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In the present work, DDR3 zeolite crystals were synthesized using two different methods. The silica sources used to synthesize DDR3 crystals were tetramethoxysilane (TMOS) and Ludox-40. The resultant samples were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The XRD results showed that the peaks representing DDR3 structure were not obtained for the sample synthesized in 5 days at room temperature with ultrasonic pre-treatment of 3h using Ludox-40 as silica source. On the other hand, the XRD pattern obtained for the sample synthesized in 25 days at 160 o C using TMOS as a silica source were similar with the XRD peaks reported in the literature. From these results, it can be concluded that the synthesis conditions of 25 days at 160 o C using TMOS as silica source were the favorable conditions in obtaining DDR3 crystal structure.

Greenhouse gas (GHG) emissions such as carbon dioxide (CO2) and methane (CH4) from oil and natural gas operation at offshore platforms have significant contribution to global warming. The reduction of these GHG emissions is possible through CO2 capture technology. This study reports the absorption performance of monoethanolamine (MEA) for the removal of CO2 from natural gas (NG) at high pressure conditions. The absorption experiments were performed in an absorption column packed with Sulzer Metal Gauze Packing at 5.0 MPa operating pressure. The absorption performance was evaluated in terms of CO2 removal (%) with liquid flow rate ranging from 1.81 to 4.51 m3/m2.h and MEA concentration of 1.0 - 4.0 kmol/m3. It was found that CO2 removal (%) had increased with increasing liquid flow rate and MEA concentration.

With the depletion of low carbon dioxide (CO2) content natural gas reserves, there is a pressing need to explore the vastly undeveloped high CO2 content natural gas reserves and reduce the release of greenhouse gas CO2 into environment. Our previous investigation on the absorption performance of CO2 at high concentration level of 50% from mixture of CO2-natural gas stream for 20wt% monoethanolamine (MEA) solution in countercurrent packed column indicated efficient removal at high pressure condition. In this present work, a combination mass transfer, chemical reaction of MEA as well as mass conservation equation was developed to model the removal behavior of the high pressure, high concentration CO2 capture along the absorption column. The model developed in this study had satisfactorily represented the mass transfer behavior for high pressure and high CO2 concentration gas removal along the absorption column.

This paper presents the formation of highly crystalline ZIF-8 using microwave-assisted solvothermal method. The crystallinity of the ZIF-8 particles was characterized using X-ray diffraction. The lattice vibrations of the structure in the ZIF-8 framework were determined through Fourier transforms infrared spectroscopy. The morphology of the ZIF-8 particles was observed through scanning electron microscopy. The results showed that, 0.5 hour was sufficient for the formation of highly crystalline ZIF-8 particles using microwave-assisted solvothermal method under temperature 120 oC.

The objective of this research paper is to demonstrate the application of hybrid knowledge-based system, gauging absences of pre-requisites (GAP), and analytic hierarchy process (AHP) approaches for selecting the improvement programs for Collaborative Green Manufacturing Management (CGMM) system. In this research, a generic knowledge-based system is developed to measure the level of CGMM adoption in automotive manufacturers compared to the ideal system. Using the GAP and AHP tools, the key green manufacturing improvement programs can be prioritized and demonstrated with an illustrative example.

Helicopter rotor aerodynamics is prognosticated to be one of the most perplexing and enigmatic affliction encountered by both researchers and aviators throughout the ages. The bewilderment of the flow field around the main rotor blade ceaselessly remains unrequited in tangible flight environments. Appalling calamities repeatedly befall owing to these unforeseen and equivocal instances. In order to extricate these impediments, one must go back to the brass tacks and apprehend the cause. However, it is every so often exceedingly disconcerting to obtain experimental data due to intricacy, perplexity and substantial price tag. Subsequently, computational simulation is progressively becoming more of a preferred choice in recent times. Bearing this in mind, this study intended to simulate and visualize the air flow configuration of the main rotor blade using symmetrical and transonic airfoils to demarcate their physiognomies and behavior. Results have revealed that the transonic airfoil has a higher lift coefficient (Cl) than the symmetrical airfoil. Contrariwise, if used in an actual rotorcraft, the transonic airfoil can cause stern apprehension in terms of stability and control.

