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Journal of Mathematical and Fundamental Sciences
Published by Institut Teknologi Bandung
ISSN : 23375760     EISSN : 23385510     DOI : https://doi.org/10.5614/j.math.fund.sci.
Core Subject : Science, Education,
Astronomy Chemistry Earth & Planetary Sciences Mathematics Physics
Journal of Mathematical and Fundamental Sciences welcomes full research articles in the area of Mathematics and Natural Sciences from the following subject areas: Astronomy, Chemistry, Earth Sciences (Geodesy, Geology, Geophysics, Oceanography, Meteorology), Life Sciences (Agriculture, Biochemistry, Biology, Health, Medical, Pharmacy), Mathematics, Physics, and Statistics.
Arjuna Subject : Matematika - Matematika (Lain-Lain)
Articles 689 Documents
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Pengolahan Limbah Cair Emulsi Minyak dengan Proses Membran Ultrafiltrasi Dua-tahap Aliran Cross-flow Suprihanto Notodarmojo; Dini Mayasanthy; Teuku Zulkarnain
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 1 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.1.4

Abstract

A study on the use of cellulosa acetate membrane using cross-flow system to treat oil-water emulsion waste came from metal cutting process of automotive industry has been done. The objectives of this research are to treat oil water emulsion waste and to see the impact of pretreatment process to membrane performance. The separation mechanism of ultrafiltration process is filtration. The molecule which is smaller than membrane pore size will pass the membrane other wise, the bigger one will be rejected. The ultrafiltration process performance is determined by permeate fluks and rejection. The material of membrane used in this process is cellulosa acetate membrane with 12 % composition for first stage operation and 15 % one for second stage operation, each on 90 minutes operation time. Operation pressure used was 3,5 Bar. There are two type feeding operation treated by membrane, feeding without pretreatment and feeding with pretreatment. On the first stage membrane operation, waste without pretreatment applied flux at 17,03 L/m2.h, and for waste with pretreatment the applied flux was 59,05 L/m2.h. On the second stage membrane operation the applied flux of waste without pretreatment was 22,08 L/m2.h, and the flux of waste with pretreatment was 24,86 L/m2.h. Overall COD and surfaktan rejection involving two stage membrane operation, which COD rejection was 96,57% for waste without pretreatment, and surfactant rejection was 96,35 %. Meanwhile, for waste with pretreatment the COD rejection was 98,56 % and the surfactant rejection 97,44%. It is concluded that pretreatment process give a benefit to increase fluks and goof quality permeate.
Expanding Super Edge-Magic Graphs∗ E. T. Baskoro; Y. M. Cholily
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.2

Abstract

For a graph G, with the vertex set V(G) and the edge set E(G) an edge-magic total labeling is a bijection f from V(G)UE(G) to the set of integers {1,2,...., |V(G)|+|E(G)} with the property that f(u) + f(v) +f(uv) = k for each uv elemen E(G) and for a fixed integer k. An edge-magic total labeling f is called super edge-magic total labeling if f(E(G)) = {|V(G)+1, |V(G)+2,....., |V(G)+E(G)|}. In this paper we construct the expanded super edge-magic total graphs from cycles C, generalized Petersen graphs and generalized prisms.
Kajian Unit Pengolahan Menggunakan Media Berbutir dengan Parameter Kekeruhan, TSS, Senyawa Organik dan pH Suprihanto Notodarmojo; Andriani Astuti; Anne Juliah
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.1

Abstract

A field trial of flocculation using gravel bed has been done using PDAM's Kota Bandung as the location. The reactor used a PVC pipe that consisted of an average diameter of 2,025 cm gravel. PDAM's raw water was used as throughout the experiment. As coagulant, PAC (Poly Alumunium Chloride) is used. The results show that the reactor can reduce the organic content down to 3,02 mg/L with the removal efficiency up to 73,17%. And it also can reduce the turbidity down to 0,5 NTU with removal efficiency up to 96%. The G.td value was 6946, which down below the average G.td used in hydraulic flocculation. Overall, the flocculation has a prospect to be used in operational scale.
Effect of pretreatment to the formation of cake layer and membrane structure in the application of ultra filtration cross-flow Membrane for the treatment of oil-water emulsion waste Suprihanto Notodarmojo; T. Zulkarnain; Dini Mayasanthy; M. Irsyad
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.3

