Planar Rayleigh scattering results in helium-air mixing experiments in a Mach-6 wind tunnel

Planar Rayleigh scattering measurements with an argon—fluoride excimer laser are performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach-6 facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross-sectional area (5 cm × 10 cm) of the flow field in the absence of clusters

Performance of shear wall with external reinforcement by CFRP and steel sheets against blast load

Increase of terrorist attack in the present time detects necessity of retrofitting of existent structures or design of new structures which can resist blast loads. In this research, a shear concrete wall subjected to explosive load will be analytically investigated. CFRP sheets will be applied for retrofitting the wall, and its performance in strengthening of the wall will be studied. Also a kind of shear composite wall is modeled and analyzed under the blast load. Results are compared, and advantages and disadvantages of these types of walls will be represented. Validation of analytical simulation is done by modeling of two experimental tests and good agreements have been obtained. Results show that pasting every other CFRP layers in vertical manner will increase performance of the wall as well as warping the entire wall by CFRP sheets. External reinforcement by CFRP will significantly improve energy absorption of the wall comparing use of steel sheets. Also, increase of number of layers causes consideration improve in energy damping and negligible effect on wall displacement

Active fixturing: literature review and future research directions

Fixtures are used to fixate, position and support workpieces and represent a crucial tool in manufacturing. Their performance determines the result of the whole manufacturing process of a product. There is a vast amount of research done on automatic fixture layout synthesis and optimisation and fixture design verification. Most of this work considers fixture mechanics to be static and the fixture elements to be passive. However, a new generation of fixtures has emerged that has actuated fixture elements for active control of the part–fixture system during manufacturing operations to increase the end product quality. This paper analyses the latest studies in the field of active fixture design and its relationship with flexible and reconfigurable fixturing systems. First, a brief introduction is given on the importance of research of fixturing systems. Secondly, the basics of workholding and fixture design are visited, after which the state-of-the-art in active fixturing and related concepts is presented. Fourthly, part–fixture dynamics and design strategies which take these into account are discussed. Fifthly, the control strategies used in active fixturing systems are examined. Finally, some final conclusions and prospective future research directions are presented

Convergent synthesis of new N -substituted 2-{[5-(1H -indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetamides as suitable therapeutic agents

abstract A series of N-substituted 2-{[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetamides (8a-w) was synthesized in three steps. The first step involved the sequential conversion of 2-(1H-indol-3-yl)acetic acid (1) to ester (2) followed by hydrazide (3) formation and finally cyclization in the presence of CS2 and alcoholic KOH yielded 5-(1H-indole-3-yl-methyl)-1,3,4-oxadiazole-2-thiol (4). In the second step, aryl/aralkyl amines (5a-w) were reacted with 2-bromoacetyl bromide (6) in basic medium to yield 2-bromo-N-substituted acetamides (7a-w). In the third step, these electrophiles (7a-w) were reacted with 4 to afford the target compounds (8a-w). Structural elucidation of all the synthesized derivatives was done by 1H-NMR, IR and EI-MS spectral techniques. Moreover, they were screened for antibacterial and hemolytic activity. Enzyme inhibition activity was well supported by molecular docking results, for example, compound 8q exhibited better inhibitory potential against α-glucosidase, while 8g and 8b exhibited comparatively better inhibition against butyrylcholinesterase and lipoxygenase, respectively. Similarly, compounds 8b and 8c showed very good antibacterial activity against Salmonella typhi, which was very close to that of ciprofloxacin, a standard antibiotic used in this study. 8c and 8l also showed very good antibacterial activity against Staphylococcus aureus as well. Almost all compounds showed very slight hemolytic activity, where 8p exhibited the least. Therefore, the molecules synthesized may have utility as suitable therapeutic agents

Yield and Production Gaps in Wheat in Parsabad Moghan, northwest of Iran

Wheat has an important role in food production of the world and Iran as well. It provides around 40 percent of energy and protein intake of Iran’s people. Closing yield gap can increase wheat production. The first step of closing yield gap is to quantify the yield gap at a given region or country. The objective of this research was to determine wheat (Triticum spp. L.) yields and production during the two cropping years (2013-2015) in the Parsabad Moghan in Ardabil province, northwest of Iran. To calculate the actual yield, a 22-year of official data and 460 farms under the management of farmers during 2014-2016 were used. The average and maximum attainable yield was estimated using field experiment results (FLD), comparative performance analysis (CPA) and the 90th percentile of record yield distribution. Based on the results of this research, a significant management yield gap was observed between attainable and actual yield (22%). In addition; genetic (i.e., gaps due to genetic selection) and total gaps in wheat were 11% and 36%, respectively. The increase in wheat production with the genetic selection and optimal crop management for the studied 28154 ha was estimated to be approximately 59000 tons with an economic value of 2.59 million dollars. Based on the results of this research, the yield potential of wheat genotypes can be achieved by closing yield gaps in the study area