JETT- Volume 1, Issue 2, (2013)

Volume 1, Issue 2, (2013)

Schwarzschild Geometry from Exact Solution of Einstein Equation

Volume 1, Issue 2, Pages: 69-75 | [Full Text] PDF (151 KB)

Haradhan Kumar Mohajan

Premier University, Chittagong, Bangladesh.

Abstract — An exact solution of Einstein equation is easier than actual solution. The Schwarzschild metric is established on the basis of Einstein’s exact solution and it is also a static and stationary solution. The Schwarzschild solution expresses the geometry of a spherically symmetric massive body’s (star) exterior solution. It predicts small observable departures from the Newtonian gravity. It also represents theory of black holes when sufficiently massive stars unable to support themselves against the pull of self gravity and must undergo a complete gravitational collapse when they have exhausted their internal nuclear fuel. Various sides of Schwarzschild geometry, such as, Kruskal–Szekeres extension, space-time singularities and black hole formation, are discussed with simple but detail calculations. The black hole is a region from which no causal signals can reach to the external observers and it contains a space-time singularity hidden within the event horizon.

Keywords — Einstein equation, Schwarzschild solution, Black hole, Space-time singularity.

Identification of Gaps to Conduct a Study on Biological Self-healing Concrete

Volume 1, Issue 2, Pages: 62-68 | [Full Text] PDF (239 KB)

Amirreza Talaiekhozan^1,2, Mohamad Ali Fulazzaky¹,Ali Keyvanfar³, Ramin Andalib³, Muhd Zaimi Abd Majid³, Mohanadoss Ponraj¹, Rosli Bin Mohamad Zin³, Chew Tin Lee⁴, Arezou Shafaghat³, Mohd Warid Hussin Ir³

1- Institute of Environmental and Water Resources Management, Water Research Alliance, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor Bahru, Malaysia.

2- Department of Civil and Environmental Engineering, Jami Institute of Technology, Fooladshahr, Iran.

3-Construction Research Alliance, Faculty of Civil engineering, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor Bahru, Malaysia

4- Bioprocess Engineering Department, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.

Abstract — Biological self-healing concrete is a new idea to have concrete structures with more durability. Although, several papers have been published on biological self-healing concrete, a suitable instruction to conduct this type of studies is not reported. Aim of this paper is collecting comprehensive information about conducting a study on self-healing concretes based on previous studies. This paper present many new ideas that have not been completely study. Some idea such as application of fungi, thermopiles bacteria, mix culture of microorganisms or using of aerobic or anaerobic bacteria to design biological selfhealing concrete are suggested in this paper. Ideas of this paper can help researchers to find a suitable and novel subject in biological self-healing area to conduct a strong research.

Index Terms — Self-healing concrete, bio-concrete, cement

A review on microalgae as potential lipid container with wastewater treating functions

Volume 1, Issue 2, Pages: 76-80 | [Full Text] PDF (254 KB)

Hesam Kamyab1*, Mohammad Soltani2, Mohandoss Ponraj1, Mohd Fadhil MD DIN1, Erisa Viony Putri1

1- Institute of Environmental Water Resources and Management (IPASA), Water Research Alliance, Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Johor 81310, Malaysia

2- Department of Bioprocess, Faculty of Chemical Engineering (FKK), Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor, Malaysia

Abstract — Microalgae are reported as potential source to produce lipids from their biomass cells. Lipid as a group of organic compound is a primary raw material used in biofuel production as well as component for foods, cosmetic products, fertilizers and animal feed. As the resources of manufacturing lipid from synthetic media are costly, the derivation of inexpensive carbon and nutritional sources from wastewater such as palm oil mill effluent (POME) is useful in massive scale. Furthermore, unique characteristic of microalgae as alternative agents to treat POME wastewater is another encouraging aspect of its application. In addition, biodiesel production from algae can produce 5,000 –15,000 gallons of biodiesel per acre/year. However, high yield production of high-lipid-content-algae biomass, determination of effective techniques in order to harvest grown algae, algal oil extraction and trans-esterification of extracted oil for converting into biodiesel are challenging issues need deep investigation. This review is focused on previous studies on POME as possible carbon and nutritional source used to treat environmental pollution caused by POME discharges and to increase the growth rate of microalgae in order to high-lipid content production.

