889 research outputs found

    A knowledge based decision support system for tool changeover in CNCs

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    This paper describes an application of an adaptive planning system for automatic tool changers in flexible manufacturing systems. The conventional models of predictive control usually cannot adapt to a real time dynamic environment. The proposed adaptive control model is capable of self adjusting to changing environments. The algorithm is based on a decision logic, which is constructed by breaking up knowledge and converting them into mathematical form in order to cover all possible conditions that can exist during the implementation phase. Expert thoughts and knowledge from decision logic are stored in the decision tree, which consists of circular nodes, arcs and decision nodes. The suggested system is capable of accepting further rules, new nodes and branches to the tree when additional attributes are needed. This whole knowledge is encoded in the form of production rules and each rule represents a small chunk of knowledge relating to the given domain of tool replacement. A number of related rules collectively respond to highly useful conclusions.The system uses VP Expert development shell, contains an inference engine and, a user interface. The originality of the proposed strategy lies in that a knowledge-based expert system is developed to identify and analyze the current conditions and then readjust the output that reflects the real-time environment. Compared with the various classical models, the approach can synthesize and analyze as many variables as possible to adequately and reliably identify the real-time conditions. Simulation results demonstrate the effectiveness and practicality of this tool-change planning and control strategy

    Epimorphisms, dominions and H-commutative semigroups

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    In the present paper, a series of results and examples that explore the structural features of H-commutative semigroups are provided. We also generalise a result of Isbell from commutative semigroups to H-commutative semigroups by showing that the dominion of an H-commutative semigroup is H-commutative. We then use this to generalise Howie and Isbell's result that any H-commutative semigroup satisfying the minimum condition on principal ideals is saturated

    Competition Kinetics: An Experimental Approach

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    In this chapter, free radical kinetics with the help of competition kinetics and some experimental results calculated by competition kinetics to find out the rate constant of reactive species (●OH, eaq−, ●H) with target compound, which is used by radiation chemists is briefly discussed. The competition kinetics method is well validated by taking ciprofloxacin, norfloxacin and bezafibrate as example compounds. The bimolecular rate constants of hydroxyl radical, hydrate electron and hydrogen atom has been calculated for example solute species (ciprofloxacin, norfloxacin and bezafibrate)

    Genetic basis of variation for seedling traits in Gossypium hirsutum L.

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    A 6 × 6 complete diallel analysis was performed to study the inheritance of seedling traits in cotton. Significant differences among genotypes showed the genetic variation and formal analysis predicted the presence of both additive and non-additive genetic variation for inheritance of seedling traits. Further, the estimates of genetic components D, H1 and H2 confirmed the presence of both additive and non-additive genetic effects for all the characteristics. Dominant genes were responsible for theincrease of seedling shoot length, root length, shoot weight and root weight. However, recessive genes were accountable for the increase of shoot root ratio by length and by weight. Seedling shoot length, root length and root weight can be improved through heterosis breeding. The magnitude of broad sense heritability was greater than narrow sense for all the six traits under study hence diminished the scope of selection in the early segregating generation therefore pedigree breeding method is suggested for the improvement of these traits.Key words: Additive dominance model, gene action, Gossypium hirsutum L, heritability, seedling traits

    Distinct gene mutations, their prognostic relevance and molecularly targeted therapies in Acute Myeloid Leukemia (AML)

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    Acquired genetic alterations which include balanced and unbalanced chromosome aberrations and submicroscopic gene mutations and changes in gene expression strongly influenced by pretreatment clinical features and prognosis of adults patients with acute myeloid leukemia (AML). Cytogenetic profiling separate AML patients into three broad prognostic groups: favorable, intermediate and adverse. The cytogenetic risk classifications vary to some extent for younger adult patients and for those aged 60 years or older. In many cases, patients with specific cytogenetic rearrangement such as those with a normal karyotype or those with either RUNX1-RUNX1T1 or CBFB-MYH11 feature of core-binding factor (CBF) can be further subdivided into prognostic categories depend on the presence or absence of specific gene mutations or changes in gene expression. Advancement in the understanding of cancer genetic and discovery of recurrent mutations in AML provide opportunity to develop targeted therapies and improve the clinical outcome. The identified gene mutations, mainly targetable lesions are gain of function mutations of JAK2 and cKIT and FLT3 in APL have been associated with clinical features and/ or outcome of patients with these AML subtypes. These data emphasize the significance of genetic testing for common translocations for diagnosis, prognosis and increasingly targeted therapy in acute leukemia. Notably, these several molecular genetic alterations constitute a variety of diverse new targets for salvage therapies. These approaches intend to develop targeted treatment concepts that depend on interference with molecular genetics or epigenetic mechanisms. This report provides an overview on characteristic gene mutations, discuss their biological functions and Prognostic significance, which serve as basis for selected therapy approaches now or might represent options for such approaches in the future and expected to have a role in treating AML subtypes with characteristic molecular alterationsMuhammad Tayyab, Mahwish Khan, Zafar Iqbal, Sara Altaf, Zain Noor, Nida Noor, and Tanveer Akhta

    Studies on the effect of H+ carrier toward ionic conduction properties in alginate-ammonium sulfate complexes–based polymer electrolytes system

