3-Acetyl-5-phenyl-1-p-tolyl-1H-pyrazole-4-carbonitrile

In the title pyrazole derivative, C19H15N3O, the central pyrazole ring makes dihedral angles of 42.71 (9) and 61.34 (9)°, respectively, with the phenyl and p-tolyl rings. The dihedral angle between the phenyl and p-tolyl rings is 58.22 (9)°. The 3-acetyl-1H-pyrazole-4-carbonitrile unit is essentially planar, with an r.m.s. deviation of 0.0295 (1) Å for the ten non-H atoms

1-(4-Methyl­phen­yl)-2-(phenyl­sulfon­yl)ethanone

In the title compound, C15H14O3S, the benzene and phenyl rings make a dihedral angle of 33.56 (16)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into a layer parallel to the ab plane

(Z)-2-(4-Chloro­benzyl­idene)benzo[d]thia­zolo[3,2-a]imidazol-3(2H)-one

The mol­ecule of the title compound, C16H9ClN2OS, is approximately planar, the dihedral angle between the thia­zolo[3,2-a]benzimidazole ring system and the 4-chloro­phenyl ring being 2.10 (5)°. An intra­molecular C—H⋯S inter­action generates an S(6) ring motif. In the crystal, mol­ecules are stacked into columns along the b axis by π–π inter­actions with centroid–centroid distances of 3.6495 (7)–3.9546 (8) Å

A study of the climate of Egypt with special reference to agriculture

This thesis contains a study of the climate of Egypt with special reference to agriculture. It is organised in three main sections. The main body of the thesis, beginning with Chapter 3 (Temperatures in Egypt), deals with surface, earth and water temperatures in detail. Analysis of daily maximum temperatures at selected stations during the 15 year period (1960 - 1974) showed that spring is the period during which the frequency and severity of hot spells is greatest. Analysis of precipitation over Egypt showed that the rainy season in Egypt occurs between October and May and the maximum rainfall over the coastal Mediterranean region occurs in January, but in Middle and Upper Egypt this maximum occurs in October and May. Evaporation and evapotranspiration was estimated using the Penman equation and the Thornthwaite formula for selected stations in Egypt. These indicated that the evaporation and evapotranspiration values for each month are very high at Aswan, Kharga and Dakhla stations, in comparison to Alexandria and Tanta. The main weather features which are sufficient to specify what is called Khamsin weather have been analysed. These are excessively high surface temperatures and extremely low humidities, associated with the invasion of south and south-east winds which produce rising dust and duststorms. It is also seen that there are two types of Khamsin depressions. The first originates over the Atlantic and the second forms to the south of the Atlas mountains. Factor analysis techniques have been used to classify the climate of Egypt. The results showed that the climate of Egypt can basically be divided into two climatic zones. The first comprises the Mediterranean Coastal area, including the Delta. The second zone covers the rest of the country south of Cairo. Multiple regression equations have been used to explain the relationships between the crop yields and selected climatic variables. The results derived show that the multiple regression equations analysing climatic data have good predictive qualities in terms of annual yields

N′-[(1E,2E)-1-(2-Phenyl­hydrazin-1-yl­idene)-1-(phenyl­sulfon­yl)propan-2-yl­idene]benzohydrazide

The configuration about each C=N bond in the title compound, C22H20N4O3S, is E. While to a first approximation the phenyl­hydrazin-1-yl­idene and benzohydrazide residues are coplanar, in part due to the presence of an intra­molecular N—H⋯N hydrogen bond, significant twists are evident in the orientations of the hydrazine [N—N—C—C torsion angle = −170.74 (11)°] and benzoyl benzene [N—C—C—C = −21.72 (18)°] rings. The sulfonyl benzene ring occupies a position almost normal to the rest of the mol­ecule [C—S—C—N = −92.28 (10)°]. Centrosymmetric aggregates mediated by pairs of hydrazide–sulfonyl N—H⋯O hydrogen bonds are the predominant packing motif in the crystal. These are connected into linear supra­molecular chains via C—H⋯O inter­actions which are, in turn, linked into layers in the ac plane via C—H⋯π inter­actions. Connections between layers along the b-axis direction are of the π–π type and occur between centrosymmetrically related hydrazine-bound benzene rings [centroid–centroid separation = 3.7425 (9) Å]

Electrical performance study of a large area multicrystalline silicon solar cell using a current shunt and a micropotentiometer

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell by using multimeters suffer from some problems because the cell has high current intensity with low output voltage. So, the solar cell short circuit current values are obtained by measuring the voltage developed across a known resistance Current Shunt. Samples of the obtained current values are accurately calibrated by using a Micropotentiometer (μpot) thermal element (TE) to validate this new measuring technique. Moreover, the solar cell open circuit voltage has been measured. Besides, the cell output power has been calculated and can be correlated with the measured incident radiation

Ethyl 1-(4-methyl­phen­yl)-5-phenyl-4-phenyl­sulfon­yl-1H-pyrazole-3-carboxyl­ate

The title compound, C25H22N2O4S, features a tetra-substituted pyrazole ring. The dihedral angles formed between the five-membered ring (r.m.s. deviation = 0.007 Å) and the N- and C-bound phenyl rings are 48.10 (7) and 72.01 (7) °, respectively, indicating that the planes through the residues are significantly twisted from the plane through the heterocycle. The ester-CO2 group is also twisted out of this plane, with an O—C—C—N torsion angle of −29.04 (11)°. The sulfonyl-O atoms lie to one side of the pyrazole plane and the sulfonyl­phenyl ring to the other. The dihedral angle between the two ring planes is 70.63 (7) °. Supra­molecular arrays are formed in the crystal structure sustained by C—H⋯O and C—H⋯π(pyrazole) inter­actions and methyl-C—H⋯π(N-bound benzene) contacts