Lost metals through processing polymineral lead and zinc in the flotation Stan Terg, Trepça

S. M. Hyseni, B. N. Durmishaj, A. Xh. Bytyqi, R. Krasniqi and Sh. Abazi

In this paper we presented lost metal through mineral processing poly-mineral lead-zinc in concentrator Stan Terg (Tuneli pare) in Trepça - Kosovo. Reasonable study this live issue is because in practical processing mineral we have lost metal in flow of Stan Terg. Lost research in metals has an important theoretical but more practical where we need this mines lead zinc with flotation seven year ago restarting production processing. In this base reaches in conclusion for optimal choose processing for decrease lost metal along processing mineral.

Higher test pattern compression for scan based test vectors using weighted bit position method

S. Saravanan, R. Vijay Sai and Har Narayan Upadhyay

Present System on Chip (SOC) complexity has brought new challenges in volume of test pattern, low power testing and area complexity. This also shows that implementing huge test pattern and its corresponding storage space are the major problems. Due to this large number of test patterns the data transition time is also increased. This paper considers this problem in scan based test pattern. This proposed approach is based on the compression of huge test pattern by weighted bit position. Test patterns with unspecified bits are considered for specified values and partitioned into necessary weighted value. Depending upon weighted bit position specified test bit is compressed. This in turn reduces the test pattern for scan based testing. The proposed technique tested on ISCAS89 shows significant compression achieved on scan based test pattern.

Pseudotime application to hydraulically fractured vertical gas wells and heterogenous gasreservoirs using the TDS technique

Freddy Humberto Escobar, Laura Yissed Martinez, Leidy Johanna Mendez and José Humberto Cantillo

Contrary to liquid flow, the viscosity and compressibility of gases change substantially as pressure varies. This phenomenon has to be carefully modeled, so the gas flow equation can be adequately linearized to allow the liquid diffusivity solution to satisfy gas behavior when analyzing gas transient test data. The first solution to this problem was the introduction of the pseudopressure function that responds for variations of viscosity, density and compressibility which are combined into a single “pseudopressure” variable. Since, the dimensionless time function is also sensitive to changes in both viscosity and compressibility of gases, then, the pseudotime function was incorporated to combine these simultaneous variations into a single variable. This makes more accurate the estimation of the reservoir parameters. A recent study using the TDS technique has found little differences in estimation of permeability, wellbore storage coefficient and skin factor using either pseudotime or real time. However, the estimation of the drainage area is better determined when using pseudotime. This paper has the objective of extending the TDS technique for hydraulically fractured gas wells and heterogeneous gas formations and conducting a comparative study in the estimation of both the half-length and conductivity of a vertical fracture and the naturally fractured reservoir parameters. The new relationships were successfully tested on synthetic and actual field data. It was found better results when using the pseudotime function.

Corrosion inhibition of mild steel in 0.1m hydrochloric acid media by chloroquine diphosphate

Stanley Udochukwu Ofoegbu and Pearl Ugochi Ofoegbu

The results of  trials on Chloroquine phosphate as eco-friendly corrosion inhibitors for mild steel in 0.1M HCl solutions using weight loss technique over a duration of 49 days (1176 hours) are reported. The results obtained indicated that Chloroquine phosphate had promising inhibitive effect at all concentrations used in the study on the corrosion of mild steel in 0.1M HCl with the inhibitive effect reducing with time. The Langmuir adsorption isotherm is proposed for the Chloroquine phosphate adsorption in HCl solution.

Effect of the type of binder on physico-mechanical and thermal properties of mortars with a basis of coir

Athanas Konin

This paper aims to study the effect of type of binder on properties of mortars with coir. Two types of binders were used for the manufacturing of mortars containing coir: lime is used as binder for mortar n°1 (Mortar 1) and cement is used for mortar n°2 (Mortar 2). The measurements of the physical, mechanical and thermal properties of the specimens show that Mortar 1 has higher water absorption values than those of Mortar 2 and consequently has the lowest values of thermal conductivity. The results also indicate that dry density of the specimens has more important role than the type of binder on mechanical properties. Relationships were established between mechanical properties and dry density of these mortars. These relationships are independent to the type of binder. The mortars also satisfied most recommended thermal insulation standards.