The inhibition of corrosion of stainless steel (SS)-410 in sulfuric acid using thiourea and three different surfactants, cetyle trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and X-Triton was studied. Corrosion rates were determined by using corrosion coupons. The corrosion rate was found to be decreased with increase in inhibitor concentration. It was observed that the maximum corrosion inhibition occurred in the post micellar concentration of the surfactants. By optimizing the corrosion inhibition performance of different blends of surfactants and thiourea in 3 M H2SO4,the corrosion inhibition order was found as: Triton X-100 + thiourea > CTAB + thiourea > SDS + thiourea. The best results obtained by the addition of 200 ppm thiourea in 500 ppm of Triton X-100 in 3 M H2SO4acid solution. This blend decreased the corrosion rate of SS-410 to 657.66 mpy.

CO2solubility in aqueous potassium carbonate promoted with amino acid (glycine) was measured at temperatures (303.15, 313.15, and 333.15) K over the partial pressure range from 200 to 1000 kPa. The solubility of CO2is reported as the loading capacity of the CO2in the solvent, defined as (moles of CO2per mole of solvent). It was found that the loading capacity of the CO2increases by increasing the partial pressure of the CO2, whereas, it reduces with increase in temperature. CO2loading capacity in aqueous potassium carbonate (PC) promoted with glycine (GLY) was also compared with different solvents, which shows that the new solvent blend is considerably better than various solvents.

The precious demand not in the push away and broad off from receive forward developed technology approaches place the hand almost several lacks of warns and in-needed developed technique and techniques for greater than before contract and analysis for several issues, no complimentary and talk to studies within the literature describe the system comes in multi component and dual phase particularly for those that ought to be investigated at offshore conditions, the novel technique and setup has been created for such scope, the recently developed set up has the flexibility to analyses the sorption isotherms and kinetic for multi component and dual phase mixtures (gas and vapor) at offshore conditions in term of temperature up to 150 oC and pressure up to 150 bar. Additionally to the pretreatment that would be finished to the sorbents used at temperatures up to 400 oC and vacuumed pressure. The primer experiments are done using 13 X zeolites for the sorption of pure CO2 and binary mixtures (CO2 and CH4) at elevated conditions.

The solubility of carbon dioxide (CO2) was measured in aqueous solutions of 2-amino-2-methyl-1-propanol (AMP) and Piperazine (PZ) activated aqueous solutions of (AMP) at two different temperatures (303.15 and 333.15)K and at various concentrations of studied solvents. The measurements were made over the pressure range of 5 to 60 bar. The results are presented as a function of pressure. It has been found that the addition of PZ to the aqueous solutions gives significantly higher CO2 loadings at higher pressures. The influence of pressure on solubility is found to be positive. However, solubility decreases with the increase of temperature.

The supported TiO2 photocatalyst has been reported for the photodegradation of different organic pollutants. These supported TiO2 photocatalysts include metal and non metal doped TiO2 photocatalysts. The photodegradation can be explained in terms of adsorption. The adsorption of the dye is an significant and obvious parameter in the photodegradation process. The photodegradation is directly related to the adsorbed quantities of the pollutant onto the surface of adsorbant. Adsorption of Orange II, an azo dye has been reported using different adsorbents like fly ash, activated carbon and porous titanium dioxide. This review presents a comparison of maximum adsorption capacities (Qm; mg.g–1) and Langmuir adsorption constant (Kads; L.mg–1) for the adsorbents reported in previous studies.

Work permit is something not to take lightly because it involved non-routine work such as hot work which failure to comply with the work permit procedures could resulted in large-scale loss of life and/or property. Investigations by Chemical Safety Board (CSB) have reported 60 fatal hot work accidents in about 20 years in the USA though hot work permits were issued for all operations. No matter how simple the procedure and work permit forms are, it is the strict application of the procedures and practices associated with the assessment of risk and application of permit to work conditions that ensures work can be done safely. A model for hot work permit that is incompliance with the Process Safety Management (PSM) regulations requirements is introduced that includes necessary fire preventive actions to be taken. In addition, a few existing hot work permits were studied to verify this model. It was found that the model required more information to safeguard an effective hot work permit system and better compliance with the PSM regulation. In addition, the model is also more precise, adaptable, user-friendly and easier to comprehend. As a conclusion, the model created could improve the conventional hot work permitting system. To ensure that the permit is more strict and effective hot work permitting system, a more sophisticated coding and software could be further expanded.

