Quick Trickle Permutation Based on Quick Trickle Characteristic Sequence

The concept of quick trickle characteristic sequence is presented, the properties and count of quick trickle characteristic sequence are researched, the mapping relationship between quick trickle characteristic sequence and quick trickle permutation is discussed. Finally, an efficient construction of quick trickle permutation based on quick trickle characteristic sequence is given, by which quick trickle permutation can be figured out after constructing quick trickle characteristic sequence. Quick trickle permutation has good cryptographic properties.

The Relationship Between Hysteresis and Liquid Flow Distribution in Trickle Beds

Experiments were conducted on a trickle bed with 0.283m ID to elucidate the relationship between hysteretic phenomena and liquid distribution. The hysteresis of pressure drop and the variance of radial liquid distribution were observed simultaneously. Residence time distribution (RTD), holdup and mean residence time (RT) of liquid phase were also found to demonstrate hysteresis of the same nature. RTD, liquid holdup and mean RT calculated with a simple model from the distribution of liquid flow rate show characteristics consistant with the experimental data, suggesting that the hyteretic phenomena originate from the multiplicity and nonuniformity of liquid flow distribution.

Peracetic Acid Synthesis by Acetaldehyde Liquid Phase Oxidation in Trickle Bed Reactor

In this paper,shorter residence time（a few minutes）with high yield in the trickle bed process for per- acetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA-5118.For acetaldehyde in acetone with ferric ion as catalyst,the optimized process conditions were presented. The main factors influencing the yield,selectivity and conversion are residence time,temperature and acetaldehyde concentration,respectively.The temperature range checked is from 30 to 65℃.High yield of 81.53%with high se- lectivity of 91.84%can be obtained at higher temperature of 55℃when the residence time is 5.5min and the acet- aldehyde concentration is 9.85%（by mass）.And there is a critical acetaldehyde concentration point（Cccp）between 18%and 19.5%（by mass）.At temperature less than 55℃,the highest yield to peracetic acid at each temperature level increases with temperature when the acetaldehyde concentration is below Cccp and decreases with temperature when the acetaldehyde concentration is above Cccp.

Intensification of Deep Hydrodesulfurization Through a Two-stage Combination of Monolith and Trickle Bed Reactors

Deep hydrodesulfurization （HDS） is an important process to produce high quality liquid fuels with ultra-low sul- fur. Process intensification for deep HDS could be implemented by developing new active catalysts and/or new types of reactors. In this work, the kinetics of dibenzothiophene （DBT） hydrodesulfurization over Ni-P/SBA-15/ cordierite catalyst was investigated at 340-380 ℃ and 3.0-5.0 MPa. The first-order reaction model with respect to both DBT and H2 was used to fit the kinetics data in a batch recycle operation system. It is found that both the activation energy and rate constant over the Ni-P monolithic catalyst under our operating conditions are close to those over conventionally used HDS catalysts. Comparative performance studies of two types of reactors, i.e., trickle bed reactor and monolithic reactor, were performed based on reactor modeling and simulation. The results indicate that the productivity of the monolithic reactor is 3 times higher than that of the trickle bed reactor on a catalyst weight basis since effective utilization of the catalyst is higher in the monolithic reactor, but the volumetric productivity of the monolithic reactor is lower for HDS of DBT. Based on simulation results, a two- reactor-in-series configuration for hydrodesulfurization is proposed, in which a monolithic reactor is followed by a tickled bed reactor so as to attain intensified performance of the system converting fuel oil of different sulfur-containing compounds. It is illustrated that the two reactor scheme outperforms the trickle bed reactor both on reactor volume and catalyst mass bases while the content of sulfur is reduced from 200 μg·g-1 to about 10 μ·g-1.

Process intensification in gas/liquid/solid reaction in trickle bed reactors: A review

As an important form of reactors for gas/liquid/solid catalytic reaction,trickle bed reactors (TBRs) are widely applied in petroleum industry,biochemical,fine chemical and pharmaceutical industries because of their flexibility,simplicity of operation and high throughput.However,TBRs also show inefficient production and hot pots caused by non-uniform fluid distribution and incomplete wetting of the catalyst,which limit their further application in chemical industry.Also,process intensification in TBRs is necessary as the decrease in quality of processed crude oil,caused by increased exploitation depths,and more restrictive environmental regulations and emission standards for industry,caused by increased environment protection consciousness.In recent years,lots of strategies for process intensification in TBRs have been proposed to improve reaction performance to meet the current and future demands of chemical industry from the environmental and economic perspective.This article summarizes the recent progress in techniques for intensifying gas/liquid/solid reaction in TBRs and application of intensified TBRs in petroleum industry.

