Experimental Investigation Regarding the Effects of Grooves on Conical Bearing Performance

An experimental investigation is made regarding conical bearing characteristics related to the introduction of grooves. Load capacities of three bearing types are compared, i.e., smooth bearings, bearings with radial grooves, and bearings with inclined grooves rotated in both directions. The obtained results indicate that the presence of grooves significantly affects conical bearing performance. It is concluded that for the maximum load capacity, a bearing with inclined grooves should be used with forward rotation, i.e., when the entry part of the groove advances ahead of the exit of the groove.     

ALKYLOXY ALKYLAMINO PROPANOLS AS MULTIFUNCTIONAL FUEL STABILIZERS

Nine different derivatives of alkyloxy alkylamino propanols were synthesised from epichlorohydrin, straight or branched chain primary and secondary alcohols and tertiary alkyl primary amines as well as straight chain primary amine. Their sedimentation inhibition characteristics in distillate fuels of various compositions were studied in comparison to tertiary alkyl primary amines as well as some known commercial additives of similar nature. It is inferred that the replacement of hydrogen in tertiary alkyl primary amines with a long chain hydroxy ether greatly improves the sediment inhibiting properties of tertiary alkyl primary amines, which were otherwise not found very effective in the fuels employed for present studies. Moreover it has been concluded that among these derivatives tertiary-dodecyl appears to be most optimum chain length for the amine moeity and eight C-atoms in the alkyl chain backbone of alcohol moiety is the most optimum for effective inhibition. Sedimentation values have been reduced from 10 mg/100 ml to 2.89 mg/100 ml for 3(3,7 dimethyl octyloxy)-1(t-dodecylamino)-Propan-2-ol employed as inhibitor.     

Removal of iron from groundwater by ash: a systematic study of a traditional method

A traditional method for removal of iron from ground water by using ash has been systematically investigated. Ashes from five different sources, viz., banana rind, banana pseudostem, banana leaf, rice husk and bamboo has been studied. The principle applied is enhanced precipitation of iron at high pH caused by ash. The study included laboratory analysis of some relevant chemical parameters of the ashes and the efficiency of the ashes in removing iron from prefabricated water with respect to quantity of ash and corresponding increase in pH of water. The ash of banana pseudostem has been found to be most suitable for removal of iron. A low-cost and easily made iron removal system for household use has been designed and tested in the laboratory. The ash of banana pseudostem has been found to remove iron to below 0.3ppm without increasing the pH above the acceptable limit. The optimum values of the different parameters for removal of iron are 200-300mgl(-1) ash, 1.0lh(-1) flow rate and 1h of contact time with ash for groundwater having [Fe] of about 2.20ppm. The amount of ash can be increased for groundwater having higher [Fe] and can be decreased gradually during continuous use of the system. Acceptability of the method has been examined based on chemical analysis of the treated water. Increase in the essential minerals such as Ca, K has been observed in the water after treatment. The designed iron removing system is expected to be suitable for household use.     

Effect of graphene concentration on performance of MEH:PPV/graphene nanocomposite based devices

Herein, we explore the effect of graphene concentration on performance of poly [2-methoxy-5-2-ethylhexoxy-p-phenylene vinylene] (MEH:PPV)/graphene nanocomposite based devices. The surface morphology of the nanocomposites analyzed through emission scanning electron microscopy suggest that increase in graphene concentration results in the formation of aggregation. Optical and structural properties of the nanocomposites examined through UV–Vis absorption and Raman spectra revealed that the addition of graphene has no affect on the conjugation length and structure of the MEH:PPV. The electrical characteristics of devices have been investigated by I–V measurement under dark and illumination at room temperature. The devices show increase in the current value and reduction on turn-on voltage with increase in the graphene concentration up to 5 wt%. However, increase in graphene concentration above 5 wt% leads to the performance degradation of the devices. Moreover, charge transport mechanisms of the devices have been explained through Ohmic behavior at lower voltages and trap charge limited conduction at higher voltages.     

