The environmental impacts of calcium chloride addition to cement on reinforcing steel corrosion

An alternative use of a specific type of cement for a particular purpose, usually we can change some properties of available cement by using the appropriate additions, with some negative side effects in some cases. In this research have been suggested values ??of calcium chloride(CaCl2) additions for use in concrete admixtures as an agent factor in accelerating the process of cement setting, to clarify the extent of the negative impacts that could be induced, such as alkalinity decline of solution and the impact of the chemical composition of used cement on reinforcing steel. Chloride ion present in low alumina cement mortar was detected quickly, while it needed to increase calcium chloride content to double in moderate alumina cement mortar. The results showed that the depth of carbonation when samples of different composition and with various w/c ratio treated by stream was faster in low ammonia cement mortar from moderate ammonia and faster in mortar poor than in mortar rich, In addition, depth of carbonation increased when the calcium chloride content in cement was very small. Electrical potential of steel in cement mortar inversely proportional with increasing calcium chloride content and with increasing in water/cement ratio and increasing sand content in cement mortar medium ammonia. The lowest level of steel oxidation observed in mortar consisting of cement medium ammonia and the rate of corrosion increases when samples treated by stream in all cases. Keywords: Calcium Chloride, Oxidation, Reinforcement, Stream Treatment, Carbonation, Concrete admixtures, Electric potentia

Intelligent control of miniature holonomic vertical take-off and landing robot

This paper discusses the development of a fuzzy based controller for miniaturized unmanned aerial vehicle (UAV).This controller is designed to control the center-of-gravity (CoG) in a new configuration of coaxial miniaturized flying robot (MFR). The idea is to shift the CoG by controlling two pendulums located in perpendicular directions; each pendulum ends with a small mass. A key feature of this work is that the control algorithm represents the original nonlinear function that describes the dynamics of the proposed system. The controller model incorporates two cascaded subsystems: PD and PI fuzzy logic controllers. These two controllers regulate the attitude and the position of the flying robot, respectively. A model of the proposed controllers has been developed and evaluated in terms of stability and maneuverability. The results show that the presented control system can be used efficiently for the MFR applications

Design, synthesis, molecular modeling and biological evaluation of novel diaryl heterocyclic analogs as potential selective cyclooxygenase-2 (COX-2) inhibitors

AbstractNew series of 3,4-diaryl-2-thioxoimidazolidin-4-ones and 3-alkylthio-4,5-diaryl-4H-1,2,4-triazoles were designed, synthesized and evaluated for their activity as anti-inflammatory agents. Compounds 20, 21, 23 and 34 are highly selective inhibitors of COX-2 enzyme at a concentration of 100mM relative to celecoxib, the standard reference. (±)-3-(4-Phenoxy-phenyl)-5-phenyl-2-thioxoimidazolidin-4-ones 23 exhibited the most active anti-inflammatory agent

Application of fractional sub-equation method to nonlinear evolution equations

In this paper, we constructed a traveling wave solutions expressed by three types of functions, which are hyperbolic, trigonometric, and rational functions. By using a fractional sub-equation method for some space-time fractional nonlinear partial differential equations (FNPDE), which are considered models for different phenomena in natural and social sciences fields like engineering, physics, geology, etc. This method is a very effective and easy to investigate exact traveling wave solutions to FNPDE with the aid of the modified Riemann–Liouville derivative

(E)-2-Cyano-N′-(1,2,3,4-tetra­hydro­naphthalen-1-yl­idene)acetohydrazide

In the title compound, C13H13N3O, the tetra­hydro­benzene ring adopts a half-boat (envelope) conformation. The mean plane of the tetra­hydro­naphthalene ring system forms a dihedral angle of 9.56 (6)° with the mean plane of the cyano­acetohydrazide group. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) loops. The dimers are connected by C—H⋯N hydrogen bonds into a chain propagating along [101]. The crystal packing also features C—H⋯π inter­actions

3-(Adamantan-1-yl)-4-methyl-1-[(4-phenyl­piperazin-1-yl)meth­yl]-1H-1,2,4-triazole-5(4H)-thione dichloro­methane hemisolvate

