103 research outputs found

    Combined Influence of Fly Ash and Recycled Coarse Aggregates on Strength and Economic Performance of Concrete

    Get PDF
    Recycled coarse aggregates (RCA) and fly ash (FA) are materials with least to very low global warming potential. Considering long term strength and durability, various studies have suggested to use RCA in concrete with FA. This research paper deals with the strength and economic performance of concrete made with individual and combined incorporation of FA and RCA. Nine different mixtures of concrete were prepared by varying the incorporation levels of RCA and FA. 0% RCA, 50% RCA and 100% RCA were used in concrete with three different levels of FA (0%FA, 20%FA, and 40%FA). The compressive strength of each mixture of concrete was determined at the age of 3, 28, 90 and 180 days. To evaluate economic performance cost of 1 m3 of each mixture of concrete was compared to that of the control mixture having 0% RCA and 0% FA. Results showed that RCA was detrimental to the compressive strength of concrete at all ages, whereas, FA reduced early strength but improved the strength at later ages of testing i.e. 90 and 180 days. FA plus RCA mixes also showed lower early age strength but gained higher strength than conventional concrete at the age of 180 days. RCA did not reduce the cost of concrete effectively. FA despite having a very high transportation cost, it reduced the cost of concrete efficiently. FA did not only reduce the cost of binder but also lower the demand of plasticizer by improving workability. Cost to strength ratio (CSR) analysis also indicated that FA significantly improve the combined economic and strength performance of RCA concrete mixes

    Measurement of cell membrane thermo-stability and leaf temperature for heat tolerance in maize (Zea mays L): Genotypic variability and inheritance pattern

    Get PDF
    The rise in ambient temperature is intimidating sustainability of maize productions worldwide. To overcome heat stress effects, identification of potential genotypes and knowledge of inheritance pattern is necessary for developing thermo-tolerant cultivars. This investigation, consisted of four experiments, was conducted for assess- ing genetic variation followed by developing and evaluating breeding material in non-stressed and heat-stressed environments. The first experiment concerning reproductive stage heat tolerance comprised one hundred maize inbred lines, was conducted at mean day/night temperatures of 33°C/19°C (field) and 40°C/23°C (plastic tunnel), respectively. Variance analysis of absolute and relative data for leaf temperature and cell membrane thermo- stability revealed statistically significant (P ≤ 0.01) genotypic variations. In second and third experiments, one heat tolerant (ZL-11271) and one susceptible (R-2304-2) lines were selected and crossed in a generation mean fashion to develop non-segregating (P , P , F ) and segregating (BC , BC , F ) plant populations. The fourth experiment involved appraisal of six basic generations in a factorial randomized complete block design replicated thrice with mean day/night temperatures of 33°C/20°C and 39°C/24°C. Data on leaf temperature and cell membrane thermo- stability recorded at reproductive phase were analyzed in a nested block design which suggested involvement of digenic epistatic interactions in controlling inheritance of both these traits. Generation variance analysis, however, revealed predominance of additive genes supported by higher estimates [> 60%] of broad sense and narrow sense heritability (F and F ). Future progress in plummeting leaf temperature and cell membrane thermo-stability of plant material is achievable through hybridization and rigorous selections in succeeding generations

    SIMULATION OF TURBULENT FLOW THROUGH TARBELA DAM TUNNEL 3

    Get PDF
    Tarbela dam is one of the largest earth filled dam in the world. The sediments inflow in the Tarbela reservoir has resulted in reduction in water storage capacity. During the recent years, a reasonable increase of sediment particles in the tunnel is observed. This is damaging tunnels, power generating units and is a severe threat to the plant equipment. To the authors knowledge, to-date no comprehensive simulation studies are performed for flooding in the reservoir or turbulent flows in the tunnels. In this paper, turbulent flow using Reynolds Stress Model in Tunnel 3 of the Tarbela Dam is analyzed with and without considering the effect of sediments particle. Results are presented for three different water heads in the reservoir i.e. considering summer, winter and average seasons and for one-way and two-way/full coupling for sediments particle tracking/deposition. The effect of cavitation erosion and damage to the tunnels due to erosion is investigated and results are compared with the experimental erosion results for similar geometries and are found in good agreement. Sediments particulate analysis is also performed for the validation of the samples collected from WAPDA. Moreover, pressure, velocity and erosion rate results are discussed to get complete behavior of the turbulent flow of water in the tunnel

    Co-inoculation with Rhizobium and plant growth promoting rhizobacteria (PGPR) for inducing salinity tolerance in mung bean under field condition of semi arid climate

    Get PDF
    Salinity stress severely affects the growth, nodulation and yield of mung bean (Vigna radiata L.). However, its growth can be improved under salinity stress by inoculation/co-inoculation with rhizobia and plant growth promoting rhizobacteria (PGPR) containing 1-Aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme. ACC-deaminase containing bacteria regulate the stress induced ethylene production by hydrolyzing the ACC (immediate precursor of ethylene) into ammonia and ketobutyric acid, thus improve plant growth by lowering the ethylene level. A study was conducted under salt affected field conditions where pre-isolated strains of Rhizobium and PGPR were used alone as well as in combination for mitigating the salinity stress on growth, nodulation and yield of mung bean by following the randomized complete block design (RCBD). The data were recorded and analyzed statistically to see the difference among treatments

