The Waveshaper Effect on Ta-MS Multiliner Explosive Formed Pojectile with Tantalum as Penetrator and Mild Steel as Stabilization Base

Numerical simulation was carried out using Autodyn 2D code to study the formation and tandem behavior of multiliner EFPs (Explosively Formed Projectiles). The main aim of multiliner configuration is to develop tandem behavior and to increase the length of explosively formed projectile in different applications. The high ductility and high dynamic material behavior of Ta (Tantalum) makes it difficult to generate a solid and stable projectile. To get these specific characteristics, mild steel was used for being the most stable liner material in the EFP technology. So when we used mild steel as a stabilization base and tantalum as a penetrator then solid and stable projectile was achieved. The tandem behavior with tantalum-mild steel multiliner configuration was studied. The effects of detonation method, confinement and waveshaper on the multiliner EFP configuration have also been determined by simulation. The detonation method has its effect on the tandem behavior whereas confinement has not. The waveshaper is found to have 40.4% more prominent and faster tandem effect on the multiliner EFPs

The Assessment and Mapping of Urban Visual Pollution through an Assembly of Open Source Geospatial Tools

Urban surroundings and spaces are losing their identity due to the visual pollution in the urban panorama of already densely populated cities in the developing countries. Quantitative assessment of visual pollution and its spatial mapping are very recent and relatively un-explored branches of urban studies. The diversity of visual pollution objects (VPOs) and their traits, the subjectivity of observers, the scale of urban space and dependency on subjective variables are the key challenges for quantification during visual pollution assessment (VPA). A paper-based score-card type VPA tool using Analytical Hierarchy Process to addressthese issues has previously been developed. However, considering the challenges associated with the deployment of paper-based tool for VPA (which include the inability to handle variety of data types such as text, numeric, geolocation, images, etc.), the natural progression is the development of a mobile-based solution which matches the fast-growing mobile penetration rate of urban centres and provides a turn-key solution to achieve efficiency and effectiveness in primary data collection. On the other hand, academic research on the spatial mapping of visual pollution has slightly progressed to explore its cartographic dimension. This research presents a spatial decision support system comprising of a combination of open source tools to collect, store and present VPA data for any urban space of any scale. The system employs Open Data Kit (ODK) to build its mobile-based VPA tool which can be used to collect VPO attributes using any Android device. The collected data is streamed to a web-based data management module of the systemin real time which is built upon ODK Aggregate and PostgreSQL. Furthermore, the web-based visualisation module of the system is built upon some other major open source tools including OpenGeo Suite and PHP.The visualisation module presents the results of visual pollution index (VPI) in the form of a web-based dashboard containing real-time choropleth maps which can be filtered for any specific VPO. This research demonstrates the strengths of open geospatial tools to solve challenges of primary data collection on a diverse range of VPOs along with the systematic capturing of their spatial location and visual images. Furthermore, it proves the ability of open source web mapping tools to display visual pollution assessments in most appropriate cartographic representation. Resultantly, it offers the practitioner urban planners a tested mechanism to assess and map the levels of urban visual pollution in an urban space and help them take effective measures to improve the visual image of the city

Application of the Online WhatIf? Planning Support System in Peri-urban Spatial Planning; Case study of Muzaffargarh, Pakistan

Out of South Asian countries, Pakistan is experiencing the fastest urbanization rate where more than half of the population will reside in urban areas after next seven years. Such a rapid transformation in urban areas calls for an extraordinary response from spatial planning agencies. Handling of complex urban phenomena with precision and time efficiency has created the dire need for shifting from manual planning processes to computer-assisted planning approaches. Although, previous studies on spatial planning practices in Pakistan have highlighted the stages and processes where adoption of planning support systems (PSS) can help improve the planning outcomes. However, the use of geospatial technologies and PSS have been quite limited in adoption and undertake by the planning profession. With the advent of Smart Cities renewed awareness and support of data driven approach and tools such as PSS have assisted in bridging this utilization gap. To improve the adoption of PSS in spatial planning, many researchers have emphasized the need for research into understandintg and documenting real world use cases in ofg PSS supported planning. This research documents the case study of Muzaffargarh as the first spatial planning practice in the country’s context where the Online WhatIf? PSS has been synchronized in the plan preparation process and used for the development of planning proposals. While documenting the detailsabout the employment of OWI in the preparation of peri-urban structure plan (PUSP), it captures the processes, opportunities and challenges along with the user feedback. The country context specific procedural details covering the datasets, planning factors and assumptions have been comprehensively explained. It has been ensured that the details are sufficient enough to act as a guide for future plan preparation tasks of similar nature. Similarly, challenges and opportunities have been documented as part of the lessons learnt. This research concludes that the Online WhatIf? (OWI) has demonstrated to be a very good fit in PUSP preparation. This PSS has shown to provide a consistent and structured process to interactively explore, future land development options, which is considered a useful approach in PUSP preparation