The asymmetric unit of the title dichloro­methane hemisolvate, C24H33N5S·0.5CH2Cl2, comprises an adamantan­yl/triazole derivative and half a CH2Cl2 mol­ecule of crystallization; the latter is disordered about a twofold axis of symmetry. The piperazine ring has a chair conformation and the two N-bound substituents occupy equatorial positions. The piperazine residue is almost normal to the triazole ring [N—N—C—N torsion angle = −79.9 (3)°] so that to a first approximation, the mol­ecule has an L-shape. Linear supra­molecular chains parallel to [001] are formed via C—H⋯S inter­actions. Two such chains are linked into a double chain via C—H⋯Cl inter­actions involving the disordered CH2Cl2 mol­ecules of solvation

3-(Adamantan-1-yl)-1-[(4-benzyl­piperazin-1-yl)meth­yl]-4-[(E)-(2-hy­droxy­benzyl­idene)amino]-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C31H38N6OS, the conformation about the N=C [1.285 (2) Å] imine bond is E. The piperazine ring has a chair conformation and occupies a position almost perpendicular to the plane through the triazole ring; the benzene ring forms a dihedral angle of 31.95 (10)° with the triazole ring. Overall, the mol­ecule has the shape of a flattened bowl. The hy­droxy group is disordered over two positions. The major component has a site-occupancy factor of 0.762 (3) and forms an intra­molecular O—H⋯N(imine) bond to close an S(6) loop. The minor component of the disordered hy­droxy group forms an O—H⋯N(piperazine) hydrogen bond. These, along with C—H⋯S and C—H⋯N inter­actions, link mol­ecules into a three-dimensional architecture

3-[(N-Methyl­anilino)meth­yl]-5-(thio­phen-2-yl)-1,3,4-oxadiazole-2(3H)-thione

In the title compound, C14H13N3OS2, the thio­phene ring is disordered over two orientations by ca 180° about the C—C bond axis linking the ring to the rest of the mol­ecule, with a site-occupancy ratio of 0.651 (5):0.349 (5). The central 1,3,4-oxadiazole-2(3H)-thione ring forms dihedral angles of 9.2 (5), 4.6 (11) and 47.70 (7)° with the major and minor parts of the disordered thio­phene ring and the terminal phenyl ring, respectively. In the crystal, no significant inter­molecular hydrogen bonds are observed. The crystal packing is stabilized by π–π inter­actions [centroid–centroid distance = 3.589 (2) Å]

Methyl 2-{6-[(1-meth­oxy-1-oxopropan-2-yl)amino­carbon­yl]pyridine-2-carboxamido}­propano­ate

In the title compound, C15H19N3O6, the amide planes are inclined at dihedral angles of 0.8 (6) and 12.1 (3)° with respect to the central pyridine ring. The mean planes of the corresponding methyl acetate groups form dihedral angles of 41.76 (13) and 86.48 (15)°, respectively with the mean plane of pyridine ring. A pair of weak intra­molecular N—H⋯N hydrogen bonds generate an S(5)S(5) ring motif in the mol­ecule. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into [001] chains. The chains are cross-linked by C—H⋯O hydrogen bonds into layers lying parallel to bc plane. The crystal packing also features a C—H⋯π inter­action

N′-[(2-n-Butyl-4-chloro-1H-imidazol-5-yl)­methyl­idene]adamantane-1-carbo­hydrazide sesquihydrate ethanol hemi­solvate

In the asymmetric unit of the title compound, C19H27ClN4O·0.5C2H6O·1.5H2O, there are two mol­ecules of the Schiff base, which has a rigid adamantyl cage at one end of the C(= O)NH–N=CH– chain and an almost planar [torsion angles = 1.3 (1) and 7.9 (2)° imidazolyl ring at the other end, three mol­ecules of water and one mol­ecule of ethanol. In both independent mol­ecules of the Schiff base, this chain displays an extended zigzag configuration. All their amino groups function as hydrogen-bond donors to water mol­ecules; these are linked to other acceptor atoms, generating a layer structure. O—H⋯O and O—H⋯N inter­actions involving the water mol­ecules also occur