In the present study, an attempt has been made to improve the electrical, dielectric and thermal properties of magnesium aluminate by doping with the binary mixtures of transition metals: Zn, Cd, Ni and Co and following five series of the doped compounds have been synthesized Mg 1-2x Zn x Ni x Al 2 O 4 , Mg 1-2x Zn x Co x Al 2 O 4 , Mg 1- 2x Zn x Cd x Al 2 O 4 , Mg 1-2x Ni x Co x Al 2 O 4 and Mg 1-2x Ni x Cd x Al 2 O 4 (where x = 0.0-0.5) by a cost effective and an energy efficient urea assisted microwave combustion method. The quantitative analysis shows that the experimental values match with the nominalcompositions and lower Zn content in all the samples is observed due to the volatile nature of Zn. Sharp and high intensity diffraction peaks are obtained with hkl values of (111), (220), (311), (222), (400), (422), (511), (440) (531), (533), (622) and (444) which closely correspond to the standard pattern of spinel MgAl 2 O 4 (ICSD ref. code No. 00-021-1152, a = 8.08 Å, V cell = 528 Å 3 ). The absence of any extra peaks in these patterns indicates that the synthesized samples exhibit a single-phase structure. While in the case of (Zn-Cd)x and the (Ni- Cd)x the pure spinel phase is produced till x = 0.3 while at higher dopant content, the extra peaks in the patterns appear along with the peaks for the spinel phase. The density of the doped samples increases gradually with the increase in the dopant content due to the larger molar mass of the double doped samples compared to the undoped magnesium aluminate The crystallite sizes are found to be in the range of 10-13 nm with the doped samples having remarkably smaller crystallite sizes than the undoped one (47 nm). The bulk density of the doped samples is lower than the undoped ones due to the enhanced porosity. The agglomeration of crystallites produces two types of the regions in electron micrographs, a region of large grains as well as a region of the small grains and the particle size of the samples is found to be within the nano regime. No appreciable changes are seen in the heating and cooling curves in differential thermal analysis (DTA). The samples are found to be thermodynamically stable up to a temperature of 1773 K. The decreasing resistivity with an increase in temperature validates the semiconducting behavior of the samples. However, magnesium aluminate is considered to be a small polaron semiconductor in which energy is required for the mobility of charge carriers. The formation of charged anti- site defects, electron-hole (Al 3+ in A-site) and traps (Mg 2+ in B-site) are responsible for the hopping of electrons in the structure of the ceramic MgAl 2 O 4 material. The resistivity of the doped samples is higher as compared to the pure magnesium aluminate sample. In the transition-metal oxides with incompletely filled 3d shells, the localization of the 3d electrons is responsible for the insulating nature of the doped oxides. In the case of (Zn-Co)x, no d shell electrons are available at Zn 2+ while 3 unpaired electrons are available at Co 2+ (3d 7 ) and this leads to a t 52g e 2g configuration. The large insulating gap is present due to the Coulomb potential difference between e g orbitals which are directed towards the oxygen ions and the t 2g orbitals which are located between the oxygen ions as the crystal field and the exchange splitting energies differ too much. Hence, disfavoring the interionictransitions at TM in (Zn-Co)x which have higher resistivity. While in the case of (Ni-Zn/Co/Cd)x, Ni 2+ (3d 8 ) have all t 2g levels and the two e g levels of parallel spin occupied resulting in t 62g e 2g configuration. The behavior of the insulator type materials under the applied field can be explained on the basis of Maxwell-Wagner type interfacial polarization mechanism. The value of έ decreases with an increase in the applied frequency and becomes eventually constant at higher frequencies. The series comprising (Ni-Cd)x has the highest value of dielectric constant followed by (Zn-Co)x and (Zn-Ni)x while (Ni-Co)x and (Zn-Cd)x has the lowest values. The Cd 2+ have a strong tetrahedral site preference so in (Ni-Cd)x some of Ni 2+ may move from tetrahedral to octahedral sites along with the movement of Al 3+ ions to the tetrahedral sites. The samples have more polarization because of easy exchange of electrons between Ni 2+ at octahedral sites hence have highest values of dielectric constant. While, (Zn-Cd)x have both the TM ions at tetrahedral sites having complete d shells so no electrons are available which can form polarons so have lowest values of dielectric constant. In all the series except (Zn-Ni)x series a dielectric relaxation is observed in some samples in which a maxima is observed at a certain frequency where a maximum loss is taking place. The thermal conductivity of MgAl 2 O 4 is 0.83 W/m.K and it increases with the increase in temperature and its value at 300 K is 1.375 W/m.K. The doped samples have lower thermal conductivities than the pure one due to the contributions of extra electons at TM ions which form polarons hence, polaron-phonon interactions may result in the scattering of phonons causing a reduction in the thermal conductivity in all the transition metal doped compounds. The values of thermal diffusivity lie between 0.0012-0.0014 m 2 /S for all the samples. The value of specific heat Cp for pure magnesium aluminate is 0.29 J/Kg. K. While for the doped samples its value ranges as follows: (Ni-Cd)x; 0.2708-0.0013 J/Kg. K, (Zn-Cd)x; 0.3058-0.3089 J/Kg. K, (Ni-Co)x; 0.2793-0.3060 J/Kg. K, (Zn-Ni)x; 0.3458-0.3612 J/Kg. K and (Zn-Co)x; 0.3087- 0.3458 J/Kg. K.