Influence of substitution of ordinary Portland cement by silica fume in the durability of slag Portland cement pastes in sea water

A. M. Radwan, E. A. El-Alfi and R. M. Othman

Abstract:

Effect of gradually substitution of ordinary Portland cement by a few percent of silica fume (0.0, 2.5, 5.0 and 7.5 wt. %) on the durability of slag-Portland cement pastes up to 12 months immersed in sea water was investigated. The results show that the substitution of Portland cement by silica fume in the granulated slag-Portland cement pastes improves the physico-mechanical properties of the hardened cement pastes especially at early ages as well as gives a better resistance of cement stone to sea water attack at all immersing time. Also, the composite cement pastes containing 7.5% silica fume showed a maximum durability than other samples.

Design and enhancement bandwidth rectangular patch antenna using single trapezoidal slot technique

Karim A. Hamad

Abstract:

Microstrip patch antennas has some drawbacks of low efficiency, narrow bandwidth (3-6 %) of the central frequency, its bandwidth is limited to a few percent which is not enough for most of the wireless communication systems nowadays. In this paper one of the efficient methods used for the enhancement of patch antenna Bandwidth is the loading of microstrip patch Antenna with a trapezoidal slot. Microstrip patch antenna that meets the requirement of operation at 2.4 GHZ, the proposed configurations is simulated and analyzed using (CST- 2010) software package. The VSWR, input impedance‚ radiation patterns and S11 performance are used for the analysis of the different configurations. The simulated results for trapezoidal slot give bandwidth of 287.2 MHZ (11.93% fractional bandwidth). Feed point on the patch that gives a good Match of 50 ohm.

Experimental approach on densification and mechanical properties of sintered powder metallurgy AISI 4140 steel preforms

Channankaiah and G. Ranganath

Due to the large number of techno-economic advantages, the powder metallurgy (P/M) manufacturing route has wide industrial applications. The investigation has been undertaken to develop and study the characteristics of hot forged AISI 4140 High Strength Low Alloy Steels by using elemental powders through powder metallurgical techniques. 1 MN Capacity hydraulic Universal Testing Machine has been used to prepare the four different aspect ratios namely 0.25, 0.50, 0.75 and 0.90. In the presence of hydrogen atmosphere, the green compacts have been sintered at 1100±10°C and it was immediately forged at 1050±10°C by Friction Screw Press. Some of the forged steels were homogenized at 1050±10°C for 1hr, 2hrs and 3hrs, in an electrical muffle furnace. The forged and homogenized AISI 4140 steels were subjected in to densification studies and mechanical properties evaluation. Lower aspect ratio preforms such as 0.25 and 0.50 show better densification properties. The two hours homogenized forged steels exhibit better mechanical properties.

Reformulation of the of elliptic flow governing equation for a more complete well test data interpretation in horizontal wells

Abstract:

Before year 2000, elliptical flow regime was considered as a transition period found in a horizontal well transient test. It is recognized by a 0.36-slope (or 0.35-slope) tendency on the pressure derivative plot. Few researches have been conducted on the transient analysis for such flow regime. Since the first model does not provide a practical way of obtaining the reservoir horizontal permeability, a new model which is function of the reservoir length along the x-direction, reservoir thickness, horizontal wellbore length, well radius and horizontal reservoir permeability, was presented in 2004. Our experience, however, has indicated to us that this model sometimes fails to provide accurate values of horizontal permeability. Therefore, the first model presented in the literature, which depends upon the permeabilities in the horizontal direction, has been retaken in this study with a slight modification and successfully tested in many scenarios. The conventional straight-line and TDS methods are used as interpretation techniques for crude and gas flow. Both real time and pseudotime were implemented for gas flow. 

Adaptive filter design for wavelet decomposition and reconstruction in image processing application

M. Santhosh, B. Stephen Charles and M. N. Giri Prasad

Abstract:

The design of filtration logic in wavelet transformation is been focused in this paper. The conventional wavelet transformation approaches are observed to be very effective in providing resolution information for each orientation. Though wavelets are been used as a prominent approach for image compression, the accuracy of the image processing is mainly depends on the filters used and their relative relation for their decomposition and reconstruction operation. In this paper an approach towards designing of filters with adaptive relation is proposed. The simulative observation presents a relatively better observation in image coding for the proposed approach.

