Engine emission characteristics of algal biofuel with micro emulsion

An experimental investigation was conducted in a diesel engine to establish the effects of tetrahydrofuran (THF) with the Caulerpa racemosa algae methyl esters (CRAME) emulsion fuel. THF is added to the CRAME at different proportions such as 1% and 2%. The CRAME was produced from the Caulerpa racemosa algae oil by transesterification process. The aim of the present study was to analyze the experimental exploration of the antioxidants THF on engine emission of a diesel engine fueled with methyl ester of CRA oil. The test is conducted with different antioxidant concentrations of CRAME mixtures. The results exhibited that THF is effectual in controlling emissions.     

Characterisation and recovery of sodium chloride from salt-laden solid waste generated from leather industry

In this present investigation, physical and chemical characteristics of salt-laden solid waste (SLSW) generated from leather industry during soaking process of raw skins/hides and reverse osmosis reject stream were determined. The disposal of SLSW onto landfill was banned due to the possibility of ground water contamination by leachate, and its treatment process becomes tedious and cost intensive. The detailed characterisation of SLSW was evaluated for the development of effective methods for the treatment and/or disposal of SLSW. In the present study, sodium chloride was recovered to reduce the impact of the disposal of SLSW. The recovery of sodium chloride was achieved by selective precipitation using hydrogen chloride gas as a precipitating agent. The optimum conditions for the precipitation of sodium chloride were concentration of SLSW, 60 % (w/w); HCl gas purging, time 3 min (for a batch volume of 100 mL); pH, 8.0; and temperature, 30–40 °C. The scanning electron microscopy images of SLSW and the recovered sodium chloride were captured to observe the surface morphology. The recovered salt showed purity equivalent to that of standard reference salt. The recovered salt can be reused within leather sector or to the other process industries that meet their specification.     

Investigation of the surface properties of heat treated electroless Ni–P coating

Electroless nickel phosphorus (Ni–P) coatings were synthesised from an acid chloride electrolyte. The synthesised coatings were heat treated at different temperatures, and the surfaces of the heat treated coating were characterised using scanning electron microscopy and X-ray diffraction. Adhesion, wettability, hardness and corrosion behaviour of the coatings were measured. The surface morphology showed the formation of a nano crystalline nickel matrix under heat treated condition. X-ray diffraction analysis of the heat treated samples revealed the recrystallisation of nickel and formation of Ni₃P phase in the coatings. The wettabilty study showed that the as-deposited Ni–P coating is hydrophobic and wettability increases to a maximum of 70.8° contact angle for heat treated temperature of 400°C due to nano crystalline formation. The Rockwell C adhesion test revealed the presence of micro cracks with increase in heat treatment temperature, however the failure is within the acceptability limit. The micro hardness of the Ni–P coating increased with increase in heat treatment temperature. Corrosion potential of the Ni–P coating shifted to a positive potential under heat treated conditions owing to oxidation and precipitation of Ni₃P phase. Decreased corrosion rate and corrosion current density (7.37–0.21?µA?cm^?2) is attributed to heat treatment at 400°C.     

Changes in physiochemical quality and browning related enzyme activity of longkong fruit during four different weeks of on-tree maturation

The optimum harvesting period of longkong from 13 to 16 weeks of maturation were used to analyse the changes in physiochemical and browning related enzymes. The colour, such as lightness (L^∗) and yellowness (b^∗) decreased and conversely redness (a^∗) increased. The fruit weight was significantly increased from 21.21 to 24.93 g and the diameter was also increased (p > 0.05). Chemical qualities, such as total soluble solids, pH, total sugar and reducing sugar increased while titratable acidity decreased at the end of maturation period (p < 0.05). The antioxidant activity, such as 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (from 4.73 to 8.97 mg/100 g), ferric reducing antioxidant power (from 5.06 to 6.83 mg/100 g) and total phenolic content increased (from 42.65 to 58.71 mg/100 g) (p < 0.05). The polyphenol oxidase activity significantly increased throughout the maturation; peroxidase and phenyl alanine ammonia lyase enzymes increased at the beginning but after that they decreased at the end of the maturation period. Peel epidermal trichomes losses on the surface and parenchyma cell changes in the cross section were found during these stages.     

Maximum error modeling for fault-tolerant computation using maximum a posteriori (MAP) hypothesis

The application of current generation computing machines in safety-centric applications like implantable biomedical chips and automobile safety has immensely increased the need for reviewing the worst-case error behavior of computing devices for fault-tolerant computation. In this work, we propose an exact probabilistic error model that can compute the maximum error over all possible input space in a circuit-specific manner and can handle various types of structural dependencies in the circuit. We also provide the worst-case input vector, which has the highest probability to generate an erroneous output, for any given logic circuit. We also present a study of circuit-specific error bounds for fault-tolerant computation in heterogeneous circuits using the maximum error computed for each circuit. We model the error estimation problem as a maximum a posteriori (MAP) estimate [28] and [29], over the joint error probability function of the entire circuit, calculated efficiently through an intelligent search of the entire input space using probabilistic traversal of a binary Join tree using Shenoy-Shafer algorithm [20] and [21]. We demonstrate this model using MCNC and ISCAS benchmark circuits and validate it using an equivalent HSpice model. Both results yield the same worst-case input vectors and the highest percentage difference of our error model over HSpice is just 1.23%. We observe that the maximum error probabilities are significantly larger than the average error probabilities, and provides a much tighter error bounds for fault-tolerant computation. We also find that the error estimates depend on the specific circuit structure and the maximum error probabilities are sensitive to the individual gate failure probabilities.     

