATLAS limits taken into accoun
A study on environmental pollutants (Organochlorine pesticides (OCPs), heavy metals, hydrocarbons and surfactants) in the southern part of Caspian Sea
At the present study, the environmental pollutants such as organochlorine pesticides (OCPs), heavy metals, hydrocarbons and surfactants were done during 22 months (Sept. 2009 through May 2011) located in southern part of Caspian Sea with longitude and latitude 48°-54° N and 36°-39° E, respectively. The aims of this study were to determine the seasonal pollutants matters in water layers and bed sediments of eight transect (24 stations) and the results are as follow: The maximum seasonal percentage range of OCPs were detected in spring water samples from 10, 50, and 50m depths such as (DDD, δ-BHC, heptachlor epoxide, endrin aldehyde),(DDD) and (aldrin, β-endosulfan) compounds about 62.5, 75 and 100%, respectively. The maximum seasonal residues fluctuation of OCPs were determined in spring water samples from 10, 50, and 50m depths such as aldrin (Babolsar station), aldrin (Tonekabon station) and heptachlor epoxide (Astara station) compounds about 5.03, 3.08 and 31.43 µg/l, respectively. The maximum percentage range of OCPs were detected in sediments samples from 10, 50, and 50m depths such as aldrin and α-BHC (winter), α-BHC (summer and winter) and aldrin (summer) compounds about 100, 75 and 87.5%, respectively. The maximum residues fluctuation of OCPs were determined in sediments samples from 10, 50, and 50m depths such as α-BHC (summer in Nushahr station), α-BHC (summer in Sefidroud station) and α-BHC (winter in Tonekabon station) and compounds about 5.96, 3.77 and 3.07 µg/l, respectively. The fluctuation and distribution of Total Petroleum Hydrocarbons (TPHs) concentration in different water layers samples were reduced from summer>spring> fall > winter, respectively. Also this trend occurred for bed sediments and reduced from winter > summer, respectively. The mean concentrations of TPHs in water samples of all seasons, regions, depths and transects were less than maximum permissible concentration (MPC). In this research, a comparison of TPHs with EPA standards shown that the desile range organic (DRO) was close to EPA standards such as TPHs and also 95 percent of water data were less than MPC. But gasoline range organic (GRO) concentrations in all stations were less than the amount of EPA standard. A comparison of TPHs concentration in sediments shown that the concentration of all stations were less than of national research council (NRC) range except west part. The maximum annual mean concentrations of Hg and Pb elements were detected in surface station (50m) at Nushahr and Amirabad transects. The most water data of Cd, Pb and Hg elements in comparison with critical concentrations with Europe, the USA and Japan standards were less than amounts of those standards. The distribution and abundance of Cd, Pb, Hg and Ni elements in water samples were detected 98, 96, 77 and 6%, respectively less than the ISQGs (Interim marine sediment quality guidelines) standards. In sediments samples, the mean and maximum concentration of Hg element detected in winter in comparison with ISQGs standards was more. But the concentrations of Cd and Pb in sediments samples of all stations were low and less than of ISQGs standards. The maximum concentration of linear alkyl benzene sulfonate (LAS) from spring through winter in Anzali (spring), Tonekabon (summer), Anzali (fall) and Nushahr (winter) were 0.07, 0.45, 0.145 and 0.087 mg/l, respectively. The maximum concentrations of LSA were detected in spring and fall in west part and summer and winter in middle part. But the lower concentration was occurred in west of southern part of Caspian Sea. According to standards of surfactants and comparison with LAS concentration of this study were less than the critical points
Rethinking justice beyond human rights. Anti-colonialism and intersectionality in the politics of the Palestinian Youth Movement
This article discusses the politics of the Palestinian Youth Movement (PYM) – a contemporary social movement operating across a number of Arab and western countries. Unlike analysis on the Arab Uprisings which focused on the national dimension of youth activism, we explore how the PYM politics fosters and upholds an explicitly transnational anti-colonial and intersectional solidarity framework, which foregrounds a radical critique of conventional notions of self-determination based on state-framed human rights discourses and international law paradigms. The struggle becomes instead framed as an issue of justice, freedom and liberation from interlocking forms and hierarchies of oppression.