Abstract

A study on the effect of pretreatment on the use of cellulose acetate (CA) membrane using cross-flow system to treat oil-water emulsion waste came from metal cutting process of an automotive industry has been done. The objectives of this research are to see the impact of pretreatment process to flux and cake forming, indicated by cake forming constant (k'), and to study membrane structure. The ultra filtration process performance was determined by obtaining the values of permeate flux and rejection. The material of membrane used in this process was cellulose acetate membrane with 12 % of cellulose acetate composition for first stage operation and 15 % for second stage operation. The duration of the process was 90 minutes operation time, by applying operation pressure at 3, 5 Bar. There were two types of feeding mode applied, the first was feeding without pretreatment and the second was feeding with pretreatment. After some operation periods, the permeate flux decreases due to fouling. On the first stage of membrane operation, for waste without pretreatment, we obtained the value of k'= 0,0004 m2/L and for waste with pretreatment k'= 0,0001 m2/L. On the second stage membrane operation, for waste without pretreatment the value of k'= 0,0009 m2/L and for waste with pretreatment k'= 0,0002 m2/L. The results mean that pretreatment reduce significantly formation of the cake. It was also obtained that the structure of the membrane is asymmetric. It was shown that deposition of contaminant also occurs within the spinger of the membrane (inner structure of the membrane). Deformation of the membrane spinger was also observed. It is concluded that pretreatment applied to feeding solution increase the running time of the membrane. The benefit of membrane operation used feed with pretreatment, beside increases permeate fluks also decreases the cake forming constant which will longer operation time of membrane.
Solusi Model Aliran Gas Dalam Pipa pada Kondisi Line Packing Menggunakan Skema Richtmyer Harry Budiharjo Sulistyarso; Suryasatriya Trihandaru; Leksono Mucharam; Septoratno Siregar; Ivanky Saputra; Sinatra Canggih
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.5

Abstract

Line packing is a process storing gas in pipeline by increasing inlet gas flow rate while outlet gas flow rate is kept constant. This difference of gas flow rate causes the gas flow in pipeline being transient. Line packing process is intended to guarantee gas supply when trouble occurs. In this paper, a transient model with boundary condition is solved numerically using Richtmyer scheme, because stability analysis showed that Richtmyer scheme is better than other explicit schemes. In the case presented, it is shown that Richtmyer scheme sufficiently agrees with the real data in gas pipeline transmission, which is in many cases unsteady-state.
Penentuan Tinggi Orthometrik Gunung Semeru Berdasarkan Data Survei GPS dan Model Geoid EGM 1996 Hasanuddin Z. Abidin; Heri Andreas; Dinar Maulana; M. Hendrasto; M. Gamal; Oni K. Suganda
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.4

Abstract

Semeru is the highest mountain in Java island with an altitude of about +3676 m above the sea level. This altitude was measured during the Dutch colonial times using the Triangulation method, which is based on angles measurements using a theodolite on the measurement points. At the present times, with the advancement in positioning technology and better knowledge on the Earth's gravity field, an orthometric altitude of a mountain can also be determined by utilizing GPS satellites observation data and a global geopotential model. In this paper, the methodology, mechanism and results of the altitude determination of Semeru mountain using the August 2003 and August 2004 GPS survey data and EGM 1996 geoid model will be described and discussed.The obtained results show that the altitude of Semeru at the present times is about +3677 m above the mean sea level.The paper will be sum up with some closing remarks.
Studi Pengembangan Model Turbulen κ-ε untuk Sirkulasi Arus I: Aliran Dua Dimensi pada Sebuah Tampungan Air M. Syahril Badri Kusuma; M. Cahyono; Eka Oktarianto
Journal of Mathematical and Fundamental Sciences Vol. 36 No. 2 (2004)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2004.36.2.6

Abstract

This paper present the results of the κ-ε model development for simulating two dimensions flow in a small reservoir. The study was aimed to see wether the turbulent component could be better accounted by using the κ- ε model. The numerical model was developed using finite difference method where hydrodynamic equation was solved by the combination of Mc Cormack and splitting methods. The mirror method is used as the boundary condition of the model.Comparison study were done by using the field measurement result on fishery ponds and model results by other methods. Better agreement is found between field measuremenst and model results due to the increasing accuracy in turbulent model prediction.
Penggunaan Matrix Analytic Technique pada Perhitungan Parameter Kinerja Proses Handoff R. Hadianti; J. Naiborhu; L. Dahliantini
Journal of Mathematical and Fundamental Sciences Vol. 37 No. 1 (2005)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2005.37.1.4

