Cadmium (Cd) bioaccumulation in the wheat (Triticum aestivum L.) and rice (Oryza sativa L.) and the Cd translocation into grains have become a vital global environmental constraint for food security. Cadmium shows higher risk than other heavy metals owing to its toxic effects on plants, animals, and humans. Thus, the present research work was conducted to evaluate the Cd bio-availability, bioaccumulation and toxicity to the plants grown in aged contaminated soil amended with various levels of biochar (BC) either applied alone or under the salt and drought stress. For the achievement of these goals sequential pot experimental studies were carried out in the seasons of wheat and rice cropping system in Cd-contaminated soil under ambient conditions amended with different levels of BC (0, 1.5, 3.0 and 5% w/w) produced from rice straw. First, wheat was sown in the BC-amended soil and divided into three parts such as only BC applied in Cd-contaminated soil, BC applied in the same soil under salt stress (0 mM, 25 mM and 50 mM), and BC under drought stress; well-watered control (70% of soil water holding capacity, WHC), mild drought (MD, 50% of WHC), and severe drought (SD, 35% of soil WHC). Plants were harvested at physiological maturity (130 days of germination). Result showed that BC supply increased the growth, photosynthesis, dry weights, mineral nutrients as well as antioxidant enzymes whereas reduced the oxidative stress and Cd concentrations in different parts of wheat. The BC supply reduced bioavailable Cd in the soil whereas increased EC and pH of the soil than control treatment. However, higher rate of BC (5.0%) was not affective under higher salt stress (50 mM NaCl) where reduction in plant growth and photosynthesis was observed. Second, rice was sown in the same soil without further amendment of BC and salt whereas drought stress was applied to 35-d-old plants as follows; well-watered control (1-2 cm water layer on soil), MD, 50% of WHC), and SD, 35% of soil WHC) for an additional 35 days. All plants were harvested after 70 days of growth and analyzed for various physiological and biochemical parameters. Biochar supply increased plant height, biomass and photosynthesis whereas reduced oxidative stress and Cd contents in plants which confirmed the residual effects of BC in enhancing plant growth and reducing Cd uptake by plants. Continuous flooding plus BC application was the most effective in reducing Cd concentration in rice than MD and SD. However, plant growth and photosynthesis were reduced with BC amendments under 50 mM salt stress. The BC application reduced the bioavailable Cd in the soil whereas increased soil pH than control. It can be concluded that BC amendment can be used to reduce Cd contents in plants and also had a significant residual effect on decreasing Cd uptake in latter crop. However, BC levels should be carefully applied in the soils having higher salinity.
پیپلز پارٹی کا یہ بہادر نوجوان 1963ء کو دھرم پورہ لاہور میں پیدا ہوا ۔سولہ سال کی عمر میں 1979ء کو پی ایس ایف میں شامل ہوا ۔ضیاء آمریت کے دور میں گھر پر مسلسل چھاپوں اور اہل خانہ کو ہراساں کر نے پر کابل چلا گیا ۔واپسی پر گرفتار ہوا ۔1983ء میں پھانسی دی گئی ۔پھانسی کے وقت آپ کی عمر 21سال تھی ۔
Muḥmood Sami al Barodi is a famous poet who was named the Resurrector of poetry in the early times when many poets of the old era were the cause of the decline in poetry. His poems had been studied from many aspects and by many scholars but no one ever spoke about al Barodi’s writings about wisdom. This article is focusing on the verses and poems that focus on the meaning of wisdom and everything that relate to it. He talked about the importance of wisdom in the poems as he encouraged the other poets to give attention to this meaning. Some published books and articles helped me write this article but I haven’t found any of them that gave this point enough significance though his poetry is full of verses about wisdom and so I chose to write about it.
Safety and availability are prime factors for nuclear power plant operation. Safe operation requires a well-built backup of safety systems for saving plant capital cost, environment and the public. The backup system is maintained with the use of active and passive safety systems in the form of engineered safety features. Traditionally, active safety systems have been utilized for counteracting accidental conditions. These systems require proper and timely operator actions, which is some time misleading. Now a day, passive safety systems are becoming more popular due to their dependence on forces of nature for operation and actuation. Passive operations include, under gravity flow, natural recirculation of fluid and nitrogen gas pressure. For such type of systems, when certain conditions are met and the passive operation is started automatically. Therefore, world nuclear community has started using passive safety systems in the present nuclear power plant technology due to the simplicity in operation, maintenance and safety enhancement. This thesis concentrates on the augmentation of passive safety features in small scale pressurized water reactor design. The research was started with the study and simulation of a small scale reference power plant. The scope of simulation includes safety systems including necessary nuclear and conventional island. The individual process systems and related electrical systems are simulated and integrated within the frame work of their respective instrumentation and control to form a standalone simulated model for a reference power plant. Using this model, design basis accident has been modeled and the response of the safety systems together with related primary systems has been observed. Satisfactory results have been experienced in this regard. The research was extended by designing and simulating a passive safety injection system. This proposed system consists of many passive components and functions in place of an existing safety injection system for mitigating loss of coolant accidental condition. The use of proposed passive system has been suggested only for intermediate type pipe breaks because for small breaks, the depressurization is slow and only high pressure charging system is utilized whereas for larger breaks, the depressurization is very fast and low pressure safety injection system is actuated rapidly. Therefore, in a simulation test run this proposed system has been tested and verified for intermediate coolant loss accident. It has been found that the response of the proposed passive system is satisfactory and it keeps all necessary safety parameters within range. Through this research, it is concluded that the proposed passive system could be a potential candidate for handling intermediate type breaks representing loss of coolant accidents in small scale pressurized water reactors. For other accidental conditions of the plant like steam generator tubes rupture and steam line break, the use of conventional way of accidental management has been suggested. Keywords: Advance NPP, Passive safety, Analysis, LOCA, Reliability