Archives for July 21st, 2012 | Academic Articles

July 2012
M	T	W	T	F	S	S
« Jun		Aug »
	1
2	3	4	5	6	7	8
9	10	11	12	13	14	15
16	17	18	19	20	21	22
23	24	25	26	27	28	29
30	31

Archive for July 21st, 2012

My two minds

The article looks at the effects of speaking a second language on cognitive ability in areas such as learning, problem solving, and multitasking. Although scientists once believed that exposure to a second language could delay cognitive development in infants, bilingual children outperform monolinguals on developmental tests, and research using functional near-infrared spectroscopy (fNIRS) brain imaging showed that bilingual infants displayed greater neural activity in response to new language. Research into bilingualism indicates deep connections between language and thought, influencing human social skills, delaying brain aging, and shaping personality.

July 21, 2012 Tags: ABILITY testing, BILINGUALISM, BILINGUALISM in children, BRAIN -- Aging, BRAIN -- Imaging, COGNITIVE ability, COGNITIVE development, HUMAN multitasking, LEARNING, PERSONALITY, PROBLEM solving, RESEARCH, SOCIAL skills, THOUGHT & thinking
Category: Articles No Comments

Multiple regression models up to first-order interaction on hydrochemistry properties

This study illustrated the procedure in selecting the best model in estimating the Electrical Conductivity (EC) levels based on the hydrochemistry properties and nature effecting factors using multiple regressions. The six independent variables and two dummy variables considered in this data set. The Multiple Regression (MR) models were involved up to first-order interaction and there were 57 possible models considered. This study is the extension of prior research which had generated 63 possible models, by using the same technique but no interaction involved between the independent variables. In this study, the process of getting the best model from the total of 120 possible models had been illustrated. The backward elimination of variables with the highest p-value was employed to get the selected model. The best model includes the combination of single and first order interaction (Li, Mg, Na-SO4, Na-Li, Na-Mg and SO4-Mg). The best model obtains then being verified by the Mean Absolute Percentage Error (MAPE) calculation to measure the models’ relative overall fit. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: ELECTRIC conductivity, ERROR analysis (Mathematics), MANAGEMENT science, REGRESSION analysis, VARIABLES (Mathematics), WATER chemistry
Category: Articles No Comments

Molecule-specific determination of atomic polarizabilities with the polarizable atomic multipole model

Recently, many polarizable force fields have been devised to describe induction effects between molecules. In popular polarizable models based on induced dipole moments, atomic polarizabilities are the essential parameters and should be derived carefully. Here, we present a parameterization scheme for atomic polarizabilities using a minimization target function containing both molecular and atomic information. The main idea is to adopt reference data only from quantum chemical calculations, to perform atomic polarizability parameterizations even when relevant experimental data are scarce as in the case of electronically excited molecules. Specifically, our scheme assigns the atomic polarizabilities of any given molecule in such a way that its molecular polarizability tensor is well reproduced. We show that our scheme successfully works for various molecules in mimicking dipole responses not only in ground states but also in valence excited states. The electrostatic potential around a molecule with an externally perturbing nearby charge also exhibits a near-quantitative agreement with the reference data from quantum chemical calculations. The limitation of the model with isotropic atoms is also discussed to examine the scope of its applicability. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: ATOMS -- Models, DIPOLE moments, ELECTROSTATICS, MOLECULAR dynamics, POLARIZABILITY (Electricity), QUANTUM chemistry
Category: Articles No Comments

Mineralization, alteration, structure, and re–os age of the lanjiagou porphyry mo deposit, north china craton