Development of novel mixed matrix membranes (MMMs) has become frontier candidates for improving the upper bound trade-off curve between permeability and selectivity of gases for industrial polymeric membranes. However, fabrication of ideal MMMs is practically challenging as the dispersion of inorganic phase into the polymer may produce polymeric-inorganic interfacial defects at the vicinity of the polymer matrix. For instance, the inorganic phase may cause interfacial void, polymer chain rigidification or partial pore blockage on the overall MMMs. Since there are only few studies that specifically focus on the issues of the interfacial morphology of MMMs, therefore, the present study provides brief description of the aforementioned interfacial (non-ideal) defects of MMMs and summarizes the techniques used to repair the interfacial defects for enhanced gas separation in MMMs.

In this research work, ZIF-8 was synthesized at room temperature using different synthesis solutions contained different molar ratios of methanol to zinc nitrate. The properties of the resultant particles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The basicity of the ZIF-8 samples was measured using temperature programmed desorption (TPD). Results showed that ZIF-8 samples synthesized in the present work were thermally stable up to 700 oC. ZIF-8 synthesized using synthesis solution contained lowest molar ratio of methanol to zinc nitrate of 86.7 possessed highest crystallinity and largest average particles sizes of ~250 nm. Besides, this sample also demonstrated highest CO2 uptake rate due to the presence of highest amount of basic site of 0.70 mmol/g among the ZIF-8 samples.

There is a growing need of counter assessing the increase of releases greenhouse gases such as carbon dioxide by researching an alternative technology that can help to reduce carbon dioxide content in atmosphere. This research work investigates the potential of MIL-53 as CO2capture and storage candidate by conducting an experiment with different pressure between the synthesised and modified MIL-53. To investigate the effect of the Multi-wall carbon nanotubes (MWCNTs) and carbon nanofibers (CNFs) in MIL-53 towards CO2adsorption performance. The synthesised samples were characterized by Fourier Transform Spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) techniques. A significant change is observed in the region of the aromatic deformation vibrations due to the different substitution patterns of the aromatic ring. BET surface area for MWCNT@MIL-53 is higher than CNF@MIL-53 and MIL-53. MWCNTs showed the adsorption of CO2uptake is 0.3mmole-1/g at 100Kpa.

This paper proposes a new technique to evaluate the level of inherent safety of process plant during the preliminary design stage by using the combined assessment of process routes, streams and inherent risk for toxic release accidents. This technique is known as 3-Tier Inherent Safety Quantification (3-TISQ). The first tier is to screen the process routes and to select the ‘best’ route that is inherently less hazardous. Next, the inherent safety level of the streams within the selected process route can be prioritized using Toxic Release Stream Index (TRSI) as the second tier. Afterwards, the inherent safety level of the selected streams can be determined using toxic release inherent risk assessment (TRIRA) as the third tier. The acceptability level of the inherent risk for the selected streams can be obtained using a two-region risk matrix concept. If the inherent risk level is not acceptable, the improvement of the design can be done using the inherent safety principle until the level of the inherent risk is at the tolerable or acceptable region. 3-TISQ can also be extended to evaluate the inherent safety level of fire and explosion accidents.

Accident is one of the big issues that occur repeatedly in the process industries today though there is numerous application of the variety safeguarding measures that have been introduced. Equipment failure is identified as one of the root causes of these major accidents. One of the established standards that addressed the above issue is a Mechanical Integrity (MI) element of Process safety Management System (PSM) 29 CFR 1910.119(j). The main objective of this study is to introduce a systematic technique to implement PSM MI in process industries. This study covered analysis of requirements of the standard, development of framework and prototype tool as well as concept validation through a case study. Implementation of this technique will help employers to prevent major accidents and compliance to the PSM standard simultaneously.

This study aims to optimize the temperature rise during CO2 absorption process using response surface methodology (RSM). Verification experiments were performed using a pilot scale experimental set up to validate the optimization condition generated from RSM analysis. The magnitude of temperature rise was observed to increase with increase of pressure and it was especially significant with the increase of CO2 inlet concentration. However, the increase of temperature with higher CO2 inlet concentration was not very obvious after 60% of CO2 inlet concentration. The predicted values of the optimized temperature rise were generally in good agreement with the actual experimental results and this indicated that the empirical correlation generated was well suited with the experimental results.