چاچا اﷲ دتہ نے اپنے ہرے رنگ دے کوٹ دا اپر والا بٹن بند کردے آکھیا ’’انور پتر! شام نوں بازار توں پرتدے ہویاں میرے لئی دلیے دا اک ڈبہ تے لے آویں‘‘ ایہہ کہہ کے اوہناں دو پرانے دس دس والے نوٹ میرے ول وادھائے ’’چاچا! ایس دی کیہہ لوڑ اے؟ میں لے آواں گا‘‘ میں رسماً آکھیا۔
’’او نئیں پتر! میرے کول نہ ہوون تاں ہورگل اے‘‘ میں چاچے کولوں پیسے پھڑے تے بازار ٹرگیا، چاچا اﷲ دتہ ساڈے پنڈدے بزرگاں وچوں سن۔ ساڈے گھر توں اوہ تن گھر چھڈ اک کلی ورگے گھر وچ رہندے سن جس دا صرف اک ای کمرہ سی۔ بچے ہے نئیں سن تے گھر والی کدوں دی اﷲ کول ٹرگئی ہوئی سی۔ عمر وچ اوہ سٹھ دے لگ بھگ ہوون گے۔ جدوں وی اوہناں نوں کوئی بازار دا کم ہوندا تاں اوہ کسے وی بازار جارہے ہوندے بندے نوں آکھ دیندے۔ ہر بندہ ہس کے اوہناں دا کم کردا سی۔ اج مینوں بازار جاندے ویکھ کے اوہناں مینوں اپنے کم دا آکھ دتا۔ میں شامیں دلیا اوہناں نوں لیا کے دے دتا۔ چاچا اﷲ دتہ نوں سارے پنڈ والے وڈے چھوٹے چاچا ای آکھدے سن۔ اوہناں دی شخصیت بہت گنبھل دار سی تے اوہناں دا ہرے رنگ دا کوٹ جس نوں اوہ ہر ویلے پائی رکھدے اوہناں دی شخصیت نوں ہور گھنجل دار بنا دیندا سی۔ کوٹ اتے دو چوڑیاں لکیراں سن گرمی ہووے بھانویں سردی کوٹ ہر ویلے اوہناں دے جثے اتے رہندا۔ مینوں یاد نئیں کہ میں کدے اوہناں نوں بغیر کوٹ دے ویکھیا ہووے۔ چاچا نوں کئی لوک مذاق وچ کہہ دیندے سن ’’بھئی ایس کوٹ اند رکیہڑا خزانہ اے جو ایس نوں ہر ویلے پائی پھر دا ایں‘‘...
