Intelligent forecaster of concentrations (PM2.5, PM10, NO2, CO,O3, SO2) caused air pollution (IFCsAP)

Neural Computing and Applications - Upgrading health reality is the responsibility of all, it is necessary to think about the design of a smart system based on modern technologies to reduce the...     

Upregulation of imidazoline receptors in the medulla oblongata accounts for the enhanced hypotensive effect of clonidine in aortic barodenervated rats

The present study tested the hypothesis that an upregulation of the imidazoline receptor in the rostral ventrolateral medulla (RVLM) of aortic barodenervated (ABD) rats may account for the enhanced hypotensive effect of clonidine. In vitro autoradiographic radioligand binding studies were utilized to investigate the binding characteristics of imidazoline receptors in the RVLM and nucleus tractus solitarius (NTS), areas that play critical roles in cardiovascular regulation and elicitation of clonidine responses. ABD but not sham operation (SO) caused immediate and significant (P < 0.05) increases in mean arterial pressure (MAP) and heart rate (HR) and an impairment of the baroreflex-mediated HR response (baroreflex sensitivity, BRS). Two days after ABD, these parameters, except BRS, subsided to near-control (SO) levels. Intracisternal (i.c.) administration of clonidine (0.1 micrograms) elicited a 3-fold greater decrease in BP of conscious ABD compared with SO rats (-20.3 +/- 2.6 vs. -7.4 +/- 0.9 mmHg) thus demonstrating the ability of ABD to enhance centrally-mediated hypotensive responses. Autoradiographic visualization of brain sections obtained from separate groups of ABD and SO rats 48 h after surgery preincubated with [3H]idazoxan (2.5-3.5 nM) showed that [3H]idazoxan binding in RVLM, middle NTM (mNTS) and rostral NTS (rNTS) was saturable and of high affinity. Uneven distribution of imidazoline binding sites was evident since in control (SO) rats, Scatchard analysis of binding data revealed similar densities (Bmax) of [3H]idazoxan binding sites in the RVLM and mNTS versus significantly higher density in the rNTS. In ABD rats, the binding dissociation constant (Kd) was significantly decreased in both the RVLM (8.1 +/- 3.1 vs. 21.4 +/- 5.0 nM) and rNTS (12.3 +/- 1.3 vs. 18.6 +/- 3.1 nM) compared with SO rats while the Bmax was not affected. This finding suggests an increased receptor affinity in the RVLM and rNTS of barodenervated rats. The mNTS of ABD rats exhibited significant increases in the Bmax (861 +/- 96 vs. 570 +/- 87 fmol/mg protein) compared with values of SO rats but the receptor affinity was not affected. It is concluded that: (i) aortic baroreceptors exert a tonic inhibitory influence on central imidazoline receptor function; and (ii) the enhanced hypotensive effect of clonidine in conscious ABD rats may be accounted for by the increased affinity of the medullary imidazoline receptors particularly in the RVLM.     

s-Triazole systems. Part IV: Novel substituted thio-s-triazole derivatives

Interaction of (3-aryloxymethyl-4-phenyl-striazol-5-yl)thioacethydraz-ide ( la -c) with phenyl isocyanate and/or with methyl/phenyl isothiocyanate gave semicarbazides ( 2a -c) and thiosemicarbazides ( 3a-f ) respectively. Cyclization of ( 3a-f ) yielded s-triazoles ( 4a-f ). Compounds 4b,d,f were easily alkylated giving S-substituted thio-s-triazoles ( 5a-e ). Furthermore, compounds 4b,d,f underwent a Mannich reaction to give the expected Mannich bases ( 6a-f ). All compounds were fully confirmed by elemental and spectral analyses and have been screened in vitro, for antimicrobial activity.     

A rotary flange forming process on the lathe using a ball-shaped tool

Flanging of tube ends is carried out using casting or assembly joining, which have drawbacks due to improper strength, defect generation or low efficiency. In this work, flange forming of Al tubes was performed on the lathe utilizing a ball-shaped tool attached to the lathe carriage, and fed outwards radially while the specimen clamped to the lathe chuck and rotated. Tubular specimens, were rotated at 500 rpm, and the tool feed was 0.314 mm/rev. Ball diameter (D_ball) of 12.8 mm was fixed, while the tool advance distance (T_a) at the start of flanging was 0.125, 0.25, 0.5, 0.625D_ball. Oil was used as a lubricant. Results showed that the radial flanging force was increased as t₀ and T_a increased. An approximate contact area calculation was presented and the calculated loads were in agreement with the experimentally obtained ones. Relatively large flanging ratios (FR) were obtained and those were found to increase as t₀ decreases and T_a increases. Maximum thinning was observed at the flange edge followed by an increase in thickness towards the area between the tube and flange. Surface hardness increased as t₀ increased.     

