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Articles 24931 - 24960 of 27367

Full-Text Articles in Engineering

The Impacts Of Conflicts On Requirements Uncertainty And Project Performance, Houn-Gee Chen, James J. Jiang, Jun-Cheng Chen, J T. Shim Jan 2004

The Impacts Of Conflicts On Requirements Uncertainty And Project Performance, Houn-Gee Chen, James J. Jiang, Jun-Cheng Chen, J T. Shim

Journal of International Technology and Information Management

Conflict is a pervasive phenomenon that permeates information systems development and implementation. The literature has indicated that conflicts, due to their association with negative emotion, will negatively influence IS project development, even after controlling for the effects of conflict management and resolution; however, the negative emotional characteristic of conflict alone has a limited explanatory power of IS project success. The purpose of this study is to provide additional insight, by including requirement uncertainty as the mediator variable, of the impacts of conflicts on project performance. Surveys were sent to Taiwan’s top 1600 companies and the results support the hypotheses. The …

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Development Of An It Balanced Scorecard, Theophilus B.A. Addo, Chee W. Chow, Kamal M. Haddad Jan 2004

Development Of An It Balanced Scorecard, Theophilus B.A. Addo, Chee W. Chow, Kamal M. Haddad

Journal of International Technology and Information Management

There is a generally acknowledged dearth of metrics for effectively measuring organizational performance. This is particularly true of the IT function, whose contribution to a firm’s “bottom line” has been frequently called to question. This paper describes the development of a performance measurement tool called the Balanced Scorecard, which can be used to assess IT performance within the context of overall corporate strategy and financial performance. Data for the scorecard was obtained via a survey of senior IT executives in various organizations. The paper concludes with a set of guidelines for successfully implementing an IT Balanced Scorecard, as well as …

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The Demand For Information Technology Knowledge And Skills: An Exploratory Investigation, Stuart D. Galup, Ronald Dattero, Jim J. Quan Jan 2004

The Demand For Information Technology Knowledge And Skills: An Exploratory Investigation, Stuart D. Galup, Ronald Dattero, Jim J. Quan

Journal of International Technology and Information Management

Organizations are always in search of appropriate information technology knowledge and skills to carry out normal business operations. Such demand is directly impacted by the overall economic conditions. During stressful economic times, managers, facing tough budgetary pressure, are forced to examine more thoroughly what knowledge and skills are needed to survive. This paper investigates the desired information technology knowledge and skills that employers are searching for in these turbulent times. We examine the content of job advertisements for information technology professionals placed in an online job placement website over a 2 year period, 2001-2002.

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Prediction Of The Response Of Rectangular Cladding Panels To Wind Loading In The Time Domain, Ambrose Shirima Dec 2003

Prediction Of The Response Of Rectangular Cladding Panels To Wind Loading In The Time Domain, Ambrose Shirima

Tanzania Journal of Engineering and Technology (TJET)

The analysis and subsequent design of cladding panels is traditionally based on quasi-static calculation of the wind loads. Pressure coefficients, which are derived from wind tunnel measurements and a design wind speed, are used to compute the wind loading. The codes of practice give the pressure coefficients and the guidelines of deriving the design wind speed from factors, which are specific to the site namely basic wind speed, topography, ground roughness and height above the ground. The concept of design wind speed is simple but it overlooks the resonant vibrations caused by the wind. The paper discusses a procedure for …

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Salt Balance, Fresh Water Residence Time And Budget For Non-Conservative Materials For Makoba Bay During Wet Season, As Ngusaru, Aj Mmochi Dec 2003

Salt Balance, Fresh Water Residence Time And Budget For Non-Conservative Materials For Makoba Bay During Wet Season, As Ngusaru, Aj Mmochi

Tanzania Journal of Science

Water and salt budgets suggest that in order to balance the inflow and outflow of water at Makoba bay, there is net flux of water from the bay to the open ocean during wet season. Residual salt fluxes between the bay and the open ocean indicate advective salt export. Exchange of water between the bay with the open ocean plays a role of replacing exported salt via mixing. Calculated freshwater residence time for the bay is 63 days during wet season. Budget results for non-conservative materials indicate net DIP flux from the ocean to the bay and a net DIN …

