379 research outputs found
Discriminating cool-water from warm-water carbonates and their diagenetic environments using element geochemistry: the Oligocene Tikorangi Formation (Taranaki Basin) and the dolomite effect
Fields portrayed within bivariate element plots have been used to distinguish between carbonates formed in warm- (tropical) water and cool- (temperate) water depositional settings. Here, element concentrations (Ca, Mg, Sr, Na, Fe, and Mn) have been determined for the carbonate fraction of bulk samples from the late Oligocene Tikorangi Formation, a subsurface, mixed dolomite-calcite, cool-water limestone sequence in Taranaki Basin, New Zealand. While the occurrence of dolomite is rare in New Zealand Cenozoic carbonates, and in cool-water carbonates more generally, the dolomite in the Tikorangi carbonates is shown to have a dramatic effect on the "traditional" positioning of cool-water limestone fields within bivariate element plots. Rare undolomitised, wholly calcitic carbonate samples in the Tikorangi Formation have the following average composition: Mg 2800 ppm; Ca 319 100 ppm; Na 800 ppm; Fe 6300 ppm; Sr 2400 ppm; and Mn 300 ppm. Tikorangi Formation dolomite-rich samples (>15% dolomite) have average values of: Mg 53 400 ppm; Ca 290 400 ppm; Na 4700 ppm; Fe 28 100 ppm; Sr 5400 ppm; and Mn 500 ppm. Element-element plots for dolomite-bearing samples show elevated Mg, Na, and Sr values compared with most other low-Mg calcite New Zealand Cenozoic limestones. The increased trace element contents are directly attributable to the trace element-enriched nature of the burial-derived dolomites, termed here the "dolomite effect". Fe levels in the Tikorangi Formation carbonates far exceed both modern and ancient cool-water and warm-water analogues, while Sr values are also higher than those in modern Tasmanian cool-water carbonates, and approach modern Bahaman warm-water carbonate values. Trace element data used in conjunction with more traditional petrographic data have aided in the diagenetic interpretation of the carbonate-dominated Tikorangi sequence. The geochemical results have been particularly useful for providing more definitive evidence for deep burial dolomitisation of the deposits under the influence of marine-modified pore fluids
Chiral Magnetic Effect on the Lattice
We review recent progress on the lattice simulations of the chiral magnetic
effect. There are two different approaches to analyze the chiral magnetic
effect on the lattice. In one approach, the charge density distribution or the
current fluctuation is measured under a topological background of the gluon
field. In the other approach, the topological effect is mimicked by the chiral
chemical potential, and the induced current is directly measured. Both
approaches are now developing toward the exact analysis of the chiral magnetic
effect.Comment: to appear in Lect. Notes Phys. "Strongly interacting matter in
magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A.
Schmitt, H.-U. Ye
STABILIZATION POND FOR WASTEWATER TREATMENT
This research is concerned with study and check the suitability of waste stabilization ponds (WSPs) for treating wastewater in Al-Dewaniyah province by taking a sample of community of 10000 population.Experimental work had three cases depending on many considerations such as economical and specification of final effluent. A model of two ponds (facultative and aerobic) in series was used as first case of experimental work. Then third pond with aeration process to aerobic pond were added to the series as second case to improve the effluent. At last, sand filter was used to polish the final effluent from aerobic pond.The three ponds had the same surface area (5.75m*2m) but with different depths, where it was 2m for anaerobic pond, 1.5m for facultative pond and 0.75m for aerobic pond. From the tests taken for the three cases, the results obtained for the last two cases were much better when compared with first case. Sand filter contributed in improving final effluent by decreasing total suspended solid (TSS) also in increasing removal efficiency of biochemical oxygen demand (BOD) and chemical oxygen demand (COD). At the end, the results of this work could be an invitation to use waste stabilization pond for wastewater treatment in rural areas or even small communities but it may need more examinations to get best results
Lattice QCD Simulations in External Background Fields
We discuss recent results and future prospects regarding the investigation,
by lattice simulations, of the non-perturbative properties of QCD and of its
phase diagram in presence of magnetic or chromomagnetic background fields.