Index Terms — Lipid production, Microalgae, POME, Wastewater treatment

Nutrient uptake and wastewater purification by Water Hyacinth and its effect on plant growth in a batch system

Volume 1, Issue 2, Pages: 81-85 | [Full Text] PDF (229 KB)

Shahabaldin Rezania, Mohd Fadhil Md Din, Mohanadoss Ponraj*, Fadzlin Md Sairan, Siti Fatimah binti Kamaruddin

Institute of Environmental and Water Resources Management, Department of Environmental Engineering, Faculty of Civil Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia

Abstract — Nowadays, the ability of waste water purification by water Hyacinth has been investigated in many studies. A pilot plant fabrication system was constructed near domestic waste water treatment plant, and water hyacinth (Eichhornia crassipes) was chosen as an aquatic plant for wastewater purification. The objective of this study was to test the role of water hyacinth in purifying nutrient-rich wastewater and also to determine its effects on nutrient uptake and biomass growth based on pollutant removal rate in a defined time. The result shows that the constructed fabrication could remove 80% of chemical oxygen demand (COD), 75% of total nitrogen (TN) and 75% of total phosphorus (TP) during the first week of experiment. Also the ratio of water loss in tanks and its effect on biomass growth was evaluated, which was found to be 20 % or 15 L of water reduction weekly and 40% increase in plant biomass was achieved at the end of the experiment as compared to initial. Thus it can be concluded that water hyacinth system was effective in purifying wastewater obtained from a stabilization pond during its optimum growth period.

Index Terms — Biomass growth, Nutrient uptake, Wastewater purification, Water hyacinth

The Role of Operating Parameters on the Rejection of Copper in Nanofiltration Process

Volume 1, Issue 2, Pages: 86-90 | [Full Text] PDF (319 KB)

Nafari J.*, Mirbagheri S.A.

Dept. of Civil Eng., K.N.Toosi University of Technology, Tehran, Iran

Abstract — Copper is one of the important sources of environmental pollution and is non-degradable, and therefore, continues to exist in water. Separation of copper ions from aqueous solutions by membrane technology is shown to be a feasible process to accomplish an effective copper removal over a broad operational range. This paper aims at the effect of operating pressure, pH and TDS on the rejection of copper ion and permeation flux in different feed concentrations by nanofiltration. Experiments were performed with synthetic solution using N90-4040 nanofiltration membrane. Isotherm experiments were carried out. Permeate flux, pH and copper concentration in permeate were measured to determine the membrane characteristics and performance. Experimental results indicated that the rejection of copper ions increases with increasing of operating pressure, pH and TDS of the solution. The rejection efficiency varied from 94% to approximately 99.9% in different operating conditions. In addition, the permeate flux increased with increase in operating pressure in four different feed concentrations. On the other hand, increasing pH and TDS resulted in decline in permeate flux.

Index Terms — Nanofiltration, Copper rejection, Membrane process, Permeate flux, Applied pressure

Assessment of Water Quality in Chandpur District of Bangladesh

Volume 1, Issue 2, Pages: 91-100 | [Full Text] PDF (880 KB)

Md. Lokman Hossain*, Kazi Shariful Islam

Institute of Forestry and Environmental Sciences, University of Chittagong, Chittagong-4331, Bangladesh