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An Integrated Model For Technology Assessment And Choice For Rural Development In Developing Countries, Abdallah Chungu Dec 2003

An Integrated Model For Technology Assessment And Choice For Rural Development In Developing Countries, Abdallah Chungu

Tanzania Journal of Engineering and Technology (TJET)

Abstract

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Evaluation Of Pollution Loading Into Msimbazi River By Rapid Assessment And Direct Measurement Methods, J. H. Y. Katima Dec 2003

Evaluation Of Pollution Loading Into Msimbazi River By Rapid Assessment And Direct Measurement Methods, J. H. Y. Katima

Tanzania Journal of Engineering and Technology (TJET)

This paper assesses the suitability of Rapid Assessment (RA) methodology as a tool for making an environmental pollution inventory in data poor situation. The RA method was applied to estimate Biological Oxygen Demand (BOD), nitrogen and phosphorous loading into the Msimbazi River in Dar es salaam, Tanzania. The Direct Measurement (DM) was done to validate the results obtained from RA. The methodology is based on estimating waste loads from function variables such as production rate, population, etc. and pollution intensities from domestic, industry and agricultural sources. The incorporation of penetration factors for waste loads reduction refines the assessment procedure. The …

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Surface Titration Of Colloidal Alpha-Alumina, J. W. Ntalikwa Dec 2003

Surface Titration Of Colloidal Alpha-Alumina, J. W. Ntalikwa

Tanzania Journal of Engineering and Technology (TJET)

The surface charge density (σ₀) of colloidal alumina (α-Al₂O₃) suspended in 1:1 electrolytes (NaCl, NaNO₃, CsCl and CsNO₃) at different electrolyte concentration (c₀) was determined using acid-base titration. The data were described in terms of the Triple Layer Model (TLM) of electric double layer. It was observed that the polarity of σ₀ could be varied through a point of zero charge (PZC) by varying the pH of the suspension. The PZCs were observed to occur at pH = 7.8 ± 0.1, 7.6 ± 0.2, 8.5 ± 0.1 and 8.3 ± 0.1 in NaCl, NaNO₃, CsCl and CsNO₃, respectively. It was …

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Centrifugal Extraction Of Avocado Oil From The Pulp, J. W. Ntalikwa Dec 2003

Centrifugal Extraction Of Avocado Oil From The Pulp, J. W. Ntalikwa

Tanzania Journal of Engineering and Technology (TJET)

Absract

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Load Flow Solution For Three-Phase Mv Radial Distribution Connected Network Supplying Different Line Topologies, B. J. Kundy Dec 2003

Load Flow Solution For Three-Phase Mv Radial Distribution Connected Network Supplying Different Line Topologies, B. J. Kundy

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a load flow solution for the Medium Voltage (MV) three-phase radial distribution in delta-delta (Δ–Δ) connected network supplying different line topologies such as three phase, phase to phase and single-wire earth return (SWER) networks is presented. The general voltage related network equations are developed using Kirchhoff’s voltage and current laws. Development of a solution to the load flow analysis applying the developed general voltage related network equations is proposed in order to evaluate the network voltage profile. Various numbers of arrays are developed for the identification of the network under study. The proposed method is a new …

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The Inclusion Behaviothe Inclusion Behavior Of Sodium Compounds In Sub-Micron Particles Formed During Coal Combustionr Of Sodium Compounds In Sub-Micron Particles Formed During Coal Combustion, Iddi Mkilaha Dec 2003

The Inclusion Behaviothe Inclusion Behavior Of Sodium Compounds In Sub-Micron Particles Formed During Coal Combustionr Of Sodium Compounds In Sub-Micron Particles Formed During Coal Combustion, Iddi Mkilaha