Lanjiagou is a porphyry Mo deposit in terms of its alteration zonation and mineralization associated with granitic intrusions and predominance of quartz vein-hosted molybdenum mineralization. It is the largest Mo deposit in North China Craton (404,000 t). There is an intimate spatial/temporal association between all stages of mineralization and Early Jurassic granitic intrusions at Lanjiagou. Most of the molybdenum was emplaced during the principal hydrothermal (PH) stage (184.6 ± 1.3 – 185.6 ± 1.4 Ma), contemporaneously with intrusion of fine-grained porphyritic granite (188.9 ± 1.2 Ma) into a granite batholith (193 ± 3 Ma). The PH mineralization stage is mainly hosted by a quartz-dominated stockwork associated with phyllic alteration in the fine-grained porphyritic granite. This stage was followed by the late hydrothermal (LH) activity. Thick Mo-rich quartz veins were emplaced during the LH stage and cut the porphyry ore bodies. A ring breccia zone formed during the last hydrothermal stage and apparently cuts both the porphyry and the quartz vein ore bodies. The main hydrothermal vein stages have predominantly concentric and radial vein orientations centred on the ring breccia zone. Most of the concentric veins have shallow dips, whereas the radial veins are subvertical. The LH veins have predominantly NEE and NW orientations in the deposit and are moderately inclined. We surmise that the veining was controlled by the local stress regime generated by the intrusion of a large, deep pluton that we interpreted to be the source of the granites, the breccia zone, and the molybdenum mineralization. Resurgence within the magma chamber reactivated the steep concentric structures in a reverse sense, and accumulation of magmatic and/or fluid pressure resulted in explosive brecciation, producing the ring breccia zone. A predominantly late set of NW-trending, post-ore felsic dikes, associated with the regional structures, are a consequence of far-field stresses exceeding local stresses in the deposit. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: CRATONS, GRANITE, INTRUSIONS (Geology), MOLYBDENUM ores, ORE deposits
Category: Articles No Comments

Material man

The article explores the reluctance of British inventor Maurice Ward to divulge his secret for a way to protect homes, airplanes, and spacecraft from fire and heat. Topics include Ward’s demonstration on the British television show “Tomorrow’s World” of a protective coating he invented, called Starlite, his reluctance to share Starlite’s formula with researchers, and multiple attempts to discover how Starlite worked following his death in May 2011.

July 21, 2012 Tags: FIREPROOFING agents, INVENTORS, PROTECTIVE coatings, THERMAL barrier coatings
Category: Articles No Comments

Management of the taxation on tourism operators, an important component of revenues and investments in the tourism sector

We are trying to bring here the importance that tourism taxation has. Based on the fact that tourism industry is becoming one of the most important branches of the economy, it is essential to find the best solution, the best taxes rates that would encourage tourism development, and the most important part is that this funds should be used to invest, to refund tourism industry. In this way we will have an increase of the income from the tourism. Of course, a strong taxation system will have negative impact on tourism industry. High rates of taxes would have negative impact on competitiveness, and would be a great disaster towards competitiveness and incomes. It is extremely important, to do the best towards the tax system, in this way the tourism could be encouraged. To better understand the system taxation in tourism we did the SWOT analyses. Based on these analysis we are going to bring here some conclusions and recommendations. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: COMPETITION (Economics), INCOME, SWOT analysis, TAX administration & procedure, TOURISM -- Taxation
Category: Articles No Comments

Latest technologies of rotating machine lubrication and lubricant selection

Practical notes and latest achievements on lubrication of rotating machines, including reciprocating compressors, screw compressors, centrifugal compressors, axial compressors, steam turbines, gas turbines, engines, pumps, electrical motors and generators, are discussed. Also recommendations about mineral oils, synthetic oils, synthesised hydrocarbon lubricants, gear unit lubrication and bearing lubrication are presented. Moreover, practical recommendations on correct lubrication oil selection, modern lubrication oil systems and effective lubricant change-over are described. Some case studies are also presented. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: AXIAL flow compressors, LUBRICATION & lubricants, ROTATING machinery, SCREW compressors, STEAM-turbines
Category: Articles No Comments

Land price model considering spatial factors

Many studies have highlighted that Ordinary Least Square (OLS) regressions lack the ability to consider spatial dependency including spatial n on-station arity which then lead to bias and inefficient estimations. Land prices are usually depending on locations yielding the prices vary from place to place. Therefore, estimates obtained from the OLS ignoring spatial factors may be inappropriate. Geographically Weighted Regression (GWR) is an alternative model considering spatial non-stationarity. In addition to its appropriateness, GWR produces local specific parameter estimates which then are very useful for the policy makers to avoid a misleading judgment. Some geographic social characteristics and related infrastructures are often used as the determinants or the explanatory variables of applied models for the land prices. In this study, the residuals of both GWR and OLS models were contrasted to obtain the best model. The maps of coefficients of the determinants varied from place to place. Also, we found that the most influential factors were the distance to the high-way gate, the distance to the artery-road and the distance to public facilities. [ABSTRACT FROM AUTHOR]

July 21, 2012 Tags: CORRELATION (Statistics), LAND use, LEAST squares, MATHEMATICAL statistics, REGRESSION analysis, SPATIAL ability
Category: Articles No Comments

academic articles on popular topics

Academic Articles

Archives

Recent Posts