ڈاکٹر ضیاء الدین ڈیسائی مرحوم
(ڈاکٹر محمد الیاس الاعظمیٰ)
۲۴؍ مارچ ۲۰۰۲ء کو آثارِ قدیمہ و علمِ کتبات کے ماہر اور مرکزی حکومت کے ادارے برائے کتبہ شناسی ناگ پور کے سابق ڈائریکٹر ڈاکٹر ضیا الدین ڈیسائی نے ۷۷ سال کی عمر میں احمد آباد میں داعیِ اجل کو لبیک کہا، اناﷲ وانا الیہ راجعون۔
وہ کئی ماہ سے علیل اور احمد آباد کے ایک اسپتال میں داخل تھے، ان کی وفات کی اطلاع اس لیے تاخیر سے ملی کہ ان دنوں احمد آباد بلکہ گجرات میں آگ اور خون کی ہولی کھیلی جاری تھی جس میں ہزاروں انسان زندہ جلادئے گئے اور لاکھوں بے خانماں اور برباد ہو کر اپنے ہی وطن میں بے وطن ہوکر رہ گئے۔ خود ڈیسائی صاحب مرحوم کے صاحبزادے کی دوا کی دکان بھی شرپسندوں نے جلادی تھی، چنانچہ اس ہولناک قتل عام کی وجہ سے اور خبریں دب گئیں اور ڈاکٹر ضیاء الدین ڈیسائی کے حادثہ انتقال کی خبر بھی نہ لگ سکی اور وہ کرفیو کے دوران سپرد خاک کردئے گئے۔
ڈاکٹر ضیاء الدین ڈیسائی مرحوم احمد آباد کے رہنے والے تھے۔ ۱۸؍ مئی ۱۹۲۵ء میں پیدا ہوئے۔ ان کی تعلیم بمبئی میں ہوئی تحصیلِ علم کے بعد وہ درس و تدریس سے وابستہ ہوگئے کچھ دنوں تک اسمٰعیل یوسف کالج بمبئی اور دھرمندر سنگھ کالج راج کوٹ سے بطور لکچرر وابستہ رہے۔ ۱۹۵۳ء میں آرکیالوجیکل سوسائٹی آف انڈیا ناگ پور کے اسسٹنٹ سپرنٹنڈنٹ برائے کتبات مقرر ہوئے پھر سپرنٹنڈنٹ ہوئے اور آخر میں ترقی کر کے ڈائریکٹر برائے کتبات کے عہدہ پر فائز ہوئے اور اسی عہدہ سے ۱۹۸۰ء میں سبکدوش بھی ہوئے۔
ڈاکٹر ضیاء الدین ڈیسائی مرحوم ملک کے ممتاز عالم و محقق تھے۔ تاریخ و آثار اور کتبات ان کا خاص موضوع تھا، ہندوستان کے عہد و سطیٰ کی تاریخ پر گہری نظر رکھتے تھے۔...
Dengue fever is a vector borne disease and is caused by DEN Virus. This virus has four different serotypes. The vectors are two mosquitoes known as Aedesaegypti (the yellow fever mosquito) and Aedesalbopictus(the Asian tiger mosquito). First case of dengue fever was reported back in 1994 in Karachi. A complete outbreak of this epidemic shook the whole nation in 2012. Uptill now, Lahore a city full of culture, witnessed about 16,580 confirmed cases and 257 deaths. About 5000 confirmed cases with 60 deaths were reported from the rest of the provinces. Under guidelines of WHO, Government has made efforts to combat this epidemic. Although the overall efforts have minimized the outbreak on controllable levels but dengue fever is a continuous threat. Since no permanent cure is available, the transmission of DEN virus is controlled indirectly. So the prime focus is to control mosquito population and decrease the possible hot spots i.e. Mosquito breeding sites in human habitations. Every year, the country witnesses monsoon season which brings vast areas full of clear standing waters providing breeding sites for mosquitoes which ultimately leads to increased number of patients suffering from dengue fever. Efforts have been made to fight against dengue including formation of dengue wards in hospitals, vector surveillance, community education, reactive vector control etc. A study has shown prevalence of four mosquito genera in Pakistan including Aedes, Culex, Armigeresand Anopheles. All of the above mentioned genera are associated with disease transmissions as they are the vectors of different viruses and parasites. It is the need of hour to do a collaborative effort stressing the community mobilization and management in war against dengue.
Structural and Optical Modulations of Wide Band Gap Semiconductor: Titanium Dioxide (TiO 2 ) Titanium dioxide (TiO 2 ) is a very interesting material due to its number of applications, e.g., high dielectric constant, photocatalytic application. The photocatalytic activity of TiO 2 was first demonstrated in 1972. TiO 2 has a wide band gap (3.0 - 3.2 eV), thus most of the absorption occurs in the UV range, where solar spectrum consists of only 5 - 8%. It is of immense importance to enhance its photocatalytic activity in the visible part of the solar spectrum. This requires band gap tailoring, which can be achieved by doping. However, finding a suitable dopant for TiO 2 is quite critical. In the present work, structural properties and chemical composition of the Nd doped sputter deposited TiO 2 thin films were studied by varying the Nd concentrations from 0 to 2 at. % using RF sputtering. The results suggested that the incorporation of Nd produced stresses in lattice, which shifted diffraction peaks to a lower 2θ values, reduction in crystallite size, elongation of lattice along c-axis and specific texturing along (004) plane. Raman spectroscopy also confirmed asymmetry of bonds. Theoretical modeling of structure was also performed using VESTA code. SEM images confirmed the transformation of faceted to planar surface. XPS showed the presence of O vacancies and non-stoichiometry in films with increased dopant concentration. V doping in the TiO 2 films also displayed interesting results as V existed in many oxidation states with different ionic radii. With the addition of V, preferential growth along (211) plane occurred. The morphology was transformed from faceted to small elongated grains as the concentration of V increased. The substitution of V in place of Ti made the V−O bonds asymmetrical, which created stress to modify the crystallite and grain sizes. XPS showed low binding energy (L.B.E.) shift and an increase in the (D) B.E. difference of Ti-2p doublet peaks, which was due to increased nonstoichiometry in the films. This was also attributed to the substitution of V in the V 3+ and V 5+ states. Raman spectroscopy confirmed the increase in nonstoichiometry, phonon confinement, and asymmetry in the bonding with the increase in V concentration. This was also evident in the PL spectra, where strong xicontributions came from the states associated with V 5+ and V 3+ and dominated the spectra on oxygen vacancies (OV) and defect associated PL. Finally, the role of oxygen concentration and doping concentration in affecting the structural, phase transformation and chemical composition was studied using pulsed laser deposition (PLD). Oxygen partial pressure was varied from 100 mtorr (O 2 rich) to 0 mtorr (O 2 absent) and three concentrations of Nd were used as 1.0, 1.5 and 2.0 at.%. With the variation of oxygen and dopant concentrations, a sequence of phase transformations was observed. This also reduced the crystallite size and caused the film thickness to reduce. A reduction of Ti (Ti 4+ to Ti 3+ ) was observed and emergence of the O vacancies and consequently generation of nonstoichiometry in TiO 2 lattice, which resulted in the short range ordering of the TiO 2 structure. The present work suggested that the incorporation of Nd inhibits the phase transformation, which can be allowed by increasing the oxygen partial pressures.