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Quetta, Pakistan

Journal of Industrial Textiles | Year: 2016

An increasing number of flying hours requires an improved level of confidence in safety and comfort for crew staff, passengers, and valuables. Alternative or improved material utilization in interior furnishing and structure is perceived important in producing an aircraft. Fibrous material used in an aircraft may enhance the level of safety and the desired effects in producing the structural components. Aircraft accidents and loses to lives and valuable caused by fire are known in aviation history. Flammability in an aircraft as a leading cause or as a subcause may be prevented through an appropriate utilization of flame-retardant (FR) fibrous materials used in aircraft design and manufacturing and in interior furnishing. Improving the prevention of fire hazard through reduced flammability materials was a desired activity for achieving safer air travel. Important FR fibers (FR finished natural fibers and high-performance fibers including synthetic polyamides, carbon, and ceramic fibers), finishes (organophosphorus reagents), and fibrous structural components in aircraft are discussed. FR finishes including brominated FR with reference to recent environmental concerns are described. Standard testing of FR fibrous material based on the Federal Aviation Administration regulations are introduced for any flammability requirements. This study is particularly conducted to appreciate how fibrous materials are useful in improving the flame retardancy and any other performance factor including safety and reduced fuel consumption in an aircraft. © 2014, © The Author(s) 2014.

Siddiqui Q.,Donghua University | Abro Z.,BUITEMS | Yu C.,Donghua University
Textile Research Journal | Year: 2015

To produce an evener fiber assembly, it is important to understand fiber dynamic behavior during the drafting process. Drafting force and its variability is an alternative approach to understand the fiber’s velocity–friction characteristics, representing a combined effect of multiple fiber properties. In this study, online drafting force and its variability was measured with different break draft ratios and back roller gauges to analyze its effect on sliver short-term evenness. Drafting force variability well correlated with sliver evenness with correlation coefficient R2 = 0.81. The coefficient of variation (CV%) of drafting force was highest (2.3%) at low break draft 1.1–1.2, and then reduced gradually to its minimum value (1.5%) around a break draft of 1.6–1.7. The minimum variability of drafting force well corresponds with lower irregularity of sliver at certain break draft ratios. This indicates that a stable drafting force promises better fiber distribution along the sliver length. The variability of drafting force and sliver irregularity also increased as the back gauge increased from 43 to 51 mm. Furthermore, the impact of short fiber content on the drafting force was investigated at three back gauges. The increase in short fiber content gives higher magnitude of drafting force. Drafting force was also compared with the number of neps and change in fiber length in sliver for each break draft. Better nep opening and improved fiber lengths were also found around (1.6–1.7) break draft and follow the same trend of variability of drafting force as the break draft changed. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Khan H.U.,BUITEMS | Shafiq M.,Quaid-i-Azam University | Zakaullah M.,Quaid-i-Azam University
Radiation Effects and Defects in Solids | Year: 2013

The sheath dynamics is an important parameter in dense plasma focus. In this paper, the effect of preionization on sheath dynamics, pinching and its filamentary structure is studied by measuring the axial run-down velocity and its confinement time. A discharge is produced in a 3.3kJ pure He plasma. The Rogowski and high-voltage signals reveal the formation of an axisymmetric parabolic current sheath, high focusing amplitude during collapse phase with preionization source. The working pressure effect on sheath dynamics and spatial evolution is also studied. The enlarge and symmetric pinhole images with preionization support and conform with the results obtained. © 2013 Copyright Taylor and Francis Group, LLC.

Kakar N.,University of Ulm | Ahmad J.,BUITEMS | Morris-Rosendahl D.J.,Imperial College London | Altmuller J.,University of Cologne | And 9 more authors.
Human Genetics | Year: 2014

Holoprosencephaly is a clinically and genetically heterogeneous midline brain malformation associated with neurologic manifestations including developmental delay, intellectual disability and seizures. Although mutations in the sonic hedgehog gene SHH and more than 10 other genes are known to cause holoprosencephaly, many patients remain without a molecular diagnosis. Here we show that a homozygous truncating mutation of STIL not only causes severe autosomal recessive microcephaly, but also lobar holoprosencephaly in an extended consanguineous Pakistani family. STIL mutations have previously been linked to centrosomal defects in primary microcephaly at the MCPH7 locus. Our results thus expand the clinical phenotypes associated with biallellic STIL mutations to include holoprosencephaly. © 2014, Springer-Verlag Berlin Heidelberg.

Khan H.U.,BUITEMS | Shafiq M.,Quaid-i-Azam University
Radiation Effects and Defects in Solids | Year: 2012

In the dense plasma focus (PF) device, the dynamics of the current sheath is an important parameter for good focusing or pinching. In this paper, we present the effect of preionization on current sheath dynamics, its pinching evidence and details of its filamentary structure by measuring the axial run-down velocity, confinement time and focus amplitude in a miniature PF device using a Rogowskicoil and high-voltage (HV) probe. For this purpose, the discharge is produced in deuterium gas with deposited energies lying in the range of 3.3kJ. The Rogowski coil and HV probe signals reveal the formation of an axisymmetric parabolic current sheath propagating down the coaxial tube, and longer confinement time of it during the collapse phase and increase in focus amplitude with preionization source. The axial run-down velocity of the current sheath is increased from 2.1 to 3.2cm/ s. The focus duration is from 45 to 72ns and the focus amplitude is from 1.8, which increases to 2.9 with preionization at the optimum pressure. The effect of the working pressure on the current sheath dynamics and its spatial evolution are also studied. © 2012 Copyright Taylor and Francis Group, LLC.

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