Tanzania Journal of Engineering and Technology (TJET)

During combustion of coal, biomass and sewage sludge, metallic compounds especially alkali metals such as sodium and potassium vaporize and form fumes which are emitted with the exhaust gases. These fumes are corrosive to the turbine blades of power plants. To minimize corrosion, efforts have been made to control the condensation phase of these metals. In this study, the evolution and inclusion of sodium in sub-micron particles was investigated using a drop tube furnace and a low-pressure impactor (LPI). Four types of coal with different chemical properties were tested. The results suggest that a reaction-controlled mechanism and nucleation via chemical …

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A System Thinking Approaching Maintenance, Production And Quality, E. A. M. Mjema Dec 2003

A System Thinking Approaching Maintenance, Production And Quality, E. A. M. Mjema

Tanzania Journal of Engineering and Technology (TJET)

The concepts of system thinking and its applicability in maintenance management was analysed in this article. The author analysed various maintenance policies, which have inclination to the concept of system thinking. The maintenance policies revisited include the Integration of Maintenance (IM), Total Quality Maintenance (TQMain), Failure Mode and Effect Analysis (FMEA), and Total Productive Maintenance (TPM). All these strategies are aimed at utilising effectively the maintenance personnel by giving some of the responsibilities of maintenance to production personnel. It was found that, although the founder of these techniques did not mention the concepts of system thinking in their methods, however, …

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Simulation Of The Communication Process In A Pin Mill, Ambrose J. M. Itika Dec 2003

Simulation Of The Communication Process In A Pin Mill, Ambrose J. M. Itika

Tanzania Journal of Engineering and Technology (TJET)

Prediction of the performance of comminution equipment by mathematical models and simulation poses a great challenge to the chemical engineer. This paper describes the simulation of grinding results obtained using an impact mill. Single particle results have been used to generate breakage and selection coefficients that were used for the evaluation of the model. Results have shown that simulation model is in good agreement with the experimental data obtained at a circumferential speed above 60 m/s. At lower speeds, the models shows only partial agreement in the middle particle size ranges. The application of the model is therefore limited for …

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Using Pedotransfer Functions To Predict Saturated Hydraulic Conductivity For Layered Soil Profiles A Case Study At The Sokoine University Of Agriculture Farm, Tanzania, M. K. Mulengera Dec 2003

Using Pedotransfer Functions To Predict Saturated Hydraulic Conductivity For Layered Soil Profiles A Case Study At The Sokoine University Of Agriculture Farm, Tanzania, M. K. Mulengera

Tanzania Journal of Engineering and Technology (TJET)

Saturated soil hydraulic conductivity (SHC), is useful for land resources management. But it is difficult, time consuming, and labour intensive to measure in the field. These problems can be overcome through the use of pedotransfer functions (PTFs), which relate the SHC to readily available soil physical, chemical, and biological parameters. The existing PTFs were developed in temperate countries using homogeneous core soil samples. Thus, these PTFs are not useful for tropical soils with different properties and for layered soil profiles. In this paper, field measured SHC values are related to representative profile soil properties (RSPSPs) that are determined using horizons’ …

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Thermal Analysis Of Welding On Aluminum Plates, Rong-Hua Yeh, Shih-Pin Liaw, Hong-Bin Yu Dec 2003

Thermal Analysis Of Welding On Aluminum Plates, Rong-Hua Yeh, Shih-Pin Liaw, Hong-Bin Yu

Journal of Marine Science and Technology–Taiwan

This study investigated the temperature distribution of aluminum plates welded by gas tungsten arc. The heat of fusion, the size and distribution of heat source, the travel speed, the heat conduction in the welding direction and the surface heat loss during welding were considered. A numerical scheme was developed to solve the threedimensional problem. With the help of a mathematical model, the effect of welding parameters such as heat input of the weld, preheating of the workpiece and moving velocity of heat source on weld penetration in moderately thick plates were discussed. The steady-state temperature profiles of the welded plate …

