ESTIMATION OF THE REAL AREA OF AU NANOPARTICLES OVER HOPG USING ELECTROCHEMICAL TECHNIQUES

The metallic electrodes show a high affinity for the electroadsorption processes of hydrogen and/or oxygen in acid solutions, so it is possible to characterize them by electrochemical techniques. In the present work the electroreduction of oxygenated species will be used to estimate the real areas of the electrodes designed with Au nanostructures in HOPG at different times of deposition. The results allow to conclude that Au nanostructures in HOPG can reach important electroactive areas. That is to say that despite their nanometric sizes they have a great capacity to experience the transfer of charge.

Development of a solar element model using the method of fractal geometry theory

It is shown that in the existing models of the solar cell, assumptions were made about the ideally smooth surface topography, which had a significant impact on the calculation of the output parameters. It is proposed to take into account the real working area of the receiving surface of the solar cell to improve the accuracy, linearity and stability of the current-voltage characteristics. A geometric model of the structure of the receiving surface of a solar cell has been developed, which describes and takes into account geometric changes in the structure of a semiconductor conducting layer, in the presence of damaging defects in the form of local inhomogeneities, micropores and macrocracks. It was found that the receiving surface with damaging defects is a porous inhomogeneous structure and has fractal properties: self-similarity, invariance, scalability. It is proposed to determine the real working area, to use the method of the theory of fractal geometry and, as an effective quantitative parameter for assessing the change in fractal structure, to choose the value of the fractal dimension. The obtained analytical expressions for the improved model establish the relationship between the output parameters and determine the degree of filling of the current-voltage characteristic for the output power and efficiency. The computational experiment showed that the real area can be much less than the geometric area of the topological relief and is quantitatively related to the change in fractal dimension in the range from 2.31 to 2.63. The obtained data on the real area, when solving analytical expressions for the solar cell model, play an important role in ensuring the stability and linearity of the current-voltage characteristic, increasing its accuracy up to 5 %.

Does Linearity Always Hold between Friction Force and Real Contact Area: An Experimental Study

Classical laws of friction suggest that friction force is proportional to the normal load and independent of the nominal contact area. As a great improvement in this subject, it is now widely accepted that friction force is proportional to the real area in contact, and much work has been conducted based on this hypothesis. In present study, this hypothesis will be carefully revisited by measuring the friction force and real contact area in-site and real-time at both normal loading and unloading stages. Our experiments reveal that the linear relation always holds between friction force and normal load. However, for the relation between friction force and real contact area, the linearity holds only at the loading stage while fails at the unloading stage. This study may improve our understanding of the origin of friction.

On the Influence of Microtopography on the Sliding Performance of Cross Country Skis

The sliding performance of cross country skis is mainly influenced by the ability of the ski base to minimize capillary forces and contact area. Whereas, the first condition depends on hydrophobicity, the second one is controlled by the ski grinding structure and the morphology of snow. In this contribution the results of sliding tests with five typical grinding structures will be presented and compared to calculations of the real area of contact. Surface topographies were measured and corresponding roughness features were analyzed by 3D optical microscopy. The measured ski base profiles and the measured grain size distribution of granular snow at −2°C were employed within a bearing model for a rough surface in contact with loose and freely-moving snow grains treated as ice spheres. For the five grinding structures, this model revealed a good correlation of the real area of contact between ski and snow with run times in lab-condition sliding tests. The results indicate that the snow-containing volume of the grinding structure is pivotal for tailoring the sliding behavior.

Religion - The Discipline of Restoring Communion Between People

We are tempted to make a hierarchy of disciplines, both in pre-university education, but sometimes even in university. Usually, the emphasis is on the disciplines in the real area, to the detriment of those in the human area. We go further and do the hierarchy in the same area and we have the feeling that physics is more important than mathematics, or chemistry is more valuable than technology and so on. As for the humanist side, philosophy and political science have long surpassed linguistics and history. In this context we ask ourselves: where is the place of theology or religion? To what extent can religion or theology contribute to the completion of the profile of the new man? As the importance of the spiritual component in the formation of young people is increasingly relativized and diminished, to the detriment of the somatic one, we wonder if religion was not misperceived and taught. This is why we would like to proclaim the truth about Christianity, which we should discover as clean and clear as spring water, in the discipline taught in schools.

