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Search Results: 1 - 10 of 12984 matches for " Monica Stefan "
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Monica Stefan,Florentina Ciomo?
Acta Didactica Napocensia , 2010,
Abstract: The students’ interest and attitude towards Physics have been the object of internationaltesting, the most recent of which is the PISA testing from 2006. The students’ attitude towards sciences isconsidered to be a significant predictor of their school results in science, respectively of pursuing a careerin areas related to Science. The present paper had in view to discover the existence of convergences ordivergences among the attitudes of the students in 8th and 9th grade towards the study of natural sciencesand towards the teacher’s role in studying for the natural sciences. The obtained results have not renderedevidently the existence of major differences but have allowed for the shaping of a profile for Physics as aschool subject, from the interviewees’ perspective. Thus, Physics is considered to be a difficult butpleasant and interesting subject, with use for oneself but for others as well. Our investigation has pointedout the fact that the students study too little for Physics at home, but that the Physics teacher is effectivein teaching and motivating the students to learn. Although this is a pilot research project, ourinvestigation signals a state of fact that implies reflection, mainly on the Physics curriculum but also onthe teaching methods.
Microbiologic study regarding the risk of cross infection in the technical laboratory
Monica Tatarciuc,Ionut Cristian Zamfirache,Marius Stefan,Anca Vitalariu
Analele ?tiin?ifice Ale Universit??ii Alexandru Ioan Cuza din Ia?i,Sectiunea II A : Genetica si Biologie Moleculara , 2010,
Abstract: The purpose of this paper is to highlight the influence of amino acids (histidine, glutamic acid, serine, valine, methionine, asparagine, α-alanine) on catalase and peroxidase activity in Phanerochaete chrysosporium grown on media containing fir and beech sawdust. In view of this research, Sabouraud medium carbon source was replaced by pine and beech sawdust 4 g per 100 ml medium and nitrogen source in the corresponding amino acid with different amounts of 100 mg N / L, resulting in the final eight work variants for each type of sawdust namely V1- valine, V2- histidine, V3- asparagine, V4- methionine, V5-glutamic acid, V6-α-alanine, V7- serine and V8 control who did not introduce any source nitrogen. Determination of catalase activity was done by spectrophotometric Sinha method and the peroxidase with ortho-dianisidine method at 11 days and 18 days after seeding, in fungus mycelium and culture liquid. Following the study found that the activity of these two enzymes was influenced by the type of amino acid, the nature of sawdust and fungus age.
Analysis of Convective Thunderstorm Split Cells in South-Eastern Romania
Daniel Carbunaru,Sabina Stefan,Monica Sasu,Victor Stefanescu
International Journal of Atmospheric Sciences , 2013, DOI: 10.1155/2013/162541
Abstract: The mesoscale configurations are analysed associated withthesplitting process of convective cells responsible for severe weather phenomena in the south-eastern part of Romania. The analysis was performed using products from the S-band Doppler weather radar located in Medgidia. The cases studied were chosen to cover various synoptic configurations when the cell splitting process occurs. To detect the presence and intensity of the tropospheric jet, the Doppler velocity field and vertical wind profiles derived from radar algorithms were used. The relative Doppler velocity field was used to study relative flow associated with convective cells. Trajectories and rotational characteristics associated with convective cells were obtained from reflectivity and relative Doppler velocity fields at various elevations. This analysis highlights the main dynamic features associated with the splitting process of convective cells: the tropospheric jet and vertical moisture flow associated with the configuration of the flow relative to the convective cells for the lower and upper tropospheric layers. These dynamic characteristics seen in the Doppler based velocity field and in the relative Doppler velocity field to the storm can indicate further evolution of convective developments, with direct implications to very short range forecast (nowcasting). 1. Introduction In south-eastern Romania, in the convective season (from May to September), severe weather phenomena develop frequently and evolve [1–5], sometimes leading to significant damages. Analysis of severe convective events and their structure, at least for certain classes of phenomena (isolated convective cells), taking into account the mesoscale configuration can improve the nowcasting procedures. Using an S-band Doppler radar (10?cm wavelength), we see that the mesoscale phenomena (supercellular thunderstorms) have certain features during their dynamic evolution. Of great importance in understanding the evolution of supercells is the splitting process (separation of the convective cells in two other ones rotating opposite to one another, namely, cyclonic and anticyclonic), a process that takes place during the evolution of convective developments and is closely linked to the state of mesoscale dynamic configuration, especially vertical wind shear [6, 7]. This process has been studied both qualitatively [8–18] and by numeric analysis [19–21], highlighting the interaction between horizontal vorticity from the vertical profile of horizontal wind and the updraft. Depending on the curvature of the hodograph, the
Correspondence Analysis on a Space-Time Data Set for Multiple Environmental Variables  [PDF]
Palma Monica
International Journal of Geosciences (IJG) , 2015, DOI: 10.4236/ijg.2015.610090
Abstract: Applications of the multivariate technique called correspondence analysis for environmental studies are relatively new and are limited to spatial multivariate data set. In this paper, a procedure of applying correspondence analysis to a large space-time data set for multiple environmental variables is shown. In particular, nitrogen dioxide and carbon monoxide hourly concentrations measured during January 1999 at several monitored stations in a district of Northern Italy are analyzed. The procedure consists in transforming the continuous variables into categorical ones by the means of appropriate indicator variables, generating special contingency tables and applying correspondence analysis. The use of this classical multivariate technique allows the identification of important relationships among pollution levels and monitoring stations and/or relationships among pollution levels and observation times.