The present study investigates the effects of intercalation process of protonated primary, secondary and tertiary amines on structural and surface characteristics of sodium form of bentonite clay. For this purpose, sodium form of bentonite clay was prepared and then exchanged with mono-, di-and triethanolammonium cations via intercalation mechanism into the interlayer space of the clay. The prepared samples were characterized by XRD and BET techniques. An increase in the d-spacing of bentonite clay with the molar mass of amines was observed in their x-ray diffractograms, following the order of: triethanolamine > diethanolamine > monoethanolamine. The BET results showed a gradual decrease in the BET surface area with the increase in the molar mass of amines used. Based on the results obtained, it can be concluded that the molar mass of amines has significant effects on structural and surface properties of bentonite clay.

A solution could be made supersaturated when the physical conditions was altered. The supersaturated gas would form bubble to bring the solution back to the equilibrium condition. Bubble would first nucleated and then growth in the solution. This work was aimed to simulate the bubble formation across an orifice, with sufficient pressure drop. The CO2 was assumed to be made saturated at 6 atm in water, and formed bubble when the solution flowed across the orifice. As the CO2 bubble formed across the orifice, the volume of the CO2 gas occupied almost the whole space in the orifice. The mass of the dissolved CO2 in water had decreased too as it had transferred into gas CO2.

The precious demand not in the push away and broad off from receive forward developed technology approaches place the hand almost several lacks of warns and in-needed developed technique and techniques for greater than before contract and analysis for several issues, no complimentary and talk to studies within the literature describe the system comes in multi component and dual phase particularly for those that ought to be investigated at offshore conditions, the novel technique and setup has been created for such scope, the recently developed discovered has the flexibility to analyses the sorption isotherms and kinetic for multi component and dual phase mixtures (gas and vapor) at offshore conditions in term of temperature up to 150 oC and pressure up to 150 bar. Additionally to the pretreatment that would be finished to the sorbents used at temperatures up to 400 oC and vacuumed pressure. The primer experiments are done using 13 X zeolites for the sorption of pure CO2 at numerous conditions and binary mixtures (CO2 and CH4) with the existence of water vapor.

The paper presents the concept of cryogenic growth kinetics during separation of CO2from natural gas using Avrami nucleation model. The interface frost layer on the glass packing of cryogenic bed is assumed asgerm nuclei. The bed porosity is considered time dependent. The expression for time varying bed porosity is derived based on Avrami model. The experimentation was conducted to validate the model and the resulting simulation studies show good resemblance with experimental results.

Thermodynamic model is one of the important elements in designing and operating CO2removal systems, thus accurate determination of the thermodynamic properties of CO2in aqueous amine is of major interest for both technical and economical considerations. Quantitative Raman study of aqueous monoethanolamine (MEA) solutions of concentration ranging from 0 to 99 mass % in the spectral region between 300 and 3100 cm− 1was performed. Band envelopes were resolved with Gaussian Lorentzian function. Progressive growth of area under these peaks with increasing concentration was used as the parameter to construct calibration curve. Area ratio of selected peaks was plotted against MEA concentration to depict the relationship between MEA concentration and each area ratio. Correlation for A1460/A933has coefficient of determination closest to unity and lowest mean squared area. MEA concentration can be calculated from the equation derived from correlation between A1460/A933and MEA mass %.

The use of compact, inline separator has gain interest in the effort of reducing the size of topside facilities to reduce the capital cost associated with natural gas exploration. This paper discusses the effect of superficial gas velocity on the separation performance of an inline horizontal swirl tube separator. In this study, the superficial velocity is varied from a minimum of 5 m/s up to a maximum velocity of 12 m/s at different operating pressure. The pressure is varied from 40, 50 and 60 bars, corresponding to different centrifugal force on the incoming gas stream. Results shows that the best separation performance is achieve at higher operating pressure, in this case at 60 bar, regardless of the incoming fluid velocity and liquid load (of up to 30% by mass).

The presence of carbon dioxide (CO2) in natural gas stream is a critical problem; besides causing corrosion it also reduces the energy contents and heating value of natural gas. Various separation techniques are available to separate CO2from natural gas, such as metal organic framework (MOF), covalent organic framework (COF) and Covalent Organic Polymer (COP) adsorbents. The criteria of adsorbent selection that need to be fulfilled include high adsorption capacity, high selectivity of CO2and hydrothermal stability at operating conditions. COPs are crystalline porous materials having high CO2capacity and selectivity in the presence of water vapors. However, the research on COP material development is new and scarce information is available in literature. In this prospect, the paper highlights the different types of COPs, their basic constituents and the adsorption capacities.