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    The present work highlights the contribution of ammonium sulfate (NH4)2SO4 as H+ carriers in alginate-based solid polymer electrolytes (SPEs) that were successfully prepared via a solution casting technique. The Fourier transform infrared analysis revealed that molecular interactions between the host polymer and the ionic dopant complexes occurred at the wavenumbers 3700–2500 cm-1, 1800–1500 cm-1, and 1200–900 cm-1. These regions corresponded to the O-H stretching, COO− and C-O-C, moieties of alginate, respectively, which coordinated with the H+ carrier from (NH4)2SO4. At ambient temperature, the optimum ionic conductivity was obtained at 3.01 × 10−5 S cm-1 for the sample containing 10 wt.% of (NH4)2SO4. The IR-deconvolution approach shows that the ionic conduction enhancement is governed by the ionic mobility and the diffusion coefficient of H+ carriers, and the findings show that the present biopolymer, which is an alginate-based SPEs system, has an excellent possibility to be used as electrolytes for application in electrochemical device

    FEM analysis of the impact of surface undulations on the natural convective flow of viscous fluid in a permeable trapezoidal enclosure

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    Examination of the transport mechanism in a permeable trapezoidal enclosure with an undulation effect is commenced. A formulation describing naturally convective flow in a permeable domain is conceded by employing Boussinesq and Darcy approximations. Uniform temperature is provided at the circular cylinder and base wall of the enclosure, whereas non-parallel side extremities are kept cold. No heat flux condition is applied at a wavy surface (upper) to maintain the potential difference in temperature for generation of convection. A finite element scheme is opted to resolve the governing system for accounted physical problems. The grid sensitivity test is also executed to assure the credibility of the code and results. A wide range of physical parameters is selected to comprehend their impact on streamlines and isotherm patterns. Results are revealed comparatively for zero undulation (upper solid straight wall) and with undulations (wavy wall). Heat flux and kinetic energy are also enumerated as key quantities against concerning parameters. It is depicted that the average Nusselt number and kinetic energy are more in the absence of undulations than when it is present. Additionally, it is manifested that the placement of a heated cylinder helps transfer heat in the domain and the production of thermal convective potential

    Temperature-dependent development of Helicoverpa armigera (HĂŒbner) (Lepidoptera: Noctuidae) and its larval parasitoid, Habrobracon hebetor (Say) (Hymenoptera: Braconidae): implications for species interactions

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    Habrobracon hebetor (Say) is a parasitoid of various Lepidoptera including Helicoverpa armigera (HĂŒbner), a key pest of different crops and vegetables. The development of both H. armigera and H. hebetor were simultaneously evaluated against a wide range of constant temperatures (10, 15, 17.5, 20, 25, 27.5, 30, 35, 37.5 and 40 °C). Helicoverpa armigera completed its development from egg to adult within a temperature range of 17.5–37.5 °C and H. hebetor completed its life cycle from egg to adult within a temperature range of 15–40 °C. Based on the Ikemoto and Takai model the developmental threshold (T o) and thermal constant (K) to complete the immature stages, of H. armigera were calculated as 11.6 °C and 513.6 DD, respectively, and 13 °C and 148 DD, respectively, for H. hebetor. Analytis/Briere-2 and Analytis/Briere-1 were adjudged the best non-linear models for prediction of phenology of H. armigera and H. hebetor, respectively and enabled estimation of the optimum (T opt) and maximum temperature (T max) for development with values of 34.8, 38.7, 36.3, and 43 °C for host and the parasitoid, respectively. Parasitisation by H. hebetor was maximal at 25 °C but occurred even at 40 °C. This study suggests although high temperature is limiting to insects, our estimates of the upper thermal limits for both species are higher than previously estimated. Some biological control of H. armigera by H. hebetor may persist in tropical areas, even with increasing temperatures due to climate change

    ESBL determination and antibacterial drug resistance pattern of Klebsiella Pneumoniae amongst patients at PIMS Islamabad

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    Background: A number of life threatening infections due to various bacterial pathogens are major cause  of death in Pakistan. In a situation like the other developing countries, there is a general increase in the  drug resistance due to the irrational use of the antibiotics. The present study was carried out to evaluate the prevalence and development of resistance in Klebsiella pneumoniae against commonly used antibiotics.Methods and Materials: A total of 200 samples from different wards of the hospitals were received by the pathology laboratory of Pakistan Institute of Medical Sciences, Islamabad, which comprised of urine  65, blood 50 and other miscellaneous samples from various sources. Klebsiella pneumoniae was isolated and characterized using morphological, cultural, and biochemical methods and were further confirmed by using commercially available API 20E kit. The isolates were subjected to culture sensitivity test using  Kirby Bauer disc diffusion method.Results: The organism was found to be the most prevalent Gram-negative bacilli. K. pneumoniae showed  highest resistance against coamoxiclav and cephalosporins.Conclusion: The study revealed that ESBL producing strains were resistant to most of the beta-lactam antibiotics. This trend therefore has become a significant problem and can be controlled with continued surveillance or monitoring for rationally improved antibiotics usage, in order to prevent the drug resistance and re-emergence of infection.Key words: Klebsiella pneumoniae, ESBL (Extended-spectrum beta-lactamase), API (Analytical Profile Index
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