In this article, we introduce the concept of co-covering which is the dual of covering concept. Then, we prove several theorems being similar to the theorems that have been de-veloped for the covering concept. For example, we provide the lifting criterion for co-coverings of a topological space X, which helps us to classify them by subgroups of the group of all homeomorphisms of X.

we give the concept of ‘braiding’ for 2-groupoids, and we show that this structure is equivalent tobraided regular, crossed modules.

background: the detrimental effects of partially hydrogenated vegetable oils (phvos) on apolipoproteins have been reported from several parts of the world; however, few data are available in this regard from the understudied region of the middle east. the present study aimed to evaluate the association between type of vegetable oils, serum lipids and apolipoprotein levels among iranians. method...

scholars have divided novels into various types based on differentcriteria including content, structure, place, etc. some novels have been writtenwith the key topic of oil and its relevant issues, thus having a specialautonomy which bans them to be placed under the novel category. therefore, anew name should be chosen for these novels, something which seems forgotten innovel categorization. usi...

The paper presents the rationale, significance, method and procedure of building a taxonomy of semantic relations in the oil spill domain for supporting knowledge discovery through inference. Difficult problems during the development of the taxonomy are discussed and partial solutions are proposed. A preliminary functional evaluation of the taxonomy for supporting knowledge discovery was perfor...

Produced water is present in oil and natural gas reservoirs transported to the surface along with oil. Total grease content (TOG) main parameter evaluated this waste disposal category. Today, validation of methods laboratory not done using petroleum. The objective work was develop synthetic oily standards that can be applied for internalization laboratory. Oil weighing protocols, influence vola...

This program aims to help the people of Pasenan Village be able make a simple distillation device, which is used by residents convert patchouli plants into essential oils. Most have gardens planted with plants, but local not done conversion oil. The limited knowledge community about process one obstacles faced community. Patchouli are only dried and sold directly collectors. condition Village, ...