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A Novel Approach To Determine The Astronomical Vessel Position, Chih-Li Chen, Tien-Pen Hsu, Jiang-Ren Chang Dec 2003

A Novel Approach To Determine The Astronomical Vessel Position, Chih-Li Chen, Tien-Pen Hsu, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

In this paper, a novel approach based on the trigonometric equation solving technique is developed to solve the classical problem of celestial navigation. It is shown that this approach, namely, the simultaneous equal-altitude equations method (SEEM), can directly calculate the astronomical vessel position (AVP) without an additional graphical procedure. It is also found that the SEEM is not only simpler than the matrix method but is also more straightforward as compared with the spherical triangle method. In addition, aimed at the drawbacks of the intercept method, an improved approach with the new computation procedure is presented to plot the celestial …

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Cost Comparison Of Straddle Carrier Direct And Relay Systems In Container Terminals, Wen-Chih Huang, Chin-Yuan Chu Dec 2003

Cost Comparison Of Straddle Carrier Direct And Relay Systems In Container Terminals, Wen-Chih Huang, Chin-Yuan Chu

Journal of Marine Science and Technology–Taiwan

The main characteristics of straddle carrier direct system and straddle carrier relay system are stated and factors affecting the economics of this two handling systems are also studied. A cost function model is proposed to make the comparison. It includes land cost, equipment cost, transportation cost between quayside and storage yard, annual throughput, handling efficiency, labor cost and their constituent factors. A "handling cost comparison indicator" (RD) is also submitted to determine the preferred system. For RD > 1 scenario, straddle carrier direct system is preferred, and on the contrary, straddle carrier relay system is preferred, if RD < 1.

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Computer-Aided Optimal Design Of A Single-Chamber Muffler With Side Inlet/Outlet Under Space Constraints, Long-Jyi Yeh, Ying-Chun Chang, Min-Chie Chiu, Gaung-Jer Lay Dec 2003

Computer-Aided Optimal Design Of A Single-Chamber Muffler With Side Inlet/Outlet Under Space Constraints, Long-Jyi Yeh, Ying-Chun Chang, Min-Chie Chiu, Gaung-Jer Lay

Journal of Marine Science and Technology–Taiwan

Whilst the muffler dimension is often limited inside a building or machine room, the consideration of maximal sound transmission loss (STL) under space constraints becomes important and essential to the field of acoustics. In this paper, the optimal design of a singlechamber muffler with side inlet/outlet is comprehensively presented. Both the graphic analysis and the computer-aided numerical assessments are also fully described in this study. With the computer graphic analysis on sensitivity, one set of design data is derived primarily, and the numerical searching algorithm of iteration technique and the initial design data are then carried out. These results are …

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A Normalization Scheme Of Bidirectional Reflectances And Normalized Vegetation Indices For Short-Term Multi-Angular Spot Satellite Images, Chien-Hui Liu Dec 2003

A Normalization Scheme Of Bidirectional Reflectances And Normalized Vegetation Indices For Short-Term Multi-Angular Spot Satellite Images, Chien-Hui Liu

Journal of Marine Science and Technology–Taiwan

Though the view angle range of SPOT HRV is smaller as compared to those of NOAA AVHRR, EOS MODIS/MISR and ADEOS POLDER, numerous researchers had showed significant bi-directional effect of ground reflectance for decades. Currently, there's no existing normalization method of bidirectional reflectances for multitemporal SPOT images. In this study, a normalization scheme for multi-angular SPOT data is proposed. This scheme will correct both atmospheric and bidirectional effect for short-term multi-temporal SPOT data. Five SPOT images scanned within twelve days are used. The results show that the variation of trees reflectance to viewing zenith angle is very significant. The proposed …

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A Novel Earplug System For Filtering Out Dental Noise, Jiang-Ren Chang, Huan-Kun Cheng, Sheng-Yang Lee, Mingsian R. Bai, Rong-I Lean Dec 2003

