Optimization of surface roughness has been one of the primary objectives in most of the machining operations. Poor control on the desired surface roughness generates non conforming parts and results in increase in cost and loss of productivity due to rework or scrap. Surface roughness value is a result of several process variables among which vibration is of great significant. In this study, experimentation was carried out to investigate the effect of vibrations, forced and self excited, on surface roughness. For forced vibration, variable used to represent machine tool’s condition was vibration amplitude. Input parameters used, besides vibration amplitude, were feed rate and insert nose radius. Cutting speed and depth of cut were kept constant. Based on Taguchi orthogonal array, a series of experimentation was designed and performed on AISI 1040 carbon steel bar at default and induced machine tool’s vibration amplitudes in external turning operation. Analysis of variance, ANOVA, revealed that vibration amplitude and feed rate had moderate effect on the surface roughness and insert nose radius had the highest significant effect on the surface roughness. It was also found that a machine tool with low vibration amplitude produced lower surface roughness. Insert with larger nose radius produced lower surface roughness at low feed rate. The optimum conditions obtained through Taguchi were found in reasonable agreerment to those obtained with full factorial design through Genetic Algorithm. Department of Industrial and Manufacturing Engineering Secondly, experiments related to self excited vibration in internal turning operation were selected. Taguchi method was employed to minimize the surface roughness by investigating the rake angle effect in boring performed on a CNC lathe. The control parameters included, in addition to rake angle, were insert nose radius, cutting speed, depth of cut, and feed rate. Slight tool wear was taken as a noise factor. Based on Taguchi Orthogonal Array L18, a series of experiments were designed and performed on AISI 1018 steel. It was found that tool with a high positive rake angle and smaller insert nose radius produced lower surface roughness value due to low cutting forces generated. It was also revealed that high feed rate and low cutting speed has produced the lowest surface roughness. Key words: turning; optimization; Taguchi; surface roughness; vibration amplitude, ANOVA
نعتیہ ادب میں ڈاکٹر شہزاد احمد کامقام و مرتبہ نعت ہر دور اور ہر دیار میں لکھی گئی ہے۔ نعت گو شعرا بارگاہِ رسالتصلی اللہ علیہ و آلہٖ وسلم میں اپنے اپنے انداز میں عقیدت ومحبت کے پھول پیش کرتے رہے ہیں۔ نعت کا سلسلہ ازل سے جاری ہے اور ابد تک جاری رہے گا۔ اُردو زبان نعت کے تخلیقی سرمائے سے مالامال ہے اور دنیا کی دیگر زبانوں سے نعت کے معاملے میں کسی طرح پیچھے نہیں۔ دکنی دور میں نعت معراج ناموں جنھیں چرخیات سے بھی موسوم کیا جاتا ہے، کی صورت میں اور سراپائے رسول کریم صلی اللہ علیہ و آلہٖ وسلمکے روپ میں صورت پذیرہوتی رہی۔ اسی دور میں نعت، قصیدے، مثنوی اور پھر غزل کی ہیئت میں بھی پنپتی رہی۔ عہدموجود میں نعت کے نمونے ہر صنف سخن میں دستیاب ہیں لیکن نعت کو جو مقبولیت غزل کی ہیئت میںملی وہ کسی دوسری ہیئت کو میسر نہ آسکی۔ گزشتہ صدی میں تخلیق نعت کا سفر ماضی کی نسبت بہت تابناک نظر آتا ہے۔ اس میں نعت نے تخلیق سے تحقیق اور تنقید کے شعبوں میں بھی قابل قدر پیش رفت کی ہے۔ نعت کے الگ رسائل کی اشاعت کا سلسلہ شروع ہوا۔ نعتیہ تذکرے لکھے جانے لگے، نعتیہ مقالات کی طرف توجہ مرکوز کی گئی۔ نعتیہ صحافت کا آغاز ہوا اور نعتیہ انتخابات کا اہتمام ہونے لگا۔ نعت کے مختلف شعبوں میں مختلف شخصیات نے خدمات انجام دی ہیں۔ ان شخصیات میں ایک اہم نام ڈاکٹر شہزاد احمد کا ہے۔ انھوں نے شعبۂ نعت کے ہر شعبے میں گراںقدر خدمات انجام دی ہیں۔ ڈاکٹر شہزاداحمد نعت کے میدان میں بیک وقت ایک محنتی محقق، خوش ذوق تذکرہ نگار، خوش مذاق مدون، خوش الحان نعت خواں، نکتہ رس نقاد، راست باز صحافی او ر منکسر المزاج شاعرکی حیثیت سے جانے جاتے ہیں۔...
To serve humanity and nation leadership is a noble and glorious position. Sensible, talented, honest and true leadership not only works honestly with dedication and commitment in solving internal and external challenges, but also plays a key role in the development of peace and prosperity in society. Due to the lack of spirit and training of the people, especially of the younger generation, these incompetent leaders succeed in befooling many people and it transferred from generation to generation, in order to change this scenario, education and training of the young generation is urgently needed. True spirit of leadershipcan be promoted by creating sincerity, awareness in students in the light of Islamic teachings. This article focuses on the Islamic attributes of leadership through which a person can have opportunities to transform social system by bringing reforms and development in social system to perform the duties by guiding and governing people with the noble aim to serve humanity according to modern requirements in the light of the teachings of holy Prophet.
Charged particle induced nuclear reactions for the production of 52Fe and 72As were studied. A critical analysis led to consider proton induced nuclear reaction sections on 72Ge, 73Ge, 74Ge and 76Se to investigate for the production of 72As while for the production of 52Fe, the proton induced reactions on 58Ni, 55Mn and alpha induced reaction on 50Cr were chosen. The experimental results obtained via 72Ge(p, n)72As, 73Ge(p, 2n)72As, 74Ge(p, 3n)72As, 76Se (p, x)72As and 58Ni (p, x) 52Fe, 50Cr (4He, 2n) 52Fe and 55Mn(p,4n)52Fe reactions were compared with the results of nuclear model calculations using the codes ALICE-IPPE, EMPIRE 3.2 and TALYS 1.9 to check the reliability and discrepancy in the experimental data. Polynomial fittings were applied using Origin-Lab Pro 2017 to maintain the consistency of experimental and calculated data. Recommended data were generated using the well-established evaluation methodology. The thick target yields (TTY) of 52Fe and 72As is calculated from the recommended excitation functions. Analysis of radionuclidic impurities was also discussed for both radionuclides. Comparison of the various radionuclidic impurities is done. On the basis of TTY and radio-nuclidic impurity analysis; the production routes and optimum energy ranges for the production of 52Fe and 72As are proposed. Our evaluation scheme showed that for the production of 52Fe via 55Mn(p,4n)52Fe reaction, energy ranges from 70→45 MeV could be the method of choice, which gives high yield with minimum impurities to make it as a potential candidate for theranostic applications in nuclear medicine and in particular, Positron Emission Tomography (PET). For the 72As; 72Ge(p, n)72As reaction in the energy ranges 10→20 MeV is the optimized nuclear reaction with a negligible impurity ratio and maximum production yield. Being in the low energy range, a small cyclotron can be engaged for the production of 72As to be used it in the medical applications.