Alterations in reducing sugar in Triticum aestivum under irrigated and non-irrigated condition

This research was conducted with the objective of observing alterations in reducing sugars, which may play a part in distinguishing tolerant and susceptible genotypes. The experimental material consisted of thirteen wheat genotypes including eleven bread wheat advanced lines, one synthetic hexaploid and its durum parent. Seeds were sown in plastic pots and allowed to grow under normal irrigation for 32 days. Stress was imposed by withholding water for a period of 12 days. Subsequently, shoots were collected from stressed and non stressed young plants and the total reducing sugars were estimated. The agronomic performance of those advanced lines that were stable, such as CIM-47, CIM-51, NR-234, NR-241 and NR-264, had more elevation in reducing sugars as compared to others. This study therefore showed that stress tolerant varieties accumulated more glucose than sensitive ones. On the contrary, CIM-48 and NR-175 showed inhibition of sugars; and from their agronomic performance, they were also unstable with respect to yield and yield components. It was concluded that tolerant genotypes depict an elevated reducing sugar, and hence they could be useful in selecting tolerant varieties against water stress.Key words: Reducing sugars, water stress, tolerant and susceptible genotypes, Triticum aestivum

Investigating tool performance and wear when simulating bandsawing of nickel-based superalloy under interrupted orthogonal turning condition

© 2017, IMechE 2017. The manufacturing industries still face the most challenging job at hand to machine nickel-based superalloy, Inconel 718, efficiently and economically. In contrast to the extensive research efforts in secondary machining processes such as turning, milling and drilling, very little or no attention is paid on bandsawing of Inconel 718. This article presents an experimental investigation of machining Inconel 718 using carbide-tipped bandsaw teeth in a custom-made experimental facility. Cutting forces were measured during the bandsawing operation using a dynamometer, and the wear modes and mechanisms in the bandsaw teeth were investigated in a scanning electron microscope. Three different feeds or depths of cut (10, 20 and 30 μm) were employed with a cutting speed of 30 m/min during the machining tests. At smaller feed or depth of cut (10 μm), abrasive wear, adhesive wear and some degree of plastic deformation were identified as the governing mechanisms of tool wear. The higher depth of cut (30 μm) could cause cracking, chipping or premature failure of the carbide tip in bandsaw tooth. Strong welding of workpiece material to the cutting edge formed a built-up edge, which would impair the bandsawability due to the modification of the cutting edge. The higher depth of cut significantly improved the machining performance due to the reduction in specific cutting energy. However, it was not recommended to apply higher depth of cut as there were obvious possibilities of premature tooth failure. Machining force and specific cutting energy results along with chip characteristics were correlated with the tool performance and tool wear. The results of this investigation would be helpful for bandsaw manufacturers and end users to get a fundamental understanding of the bandsawability of Inconel 718 with the carbide-tipped bandsaw

Chromatic dispersion monitoring for multiple modulation formats and data rates using sideband optical filtering and asynchronous amplitude sampling technique

Author name used in this publication: P. K. A. Wai2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Modulation format identification in heterogeneous fiber-optic networks using artificial neural networks

Author name used in this publication: Faisal Nadeem Khan2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Machining characteristics of inconel with carbide tipped bandsaw

Bandsawing is generally preferred over other sawing techniques (e.g., circular sawing) owing to its lower kerf width, higher metal removal rate and competitive surface finish. Investigations on machining Inconel alloys are generally limited to turning or milling processes with very little or no attention paid on bandsawing Inconel. The paper presents an experimental investigation on machining Inconel 718 using carbide tipped bandsaw teeth. The machining tests were carried out using a modified machine tool with a single bandsaw tooth. Cutting forces were measured during the bandsawing operation and the wear modes and mechanisms in the bandsaw teeth were investigated in a Scanning Electron Microscope (SEM). Abrasive wear, adhesive wear and some degree of plastic deformation were identified as the main wear mechanisms on the flank face of the bandsaw teeth. The higher depths of cut applied during machining could cause chipping or premature failure of the carbide tip in bandsaw tooth

Analysis of signed chromatic dispersion monitoring by waveform asymmetry for differentially-coherent phase-modulated systems

Author name used in this publication: P. K. A. Wai2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Response surface approach to minimize the residual stresses in full penetration pulsed TIG weldments of Ti-5Al-2.5Sn alloy