Compressibility and collapse potential upon wetting of cemented loose sands

Anuchit Uchaipichat and Cheevin Limsiri

Abstract:

This paper presents an experimental investigation on compressibility due to loading and a collapse potential upon wetting of cemented loose sands, which is proposed to be used as a material for construction of artificial aquifer. The experiments were performed on the cemented loose sand samples with various cement contents and periods of curing time.  The results show a decrease in compressibility due to loading and collapse potential upon wetting of cemented loose sand with increasing period of curing time. Moreover, it was found that, with increasing applied stress, the compressibility due to loading increased while the collapse potential upon wetting decreased. The total compression due to both loading and wetting increased with increasing applied stress.

Flexural and tensile strength properties of concrete using lateritic sand and quarry dust as fine aggregate

Joseph. O. Ukpata and Maurice E. Ephraim

Abstract:

This is part of a research on the structural characteristics of concrete using lateritic sand and quarry dust as fine aggregate. This paper presents the results of an experimental study investigating the flexural and tensile characteristics of concrete using combinations of lateritic sand and quarry dust as complete replacement for conventional river sand fine aggregate. Samples of concrete (eg. cylinders, beams) were made using varying contents of lateritic sand and quarry dust as fine aggregate. The proportion of lateritic sand was varied from 0 % to 100 % against quarry dust at intervals of 25 %, using concrete mix of 1:1.5:3 and water/cement ratio of 0.65. Concrete samples were prepared, cured for 28 days, and tested in the laboratory to destruction in order to determine their flexural and tensile strength properties. The results show that flexural strengths were 3.28N/mm² for 50% laterite: 50 % quarry dust and 2.88N/mm² for 25 % laterite: 75 % quarry dust. Similarly, tensile strengths were 2.91N/mm² for 50 % laterite: 50 % quarry dust and 1.67N/mm² for 25 % laterite: 75 % quarry dust. These indicate that both flexural and tensile strengths increase with increase in laterite content. The results suggest that concrete containing mixtures of lateritic sand and quarry dust can be reasonably used in structural elements as for normal concrete (Concrete with river sand as fine aggregate).

E-learning as a new technology for sustainable development

Marzyeh Bordbar, Mohammad Sadegh Allahyari and Meysam Solouki

Abstract:

Achieving sustainable development is, without a doubt, the single most critical challenge necessary to ensure the well being of our world and its people. Development is a process fueled by resources and it is imperative that much more be done to make certain that these can equitably meet present needs and also remain available for the development needs of generations to come. There are no easy solutions. There is, however, a considerable amount of consensus that the most successful approach will involve two key elements. The first of these is education. More people at all levels must be empowered to develop the values, attitudes and skills necessary to change behavior in regard to natural resource management. The second component is greater collaboration among key entities working to make a difference. Education and working together are the fundamental principles of the Sustainable Development e-Learning Network. This network has, and is developing and delivering quality online courses that address the priority learning needs of a range of development professionals and help to disseminate key information and knowledge of its members. One of the ways that businesses can manage their climate change risk is through the comprehensive implementation of sustainable development strategies. These strategies require a paradigm shift toward more systems, future and critical thinking skills, by everyone in the company. This will require the re-education of the workforce from the current, largely one dimensional focus on economic value; to a multi-dimensional, interdependent, values-based, focus on environmental, social and economic issues. This transformation will be complex and will evolve over the lifetime of a learner. In this paper we will emphasis on how E-learning to achieve sustainable development.

Characteristics of Portland cement pastes with high replacement of slag

A. M. Radwan, E. A. El-Alfi and R. M. Osman

Abstract:

The influence of substitution of Ordinary Portland cement by ground granulated blast-furnace slag up to 70 % on the properties of silica fume-Portland cement composite pastes up to 12 months was studied. After one year, the composite cements pastes containing 50-70 % slag exhibit suitable strength values compared to without slag sample. Also, The XRD results show that the C-S-H are intensified with available increase indicating more dense structures and large amount of additional C-S-H in the  presence slag content.