Pilot-Scale Simulation of Landfill Bioreactor and Controlled Dumping of Fresh and Partially Stabilized Municipal Solid Waste in a Tropical Developing Country

Four pilot-scale lysimeters were used to study the benefits of landfill operation with and without leachate recirculation in tropical weather conditions. Young and old landfills were simulated by filling lysimeters with a segregated fraction of fresh municipal solid waste (MSW) and MSW mined from an open dump site, respectively, and periodically monitoring leachate quantity and quality and biogas quality. For each substrate, one lysimeter was operated as a bioreactor with leachate recirculation and another lysimeter was operated as a controlled dump, for a period of 10 months. Densities between 652 and 825??kg/m3 could be achieved with fresh and mined MSW. Despite such compaction during waste placement, bioreactor technology helps in leachate management, especially in the case of the young landfill lysimeter operated in tropical weather. The benefits of leachate recirculation in the young landfill lysimeter were evident from the significant decrease in chemical oxygen demand (COD) (86%), biochemical oxygen demand (BOD) (82%), dissolved organic carbon (DOC) (85%), and volatile solids (75%) in leachates. However, ammonia nitrogen (amm-N) and chlorides in the leachates accumulated in bioreactor landfills. Operating an old landfill lysimeter as a bioreactor seemed to have no exceptional advantage in the context of leachate management, although leachate recirculation enhanced the methane potential of both fresh and mined MSW.     

铁鞣新方法(续)

将铁鞣与铬鞣进行了优化结合,这种鞣制技术不仅可以加工出质量上乘的皮革制品,同时又可以满足废液中铬与铁的含量低于100mg/kg的标准。此工艺制造的皮革可耐沸水试验,阐述了其鞣制技术和鞣制机理。对铁鞣法在加工山羊绒面革和绵羊全粒面服装革中出现的问题进行了研究。用扫描电镜对鞣革的结构特性进行了研究,对成革的物理机械性能及染色特性也做了分析和阐述。     

锌-三氧化二铬复合镀层的特性

采用由氧化锌12g/L、氢氧化钠94 g/L、2-氨基-3-羧基吡啶4.2 g/L、四乙烯五胺17g/L、三乙醇胺2g/L、专利表面活性剂0.5 g/L及碳三氧化二铬(粒径2μm)0～ 11 g/L组成的镀液,于温度50℃、pH 6.5和电流密度4A/dm2的条件下,在低碳钢上电镀Zn-Cr2O3复合镀层.其显微硬度采...     

Synthesis and characterization of proton conducting polymer electrolyte based on poly(N‐vinyl pyrrolidone)

This work aims at developing and characterizing a proton conducting polymer electrolyte based on Poly(N‐vinyl pyrrolidone) (PVP) doped with ammonium bromide (NH₄Br). Proton conducting polymer electrolytes based on PVP doped NH₄Br in different molar ratios have been prepared by solution casting technique using distilled water as solvent. The XRD pattern confirms the dissociation of salt. The FTIR analysis confirms the complex formation between the polymer and the salt. The conductivity analysis shows that the polymer electrolyte with 25 mol % NH₄Br has the highest conductivity equal to 1.06 × 10^?3 S cm^?1 at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plot is low (0.50 eV) for 25 mol % NH₄Br doped polymer electrolyte. The influence of salt concentration on dc conductivity and activation energy of the polymer electrolyte has been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Cache Optimization on Hot‐Point Proxy Caching Using Weighted‐Rank Cache Replacement Policy

The development of proxy caching is essential in the area of video‐on‐demand (VoD) to meet users' expectations. VoD requires high bandwidth and creates high traffic due to the nature of media. Many researchers have developed proxy caching models to reduce bandwidth consumption and traffic. Proxy caching keeps part of a media object to meet the viewing expectations of users without delay and provides interactive playback. If the caching is done continuously, the entire cache space will be exhausted at one stage. Hence, the proxy server must apply cache replacement policies to replace existing objects and allocate the cache space for the incoming objects. Researchers have developed many cache replacement policies by considering several parameters, such as recency, access frequency, cost of retrieval, and size of the object. In this paper, the Weighted‐Rank Cache replacement Policy (WRCP) is proposed. This policy uses such parameters as access frequency, aging, and mean access gap ratio and such functions as size and cost of retrieval. The WRCP applies our previously developed proxy caching model, Hot‐Point Proxy, at four levels of replacement, depending on the cache requirement. Simulation results show that the WRCP outperforms our earlier model, the Dual Cache Replacement Policy.