Absorption Enhanced Methanol Synthesis in a Trickle Bed Reactor over Cu/Zn/Al₂O₃Catalyst

Methanol synthesis in a trickle bed reactor with tetraethylene glycol dimethyl ether (TEGDME) as the liquid phase over a Cu/Zn/Al2O3 catalyst was investigated. The pressure was kept constant at 5.0 MPa, while the temperature ranged from 230℃?to 260℃?and the mass space velocity varied between 294 L·Kg-1·h-1 and 1655 L·Kg-1·h-1. The effects of temperature and space velocity on CO conversion and methanol productivity were studied. Methanol synthesis processes in trickle bed with the TEGDME and paraffin oil as liquid phase were compared with the fixed bed process. The results indicated that the optimal temperature was approximately 240℃. When the space velocity was increased, the CO conversion decreased while the methanol productivity increased. The liquid introduced can help to keep the reactor nearly isothermal. For methanol synthesis in trickle-bed reactor, TEGDME was better than paraffin oil. Effect of TEGDME on the reaction was twofold. On one hand, it absorbs the methanol and speeds up the reaction. On the other hand, it also increases the mass transfer resistance and hinders the reaction.

HYSTERESIS OF GAS-LIQUID MASS TRANSFER IN A TRICKLE BED REACTOR

1 INTRODUCTIONTrickle bed reactors are widely used in the process industry,particularly in petroleumhydroprocessing operations,and have been extensively studied by chemical engineers.In atrickle bed reactor,the gas and liquid flow cocurrently down through the packed bedand undergo chemical reactions.However,there exist multiple hydrodynamic stateswhich correspond to either uniform or,in most cases,nonuniform radial distributionof the gas and liquid flows in the packed section.Moreover,the hydrodynamic state

Analysis of Operating Variables in the Catalytic Purification of Butene-1 in a Trickle Bed

A mathematical model for analyzing and simulating selective hydrogenation of butyne-1 and 1,3-bu-tadiene in industrial trickle bed reactors operated to obtain high purity butene-1 is presented in this work.Fromthe analysis of typical operating conditions,only the relevant phenomena are finally retained in the model formu-lation.The model is then employed to analyze the effect of operating variables and catalyst selectivity in processperformance.In particular,the search for the minimum hydrogen flow rate necessary to fulfil butene-1 purityspecifications is undertaken.

Experimental study on the particle flow patterns in a cyclone dipleg with a trickle valve

An experimental apparatus including a dipleg and a trickle valve was established to simulate the operation of a suspended dipleg-trickle valve system of cyclone used in fluid catalytic cracking(FCC)unit.The flow regimes in the dipleg and the discharge modes in the trickle valve were studied by combining the observation of experimental phenomena with the analysis of transient pressure fluctuation.The results show that the flow regimes in the dipleg have two types-the dilute–dense phase coexisting falling flow and the dilute falling flow.Correspondingly,the trickle valve also has two discharge modes-the intermittent periodic dumping discharge and the continuous trickling discharge.The power spectrum density of pressure fluctuation displays that the gas–solids flow in the dipleg-trickle valve system is characterized by a low-frequency pulsation.The coherence coefficient explains the origin and propagation of pressure fluctuation in the system.Eventually,a map describing the flow regimes and discharge modes related to the operation parameters was proposed,which can provide a helpful guidance for the operation of cyclone dipleg-trickle valve system in FCC unit.

Prediction of Pulsation Frequency of Pulsing Flow in Trickle Beds Based on Artificial Neural Network

An extensive database (946 measurements) for the frequency of pulsing flow in trickle beds was established by collecting the experimental results published over past 30 years. A new correlation based on artificial neural network (ANN) to predict the pulsation frequency was developed. Seven dimensionless numbers (groups) employed in the proposed correlation were liquid and gas Reynolds, liquid Weber, liquid Eotvos, gas Froude, and gas Stokes numbers and a bed correction factor. The comparisons of performance reported in the of literature and present correlations show that ANN correlation is a significant improvement in predicting pulsation frequency with an average absolute relative error (AARE) of 10% and a standard deviation less than 18%.