Metal organic frameworks (MOFs) are presently under substantial investigation due to their properties and high potential as new class of porous material for carbon dioxide (CO2) capture. Experimentally, Cu-BTC crystalline frameworks with diameter of approximately 6-13 μm were found. The washing method of Cu-BTC was examined using three different solvent, (a) ethanol and water (1:1), (b) water, and (c) acetone to improve the BET surface area. These materials display approximately type I isotherms with no hysteresis and saturation. CO2 adsorption capacities study shows that acetone wash material can store about 5.98 mmolg-1of CO2 at 25oC and 1.2 bar.

The confinement and storage of carbon dioxide has been acknowledged as a prospective solution towards the greenhouse gas effect which in turn cause climate change. Proficient separation technologies are required for removal of carbon dioxide from natural gas streams to allow this solution to be extensively feasible. An emerging technology is the membrane gas separation, which is more dense, energy efficient and possibly more economical than older technologies, such as solvent absorption. Amine has a natural affinity for both carbon dioxide and hydrogen sulphide, allowing it to be a very effective removal process. In this context blending of glassy polymer that is polysulfone and amines, which are diethanol amine, methyl diethanol amine, mono ethanol amine in dimethyl acetamide solvent, flat sheet membranes were developed with desirable properties. Gas permeability study of PSU with amines, blend membranes were evaluated using pure gas CO2and CH4at different feed pressures.

Mixed matrix membrane (MMM) has shown significant progress towards gas separation. Rigid polymers are suitable materials for MMM fabrication but adhesion problems with filler need to be addressed. A variety of inorganic fillers have been studied for CO2 separation but clay minerals were not considered much in this class. The layered silicate structure of nanoclay such as montmorillonite provides excellent opportunity to manipulate its properties, leading towards better dispersion and adhesion towards the polymer matrix. This paper reviews the potential of polymer-nanoclay MMM for CO2/CH4 separation.

Compliance audit for process safety management (PSM) is a technique to verify that the implementation of the PSM program is in compliance with OSHA standards and to identify potential deficiencies in the PSM program used. However, unavailability of an easy audit techniques hinders the compliances to PSM standards in industries. An audit model is introduced based on OSHA PSM standard to provide a standardize format that utilizes the Piping and Instrumentation Diagram (P&ID) as a basis. A case study based on the training element of OSHA PSM is performed to verify the effectiveness and to ensure the PSM standard compliances. The model is based on Microsoft Access which enables the user to input data, manage and track information. The model is useful to the employee as the weaknesses in the PSM program can be identified and rectified to prevent any major accidents.

A “Multi-component Progressive Cell Balance” approach has been applied to characterize the gas separation of the radial crossflow hollow fiber membrane module. The mathematical model is an indispensable tool to evaluate the separation performance of membrane material towards different components. The approach is required to be implemented since there is scarcely available mathematical model to characterize the two dimensional radial crossflow. In addition, the currently available mathematical model is confined to the ideal binary system, which constraints its applicability in real membrane separation process with many components. The significance of the developed multi-component mathematical model as compared to the model adapting the ideal binary simulation condition is demonstrated in this study.

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.

Pixel value graphical password scheme was introduced with the aim to solve problems faced by users during authentication process that arising from current graphical password scheme weaknesses. Even though the idea of graphical password scheme is still under analysis stage, many researchers have come out with a lot of vulnerabilities finding for current graphical password scheme. Literature studies on vulnerabilities finding has contributed for a development of method design features and requirements for pixel value graphical password scheme. This paper is organized as begin with a brief introduction on graphical password scheme, followed by literature study outcome, discussion on features and requirements, and enclosed with topic conclusion.

The aerodynamics of the helicopter rotor is one of the most elating and exigent tribulations faced by the aerodynamicists today. Study through flow visualization process plays a key role in understanding the airflow distinctiveness and vortex interaction of the helicopter main rotor blade. Inspecting and scrutinizing the effects of wake vortices during operation is a great challenge and imperative in designing effective rotor system. This study aimed to visualize the main rotor airflow pattern of the Hirobo-FALCON 505 controllable subscale helicopter and seek for the vortex flow at the blade tip. The experimental qualitative data is correlated with quantitative data to perform scrupulous study on the airflow behavior and characteristics along with its distinctiveness spawned by the main rotor blade. Simulation using design software is performed in analogous stipulations to endow with comparability between the flow visualization results. Throughout the blade span several dissimilar flow patterns have been identified. The main rotor hub has turbulent flow at its center due to low energy of air amassed in this region whereas in the middle portion of the rotor blade, the air encompasses high kinetic energy with a clear straight streamline pattern.