Abstract

This paper discusses performance evaluation of mobile cellular telecommunication system that is related to the handoff process. We focus our discussion to the system with fixed channel assignment and homogeneous traffic. Performance parameters we discuss in this paper are the blocking probability and the dropping probability of handoff signals, and the blocking probability of new originating call signals.The operator of the system usually gives a service priority to handoff signals compare to new originating call signals. In this paper, the priority is given through channels reservation. A number of channels are reserved so that they can be used only for serving handoff signals. The remaining channels are used for serving new originating call signals and if there is an idle channel, it also can be used for serving handoff signals. With this priority, the arrival process and the service process of both types of signals can be modelled as a queueing network that consists of two queueing systems: one system for handoff signals and one system for both signals.The performance of the queueing network is analyzed by deriving the a two-dimensional Markov process. The system of balance equations of the process, which is needed for obtaining the stationary probability distribution of the process, is a large system. We solve this system by applying Matrix Analytic Technique to the two sub-systems simultaneously. The performance parameter values, which are expressed by the stationary probability distribution, are obtained from the solution.
Excitation Mechanism in Laser-Induced Plasma at Atmospheric Air Pressure Jojor Lamsihar Manalu; Koo Hendrik Kurniawan; Tjung Jie Lie
Journal of Mathematical and Fundamental Sciences Vol. 37 No. 1 (2005)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2005.37.1.1

Abstract

A special interferometric technique has been devised on the basis of rainbow refractometry without the use of an additional and delicate amplitude-splitting setup. This new technique was used for the characterization of plasma induced by a Q-switched Nd-YAG laser on zinc samples under atmospheric air pressure. An unmistakable signal of the density jump was detected simultaneously with the observation of the emission front signal. It was proved that the emission front and the front of the shock wave coincided and moved together with time at the initial stage of the secondary plasma expansion. However, at a later stage, the emission front began to separate from and left behind the shock wave front propagating in the surrounding air. With the use of zinc sample, the experimental results showed that the separation of the emission front and shock wave front took place at about 4 mm above sample surface for laser energy of 26 mJ. It was also found that the separation time increased by increasing the power density which further supported shock wave model. Analysis of the data of the shock front movement along with the emission characteristics has led us to the conclusion that models other than the shock wave model, such as the gas breakdown model, should be excluded, at least for a zinc sample, as not satisfactorily explaining the excitation process in the secondary plasma generated at atmospheric air pressure of 760 Torr.
Identifikasi dan Klasifikasi Sinyal EEG terhadap Rangsangan Suara dengan Ekstraksi Wavelet dan Spektral Daya Esmeralda C. Djamal; Harijono A. Tjokronegoro
Journal of Mathematical and Fundamental Sciences Vol. 37 No. 1 (2005)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.sci.2005.37.1.5

Abstract

In this research the development of identification and classification technique of three wave components of EEG signal, named alpha, beta and theta, is considered. The technique is combination of wavelet transform and power spectral analysis. Wavelet transform was used to extract the wave components so it reduces the data without loss of the information. The wavelet transform also reduces the aspects of non-stationary of the EEG signal. The EEG's wave classification was based on the appearance of the wave, synchronization between symmetric hemispheres, and the wave energy dominance, in its frequency region. The EEG signals used in this research were obtained from 5 individually-independent subjects after 2.5 minutes sound stimulation. 10 sounds of music and 2 natural sounds were used as sound stimulation in this research. Then, 16 channels of EEG signals, obtained from every individual subject after a sound stimulation, were analyzed. The technique shows that the sound stimulation increases the appearance of the alpha wave by 75% and decreases beta and theta waves by 48% and 56%, respectively. Furthermore, the sound stimulations were used in the research to increase the synchronization balance between symmetric channels by 75%. In addition, this research shows that the signal extraction using wavelet packet provided small deviation and reduced non-stationary aspects, so that it improves the power spectral analysis used in the technique.

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