5,766 research outputs found
Importance of Municipal Solid Waste Management
Solid waste management is one among the fundamental and essential services provided by municipal authorities in the developed as well as developing countries to keep urban areas clean. In certain regions of our country, the free disposal facilities have reached their own capacity and even local governments are confronted with difficult decisions. Solid waste management is an integral element of modern society. There are many ways in which solid waste can be treated, and thanks to modernized practices and technological advancement, these methods are very safe and practical
Semirings embedded in a completely regular semiring
summary:Recently, we have shown that a semiring is completely regular if and only if is a union of skew-rings. In this paper we show that a semiring satisfying can be embedded in a completely regular semiring if and only if is additive separative
Ultrahigh Strength Steel: Development of Mechanical Properties Through Controlled Cooling
Structural steels with very high strength are referred as ultrahigh strength steels. The
designation of ultrahigh strength is arbitrary, because there is no universally accepted
strength level for this class of steels. As structural steels with greater and greater strength
were developed, the strength range has been gradually modified. Commercial structural
steel possessing a minimum yield strength of 1380 MPa (200 ksi) are accepted as ultrahigh
strength steel (Philip, 1990). It has many applications such as in pipelines, cars, pressure
vessels, ships, offshore platforms, aircraft undercarriages, defence sector and rocket motor
casings. The class ultrahigh strength structural steels are quite broad and include several
distinctly different families of steels such as (a) medium carbon low alloy steels, (b) medium
alloy air hardening steel, (c) high alloy hardenable steels, and (d) 18Ni maraging steel. In the
recent past, developmental efforts have been aimed mostly at increasing the ductility and
toughness by improving the melting and the processing techniques. Steels with fewer and
smaller non-metallic inclusions are produced by use of selected advanced processing
techniques such as vacuum deoxidation, vacuum degassing, vacuum induction melting,
vacuum arc remelting (VAR) and electroslag remelting (ESR). These techniques yield (a) less
variation of properties from heat to heat, (b) greater ductility and toughness especially in the
transverse direction, and (c) greater reliability in service (Philip, 1978). The strength can be
further increased by thermomechanical treatment with controlled cooling
Protection from experimental colitis by theaflavin-3,3'-digallate correlates with inhibition of IKK and NF-κB activation
Background and purpose: Inflammatory bowel disease (IBD) is associated with activation of nuclear factor κ B (NF-κB) involved in regulating the expression of inducible nitric oxide synthase (iNOS) and proinflammatory cytokine genes. As theaflavin-3,3'-digallate (TFDG), the most potent anti-oxidant polyphenol of black tea, down-regulates NF-κB activation, we investigated if TFDG is beneficial in colonic inflammation by suppressing iNOS and proinflammatory cytokines. Experimental approach: The in vivo efficacy of TFDG was assessed in mice with trinitrobenzene sulfonic acid (TNBS)-induced colitis. Both mRNA and protein levels of proinflammatory cytokines and iNOS were analyzed in colon tissue treated with or without TFDG. NF-κB activation was determined by electrophoretic mobility shift assay and levels of NF-κB inhibitory protein (IκBα) were analyzed by Western blotting. Key results: Oral administration of TFDG (5 mg kg-1 daily i.g.) significantly improved TNBS-induced colitis associated with decreased mRNA and protein levels of TNF-α, IL-12, IFN- and iNOS in colonic mucosa. DNA binding and Western blotting revealed increase in NF-κB activation and IκB depletion in TNBS-treated mice from Day 2 through Day 8 with a maximum at Day 4, which resulted from increased phosphorylation of IκB and higher activity of IκB kinase (IKK). Pretreatment with TFDG markedly inhibited TNBS-induced increases in nuclear localization of NF-κBα, cytosolic IKK activity and preserved IκBα in colon tissue. Conclusions and Implications: TFDG exerts protective effects in experimental colitis and inhibits production of inflammatory mediators through a mechanism that, at least in part, involves inhibition of NF-κB activation
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