A Novel Earplug System For Filtering Out Dental Noise, Jiang-Ren Chang, Huan-Kun Cheng, Sheng-Yang Lee, Mingsian R. Bai, Rong-I Lean

Journal of Marine Science and Technology–Taiwan

Undergoing dental treatment is usually a very unpleasant experience for people who have toothaches, especially when they are hurting and there exists some intolerable mechanical noise. To reduce the noise and promote the work efficiency of dentists, a new noisefiltering earplug system with optional music was developed to filter out dental machine noise; if necessary, it can also be adopted as a solution to reduce pain and anxiety of patients during treatments. Furthermore, it can also simultaneously serve as a communication tool between the patient and dentist. In this study, various kinds of noises were initially collected through an off-line …

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Adoption Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte Dec 2003

Adoption Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte

Makara Journal of Technology

Site Specific Management (SSM), which also variously referred to as Variable Rate Technology (VRT), is an emerging technology that enables producers to make more precise input application decisions based on soil and field characteristics. This study analyzes factors influencing the adoption of VRT for fertilizer application for cash grain production in Ohio. Results show that producer and field characteristics might influence the adoption decision on various SSM components differently. It also provides insight as to the sequence of adoption of SSM component technologies and how this sequence might differ for producers of differing characteristics.

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Study On Electrochromic Effect Of Polyaniline Film, Lienda Handojo, Junus Simangunsong Dec 2003

Study On Electrochromic Effect Of Polyaniline Film, Lienda Handojo, Junus Simangunsong

Makara Journal of Technology

Study on Electrochromic Effect of Polyaniline Film. The light transmission factor of an electrochromic film changes reversibly with the application of an electrical voltage. Thereby the transparent film becomes reversibly opaque so that it may be used to control light transmission. In this paper the results of a study on polyaniline film as an electrochromic active material is reported. Polyaniline looks yellow transparent in the reduced state and turns to green-blue at its oxidized state. The electrochromic device considered in this paper was fabricated in planar configuration of ITO glass − polyaniline film − electrolyte − ITO glass which involved …

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Role Of K3-Xhxpw12o40 As A Catalyst In Selective Catalysis Of Methylamine Synthesis From Ammonia And Methanol, Mohammad Nasikin Dec 2003

Role Of K3-Xhxpw12o40 As A Catalyst In Selective Catalysis Of Methylamine Synthesis From Ammonia And Methanol, Mohammad Nasikin

Makara Journal of Technology

Role of K3-xHxPW12O40 as a Catalyst in Selective Catalysis of Methylamine Synthesis from Ammonia and Methanol. Synthesize of methylamine from methanol and ammonia was studied in this research work using a partially potassium heteropoly salt (K3-xHxPW12O40 abbreviated as KPW) as a catalyst. KPW was prepared from heteropoly salt and potassium carbonate by using ion exchange method. The reaction was conducted at 600 ~ 800K and at the atmospheric pressure. Reactor used was a continue flow reactor with W/F=0,1~0,9g-kat.mnt./cc.Concentration of reactants and products were analyzed by gas chromathography while catalyst structure was observed by XRD (X-ray diffraction). Isothermal adsorption method was …

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Identification Of The First Limiting Amino Acid In Cooked Polished White Rice Fed To Weanling Holtzman Rats, Mellova Masrizal, J. B. Lamb Dec 2003

Identification Of The First Limiting Amino Acid In Cooked Polished White Rice Fed To Weanling Holtzman Rats, Mellova Masrizal, J. B. Lamb

Makara Journal of Technology

Forty-eight male weanling rats (91 g) were utilized to study the nutritional adequacy of cooked polished white rice. Rats were individually housed, and allowed ad libitum access to one of six treatment diets. Treatment diets were 1) polished white rice plus 10% casein and 0.18% methionine, CAS, 2) polished white rice, WHR, 3) polished white rice plus 0.45% lysine, LYS, 4) polished white rice plus0.40% methionine, MET, 5) polished white rice plus 0.30% threonine, THR, 6) polished white rice plus 0.45% lysine, 0.40% methionine, and 0.40% threonine, COM. Rice was cooked prior diet formulation using a 3 to 1 ratio …