    Pattern of Congenital Heart Diseases in Paediatric Age Group

    Get PDF
    Background: To determine the pattern of differenttypes of congenital heart diseases, in paediatric agegroup.Methods: In this observational cross sectionalstudy cases of congenital heart defects (CHD) wereincluded, through simple random samplingirrespective of age and gender. Every patient’s dataon echocardiographic report clearly indicating hisCHD type along with age and gender was recorded.Variables of study i.e. type of CHDs, age, and genderwith relative frequencies were presented separatelygraphically.Results: Out of 298 diagnosed patients of CHD 156were males and 142 were females. Isolatedventricular septal defect found to be the mostcommon anomaly (32.6%). In combination atrialseptal defect and ventricular defect were found to bemost common with 5.4% burden rate. Out of 298patients Acyanotic CHDs were 67.1% while CyanoticCHDs were found to be 32.9%.Conclusion: Acyanotic CHDs were found to bedominant over Cyanotic CHDs with relativepercentages of 67.1% and 32.9% respectivel

    Heritability, heterosis and heterobeltiosis studies for morphological traits of maize (Zea mays L.) seedlings

    Get PDF
    Background: Maize is one of most important cereal crop in world after wheat and rice. It is grown in Pakistan as a major cash crop cultivation in the area of 1083 thousand hectares producing 3990 thousand tones. Maize is dual propose crop it is used as feed for livestock and food for human. It is also used as a raw material in textile, food and medicine industries. The present study was conducted to evaluate parents and F1 hybrids of maize for seedling traits including heritability, heterosis and heterobelteiosis.Methodology: The genetic material was comprises of twelve parents and including their 36 F1 hybrids. The parents and F1 hybrids were sown in the iron treys filled with sand in three replications following completely randomized design. The data was recorded for fresh root length, fresh shoot length, fresh root-to-shoot length ratio, fresh root weight, fresh shoot weight and fresh root-to-shoot weight ratio. The data was subjected for analysis genotypic and phenotypic coefficients of variance. The genetic advance was calculated by using Falconer (1989) formula.Results: The average batter performance was given by B-336, EV-347, EV-1097Q and B-327. The F1 hybrids, EV-1097Q × EV-347, EV-1097Q × EV-340, Raka-poshi × EV-347, B-327 × B-316 and Sh-139 × EV-347 showed higher values of heterosis and heterobeltiosis for respected studied traits of maize seedlings.Conclusion: In this study, it is concluded that the F1 hybrids, EV-1097Q x EV-347, EV-1097Q x EV-340, Raka-poshi x EV-347, B-327 x B-316 and Sh-139 x EV-347 may be used as higher yield maize hybrids and parents EV-347, EV-1097Q, B-327 and B-316 may be used to develop higher yield maize hybrids following heterosis breeding scheme

    EFFECT OF WASTE POLYETHYLENE TEREPHTHALATE BOTTLE FIBERS ON THE MECHANICAL PROPERTIES OF RECYCLED CONCRETE

    Get PDF
    The use of beverage containers, most of which are made of polyethylene terephthalate bottles, results in several problems with regard to sustainability. The purpose of this study was to evaluate and contrast the impact on the mechanical characteristics of concrete caused by the incorporation of polyethylene terephthalate bottle fibres in varying amounts. These fibres were generated by cutting bottles into precise dimensions (width of 5 mm and length of 25 mm), and they were used in various concentrations such as 0,25 %; 0,5 % and 1,0 % by volume of concrete with different amounts of recycled aggregate. To verify the reliability of the outcomes of the experiment, a statistical analysis was performed. According to the results, the concrete that contained 0 % recycled coarse aggregate and varying amounts of plastic fibres had a greater degree of workability compared with concrete that had either 50 % or 100 % recycled coarse aggregate. The comprehensive test findings demonstrated that the addition of polyethylene terephthalate fibres decreased compressive and split tensile strength. The study concluded that certain parameters, such as plastic fibres, curing days, and recycled aggregate, interacted together in a synergistic manner to impact the compressive and splitting tensile strengths of the concrete, with proposed equations for their prediction

    Toxicity and Repellency of Plant Extract and Termiticide against Fungus Growing Subterranean Termites (Blattodea: Termitidae)

    Get PDF
    Different methods such as physical, biological and chemical are used to manage soil fungus increasing termites. Synthetic insecticide plays a vital part in the management of termites. The pesticide used in big quantities causes phytotoxicity, mammalian toxicity and resistance to pesticides in target pests and insect outbreaks. Intensive pesticides exert chronic effects on living organisms with annoyance for beneficial insects. It also accompanied with environmental hazards and developed resistance. Plant leaves extracts provide a distinct variety of biochemical compounds with diverse prospective uses. Resistance development requires the discovery of fresh biological compounds with a wide spectrum of action. Plant leaves extract and Chlorfenapyr solution in methanol and water with various concentrations (15 %, 10 %, 5 % and 0 %) were applied to the soil against termites to determine mortality and repellency. Posttreatment data was obtained and evaluated through statistical analysis. The result revealed that the extract of Conocarpus lancifolius with the solution of methanol and solution of water exhibited higher mortality of subterranean termites, whereas the solution of methanol had higher repellency and mortality than water solution of botanical extract. Water and methanol solution of insecticide chlorfenapyr used against the subterranean termites, both are found to be efficacious against termites, while insecticide with the solution of methanol revealed 100% mortality. Nonetheless, plant extract of C. lancifolius with water and methanol solution and chlorfenapyr with methanol solution can be applied as new biological control tools against subterranean termites
    corecore