Microcomputer Aided Selection Of Robot Manipulators

This paper presents two programs for microcomputer aided assessment of the performance of robot manipulators. The first program automatically generates robot models based on user-supplied kinematic parameters. The program also derives a kinematic model that relates the motion of manipulator end-effector to the motion of the joints using the inverse kinematic approach. The approach uses a robust inversion technique that can handle singular conditions as well as joint redundancy. A user can optionally select evaluation of kinematic capabilities of the robot manipulator, such as the ability of the end-effector to reach a specified position and orientation in space or the evaluation of the work space. The second program generates dynamic variables, such as forces and torques, based on user-supplied dynamic parameters and equations of motion of the various joints. Both programs are written for implementation on personal computers. Several runs were carried out to demonstrate the capability and execution times of the two program

Temperature effects on the electrical performance of large area multicrystalline silicon solar cells using the current shunt measuring technique

The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5ºC up to 50ºC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed

An improved design of a fully automated multiple output micropotentiometer

This paper describes in details a new design of a fully automated multiple output micropotentiometer (?pot). A prototype has been built at the National Institute for Standards (NIS), Egypt to establish this highly improved AC voltage source in the millivolt range. The new device offers three different outputs covering a wide frequency range from only one outlet. This valuably supports the precise sourcing ranges of low AC voltage at NIS. The design and the operation theory of this prototype have been discussed in details. An automatic calibration technique has been introduced through specially designed software using the LabVIEW program to enhance the calibration technique and to reduce the uncertainty contributions. Relative small AC-DC differences of our prototype in the three output ranges are fairly verified. The expanded uncertainties of the calibration results for the three output ranges have been faithfully estimated. However, further work is needed to achieve the optimum performance of this new device

Utilization of Metakaolin as an Inhibitor of Alkali Silica Reaction in Cement Mortars Containing Chert and Silicified Limestone Aggregates

The following work aims at investigating the utilization of meta-kaolin and calcined brown smectite rich clays as inhibitors of alkali silica reaction (ASR) and improving the compressive strength in Type 1 ordinary Portland cement mortars including sand size chert or silicified limestone.   Mortars were cured and tested at 56 days age.  The compressive strength values increased to 40 MPa for the sample with 10% of Metakaolin-and 3.64% of chert content. The compressive strength values increased to 30 MPa when calcined brown clay was used instead of Meta-kaolin at the same proportion of chert.. Maximum compressive strength values of 36 Mpa and 30 Mpa were achieved when metakaolin and calcined brown clay were added to the reference mortars at a range of 5-10% and 8% respectively. Compressive strength was varied according to reactive aggregate type and percent in addition to the calcined brown clay and meta-kaolin content in the tested mortars.  Scanning electron Microscope images (SEM) have indicated the absence of cracks usually related to swelling silica gel due to the consumption of the gel through its reaction with kaolin and calcined brown clay. Keywords: chert, silicified limestone, metakaolin, alkali silica reactio

Time Management in Social Networking Sites and Its Role in Preventing the Risk of Addiction to These Sites Among Its Users

This study aimed to identify time management in social networking sites and its role in preventing the risk of addiction to these sites among its users. The researcher used  a descriptive survey method based on data and information collection tools (analysis of documents and records) to answer the questions of the study. The study sample  consisted of (412) male and female university students which was chosen based on simple random selection from (Yarmouk University, Jadara University, Irbid National university. For achieving the purposes of the study,  the researcher developed the study tool (questionnaire) which is  consisted of (22) items. After verifying its reliability and  validity the researcher calculated the means, standard deviations, frequency and percentages. The results showed that the role of time management in social networking sites in preventing the risk of addiction to these sites among its users  ranged from (moderate - very high) . The results also showed that there was a statistically significant difference to the estimates of the members of the study sample on time management in social networking sites and its role in  preventing the risk of addiction to these sites among users from the university students as a whole. It is attributed to the gender variable in favor of males and for the school year variable. The results showed that there was no statistically significant difference for the study sample due to the college variable. Keywords: time, time management, social networking sites (SNS), addiction. DOI: 10.7176/JEP/11-8-19 Publication date:March 31st 2020

Inhibition of Nischarin Expression Attenuates Rilmenidine-Evoked Hypotension and Phosphorylated Extracellular Signal-Regulated Kinase 1/2 Production in the Rostral Ventrolateral Medulla of Rats

Imidazoline (I1)-evoked hypotension is linked to enhanced phosphorylated extracellular signalregulated kinase (pERK)1/2 production in the rostral ventrolateral medulla (RVLM). Recent cell culture findings suggest that nischarin is a candidate for the I1 receptor. In the present study, nischarin antisense oligode-oxynucleotide (ODN) (AS1 or AS2), designed according to nischarin cDNA sequence, was administered intracisternally (i.c., 2 nmol/rat for 2 days) to knockdown central nischarin expression; control rats received the corresponding mismatched ODN (MM1 or MM2) or artificial cerebrospinal fluid (aCSF). We investigated the effects of AS1 or AS2 on nischarin expression in the RVLM, and on the hypotension and RVLM pERK1/2 production elicited by the I1-selective agonist rilmenidine (25 μ g/rat i.c.). Compared with aCSF, the mismatched ODN (MM1 or MM2) had no significant effect on RVLM nischarin expression or the cardiovascular and cellular (RVLM pERK1/2) responses elicited by rilmenidine. However, either antisense ODN substantially (>80%) reduced nischarin expression in the RVLM (AS1/MM1, 3 ± 1 versus 32 ± 2 positive cells; AS2/MM2, 4 ± 1 versus 31 ± 2 positive cells) and abrogated rilmenidine (I1)-evoked hypotension (AS1/MM1, −4.1 ± 0.9 versus −10.8 ± 1.9 mm Hg; AS2/MM2, −2.1 ± 1.1 versus −15.3 ± 2.5 mm Hg) and ERK1/2 activation in the RVLM (AS1/MM1, 10 ± 1 versus 15 ± 2 positive cells; AS2/MM2, 9 ± 1 versus 18 ± 2 positive cells). Finally, pERK1/2 generated by central I1 receptor activation is colocalized with nischarin in the RVLM neurons. This is the first evidence in vivo that nischarin plays a critical role in I1 receptor-mediated pERK1/2 production in the RVLM and the subsequent hypotension. Origianlly published Journal of Pharmacology and Experimental Therapeutics, Vol. 324, No. 1, Jan 200