On the yaw-angle characteristics of hot-wire anemometers

The directional sensitivity of hot-wire probes depends basically on the velocity and degree of turbulence of the flow as well as on the type of probe used. A velocity/yaw-angle calibration for different types of hot-wire probes is presented. The yaw-angle calibration was performed for a wide range of calibration velocities. It is demonstrated that the yaw parameters in the available yaw-angle techniques vary with the yaw angle and flow velocity, and therefore a constant value is not suitable with a varying velocity flow. It is further shown that the cosine-cooling approach, the simplest approach to the yaw dependence among available techniques, is as good as other techniques for yaw angles 70° and high velocities.     

Generalized algorithm for computing the 4-3-4 N-axis robotic trajectory

A generalized inversion technique and algorithm is presented for the purpose of computing the 9n coefficients pertaining to the three segments—i.e., liftoff, transitory, and setdown—of a motion trajectory of an n-axis robot manipulator. The technique and the computer program presented is general enough to be immediately applicable to an n-axis robot manipulator if only the desired initial and final position, velocity, acceleration, as well as the intermediate “via” positions are given. A number of examples are presented for a wide spectrum of these constraint conditions on the desired motion trajectories.     

Water Conservation in Oman

ABSTRACT

Limited resources and growing needs for water have triggered a nationwide campaign for water conservation in the Sultanate of Oman. A land and soil survey study of Oman shows the availability of more arable land than present water resources could support. Groundwater is the main source for agricultural production. Overpumping at rates higher than the natural recharge has resulted in lowering of the ground water table, while seawater intrusion has led to an increase in soil salinity. A comprehensive water program is underway to: (1) conserve water through efficent irrigation, use of soil additives, modern irrigation systems, agronomic management, and institutionalization; and (2) augmentation of resources via introduction of more desalinization plants, more waste water treatment, use of brackish water; water fog collection, and water harvesting by building recharge dams.     

Photoactive linear and hyperbranched polyesters based on 4-methylcyclohexanone and 4-<Emphasis Type="Italic">tert</Emphasis>-butylcyclohexanone moieties in the main chain: synthetic methodology,characterization and cytotoxicity

In this work, a variety of photoactive linear and hyperbranched unsaturated polyesters P1a-d, P2a-d and P3a-d, were successfully synthesized via ring-opening polymerization of diarylidene epoxy monomers 2a-d with terephthalic acid, isophthalic acid or trimesic acid in presence of TABI as a catalyst. First, diarylidene-epoxy monomers 2a-d were obtained from diols of diarylidene cycloalkanones derivatives 1a-d followed by epoxidation with epichlorohydrin in presence of NaOH and TBAI. These diaryldene epoxy monomers 2a-d were applied in the preparation of P1a-d, P2a-d and P3a-d. The molar masses of the resulting unsaturated polyesters were determined by gel permeation chromatography (GPC); all polymers have moderate molar masses. The photo-responsive properties of selected examples of polymers were tested in THF under UV lamp (450 nm) at different time intervals, This study revealed the occurrence of photocrosslinking behavior in the system under these conditions. The thermal properties of these polyesters were evaluated by thermogravimetric analysis (TGA). The morphological properties of selected examples of polymers were tested using scanning electron microscope (SEM). In addition, the cytotoxicity of the prepared monomers and selected polymers was tested against HeLa cervical cancer cells using MTT cell viability assay. All monomers except 2c showed significant cytotoxic effects with IC₅₀?>?21 μM. In contrast, the tested polymers were less potent against HeLa cells.

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Design of Miniature UWB-Based Antenna by Employing a Tri-Sectional SIR Feeder

A novel ultra-wideband (UWB)-based microstrip antenna is presented in this work by using a slotted patch resonator, a tri-sectional stepped impedance resonator (SIR) feeder, as well as a reduced ground plane. The whole structure was realized on an FR4 substrate. The impact of incorporating several cases of ground planes on the input reflection has been thoroughly investigated under the same tri-sectional SIR feeder and by employing a slotted patch radiator. Since the complete ground plane presents an inadequate frequency response, by reducing the ground plane, the induced UWB responses are apparent while the antenna exhibits higher impedance bandwidth. The impact of both the uniform impedance resonator (UIR) as well as the SIR feeder on the input reflection has also been examined by following the same adopted reduced ground technique and using a slotted patch radiator. As a result, the UIR feeder exhibits a dual-band frequency response, when a wide notched band is incorporated in the range from 4.5–6.5 GHz. The dual-band response of the bi-sectional SIR feeder is still apparent with a narrower notched band in the frequency range from 4–5 GHz. As far as the tri-sectional SIR feeder is concerned, the UWB response is discernible without recording the existence of a notched band. Additionally, the antenna displays a higher impedance bandwidth compared with the previously reported steps. Our proposed antenna configuration is designed with highly compact dimensions and an overall size of 14 × 27.2 mm². Moreover, it operates under the impedance bandwidth of 2.86–10.31 GHz that can be leveraged for numerous applications where wireless systems are used. Our approach presents several advantages compared with the other reported UWB-based antennas in the literature, whereas the measured S₁₁ pattern is in good agreement with the simulated one.     

Maximizing lifetime of large-scale wireless sensor networks using multi-objective whale optimization algorithm

Telecommunication Systems - The sink nodes in large-scale wireless sensor networks (LSWSNs) are responsible for receiving and processing the collected data from sensor nodes. Identifying the...