KEYWORDS: Palestine, transnational social movements, intersectionality, human rights, anti-colonialis
Study on physico-chemical characteristics of water in the southern of Caspian Sea
In this study, the characteristics of physico-chemical parameters of water done in coastal part of the southern Caspian Sea during 2010-2011 (four seasons) in 8 transects (Astara, Anzali, Sefidrour, Tonkabon, Noshahr, Babolsar, Amirabad and Torkman). For measurement of water quality parameters, 480 samples were collected in different water layers by using of APHA standards methods. According to modeling and statistical methods was used multivariate for evaluation of factor analysis (MFA) in general groups and discriminant analysis (MDA) for spatial and temporal with water quality parameters. The statistical procedure of MFA was used for data reduction and finally six factors selected with about 80.48 percent of total variances related to them. The statistical procedures of MDA were used for the role of spatial and temporal of water quality parameters in different water layer. The function one gave eight parameters (pH, salinity, EC, DO, NO^3-, water temperature, NH^4+ and N^-total) affording more than 80, 67, 80, 77 and 71 % correct assignations (return to the same transects) in spatial analysis. In all transects during four seasons, function one gave five parameters (water temperature, salinity, EC, NO^2- and NH^4+) to afford 100, 100, 100, 97 and 97 % correct assignations in temporal analysis. The results showed that, the average amounts in light penetration layers during four seasons were for EC(15.04±0.18ms/cm), pH(8.38±0.01unit), salinity (10.31±0.16g/l), DO(5.67±0.09ml/l) and water temperature (18.28 ±0.72°C). The average amount of nutrients for parameters such as organic and inorganic phosphorus, total phosphorus, NO^2-, NO^3-, NH^4+, N^-Total and SiO_2 were 0.50±0.02, 0.32±0.01, 0.82±0.02, 1.76±0.10, 0.10±0.01, 1.51±0.10, 46.82±1.80 and 8.60±0.29µM, respectively. The average amounts in dark layers during four seasons were for EC (15.46±0.38ms/cm), pH (8.34±0.03unit), salinity (10.70±0.35g/l), DO (4.55±0.13ml/l) and water temperature (9.62 ±0.16°C). The average amount of nutrients for parameters such as organic and inorganic phosphorus, total phosphorus, NO^2-, NO^3-, NH^4+, N^-Total and SiO_2 were 0.54 ±0.05, 0.33 ±0.02, 0.87±0.06, 1.92±0.21 , 0.08± 0.01, 1.55±0.25, 45.10±3.25 and 10.05±0.62 µM, respectively. The average amounts of light penetration in all transects during four seasons 4.49±0.38 meters. The maximum light penetrations during spring, summer, fall and winter seasons were 9, 8, 8.20 and 7 meters, respectively. The maximum water temperatures in light and dark layers were 32.36 and 11.50°C. Also, the maximum differences about thermocline temperature during summer and fall seasons were 19.6°C and 10°C, respectively in southern part of Caspian Sea. Data in spatial analysis were not significant (p>0.05), it means if add or removed any transect did not change occurred. But in temporal analysis were significant (p<0.01), and it means no way remove any seasons for a research work on Caspian Sea in southern part. In those transects with 100m depth. Water temperature is only highly effective parameter between other parameters. In function 1 between 3 functions in transects with 100m depth water temperature with 60% variance was the main role and effective between different seasons in depth part were very high
Targeted Skipping of Human Dystrophin Exons in Transgenic Mouse Model Systemically for Antisense Drug Development
Antisense therapy has recently been demonstrated with great potential for targeted exon skipping and restoration of dystrophin production in cultured muscle cells and in muscles of Duchenne Muscular Dystrophy (DMD) patients. Therapeutic values of exon skipping critically depend on efficacy of the drugs, antisense oligomers (AOs). However, no animal model has been established to test AO targeting human dystrophin exon in vivo systemically. In this study, we applied Vivo-Morpholino to the hDMD/mdx mouse, a transgenic model carrying the full-length human dystrophin gene with mdx background, and achieved for the first time more than 70% efficiency of targeted human dystrophin exon skipping in vivo systemically. We also established a GFP-reporter myoblast culture to screen AOs targeting human dystrophin exon 50. Antisense efficiency for most AOs is consistent between the reporter cells, human myoblasts and in the hDMD/mdx mice in vivo. However, variation in efficiency was also clearly observed. A combination of in vitro cell culture and a Vivo-Morpholino based evaluation in vivo systemically in the hDMD/mdx mice therefore may represent a prudent approach for selecting AO drug and to meet the regulatory requirement
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