Estimation of Extreme Loads of the Mi-24 Helicopter During Maneuvers Using Simulation Method

The aim of the study is to assess the loads that are transferred from the main rotor and the tail rotor to the helicopter fuselage. These loads change in the various phases of the transient flight as a result of the variable control of the maneuver and as a result of the variable flow around the blades. The knowledge of the loads allows for the proper selection of the level of excitations that should load the fuselage structure during fatigue and strength tests. The simulation model describing the helicopter flight is discussed. This model takes into account the motion of each blade relative to its hinges. Results are shown for two maneuvers - pullup/pushover and diving. The values of extreme loads transferred to the fuselage were obtained.

DEVELOPING A HYBRID DIDACTIC COURSE IN ESP

This paper proposes a hybrid didactic ESP course, which comprises Blended Learning, Flipped Classroom and Project Based Learning with adequate activities. The paper shows that most of the proposed activities stipulate a high fulfilment indicator, and a correlation between a proper selection of didactic materials and the degree of students´ achievement and satisfaction at the end of each course.

Patulin-producing mold, toxicological, biosynthesis, and molecular detection of patulin

Mycotoxin is one of the food safety problems that raise concern because of its negative health impact and significant economic losses. Patulin is the most common mycotoxin found in fruits and its products like apple, orange, grape, pear, etc. There are 167 species reported to produce patulin; Penicillium expansum is the major patulin producer among those fungi species. Patulin is not classifiable as to its carcinogenicity to humans, but some studies showed the toxicities of patulin. Patulin has a broad spectrum of toxicity such as acute toxicity, sub-acute toxicity, genotoxicity, embryotoxicity and teratogenicity, carcinogenicity, and immunotoxicity. There are several ways to detect mycotoxins, such as HPLC, TLC, ELISA, and PCR. The popular way to detect mycotoxin molecularly is PCR because of its sensitivity and specificity. To detect patulin molecularly require proper selection of target gene. Therefore, the biosynthesis of patulin, its influencing gene, and its underlying factor needs to be understood.

The influence of knot types on rope static tensile strength

The choice of material, type of braid and rope parameters are a broad issue of great importance in the designing process. An equally important issue is the proper selection of knot type used for attaching the rope to the other elements of a structure, as this is a critical point accumulating major stresses. Inappropriate tying of a rope may decrease its tensile strength by over 50%; therefore, it is an important issue in terms of structural strength. This article investigates different tying configurations of the same rope and shows the influence of knot types on rope static tensile strength.

Optimization of the drive mechanism with lead screw using Isight software

The ball screws are characterized with better positioning accuracy and higher efficiency and load ratings than the same size lead screw, but still cannot fully replace their functionality mostly due to the self-locking. Leads screws are recommended especially for such applications as grippers, lifters, presses and vertical positioning drives. By proper selection of the lead screw geometrical features and application of the modern materials, it is possible to obtain much more advantageous parameters of the drive system. In this paper, the methodology of optimization of the drive mechanism with lead screw using Isight software is presented. The performed sensitivity analysis allowed not only to find the influence of various constructional features such as: size of the thread, length of the screw and material properties, on the maximum load capacity of the drive mechanism and its inertia, but also determine its scale impact. The obtained results can improve the design process of lead screw mechanism.

Step Bunches, Nanowires and Other Vicinal “Creatures”—Ehrlich–Schwoebel Effect by Cellular Automata

Different patterns can be created on the surface of growing crystals, among which the step bunches and/or step meanders are two of the most studied. The Ehrlich–Schwoebel effect at the surface steps is considered one of the “usual suspects” of such patterning. A direct step barrier is when it is easier to attach a particle to the step from the lower terrace than from the upper terrace. Thus, during the process of crystal growth leads to the formation of meanders, while an inverse barrier leads to step bunching. Based on our vicinal Cellular Automaton model, but this time in (2 + 1)D, we show that the combination of a direct and inverse step barrier and the proper selection of the potential of the well between them leads to the formation of bunched step structures. Following this is the formation of anti-bands. In addition, changing the height of the direct step barrier leads to the growth of nanocolumns, nanowires, and nanopyramids or meanders, in the same system.

Evaluation of Turnip (Brassica rapa L.) Var PTWG for Yield and Relative Economics under Frontline Demonstrations in District Budgam

The study was conducted to evaluate the turnip variety purple top white globe for yield and yield contributing characters through front line demonstration in District Budgam for three consecutive years 2018,2019 and 2020.A total of 25 FLD’s were distributed in village Roshanabad of block Narbal, District Budgam. The results obtained reveals that the improved variety was having higher yield and hence better returns to the farmers as compared to the local variety. Study also revealed a wide gap in the production technology of turnip. The farmers themselves observed the difference between the improved variety and local. The yield increase of 57.9% over the control and B:C ratio of 3.48 in demonstration plot (2.13 in control) may be attributed to scientific cultivation method viz proper selection of variety, use of quality seed, seed treatment, proper spacing, recommended dose of fertilizers and integrated pest management.