Analysis of pharmacogenetic traits in two distinct South African populations
Ogechi Ikediobi, Bradley Aouizerat, Yuanyuan Xiao, Monica Gandhi, Stefan Gebhardt, Louise Warnich
Human Genomics , 2011, DOI: 10.1186/1479-7364-5-4-265
Abstract: The field of pharmacogenomics aims to utilise the genetic composition of an individual to personalise therapeutic regimens and improve treatment outcomes. Most of the initial examples of the clinical utility of pharmacogenomics were elucidated for cancer treatments. Currently, however, there are more than 15 drugs used in the treatment of a variety of chronic diseases, such as cardiovascular disease, HIV/AIDS and seizures, for which the US Food and Drug Administration (FDA) recommends or requires pharmacogenomic testing to prevent drug-related toxicity or improve drug efficacy [1]. The increase in the number and breadth of drugs for which pharmacogenetic tests are recommended or required by the FDA is an indication of the important role that genetics plays in predicting treatment outcomes.In order for pharmacogenetic testing to have the most impact in as many people possible, it is important to understand which genetic variants are predictive of treatment outcomes in diverse populations. Most pharmacogenetics studies to date have been conducted in a limited number of population groups, most frequently in Western European and North American Caucasians. As a result of these limitations, genotype-to-phenotype correlates of drug response or toxicity for a number of drugs are clinically applicable in relatively few treated individuals. Furthermore, pharmacogenetic profiles characterised in Caucasians are often extrapolated for use and interpretation in other populations, in spite of at least two major problems with this method. First, it is clear that the population frequency of variants can differ markedly between populations, such as Caucasians. The differences in population frequencies of variant alleles has an impact on the clinical utility of pharmacogenetic testing, being more utilised in populations with a higher frequency of the variant allele than in populations in which the variant allele is rare. Secondly, ethnically specific variants exist in non-Caucasian po
Effect of Transcranial Brain Stimulation for the Treatment of Alzheimer Disease: A Review
Raffaele Nardone,Jürgen Bergmann,Monica Christova,Francesca Caleri,Frediano Tezzon,Gunther Ladurner,Eugen Trinka,Stefan Golaszewski
International Journal of Alzheimer's Disease , 2012, DOI: 10.1155/2012/687909
Abstract: Available pharmacological treatments for Alzheimer disease (AD) have limited effectiveness, are expensive, and sometimes induce side effects. Therefore, alternative or complementary adjuvant therapeutic strategies have gained increasing attention. The development of novel noninvasive methods of brain stimulation has increased the interest in neuromodulatory techniques as potential therapeutic tool for cognitive rehabilitation in AD. In particular, repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are noninvasive approaches that induce prolonged functional changes in the cerebral cortex. Several studies have begun to therapeutically use rTMS or tDCS to improve cognitive performances in patients with AD. However, most of them induced short-duration beneficial effects and were not adequately powered to establish evidence for therapeutic efficacy. Therefore, TMS and tDCS approaches, seeking to enhance cognitive function, have to be considered still very preliminary. In future studies, multiple rTMS or tDCS sessions might also interact, and metaplasticity effects could affect the outcome.