Abstract — The study was conducted in Chandpur district of Bangladesh to assess the status of pond, supply and tube-well water quality parameters and identify water collection and distribution system. Twelve water quality parameters namely; pH, TDS, TS, SS, DO, COD, BOD, conductivity, hardness, chloride, arsenic and iron were analyzed according to standard laboratory method. The mean value of pH, TDS, TS, SS, DO, COD, BOD, conductivity, hardness and chloride for pond water of all upazilas were 7.41, 169 mg/l, 193.26 mg/l, 32.85 mg/l, 5.56 mg/l, 79.07 mg/l, 36.28 mg/l, 335.18 μs/cm, 86.15 ppm and 34.57 mg/l respectively. The mean value of pH, TDS, TS, SS, DO, COD, BOD, conductivity, hardness, chloride, iron, and arsenic for tube well water of all upazilas were 8.01, 111.81 mg/l, 122.36 mg/l, 5.58 mg/l, 46.98 mg/l, 14.81 mg/l, 249.17 μs/cm, 131.23 ppm 108.09 mg/l, 0.55mg/l and 0.078 mg/l respectively. The mean value of pH, TDS, TS, SS, DO, COD, BOD, conductivity, hardness, chloride and iron for supply water of all upazilas were 7.8, 133.42 mg/l, 155.03 mg/l, 6.19 mg/l, 66.56 mg/l, 17.13 mg/l, 248.19 μs/cm, 126.07 ppm 167.6 mg/l and 0.65 mg/l respectively. Study revealed that pond water quality was suitable in terms of pH, DO, TDS, TS, SS, chloride and hardness and not suitable in terms of COD, BOD and conductivity for different productive uses. Tube well water quality was in desired level in terms of pH, DO, TDS, TS, SS, chloride, iron and hardness and not suitable in terms of COD, BOD, conductivity, and arsenic for different productive uses. Supply water quality was in acceptable limits in terms of pH, TDS, TS, SS, chloride, iron and hardness and crossed acceptable limit in terms of COD, BOD, conductivity, and DO for different productive uses. It was found that all the parameters vary significantly with the types of water. Water quality management program should be initiated under supervision of government to maintain the acceptable limit and proper water supply scheme should be followed for effective water collection and distribution system.

Index Terms — Chemical parameter, collection, distribution, water quality, management

Minkowski Geometry and Space-Time Manifold in Relativity

Volume 1, Issue 2, Pages: 101-109 | [Full Text] PDF (345 KB)

Harahan Kumar Mohajan

Premier University, Chittagong, Bangladesh.

Abstract — Space-time manifold plays an important role to express the concepts of Relativity properly. Causality and space-time topology make easier the geometrical explanation of Minkowski space-time manifold. The Minkowski metric is the simplest empty space-time manifold in General Relativity, and is in fact the space-time of the Special Relativity. Hence it is the entrance of the General Relativity and Relativistic Cosmology. No material particle can travel faster than light. So that null space is the boundary of the space-time manifold. Einstein equation plays an important role in Relativity. Some related definitions and related discussions are given before explaining the Minkowski geometry. In this paper an attempt has been taken to elucidate the Minkowski geometry in some details with easier mathematical calculations and diagrams where necessary.

Index Terms — Causal structure, Geodesics, Ideal points, Minkowski metric, Space-time manifold

Surfactant Enhanced Washing of Soil Contaminated with Petroleum Hydrocarbons and Treatment of Produced Wastewaters Using a Biofilter

Volume 1, Issue 2, Pages: 110-116 | [Full Text] PDF (345 KB)

Evelyn Zamudio-Pérez¹, Erick R. Bandala², Luis C. Fernandez¹, Luis G.Torres*¹

1- UPIBI- Instituto Politécnico Nacional. Av. Acueducto s.n. Colonia Barrio la Laguna Ticomán. México 07340 DF, México.

2- Departamento de Ingeniería Civil y Ambiental. Universidad de las Américas, Puebla. Sta. Catarina Mártir, Cholula, 72820.

Abstract — Puebla, México. Wastewater generated by washing a real petroleum hydrocarbon-contaminated soil was treated using a submerged aerobic filter. The wastewater contained petroleum hydrocarbons, surfactants, and other compounds that leached during the soil washing process. The efficiency of the biological treatment using natural or synthetic surfactants on the hydrocarbon-contaminated soil washing process, and different operation temperatures (24, 28, and 32°C) were compared and the identification of the microbial consortium present in the biofilter was carried out. The best degradation efficiency (73% hydrocarbon removal) was obtained when the wastewater from the soil washing using locust bean gum was treated at the biofilter operated at 24°C. The microorganisms found in the microbial consortium in the biofilter were B. subtillis, C. jeikeium, Pseudomonas sp., A. sobria, A. caviae, E. sakazakii.

Index Terms — Surfactants, submerged aerobic filter, wastewaters treatment, soil washing.

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