Chrestenson Spectrum and Auto-Correlation Function of Inverse Permutations of Quick Trickle Permutations

In this paper, a sufficient and necessary condition of quick trickle permutations is given from the point of inverse permutations. The bridge is built between quick trickle permutations and m-value logic functions. By the methods of the Chrestenson spectrum of m-value logic functions and the auto-correlation function of m-value logic functions to investigate the Chrestenson spectral characteristics and the auto-correlation function charac- teristics of inverse permutations of quick trickle permutations, a determinant arithmetic of quick trickle permutations is given. Using the results, it becomes easy to judge that a permutation is a quick trickle permutation or not by using computer. This gives a new pathway to study constructions and enumerations of quick trickle permutations.

Application of Laplace Transform for a Gas-Liquid-Solid Trickle Bed Reactor by Using the Tracer Technique

Experimental evaluation and dynamic modelling were presented for a liquid flow (H2O + NaOH tracer) on solid particles in a trickle bed reactor. One-dimensional dynamic mathematical model has been described to study the gas-liquid-solid process in which the liquid phase with the NaOH tracer is treated as a continuum. The physical model has been analyzed, including the formulation of initial and boundary conditions and the description of the solution methodology. An experimental setup to measure the concentrations of the NaOH tracer has been performed. The concentration measurements of this NaOH tracer have been performed in a fixed be reactor on trickling flow of the liquid phase for a range of operating conditions. The axial dispersion (Dax) of the liquid phase, liquid-solid mass transfer (kLS) coefficient and partial wetting efficiency (fe) were chosen as the hydrodynamic parameters of the proposed mathematical model. Such parameters have been optimized with experimental measurents of the NaOH tracer at the exit of the trickle-bed reactor. The optimized parameters (Dax, kLS, and fe) were calculated simultaneously by using the theoretical model with minimization of the objective function. Results of the proposed mathematical model have been presented and compared as of the two experimental cases. These hydrodynamic parameters were fitted by means of the empirical correlations.

Modification of water application uniformity among closed circuit trickle irrigation systems

The aim of this research was determine the ma- ximum application uniformity of closed circuit trickle irrigation systems designs. Laboratory tests carried out for Two types of closed circuits: a) One manifold for lateral lines or Closed circuits with One Manifold of Trikle Irrigation System (COMTIS);b) Closed circuits with Two Manifolds of Trikle Irrigation System (CTMTIS), and c) Traditional Trikle Irrigation System (TTIS) as a control. Three lengths of lateral lines were used, 40, 60, and 80 meters. PE tubes lateral lines: 16 mm diameter;30 cm emitters distance, and GR built-in emitters 4 lph when operating pressure 1 bar. Experiments were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. With COMTIS the emitter flow rate was 4.07, 3.51, and 3.59 lph compared to 4.18, 3.72, and 3.71 lph with CTMTIS and 3.21, 2.6, and 2.16 lph with TTIS (lateral lengths 40, 60, and 80 meters respectively). Uniformity varied widely within individual lateral lengths and between circuit types. Under CTMTIS uniformity values were 97.74, 95.14, and 92.03 %;with COMTIS they were 95.73, 89.45, and 83.25 %;and with TTIS they were 88.27, 84.73, and 80.53 % (for lateral lengths 40, 60, 80 meters respectively). The greatest uniformity was observed under CTMTIS and COMTIS when using the shortest lateral length 40 meters, then lateral length 60 meters, while the lowest value was observed when using lateral length 80 meters this result depends on the physical and hydraulic characteristics of the emitter and lateral line. CTMTIS was more uniform than either COMTIS or TTIS. Friction losses were decreased with CTMTIS in the emitter laterals at lengths 40 meters compared to TTIS and COMTIS. Therefore, differences may be related to increased friction losses when using TDIS and COMDIS.

Use fuzzy interface systems to optimize land suitability evaluation for surface and trickle irrigation

In this study fuzzy logic system was used for optimization parametric evaluation system in surface and trickle irrigations.This study was performed on a surface area of 5175 ha in fathali region located in Ardabil province of Iran.It was indicated that for trickle and surface irrigation respectively an area of about 2941.35 ha(56.77%)and 159.81 ha(3%)of the lands is“highly suitable”and an area of about 246.43 ha(4.7%)and 312.69 ha(6%)is“moderately suitable”.About 797.1 ha(15.4%)and 2744.17 ha(53.02%)were respectively“marginally suitable”for trickle and surface irrigations.“Currently not suitable”suitability included about 737.58 ha(14.2%)and 1746.05 ha(33.7%)and“Permanently not suitable”suitability matched 458.54 ha(8.86%)and 212.28 ha(4.1%)in the zone under study.According to the results,there is a major difference between the“highly suitable”lands obtained through the two methods and the area of“highly suitable”lands in the trickle method is about 18 times of the area of“highly suitable”obtained through the surface irrigation method.As a result,considering the gradual changes of soil parameters,fuzzy evaluation leads to more accuracy compared to the parametric non fuzzy method.By and large,it can be said that fuzzy method,shows higher qualities about the suitability of lands for trickle irrigation.