Effect of Pixellization on Efficiency and Stability of MEH-PPV Based Polymer Light-Emitting Diodes  [PDF]
Ranbir Singh, Monica Katiyar
Journal of Encapsulation and Adsorption Sciences (JEAS) , 2012, DOI: 10.4236/jeas.2012.21002
Abstract: Organic light-emitting diodes are generally depicted as sequential deposition of active layers and electrodes onto a substrate, but commercial devices are fabricated using pixellization technique, where an insulator layer is introduced between the indium tin oxide and organic layer to define the area of the active device. Here, we have inserted a layer of photoresist (thickness ~ 200 nm) at the edge of patterned anode (indium tin oxide) and between the anode and hole transport layer (Poly 3, 4-ethylenedioxythiophene poly styrenesulfonate) to examine its effect on the leakage current of organic light-emitting diode and on the electron-hole recombination ratio in the emission area, as a result increasing the luminance efficiency. Current leakage causes the loss of charges, which adversely affects the recombination of electrons and holes in the emitting zone and results in poorer luminance efficiency. In this paper, we report the effect of pixellization on current density-voltage, luminescence-voltage and degradation behavior of single layer Poly[2-methoxy-5-(2’-ethylhexyloxy)-1, phenylene vinylene] based organic light-emitting diodes. Devices with isolation layer have 30% higher external electroluminescence quantum efficiency and reduced device degradation in comparison to without isolation layer.
Critical Factors in Managing Relationally Demanding Jobs, in Care for Very Ill and/or Dying Patients: A Phenomenological Study among Public Hospital Nurses  [PDF]
Asgerdur Bjarnadottir, Monica Lillefjell
Open Journal of Nursing (OJN) , 2015, DOI: 10.4236/ojn.2015.51007
Abstract: Background: Workload, interpersonal relationships, professional conflict and the emotional cost of providing care are potential sources of stress and burnout among nurses. Based on experiences of hospital nurses, this paper aims to identify critical factors for nurses in managing relationally demanding situations in care for very ill and/or dying patients. Methods: In-depth interviews were carried out with six nurses, working in a medium-sized hospital in Norway. The interviews were analysed using an interpretative phenomenological analysis. Results: The lack of identification with the core aspect of the job, relational contact with patients and relatives, and external motivation were found as potential barriers for managing relationally demanding jobs. The results also indicate that the nurses’ experiences of symptoms of burnout can be a result of demands that exceeded the nurses’ resources. A match between personal capacity and demands, mutual support among colleagues and leadership support, and contextual factors are critical to prevent the negative process of burnout. Conclusion: The results underscore the importance of an early response to employees who are beginning to struggle at work and the relevance of a true match between personal capacity and job demands. Moreover support among colleagues and leadership seems critical to prevent a negative process of burnout and help to manage relationally demanding jobs.
Thin Film Encapsulation at Low Temperature Using Combination of Inorganic Dyad Layers and Spray Coated Organic Layer  [PDF]
Sandeep Kumar, Monica Katiyar
Journal of Encapsulation and Adsorption Sciences (JEAS) , 2017, DOI: 10.4236/jeas.2017.74011
Abstract: Organic devices have many advantages such as low material consumption and low energy requirements, but they have serious issues regarding long term stability. Hence we need to develop a barrier film which solves this problem. Initially, the organic devices were fabricated on glass and were encapsulated using glass and epoxy (as sealant). Gradually there was a need to shift on to flexible substrates which required encapsulation to be flexible as well. Therefore, the motivation of the work is to develop thin film encapsulation that can be made flexible. The low temperature PECVD grown films of SiOx and SiNxwere used as the barrier film. Alternate inorganic layers (2-dyads) provided barrier of ~10-2 g/m2 day and increasing the number of dyads to five improved the water vapor transmission rate (WVTR) only by one order of magnitude. However, introducing organic layers in this structure resulted in WVTR value of order 10-5 g/m2 day. The organic layers were deposited by spray technique.
Comparison of Different Control Algorithms for a Gantry Crane System  [PDF]
Stefan Bruins
Intelligent Control and Automation (ICA) , 2010, DOI: 10.4236/ica.2010.12008
Abstract: For a gantry crane system, this paper presents a comparison between four control algorithms. These algo-rithms are being compared on simplicity, stability and robustness. Goal for the controller is to move the load on a gantry crane to a new position with minimal overshoot of the load and maximal speed of the load. An-other goal is to provide an insight in the behaviour of the possible controllers. In this article a parallel P-controller, cascade P-controller, fuzzy controller and an internal model controller are used. To be able to validate and design the controllers a model is derived from the gantry crane. The controllers and the model are being implemented in Matlab Simulink. Finally the controllers are validated and tuned in Labview on a laboratory gantry scrane scale model. Main conclusion is that all presented controllers can be used as a con-troller for the gantry crane system but the fuzzy controller is showing the best performance.
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