Evolution of real area of contact due to combined normal load and sub-surface straining in sheet metal

Understanding asperity flattening is vital for a reliable macro-scale modeling of friction and wear. In sheet metal forming processes, sheet surface asperities are deformed due to contact forces between the tools and the workpiece. In addition, as the sheet metal is strained while retaining the normal load, the asperity deformation increases significantly. Deformation of the asperities determines the real area of contact which influences the friction and wear at the tool-sheet metal contact. The real area of contact between two contacting rough surfaces depends on type of loading, material behavior, and topography of the contacting surfaces. In this study, an experimental setup is developed to investigate the effect of a combined normal load and sub-surface strain on real area of contact. Uncoated and zinc coated steel sheets (GI) with different coating thicknesses, surface topographies, and substrate materials are used in the experimental study. Finite element (FE) analyses are performed on measured surface profiles to further analyze the behavior observed in the experiments and to understand the effect of surface topography, and coating thickness on the evolution of the real area of contact. Finally, an analytical model is presented to determine the real area contact under combined normal load and sub-surface strain. The results show that accounting for combined normal load and sub-surface straining effects is necessary for accurate predictions of the real area of contact.

Marketing and legal status of phytomedicines and food supplements in Morocco

ObjectivesThe Phytomedicine (PM) and Food supplements (FS) Market is considerably growing in Morocco a review of state is necessarily to structure and improve it.MethodsInformation was collected directly from the pharmacist through a questionnaire-based survey who was conducted in 284 pharmacies in the region of Fez-Meknes in Morocco. Data were analyzed and classified using relative frequency of citations (RFC).ResultsMore than 98% of the pharmacies commercialized the PM and FS, 80% of the pharmacists deny the existence of a real area dedicated to them, the majority (94%) of them prefer phytomedicine rather than classic drugs. This study reported about 64 products as the most used by the population of the region of Fez-Meknes among them 48 FS (75%) and 16 PM (25%) and the most marketed products are used for Transit Disorders (28.34%), then Anxiety (22.17%) and ENT Disease (20.18%).ConclusionsDespite the fact that Morocco is a country where people use medicinal plants daily, the commercialization of the PM and FS is still unstructured. Due to legal problem the PM Sold in the market are mainly exported. To assure development and also valorization of this sector the regulation of this market is highly required.

DETERMINATION OF AN APPROPRIATE PROJECTION SYSTEM FOR FOREST AREAS IN TURKEY

Geometrical surfaces such as sphere and ellipsoid are considered as reference surfaces since there is no geometric shape that perfectly represents the earth when translating the earth into a map plane. Hence, on 3D reference surfaces, it is almost impossible to perfectly preserve the angle, direction and area properties and transfer them to a map plane without any deformations. The scaled topographic maps produced in our country under provision of map production regulations are conformal projections that do not preserve area properties but angle and shape properties. Area values calculated by projection coordinates cannot be considered the exact area values therefore, an area reduction is needed. Area values calculated by ignoring this situation in GIS based software do not represent the accurate area values on reference surfaces. The aim of this study is to determine the best area preserving projection for GIS applications in which area values are important. In this study, the real area values of 25 large-extent forest parcels are determined by employing the Danielsen method with geographical coordinates on ellipsoid surface. These parcels are also calculated by using the area-preserving projections available in ArcGIS software and are compared to their real area values.

Bazı Üzüm Çeşitlerinde ve Asma Anaçlarında Yaprak Alanının Belirlenmesi

The amount and area of the leaves should be at an optimum level in order to maintain the product quality and not to adversely affect the vine growth. Because carbohydrates, which are essential for omca and are mostly stored in fruit and wood, are formed by leaves after photosynthesis. Leaf area can be used in many areas. Among these, photosynthesis capacity and plant growth rate may. Various tools and methods (planimetry, leaf area meter, width-product, weight-area calculation, image processing programs, etc.) are used in determining leaf area. In this study, 3 American grape rootstocks (5BB, 110 R, 1103 P) and 5 grapes (Alphonse Lavallée, Italıa, Mıchele Palierı and Narince, Yalova İncisi) were used as material. 20 shoots with 15-25 nodules were taken from the rootstocks and varieties of the omca and the leaves were photocopied according to the order of the node. The actual field values of the leaves were measured with a planimeter. Leaf stem and leaf width and length of the leaves were also measured. Regression analysis was performed between leaf stem, leaf blade width and length, leaf blade × length values and real area. The maximum leaf area on one shoot was 5 BB (2484 cm2) from rootstocks and Narince (2126 cm2) from varieties. All three rootstocks gave the average value of the leaf found in 9th node. In terms of node number, which gives an average value according to the varieties, Alphonse Lavallée, Mıchele Palierı and Yalova İncisi varieties came to the forefront in 11th node. The 13th in Narince cultivar and the 12th in Italia cultivar gave the closest value to the average.

Forecasting Gas and Oil Potential of Subsoil Plots via Co-analysis of Satellite, Geological, Geophysical and Geochemical Information by Means of Subjective Logic

The purpose of the paper is to substantiate a new approach to forecasting hydrocarbon potential of subsoil plots via co-analysis of satellite, geo-geophysical and geochemical information by means of subjective logic. Basic concepts of subjective logic are given, the method of forecasting the oil and gas potential of a subsoil plots is described. The method is tested by applying it to real area with hydrocarbon deposits.