Istilahat-e-fiqhia (Juristic terms) is of vital importance in understanding the exact meaning of the Islamic injunctions. Hadith Commentators, therefore, in their Hadith commentaries, ardently explain these terms literally as well as idiomatically. The present article, with the said perspective, studies Bazl al-Majhud fi Hall Sunan Abi Dawud, a multi-voluminous Arabic commentary of classical hadith corps Sunan Abi Dawud by renowned hadith scholar Moulana Khalil Ahmad Saharanpuri. It discovers that Moulana Saharanpuri elucidates the juristic terms with all the methods adopted by the experts of Ilm Lughat, Ilm Gharib al-Hadith, etc. He, in his elucidation, not only gives the inquiries of the experts but also evaluates them and gives his observations. However in some places he just copies the experts and doesn’t comment.
Shisham (Dalbergia sissoo) is an important tree of Pakistan and is widely grown in different areas of the country mainly for furniture, timber and fuel. Dieback is a serious threat to this tree and has caused huge damage not only in Pakistan but also in India, Nepal and Bangladesh. A nursery experiment of sexually (seedlings) and asexually (cuttings) propagated D. sissoo was conducted during 2009 and 2010. Both seedlings and cuttings were inoculated with the most commonly found fungi in the dieback affected trees i.e Fusarium solani, Botryodiplodia theobromae, Curvularia lunata and Ganoderma lucidum. Overall highest disease incidence was observed in plants inoculated with F. solani (31.39%). In seedlings F. solani caused 46.18% disease while in cuttings it was only 16.61%. No disease was recorded in controlled conditions. A significant (P<0.05) correlation of seedlings and cuttings was observed with climatic variables. Good association of seedlings (r= 0.734) and cuttings (r=0.629) was observed with maximum temperature. Disease predictive models of seedlings and cuttings were developed with climatic variables; Y = -58.3 +7.58x 1 +0.0054x 2 -1.14x 3 +2.47x 4 -1.09x 5 R 2 = 0.62 (2 years data) Where Y= Disease in cuttings, x 1 = Rainfall, x 2 = Relative humidity, x 3 = Minimum temperature, x 4 = Maximum temperature and x 5 = Wind velocity R 2 =0.48 (2 years data) Y = -134 +15x 1 +0.158 x 2 -2.32 x 3 +5.27 x 4 -3.70x 5 Where Y= Disease in seedlings, x 1 = Rainfall, x 2 = Relative humidity, x 3 = Minimum temperature, x 4 = Maximum temperature and x 5 = Wind velocity A comprehensive survey of shisham was carried out in four agro-ecological zones (Sandy deserts, Northern irrigated plains, Barani areas and Sulaiman piedmont) of Punjab province. For survey eleven districts were selected being the most productive and shisham frequenting districts from the above said zones. Trees were divided into age classes and on the basis of disease severity into healthy, partially affected and fully affected trees. Age class one (1-20 years old trees) was observed as the healthiest while age class three (above 40 years) was found to be the most affected in all zones and districts. Maximum number of healthy trees was observed in age class one of Barani areas (92.16%) Maximum number of partially affected trees was seen in Sulaiman piedmont (22.89%) and less number was in Barani areas. Maximum number of dead or fully affected trees was found in class three of Northern irrigated palins (23.60%) and only 4.68% dead trees were recorded in age class one of Barani areas. In selected districts maximum number of healthy trees was in class one of Rawalpindi district (95%) and maximum partially affected trees were in age class three in Dera Ghazi Khan (22.89%). Maximum number of dead trees (33%) was found in age class three of Toba Tek Singh. Rawalpindi was the least affected district with only 5 % dead trees in class one. Water table between 15-20 feet of depth was considered as the most suitable depth where less number of dead trees were recorded in all age classes. Significant (P<0.05) correlation was observed between age class, relative humidity, minimum temperature, maximum temperature and wind velocity. Correlation was non significant with rainfall and water table. Good association was observed between tree age and dieback disease in Healthy (r=0.626), partially affected (r=0.539) and fully affected trees (r=0.613). A disease predictive model based on two years disease survey data was developed: FA = 2.51 + 4.15 x 1 + 5.25 x 2 + 0.00866 x 3 - 0.113 x 4 - 0.0611 x 5 - 0.0115 x 6 - 0.0092 x 7 + 0.541 x8 R 2 = 0.89 Where FA= Fully affected, x 1 = Age, x 2 = Year, x 3 = Water table, x 4 = Rainfall, x 5 = Relative humidity, x 6 = Minimum temperature, x 7 = Maximum temperature, x 8 = Wind velocity