一种无线传感网络代码分发协议的研究

无线传感器网络的分发协议用于更新节点程序和发送控制指令,目前普遍采用的分发协议存在传输数据量和能耗过大的问题。为此提出一种无线传感网络代码传播与维护的自调整算法,并通过设计分发协议测试系统进行算法性能测试。实验结果表明该算法能有效调节网络中数据包的传输速度,减少数据包传输量,降低能量损耗。

6LoWPAN无线心电传感网络架构与RPL优化仿真

阐述了通过心电采集节点、6LoWPAN边界路由器构建无线传感网络,实现了无线传感器网络(WSN)与IPV6网络之间的通信;针对RPL网络协议中的Trickle算法机制导致选择次优链路,影响网络路由的可靠性和稳定性问题,提出了优化方案;开展了仿真测试和优化后的网络性能指标分析;测试结果和分析表明,6LoWPAN无线传感网络不仅可以完成WSN与外部IPv6网络之间的连接承载数据收发,并且在对Trickle算法优化之后,对提高网络性能有较高影响。

Approximate Expressions to Evaluate the Performance in Butene-1 Purification Units

1 INTRODUCTIONSelective hydrogenatioll of small amounts of butynes and butadiene is industrially employedfor obtaining high purity butene-l used as co-monomer in the production of linear low-densitypolyethyene.For this purpose,the content of vinylacetylene.butyne-l and 1,3-butadiene presentin the process stream should be reduced to a few tens of ppm.

涓流算法的原理及应用方法

涓流算法是一种适用于低能耗、拓扑经常变化的无线网络(或其它共享介质网络)的路由算法。涓流算法通过对于信息发送的速率控制,在降低路由维护成本的同时,保证了对于网络变化的敏感度,比较适用于物联网领域。

Role of Fungal Biomass in N-Hexane Biofiltration

The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed;two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification.

Effect of Irrigation Method and Non-Uniformity of Irrigation on Potato Performance and Quality

Potato growth, yield, and quality under improved irrigation methods and non-uniformity of their irrigation applications are important to enhance water management in arid regions. A field experiment was conducted in 2014 spring and fall growing seasons using potato (Solanum tuberosum) grown in northern Egypt at Shibin El Kom, Menofia, Egypt to evaluate potato response to furrow or trickle irrigation. A Randomized Split-Plot Design with irrigation method randomly distributed and non-uniformity of irrigation applications evaluated along either irrigation furrow or trickle lateral as dependent variables measured at the 3rd, 13th, 23rd, 33rd, 43rd and 53rd m along the 55 m irrigation line. Traditional (TF) and partial (PF) furrows as well as trickle point (TP) and line (TL) sources were used as irrigation methods. Each treatment was repeated three times. For a 33rd m treatment, seasonal optimum water use by potato was 328, 234, 269 and 292 mm over 118 days in spring and 200, 164, 178 and 186 mm over 122 days in fall under TF, PF, TP and TL irrigation methods, respectively. Potato tuber yield and quality were significantly affected by growing season (S), irrigation method (I) and non-uniformity of irrigation application (U). Tuber yield, total soluble solid (TSS) and leaf area index (LAI) were significantly affected by I and U, and their interaction I * U;harvest index (HI) was not affected by I but U. Except for TSS by S * I and HI by U * I and S * I, results showed no significant differences. Moreover, tuber weight, number and marketable yield were significantly affected by S, I, U and I * U interaction, except medium tuber size and culls by S. A given 33rd treatment under partial furrow and trickle irrigation, relative to that of traditional furrow, enhanced tuber yield and improved quality in both growing seasons. In non-un- iform irrigation application over two growing seasons, potato crop response was developed under varied irrigation methods. Tuber yields were significantly affected in a linear relationship (r2 ≥ 0.75) by either water deficit or excessive water under irrigation methods.