Many conventional fluids, such as water, sodium alginate, organic liquids (e.g., propylene and ethylene glycols, etc.) and some others, are quite often used in various engineering and industrial processes as coolants. The use of water in car radiators is a very basic example. Nowadays, scientists are keenly looking for ways to enhance the performance of engines and such equipment where these coolants are being used. Conventionally, the heat transfer capability of these liquids is not up to the mark. Therefore several attempts have been made to enhance their thermo-physical capabilities. The use of nanofluids is one of such efforts. Scientists, over the past few decades, have been working on the idea of mono-nanofluids (nanofluids with single nanomaterials), to enhance the thermal efficiency of these traditional fluids. However, to improve the number of desirable features of mononanofluids, a novel subject of hybrid nanofluids (nanofluids with two or more nanomaterials) has come into existence. It exhibits superior thermo-mechanical properties when compared to mono nanofluids. In this manuscript, a number of thermal conductivity models, for both mono and hybrid nanofluids, have been employed to see the working of these models in different geometries. In the case of hybrid nanofluids, the modified versions of the models (such as Renovated Hamilton and Crosser’s model, Bruggeman’s model, Hamilton and Crosser’s model, Maxwell’s model, and Xue’s model) for thermal conductivity have been considered. The flow of mono as well as hybrid nanofluids inside an expanding\contracting domains, rectangular conduit with the lower stretchable wall, curved stretching surface, and curved channels, have been studied in details. A novel analysis of hybrid nanofluid flow between two Riga plates is also a part of this manuscript. Moreover, the squeezing flow of a hybrid nanofluid inside a rotating rectangular conduit, with lower stretchable walls, has also been investigated. The impact of the externally applied magnetic field, along with the internal heat generation phenomena, on the flows and heat transport mechanism of some mono and hybrid nanofluids have thoroughly been examined. Heat and mass transfer under the influence of nonlinear thermal radiation and chemical reaction effects in several geometries have been studied in this manuscript. xi In our analysis, we have used certain similarity transformations and scaling parameters to reduce the governing partial differential equations to the corresponding systems of nonlinear ordinary differential equations (dimensionless). This process reduces the number of variables, and parameters, which leads to a relatively more straightforward mathematical treatment. However, the resulting systems are still complicated enough to have an exact solution. For their treatment, we have discussed the implementation of several approximation techniques based on the method of weighted residuals and wavelet methods. We have also proposed some modifications in wavelet methods for a better and more flexible implementation. The plots for velocity, together with temperature, and concentration profiles (wherever applicable) are presented to capture the effects of involved parameters on the respective profiles. It has been found that the addition of nanomaterials significantly boosts the thermal and heat transport properties of the host fluid and that these phenomena are more prominent for the hybrid nanofluids.
. پروفیسر عبد الحق بہ طور ماہر اقبالیات پروفیسر عبد الحق کی سب سے پہلی اور نمایاں حیثیت ماہر اقبالیات کی ہے۔ آپ اس بات پر پختہ یقین رکھتے ہیں کہ : اقبال فن کی تحسین و تخلیق میں بڑی بزرگی کے مالک ہیں ۔ (1) ان کا علمی اور تحقیقی مقالہ اقبالیات ہی کے حوالہ سے ہے۔ آپ نے پی ۔ایچ ۔ڈی کے مقالے میں اقبال کے ابتدائی کلام کی چھان پھٹک اور اس کے ذریعہ سے اقبال کے افکار کا تجربہ کیا جوان کی بنیادی شناخت بن گیا۔ اقبال کی شاعری میں نعتیہ کلام پر روشنی ڈالتے ہوئے آپ کہتے ہیں: اقبال کی حکیمانہ نکات آفرینی نے نعت گوئی کو نئے امکانی جہات سے آشنا کیا ہے۔ ان کے کچھ اشعار تو نعت گوئی میں ضرب الامثال کی حیثیت رکھتے ہیں (2) انھوں نے اقبالیات کے حوالہ سے کئی کتب کی اشاعت کا کام کیا۔ اقبال کی شاعری میں پوشیدہ پہلوؤں کی نشاندہی کی اور فکر اقبال کی تفسیر و تعبیر پیش کرنے میں گراں قدر خدمات سر انجام دیں۔ کلامِ اقبال کی فنی خوبیوں پر قلم اٹھایا اور عوام الناس کو فکر اقبال کے نئے گوشوں پر گامزن کیا۔ لکھتے ہیں۔ اقبال کی نظم تخلیقی تفاعل کی عروج وانتہا ہے فنِ شعر کا معجزہ بھی (3) پروفیسر عبد الحق اقبالیات کا گہرا مطالعہ رکھتے ہیں۔ اقبال نے اجتہاد کے لیے راہوں کی نشا ن دہدی کی وہ اقبال کی فہم و فراست کا منہ بولتا ثبوت ہے۔ اس کا اوراک بھی اتنا ہی اہم ہے جتنا کہ اجتہادی نقطہ نظر خود اہمیت کا حامل ہے۔ اقبال فکری تاریخ میں امتیازی حیثیت رکھتے ہیں اور اجتہادی فکر و نظر انہیں تمام مفکرین سے منفرد بنا دیتی ہے۔ پروفیسر عبد الحق اس پہلو کواس انداز سے بیان کرتے ہیں کہ: اقبال ہماری فکری تاریخ میں...