Hydrothermal synthesis of NH2-UiO-66 and its application for adsorptive removal of dye

In this research paper we report hydrothermal synthesis of NH₂-UiO-66, a metal organic framework (MOF) with zirconium as metal and amino terephthalic acid as a linker. The synthesized MOF was characterized by XRD, FTIR, SEM and BET surface area. As a potential application in water treatment, an adsorptive removal of safranin dye was studied using the synthesized material. The effect of initial concentration and pH of the dye solution was studied on the dye adsorption capacity of the material. An optimum set of conditions resulting into maximum dye adsorption was found out. The maximum adsorption capacity of the MOF was observed to be 390?mg/g at neutral pH of the solution and at room temperature. The experimental data was fitted with Langmuir, Freundlich and Temkin adsorption isotherm models. The kinetics of adsorption was studied using pseudo first order and pseudo second order model. The dye adsorption mechanism was also attempted.     

A note on the criterion for the elimination of overflow oscillations in fixed-point digital filters with saturation arithmetic and external disturbance

A recently reported criterion for the exponential stability and H_∞ performance of fixed-point digital filters with saturation arithmetic and external disturbance is reviewed. It is shown that there is a technical error in this criterion. A corrected version of the criterion is presented. Finally, a relaxed version of the criterion is made available.     

Efficiency enhancement of organic light emitting diode via surface energy transfer between exciton and surface plasmon

Organic light emitting diodes (OLEDs) with surface plasmon (SP) enhanced emission have been fabricated. Gold nanoclusters (GNCs) deposited using thermal evaporation technique has been used for localization of surface plasmons. Size of GNCs and distance of GNCs from the emissive layer have been optimized using steady state and time resolved photoluminescence (PL) results. 3.2 Times enhancement in PL intensity and 2.8 times enhancement in electroluminescence intensity of OLED have been obtained when GNCs of size 9.3 nm has been introduced at a distance of 5 nm from emissive layer. Distance dependence of energy transfer efficiency between exciton and SPs was found to be of 1/R⁴ type, which is typically the dependence for dipole-surface energy transfer.     

AVDR: A Framework for Migration Policy to Handle DDoS Attacked VM in Cloud

Wireless Personal Communications - The recent trends of Distributed Denial of Service (DDoS) attacks in cloud computing have revealed a new menace of DDoS attacks called collateral damages on...     

An efficient fluoroionophore for selective recognition of Hg and Cu ions

An azo-phenol based receptor 2 viz., 1-(6-nitrobenzothiazole-2-ylazo)naphthalene-2-ol has been designed, synthesized and characterized. The sensing behavior of receptor for different metal ions viz. Na⁺, K⁺, Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Hg²⁺, Ag⁺ and Cd²⁺ has been studied in aqueous acetonitrile solution and was found specific for both the Hg²⁺ and Cu²⁺ transition metal ions. The chemosensor upon interaction with Hg²⁺ and Cu²⁺ ions shows well defined naked-eye visible color change from a yellow-green to pink and blue respectively, with a significant red-shift in absorption spectra. The estimated association constant and, enhancement and quenching in fluorescence emission spectra respectively, reveals the affinity of chemosensor for Hg²⁺ and Cu²⁺ ions. The FT-IR spectral analysis have suggested the probability of complexation, in the reaction medium, between metal ions and 2, through naphthol OH, azo N and thiazole N as a potential coordination sites.     

Ultradisperse and nano structures in plasma coatings hardened by electromechanical treatment

For the example of PRFBKh6-2 alloy and P6M5 steel powders, the structure of plasma coatings after electromechanical treatment is investigated by scanning probe microscopy. After such treatment, ultradisperse and nano hardening phases are formed in the coating. These phases are formed by the decomposition of the coating’s initial fast-quenched structure in high-speed treatment. The formation of characteristic structural zones hardened by nanoparticles and ultradisperse particles is analyzed; the proportions of nanoparticles and ultradisperse particles are determined by the parameters of the sprayed powder and the conditions of plasma spraying and subsequent electromechanical treatment.