A Hybrid Tool for Visual Pollution Assessment in Urban Environments

With increasing focus on more nuanced aspects of quality of life, the phenomenon of urban visual pollution has been progressively gaining attention from researchers and policy makers, especially in the developed world. However, the subjectivity and complexity of assessing visual pollution in urban settings remain a challenge, especially given the lack of robust and reliable methods for quantification of visual pollution. This paper presents a novel systematic approach for the development of a robust Visual Pollution Assessment (VPA) tool. A key feature of our methodology is explicit and systematic incorporation of expert and public opinion for listing and ranking Visual Pollution Objects (VPOs). Moreover, our methodology deploys established empirical complex decision-making techniques to address the challenge of subjectivity in weighting the impact of individual VPOs. The resultant VPA tool uses close-ended options to capture the presence and characteristics of various VPOs on a given node. Based on these inputs, it calculates a point based visual pollution scorecard for the observation point. The performance of the VPA tool has been extensively tested and verified at various locations in Pakistan. To the best of our knowledge, this is the first such tool, both in terms of quantitative robustness and broad coverage of VPOs. Our VPA tool will help regulators in assessing and charting visual pollution in a consistent and objective manner. It will also help policy makers by providing an empirical basis for gathering evidence; hence facilitating evidence-based and evidence-driven policy strategies, which are likely to have significant impact, especially in the developing countries

A Study of a Protective Container for Combined Blast, Fragmentation and Thermal Effects from Energetic Materials Detonation

A composite protective container is experimentally investigated to counter combined blast, fragmentation and thermal effects from either a 1.0 kg bare or 0.6 kg cased (pipe-bomb) TNT equivalent charge. Commercially available shaving foam was used as the internal filling material. The shaving foam quenched the initial fireball and afterburning reactions. The composite case contained the blast overpressure and prevented the escape of primary fragments. The novel combination of extended polystyrene (EPS) foam, bakelite and polyurethane (PU)-silica composite employed at the container base provided protection against in-contact explosive detonation. Maximum peak reflected overpressure of 86.87 kPa (12.6 psi) was measured at 1.0 m distance for 1.0 kg TNT equivalent charge detonation inside the container. The protective container provided 97% peak overpressure reduction compared to the equivalent surface burst detonation. The fragmentation and their impact on container were simulated using a coupled SPH-ALE approach. Steel casing fragments weighing up to 8.0 g with velocities in the range of 1260-1550 m/s were produced and impacted the container. This investigation provides a basis in the design of a device to combat terrorist devices in public places, high profile meeting venues and transportation systems

راشدی خاندان کی خدمات حدیث

There rose many scholars who rendered their services in one field of Islam or the other. But there is seldom mention of a family who geneation after geneation dedicated its services for the spread of Hadith literature. Rashidi family of Sindh is exceptionally and tremendously did the same. This family has dedicated its energies for this sacred mission for centuries. This article is an effort to encompass the services of Rashdi Family of Sindh in the field of Hadith literature.</p

Synthesis of micro porous barium nitrate with improved ignition reliability as a reliable pyrotechnic oxidant

AbstractPure barium nitrate is one of the most widely used oxidizing materials in the field of pyrotechnics. The ignition reliability of compositions based on this material is not very high and needs to be improved. In the present work, modified barium nitrate with micro porous structure has been synthesized using three different vesicants to make it more reliable as a pyrotechnic oxidant. Two pyrotechnic compositions were formulated by using pure and modified barium nitrate as oxidant and micro sized aluminum powder was used as a fuel. The ignition temperature of both the compositions was determined using differential thermal analysis. The composition formulated with the modified oxidizer ignited at lower temperatures as compared to the one formulated with pure barium nitrate depicting an improvement in the ignition behavior. SEM results show that the modified barium nitrate has obvious pores of the order of few micrometers. Bulk density of the modified oxidizer decreased due to the development of micro pores. Crystallite size of the barium nitrate also decreased after the modification

Investigation of the thermal decomposition of magnesium–sodium nitrate pyrotechnic composition (SR-524) and the effect of accelerated aging

The aging behavior of the pyrotechnics is influenced by the storage atmosphere and more specifically on the temperature and humidity levels. The investigated composition SR 524 is a military pyrotechnic composition that is used as a tracer. The accelerated aging of the SR 524 composition has been carried out at a temperature of 70 °C and relative humidity of 70 percent. The results indicate that there is significant change in the thermal behavior, kinetic parameters and the morphology of the aged composition. The decomposition temperature and the activation energy were found to be lowered in the aged composition. The activation energy of the aged composition decreased nearly 57 percent. SEM micrographs of the aged composition revealed the development of micro cracks as a result of accelerated aging. XRD spectra of the aged composition showed the presence of magnesium hydroxide indicating the reaction between magnesium and water vapors present in the highly humid atmosphere

The Waveshaper Effect on Ta-MS Multiliner Explosive Formed Pojectile with Tantalum as Penetrator and Mild Steel as Stabilization Base

Numerical simulation was carried out using Autodyn 2D code to study the formation and tandem behavior of multiliner EFPs (Explosively Formed Projectiles). The main aim of multiliner configuration is to develop tandem behavior and to increase the length of explosively formed projectile in different applications. The high ductility and high dynamic material behavior of Ta (Tantalum) makes it difficult to generate a solid and stable projectile. To get these specific characteristics, mild steel was used for being the most stable liner material in the EFP technology. So when we used mild steel as a stabilization base and tantalum as a penetrator then solid and stable projectile was achieved. The tandem behavior with tantalum-mild steel multiliner configuration was studied. The effects of detonation method, confinement and waveshaper on the multiliner EFP configuration have also been determined by simulation. The detonation method has its effect on the tandem behavior whereas confinement has not. The waveshaper is found to have 40.4% more prominent and faster tandem effect on the multiliner EFPs