An efficient cutset approach for evaluating communication-network reliability with heterogeneous link-capacities

This paper presents an efficient cutset approach to compute the reliability of a large communication network having heterogeneous link capacities. The reliability measure has been defined as capacity related reliability (CRR). The proposed method, subset cut technique (SCT), requires the cutset information of the network. For each minimal cut C/sub i/, and a given minimum bandwidth requirement W/sub min/, the method enumerates all nonredundant subset cut (SC), where each SC relates link capacities & minimum bandwidth requirements. Note that if all links in an SC fail, the capacity of the induced cut C/sub i/ will be less than W/sub min/. Given the failure probability of each link, and the nonredundant SC, any Boolean technique for generating mutually disjoint terms can be utilized to obtain a capacity related unreliability (CRU) of the network. Thus, the CRU for an (s,t) node pair is the probability that the network has a capacity of less than W/sub min/ for the given node pair. Note that CRR=1-CRU. Two SCT algorithms are proposed: Algorithm-1, and Algorithm-2; and the suitability of using either algorithm is also discussed. Examples are given to illustrate the techniques. The time complexity, and the proof of correctness for the proposed algorithms are also included. It is shown empirically that the time complexity of generating the nonredundant SC of a network is polynomial in the order of the number of cuts of the network. The proposed SCT algorithms have been implemented in C. We have utilized the SCT to generate the CRR of some large communication networks with various W/sub min/ values.     

Modeling of permeate flux of synthetic fruit juice and mosambi juice (Citrus sinensis (L.) Osbeck) in stirred continuous ultrafiltration

Ultrafiltration studies of synthetic sucrose and pectin mixture and enzymatically treated mosambi juice have been performed in a stirred continuous cell. A model based on gel layer theory is developed to predict the flux decline during filtration for both synthetic and actual juice. From the steady state flux data, the mass transfer coefficient is observed to vary with operating pressure only and a modified Sherwood number relationship is proposed for such a system. The permeate of the filtered juice contains almost all the nutritional values of the original juice with significant improvement in clarity.     

Vibration analysis of multi-walled carbon nanotubes embedded in elastic medium

We propose a method to estimate the natural frequencies of the multi-walled carbon nanotubes (MWCNTs) embedded in an elastic medium. Each of the nested tubes is treated as an individual bar interacting with the adjacent nanotubes through the inter-tube Van der Waals forces. The effect of the elastic medium is introduced through an elastic model. The mathematical model is finally reduced to an eigen value problem and the eigen value problem is solved to arrive at the inter-tube resonances of the MWCNTs. Variation of the natural frequencies with different parameters are studied. The estimated results from the present method are compared with the literature and results are observed to be in close agreement.     

Wear Behavior of Harmonic Structured 304L Stainless Steel

Wear behavior of a harmonic structured 304L austenitic stainless steel with periodically distributed fine and coarse grains was examined and compared with a sintered non-harmonic structured 304L stainless steel and a low carbon conventional 304 stainless steel using fretting wear tests at varying loads in ball-on-flat contact configuration. Characterization was accomplished using scanning electron microscope, energy-dispersive spectroscopy, optical profilometry and Raman spectroscopy. Coefficient of friction and wear volume were minimum at intermediate normal load of 5 N, whereas maximum at 10 N for the harmonic stainless steel compared to other two steels. Harmonically distributed fine- and coarse-grained structure attributes to the higher wear rate of the harmonic structured steel at higher load because of differential interaction of the ball with the harmonically distributed hard (fine) and relatively soft (coarse) regions.     

Innovative stair climber using associated wheels

The study proposes an innovative and completely new but low-cost configuration of a platform that can easily climb stairs. This platform serves the purpose of a chassis. Different versions, such as staircase-climbing wheelchair or staircase-climbing trolley for material transferring, can be derived depending on the structure built on the platform. The driving wheels have a shape that completely matches with the profile of the steps. Complex components are eliminated. Thus, this platform is conveniently applicable in the configurations useful for climbing staircases.     

The fission yeast MAPK Spc1 senses perturbations in Cdc25 and Wee1 activities and targets Rad24 to restore this balance

Mitogen‐activated protein kinases (MAPKs) play vital roles in multiple cellular processes and represent prominently pursued targets for development of therapeutic regimes. The MAPK Spc1 (p38 homologue) is known to be very important for both mitotic promotion and delay in Schizosaccharomyces pombe. However, the mechanism responsible for mitotic inhibition has remained elusive. Cdc25 (Cdc2 activator) and Wee1 (Cdc2 inhibtor) are important determinants of mitotic timing in all eukaryotes. Our results show that Spc1 can sense the perturbations in the balance of Cdc25 and Wee1 activities in S. pombe and that its function as a mitotic inhibitor is very important for controlling the same. An Spc1–Srk1–Rad24‐dependent pathway for mitotic inhibition has been reported earlier.Here we report the presence of an alternative mechanism wherein Spc1 targets the 14–3–3 protein, Rad24, independently of Srk1, leading to relocalization of Cdc25 and mitotic inhibition. Our observations suggest that this pathway can serve as a backup mechanism for Cdc2 inactivation in the absence of Wee1.     

Antitumor Perspectives of Oleuropein and Its Metabolite Hydroxytyrosol: Recent Updates

Olive fruit is a significant and promising source of potential bioactive compounds such as oleuropein and hydroxytyrosol. Oleuropein is the ester of elenolic acid and 3,4‐dihydroxyphenyl ethanol (HT). It is the main glycoside in olives, the degradation of which results in the formation of hydroxytyrosol in olive oil. Both plays a significant role in the reduction of coronary heart diseases and a certain type of cancers. Both olive oil phenols have an effective role counter to cell proliferation, cell growth, migration, invasion, and angiogenesis. They down regulate the expression of BCL‐2 and COX‐2 proteins, and reduced DNA damage. Hydroxytyrosol and oleuropein inhibited the multiple stages in colon carcinogenesis; initiation, promotion, and metastasis. They also provide protection against various human cancers including colorectal, skin, breast, thyroid, digestive, lung, brain, blood, and cervical. This review article discusses the anticancer perspectives and mechanisms of oleuropein and hydroxytyrosol in cell cultures and animal and human studies.     

8 MeV electron irradiation effect on the dielectric and optical properties of iminodiacetic acid doped ferroelectric triglycine sulphate crystals

Single crystal of iminodiacetic acid (5 mol%) doped Tri Glycine Sulphate (IDATGS) was grown by slow evaporation from its aqueous solution at constant temperature, using solution growth method. The dielectric constant (ε′) and pyroelectric current (I_P) were measured over the temperature range of 30-60 °C in the ferroelectric direction. The measured values of ε′ and I_P were found to be smaller compared to pure triglycine sulphate (TGS) crystal parameters. But increased transition temperature was observed for doped crystals. Curie Weiss constants C_P and C_f in the paraelectric and ferroelectric phases were also determined. The doped crystal was irradiated with graded dosages from 5 to 80 kGy of electron beam from 8 MeV Microtron at room temperature and radiation effects on optical and dielectric properties were studied. The UV-Vis absorption spectrum indicates that the UV lower cutoff shifts towards the higher wavelength region (red shift) and the optical band gap is found to be decreasing with the increase of electron dose. It is also observed that the electron irradiation effects in pure and doped TGS were found to be long lasting. The dielectric study shows that there is a gradual reduction in dielectric constant at T_C and shifting of Curie temperature towards lower temperature region with the increase in electron radiation dose. The material figures of merit were found increased after the crystal was irradiated. Induced changes in the physical and optical properties due to irradiation may help one to tailor the device quality and characteristics.