Application of remote sensing techniques to study hydro-meteorological changes on the dynamics of glaciers, Bhagirathi basin, Garhwal Himalaya

M. Tamil Selvan and P. Malar Kodi

Abstract:

Hydro-meteorology is an interdisciplinary science involving the study and analysis of the interrelationships between the atmospheric and land phases of water as it moves through the hydrologic cycle. The recent development in remote sensing gives an opportunity to map natural features on earth surface with more accurately as 20 years before. In this paper, the de-glaciation pattern of the Bhagirathi basin has been studied from year 1980-2006 and various climatic parameters are also analysed during this period and compared with the changes on the glacier dynamics. Bhagirathi River and its tributaries are dependent predominantly on glacier and snow melt and precipitation. The average rainfall data for the Garhwal Himalaya varies between 1000 to 2500mm of which 50-80 % falls during the monsoon period between June and September. Over the study period, average daily maximum and minimum temperatures were computed to be 14.7 and 4.1°C respectively, whereas average mean temperature was 9.4°C. The investigation was carried out with the satellite images from the Landsat images of Multispectral Scanner (MSS) and Thematic Mapper (TM and ETM+). Alongwith the Landsat images, Indian Remote Sensing Satellite (IRS) LISS-III images have been used for preparing a repetitive glacier inventory. The retreat rate was faster in year 1980-2000 compare to the year 2000-2006. With the gradual retreat, the tributaries of the glaciers are susceptible to a detachment from the main body, thus showing fragmentation.

Transient-rate analysis for long homogeneous and naturally fractured reservoir by the TDS technique

Freddy Humberto Escobar, Margarita María Rojas and Luis Fernando Bonilla

Abstract:

Normally, production data are analyzed by decline-curve fitting. However, analogous to pressure-transient analysis, the reciprocal flow rate and its derivative may be analyzed and interpreted for reservoir characterization purposes. In some cases, formation linear flow regime may be seen once the radial flow regime vanished. This flow regime is very important and can be presented in fractured well, horizontal wells and long reservoirs. Either pressure-transient analysis or rate-transient analysis may be affected by linear flow regime. For the case of production rate at constant well-flowing pressure, most of the analysis is conducted by decline-curve analysis and little attention has been given to rate-transient analysis. This paper presents the governing equations used for rate-transient analysis in elongated systems using characteristic points and “fingerprints” found on the log-log plot of reciprocal rate and reciprocal rate derivative, so analytical expressions were developed to determine reservoir parameters, following the philosophy of the TDS Technique. It allows for the estimation of reservoir permeability, reservoir width and geometrical skin factors. If the test is long enough, reservoir drainage area, well position inside the reservoir and/or reservoir length can also be determined. The methodology was successfully verified by its application to synthetic cases.

Studies on forced convection nanofluid flow in circular conduits

Harikrishna Vishwanadula and Emmanuel C. Nsofor

Abstract:

An experimental system was developed and used to study the nanofluid flow and heat transfer in circular conduits. Experiments were performed for a variety of nanofluid flow features in the system. Results obtained from the study show that the heat transfer rate for flow of the base fluid is less than that of the nanofluid used in the study. It was also found that the observed relationship between molecular diffusivity of momentum and the molecular diffusivity of thermal energy at the macroscale may not necessarily be the same at the nanoscale. A heat transfer correlation for turbulent forced convection flow in circular pipes was developed from the results in terms of Nusselt number, Reynolds number and Prandtl number. The correlation developed was compared to related correlations in the literature. Important factors that affect nanofluid flow and heat transfer in circular conduits were also determined. This type of study is essential for heat exchanger applications.

Microcontroller-based intelligent power management system (IPDMS) for satellite application

Babatunde S. Emmanuel

Abstract:

Efficient power distribution management is very crucial for satellites to navigate their orbits and achieve their mission objectives. The Satellite Electrical Power Subsystem (EPS) is responsible for power supply in satellites for housekeeping operations. This research project is aimed at the design of a microcontroller-based Intelligent Power Distribution Management System (IPDMS) for application in the efficient coordination of power savings and distribution to satellite system payloads. In the IPDMS design, 8-bits microcontroller was used to implement system intelligence. In addition, Java Programming Language was used to achieve a simulation model for virtual test for system reliability and efficiency. The IPDMS provided intelligence for real-time power storage. It managed power distribution through load shedding and power-cycling and actuated fault protection mechanism in the events of power emergencies very quickly and autonomously during eclipse and sunlight orbit periods. It monitored the battery temperature threshold levels to control destructive exothermic reaction. The IPDMS achieved an improvement over the conventional satellite power management and control systems in terms of system’s size reduction, self-contained intelligence, flexibility and improved system response to power emergencies.