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Application Of Tabu Search Algorithm In Job Shop Scheduling, Betrianis Betrianis, Putu Teguh Aryawan Dec 2003

Application Of Tabu Search Algorithm In Job Shop Scheduling, Betrianis Betrianis, Putu Teguh Aryawan

Makara Journal of Technology

Application of Tabu Search Algorithm in Job Shop Scheduling. Tabu Search is one of local search methods which is used to solve the combinatorial optimization problem. This method aimed is to make the searching process of the best solution in a complex combinatorial optimization problem(np hard), ex : job shop scheduling problem, became more effective, in a less computational time but with no guarantee to optimum solution.In this paper, tabu search is used to solve the job shop scheduling problem consists of 3 (three) cases, which is ordering package of September, October and November with objective of minimizing makespan (Cmax). …

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Alum And Pacl Coagulation, Winarni Winarni Dec 2003

Alum And Pacl Coagulation, Winarni Winarni

Makara Journal of Technology

Alum and PACl Coagulation. Coagulation occurs by interaction of aluminum hydrolysis products with the contaminant such as colloidal particles. It is necessary to consider the different aluminum species that may present during specific conditions, since the mechanism of turbidity removal is dependent upon them. PACl consists of preformed aluminum hydrolysis products, which are stable below pH 6 and less sensitive than in situ hydrolysis product, alum. The benefits of PACl relative to alum have been investigated as a function of pH and Al dosages. Specific conditions and aluminum species that exist during the certain mechanisms of coagulation are discussed. Results …

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The Selection Of Materials For Roller Chains From The Perspective Of Manufacturing Process, Rahmat Saptono Dec 2003

The Selection Of Materials For Roller Chains From The Perspective Of Manufacturing Process, Rahmat Saptono

Makara Journal of Technology

The selection of materials for an engineering component is not only requested by its design function and shape, but also the sequence through which it is manufactured. The manufacturing operation of roller chains involves drawing and trimming processes aimed at producing semi-finished chain drives component with a well-standardized dimension. In addition to final combination of properties required by design constraints, the ability of materials to be formed into a desired shape and geometry without failure is also critical. The objective of materials selection should therefore involve additional attributes that are not typically accommodated by the standard procedure of materials selection. …

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An Economic Analysis Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte, Mario J. Miranda Dec 2003

An Economic Analysis Of Variable Rate Technology, Isti Surjandari, Marvin T. Batte, Mario J. Miranda

Makara Journal of Technology

Variable Rate Technology (VRT) offers an opportunity to improve production efficiency by allowing input applications to fluctuate in response to spatial variations in soil characteristics and nutrient levels. Society may also benefit from reduced negative externalities, such as surface and groundwater contamination, from input applications. Using a dynamic spatial model, this study examines how the interaction among variability, spatial autocorrelation, and mean level of soil fertility affects optimal sampling density and the economic gains from VRT. VRT was found to be profitable under selected conditions, and the optimal grid size will vary with these conditions. In the case where variability …

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Bs News Dec 2003

Bs News

Building Services Engineering

No abstract provided.

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Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang Nov 2003

Preparation And Characterization Of Y-Type Carbon Nanotubes By Using Anodized Alumina Oxide (Aao) Template, Jing Zhang, Quan-Yong Gao, Yong Yang

Journal of Electrochemistry

In this work, potential-modulation method was used in two-step anodization process to make an AAO template with Y-type nanochannels. Then Y-type carbon nanotubes with controlled length and branch angle were prepared in the template based on chemical vapor decomposion (CVD) method with Co particles as catalyst and C2H2 as carbon source. The Y-type nanotube branches exhibit the angle distribution ranging from 20° to 120°. The results demonstrated that the oxidation potential should be responsible for the angles and length of the branches. Short pulse and high oxidation potential will result in the short and dense nanotube branches.

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