After a brief introduction to the formulation of lattice QCD in presence of
external fields, we focus on studies regarding the effects of external fields
on chiral symmetry breaking, on its restoration at finite temperature and on
deconfinement. We conclude with a few comments regarding the effects of
electromagnetic background fields on gluodynamics.Comment: 31 pages, 10 figures, minor changes and references added. To appear
in Lect. Notes Phys. "Strongly interacting matter in magnetic fields"
(Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Ye
Об использовании элементов метода ветвей и границ в схемах динамического программирования
Рассматривается возможный способ повышения эффективности алгоритмов по методу динамического программирования при решении условных экстремальных задач с аддитивными целевыми функциями, заданными на дискретных множествах. Основной идеей рассматриваемого способа является сокращение областей определения экстремума при решении рекуррентных уравнений Беллмана путем сравнения текущих значений функции Беллмана с рекордом, аналогично схеме метода ветвей и границ
Fluorescent RNA cytosine analogue - an internal probe for detailed structure and dynamics investigations
The bright fluorescent cytosine analogue tCO stands out among fluorescent bases due to its virtually unquenched fluorescence emission in duplex DNA. However, like most reported base analogues, it has not been thoroughly characterized in RNA. We here report on the first synthesis and RNA-incorporation of tCO, and characterize its base-mimicking and fluorescence properties in RNA. As in DNA, we find a high quantum yield inside RNA duplexes (<?F> = 0.22) that is virtually unaffected by the neighbouring bases (?F = 0.20-0.25), resulting in an average brightness of 1900 M-1 cm-1. The average fluorescence lifetime in RNA duplexes is 4.3 ns and generally two lifetimes are required to fit the exponential decays. Fluorescence properties in ssRNA are defined by a small increase in average quantum yield (<?F > = 0.24) compared to dsRNA, with a broader distribution (?F = 0.17-0.34) and slightly shorter average lifetimes. Using circular dichroism, we find that the tCO-modified RNA duplexes form regular A-form helices and in UV-melting experiments the stability of the duplexes is only slightly higher than that of the corresponding natural RNA (<?T m> = + 2.3 °C). These properties make tCO a highly interesting fluorescent RNA base analogue for detailed FRET-based structural measurements, as a bright internal label in microscopy, and for fluorescence anisotropy measurements of RNA dynamics
Fused Dithienogermolodithiophene Low Band Gap Polymers for High-Performance Organic Solar Cells without Processing Additives
An approach to optimize manufacturing productivity: A pilot study on labor intensive industries
A pilot study was conducted on labor intensive industries to measure the impact of intangible resource inputs on manufacturing productivity. Three intangible resource inputs, degree of skills of labor, favorable working environment, R & D knowledge, were used to measure the impact on productivity. Firm’s data of business operations of sample manufacturing industries, have been used for analysis.Study showed, a positive but weak correlation (r0.5) exists between inputs of upgraded working environment and
productivity.A strong and positive correlation is found (r>0.7) between R & D based inputs and productivity. Additionally, the productivity gain ratio was found significantly good (rp >1.3) for R & D base inputs. Study concludes, expenditure on manufacturing R & D is essentially important to generate knowledge as higher value added input to have higher productivity
Sensorless force estimation on fingertip with gravitational compensation for heavy-duty pneumatic tri-grasper robot
The paper presents the proposed sensorless force estimator design for pneumatic robot fingertip by using gravitational compensation and pressure changed in pneumatic cylinder piston. The approach is done to replace the commercial force sensor that may be expensive for heavy-duty configuration. The formulation was done by considering the torque of robot's finger joint, finger dimension as well as its actuator and the different pressures in cylinder piston. The gravitational force is calculated from the geometry of the robot's finger as dynamic gain for the force of pneumatic cylinder. The proposed method is validated on a heay-duty pneumatic Tri-grasper Robot with the simple basic movement and blocked randomly by human barehand. The results show that the force output by the estimator is almost identical to the loadcell sensor that attached on the fingertip at about 2% error in average. The sensitivity is a bit low for small and fragile material but enough for heavy-duty application that generally with hard and rough surfaces
Cement Kilns Dust Management In Iraq
Hundred thousands tons of cement kiln dust (CKD) as well as other emissionsare generated annually from existing cement plants in Iraq with significanteconomic and environmental impacts. Therefore, an environmental sector planshould be adopted to scrub the emissions and sound management of CKD wasteleading to save resources and secure better environmental quality are called for.A survey was conducted and carried out covering all cement plants. Analysis ofdata collected has shown that the production capacity was significantly decreasedto about 38 % on the average of the designed capacity. The consumption of rawmaterials and fuel per unit production was increased by about 13 % and 23 %,respectively. The amount of generated CKD is found to be variable among thedifferent cement plants. It can be estimated that the generated CKD on the averageis about (8-33) % of the production output depending on the conditions of eachplant.This study serves to establish a factual basis to develop a convenientenvironmental management plan for the cement industry sector. This studyproposes an environmental mitigation and monitoring plan to address theenvironmental and social challenges to improve the environmental performance ofIraqi cement industry sector
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