Manuscript is a handwritten book. The writer of such book is known as "khattat". In the field of research editing and Makhtoota hold primary position. No research is possible without it. Editing is the farther goal than research. Therefore, being an expert in the manuscript is an obligatory factor for editing Manuscripts are the richest treasure of the human civilization, and their great contribution. They are the chronological records of past memories, incidents and circumstances. They need great expertise to understand these. A person who is not capable expert of manuscripts, he can’t carry out the research or editing task effectively.
Fibre reinforced polymer composite panels are preferred in high performance structural panels because they are strong, stiff and light. Stress raisers such as holes or notches (for accessibility, mechanical joining, and routing of cables etc.) may be present in any engineering structure and composite structures are no exception. Theoretically, a stress raiser is simply a localization of high stress-strain concentrations quantified by the Stress Concentration Factor (SCF). It is well established in literature and engineering practice that stress-strain concentrations due to holes or notches, unless accompanied by local plastic strain hardening, reduce the apparent strength of the panels. Since SCF is a function of elastic properties of the material, so in isotropic materials, the SCF is defined with elastic SCF (entails elastic properties within the elastic range of material) and plastic SCF (entails elastic properties in the plastic range of material). However, literature is scarce of such definition for the case of anisotropic/orthotropic materials, where the SCF is also a function of its elastic properties. Contrary to isotropic homogenous materials, composite panels offer a very complex structure, where fibres are generally regarded as brittle which deform elastically to final failure exhibiting either slight or no linear deformation. Whereas matrices generally experience plastic deformation hence the failure strain in matrics is far higher than the fibres. Additionally, once a composite panel containing a hole is subjected to tensile loading, tangential stress at the periphery of the hole in a perpendicular direction to the load axis attains a magnitude three times the far field stress under plane stress conditions. However, in a composite panel, the location and magnitude of the maximum stress are at the periphery of the hole changes with the fibre orientation and stacking sequence, therefore designers opt for large safety margins. This study has been performed to investigate the pre-damaged SCF and progressive-damaged SCF for anisotropic/orthotropic material analogous to elastic and plastic deformations in isotropic material respectively. The study presents a novel technique of calculating progressive-damaged SCF which evaluates the changing SCF in response to the progressive damage development within the composite panel. Finite Element (FE) representations simulate delamination damage using cohesive elements and in-plane damage using continuum damage mechanics. In the first part of the study, test coupons have been formulated under static conditions to consider important influencing factors on the SCF for the case of the composite panel containing a central circular hole subjected to tensile loading and compared with the already published literature. Later, several xii FE coupons have been formulated to precisely investigate the pre-damaged SCF and progressivedamaged SCF for the composite panel. During the study, the investigations of pre-damaged SCF and progressive-damaged SCF have also been performed using analytical and experimental approaches where applicable. The FE results are found in good agreement with the analytical and experimental results. The study provides a novel systematic FE approach for the estimation of progressive-damaged SCF for a composite panel, which has not been reported in the literature before. Certainly, the study proposes a paradigm shift in design philosophy which at present is limited to no-damage philosophy especially in aerospace, where the weight savings due to less generous safety factors are significant.