Pulsation of current in Tungsten Inert Gas (TIG) welding is employed to obtain good quality weldments. Peak current, background current, and welding speed in TIG welding are important parameters and their effects on the induced residual stresses are studied using Box–Behnken design methodology. The location of maximum residual stress was found to be close to the weld centerline. Longitudinal and transverse residual stresses at this location were found to be dependent on the pulsed TIG welding input parameters. However, using design of experiment approach, welding speed was found to have the most dominant influence on the stress values. In order to minimize the residual stresses, a reduction in heat input also led to reduction of weld pool penetration. The results of multiresponse optimization showed that in order to achieve a full penetration weldment, a minimum value of 235 MPa for longitudinal and 84 MPa for transverse residual stress will be attained. A weldment with these features can be obtained by using a high value of peak current and a high value of welding speed

A comparative study of pulsed laser and pulsed TIG welding of Ti-5Al-2.5Sn titanium alloy sheet

Pulsed Nd:YAG laser beam welding (P-LBW) and pulsed tungsten inert gas (P-TIG) welding were used to prepare full penetration bead-on-plate weldments of 1.6 mm thick Ti-5Al-2.5Sn alpha titanium alloy sheet. The influence of welding phenomenon on the microstructure, micro-hardness, tensile properties, surface and sub-surface residual stress distribution and deformation and distortion of both the weldments were studied. Higher cooling rate in P-LBW resulted in complete α’ martensitic transformation in fusion zone whereas in P-TIG weldment α’ and acicular α was formed within equiaxed β matrix due to lower cooling rate. Hardness in fusion zone of P-LBW was higher than that of the fusion zone of P-TIG weldment due to faster cooling rate in P-LBW. The welded zone in both the weldments showed higher hardness and strength than that of the parent metal since a ductile fracture occurred in the un-welded section during tensile testing. Residual stresses in both P-LBW and P-TIG weldments showed similar trend but the distribution was much narrower in P-LBW due to less width of heat affected zone. P-LBW resulted in more nonuniformity in through thickness stress profile because of greater top to bottom width ratio. Less residual stresses, deformation and distortion and superior mechanical properties in P-LBW made the process more feasible than P-TIG for the welding of Ti-5Al-2.5Sn alloy sheet

Malaria mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.

BACKGROUND: Malaria continues to be a major cause of infectious disease mortality in tropical regions. However, deaths from malaria are most often not individually documented, and as a result overall understanding of malaria epidemiology is inadequate. INDEPTH Network members maintain population surveillance in Health and Demographic Surveillance System sites across Africa and Asia, in which individual deaths are followed up with verbal autopsies. OBJECTIVE: To present patterns of malaria mortality determined by verbal autopsy from INDEPTH sites across Africa and Asia, comparing these findings with other relevant information on malaria in the same regions. DESIGN: From a database covering 111,910 deaths over 12,204,043 person-years in 22 sites, in which verbal autopsy data were handled according to the WHO 2012 standard and processed using the InterVA-4 model, over 6,000 deaths were attributed to malaria. The overall period covered was 1992-2012, but two-thirds of the observations related to 2006-2012. These deaths were analysed by site, time period, age group and sex to investigate epidemiological differences in malaria mortality. RESULTS: Rates of malaria mortality varied by 1:10,000 across the sites, with generally low rates in Asia (one site recording no malaria deaths over 0.5 million person-years) and some of the highest rates in West Africa (Nouna, Burkina Faso: 2.47 per 1,000 person-years). Childhood malaria mortality rates were strongly correlated with Malaria Atlas Project estimates of Plasmodium falciparum parasite rates for the same locations. Adult malaria mortality rates, while lower than corresponding childhood rates, were strongly correlated with childhood rates at the site level. CONCLUSIONS: The wide variations observed in malaria mortality, which were nevertheless consistent with various other estimates, suggest that population-based registration of deaths using verbal autopsy is a useful approach to understanding the details of malaria epidemiology

Environmental Factors in the Relapse and Recurrence of Inflammatory Bowel Disease:A Review of the Literature

The causes of relapse in patients with Crohn's disease (CD) and ulcerative colitis (UC) are largely unknown. This paper reviews the epidemiological and clinical data on how medications (non-steroidal anti-inflammatory drugs, estrogens and antibiotics), lifestyle factors (smoking, psychological stress, diet and air pollution) may precipitate clinical relapses and recurrence. Potential biological mechanisms include: increasing thrombotic tendency, imbalances in prostaglandin synthesis, alterations in the composition of gut microbiota, and mucosal damage causing increased permeability