This paper studies the effect of single vacancy defect on the fundamental frequency of carbon nanotube using finite element method. Cantilevered and bridged boundary conditions have been used for carbon nanotube with and without attached mass. There is less effect on the frequency of cantilevered structure due to presence of defect at center rather than its presence at other positions. Presence of defect near to fixed end shows more effect on fundamental frequency of bridged structure as compared to other positions. Cantilevered structure with attached mass shows increase in effect due to presence of defect when mass ranges from 10-3 to 10-6 femtogram, while it seems to remain constant with further decrease in mass. This paper is mainly concerned about the overall effect of single vacancy defect at the different positions and with different parameters of carbon nanotubes with and without attached mass.

Use of rotor with heavy mounting is becoming common recently, thus the demand to study rotor dynamics of rotor is increasing day by day. It becomes complicated to study vibrations when damping effect is considered. It becomes necessary to consider effect of damping near resonance frequency. For other frequencies, role of damping is negligible. The behavior of rotor assembly is largely depends on damping. With finite element analysis we can overcome these problems and find the acceptable results. In this study, response analysis is performed for a rotating vertical pump rotor assembly with the operating speed of 2970 RPM. Modal analysis is carried out with rigid supports. Modal analysis helps to detect the natural frequency of system which we can ultimately compare with operational frequency. Stiffness and damping values are calculated for all sleeve bearing. Results shows considerable margin between natural frequencies and operational frequencies. So, the structure can be considered as safe for operating conditions. If such analyses have already been performed during the original installation, the original rotor, numerical model exist whereby small modifications (e.g. Coupling exchange, change of oil type, added mass, new rotor diameter, etc.) can easily be made and new analysis done with little effort. The objective of analysis is to analyze the system and estimate the rotor\'s first, second and third the dry bending natural frequencies & lateral critical speeds of the rotating system. Also, understand the associated mode shapes & plot Campbell diagram to determine potential resonance points with respect to the operating speed (2970 rpm). This will ensure that the system is having sufficient margin as per API 610 over the wet critical speed during the actual operation.

The analysis of regional scientific research focused on the development of ecotourism, but also of certification systems, indicates that the Delphi method has not been used in many scientific papers in Romania. The aim of this study is to show the applicability of the Delphi method in the process of identifying the knowledge of experts in the field of tourism, but also of experts in other fields, regarding ecotourism certification systems, from the definition to the factors on which a destination depends for obtain certification from such a system. Using a two-round Delphi survey, 50 experts from the country were consulted over a four-month period for certification systems and their impact on the destination of Ţara Hațegului - Retezat. The results indicate that the participants in this study have a brief knowledge of ecotourism certification systems, although half of them do not have studies in the field of tourism. The results can be applied to clarify existing frameworks for certification systems and to help develop new ecotourism frameworks.

A two-years study was conducted to assess mulch effects on irrigated tomato yield. Tomato (Roma variety) was grown using daily irrigation (IFdaily), irrigation at 3-days interval (IF3) and irrigation at 5-days interval (IF5) at 100% field capacity under five rates of Pennisetum purpureum (Pp) mulch [No mulch control (Pp0), 1 t ha-1 (Pp1), 2 t ha-1 (Pp2), 3 t ha-1 (Pp3) and 4 t ha-1 (Pp4)] in a completely randomised design. Tomato yield was higher in IFdaily than IF3 (by 53.6% and 26.6%) and IF5 (by 86.2% and 65.0%) in years 1 and 2, respectively. Among mulch rates, Pp4 and Pp3 increased fresh fruit weight by 107.5% and 99.9% relative to Pp0, respectively., while Pp2, Pp1 and were similar in year 1. In year 2, yield increase was in the order: Pp4 (215.3%) > Pp3 (125.2%) > Pp2 (104.2%) > Pp1 (84.1%). Pennisetum purpureum mulch had positive significant effects [(R2 = 0.99; p < 0.01) IFdaily; (R2 = 0.93; p < 0.01) IF3; and (R2 = 0.25; p < 0.05) IF5] on irrigated tomato yield, but was substantially limited under 5-days irrigation interval.