People are interested to spend their leisure time in spaces where variety of activities take place so more users are attracted to such spaces.Living environments lacking inappropriate social spaces, resulting poor social interaction have been causing psychological problems as well as issues on security and safety and matters with sense of belonging to the environment. This paper focuses on residents’ preference on character of spaces for social interaction in their condominiums. This study employed questionnaire surveys for selected condominium residents in Kelang Valley, Malaysia. The study found that limitations, cumbersome rules, as well aspoor connectivity of spaces have caused people to prefer outdoor social spaces where they can have free activities,view other people activities and half hear them.

Tin tailing sand is one of the residues from tin extraction. Tailing sand for sampling was taken from Batu Gajah, which was one of the active locations in tin mining in Malaysia. The silica content of tailing sand from Batu Gajah is between 95.9 to 98.9%. This research is to determine the effect of grain size by the increasing of water content on the permeability number. Grain size is a major determinant of mould and core permeability and surface finish of the casting. In this research involved the process of conducting the mechanical sieve grading to identify the grain size for this research. Sample was graded into 425 μm, 297 μm and 149 μm. Experiments were conducted according to American Foundrymen Society (AFS) standard of procedures. Cylindrical test pieces dimensioning of Ø50 mm×50 mm in height from various grain sand sizewater ratios bonded with 5wt% clay, were compacted by applying three ramming blows of 6666 g each using Ridsdale-Dietert metric standard rammer. The test pieces were tested for permeability number with Ridsdale-Dietert permeability meter. Grain sand size of 297 μm was discovered has appropriate permeability number with the water content of 4% which is within the requirement as moulding sand.

Principal axis formulations are regularly used in isotropic elasticity but they are not often used in dealing with anisotropic problems. In this paper, based on a principal axis technique, we develop a physical invariant constitutive equation for incompressible transversely isotropic solids, where it contains only a one variable (general) function. The corresponding strain energy function depends on four invariants that have immediate physical interpretation. These invariants are useful in facilitating an experiment to obtain a specific constitutive equation for a particular type of materials. The explicit appearance of the classical ground state constants in the constitutive equation simplifies the calculation for their admissible values. A specific constitutive model is proposed for soft tissues and the model fits reasonably well with existing experimental data; it is also able to accurately predict experiment data.

Railway concrete sleepers have been developed and utilized in railway industry for over 50 years. Cyclic loading because of vibration on sleepers due to the train loading and the velocity of train itself and also a small percentage of bad wheels, can eventually lead to a crack network and failure of component. The objective of this study is to investigate the load carrying capacity of the selected prestressed concrete sleepers – prepared for Keretapi Tanah Melayu Berhad, KTMB, under static and dynamic loading conditions. In order to determine the behavior of the railway concrete sleepers under repeated low-velocity impact load and to study the fatigue performance of railway concrete sleepers, the research efforts are required to perform comprehensive studies on the behaviors and dynamic response of these prestressed concrete sleepers. The fatigue performance of railway sleepers was investigated under constant amplitude load and compared with the actual train loading on site. For the laboratory work, the concrete sleepers were subjected to repeated low-velocity sinusoidal loads typical to loading from commuter trains only and attaining the fatigue toughness, energy absorption, and crack formations of the concrete sleepers.

Significant wave height is generally defined as the mean height of the highest one third of the waves in the sample and is widely regarded as an approximate equivalent to the visually observed height. Some studies assumed that wave heights can be described in terms of Log-normal, Generalized Gamma and Beta distribution, while others proposed Rayleigh distributions. In this paper, we wish to compare Rayleigh distribution with those obtained using two-parameter Weibull distributions. Both Rayleigh and Weibull distributions are used to fit the empirical data obtained from the world's oceans Global Wave Statistics. The Rayleigh distribution parameter is estimated using Maximum Likelihood Estimation (MLE) while, for the two-parameter Weibull distribution, parameter values are obtained using Maximum Likelihood Estimation and Quantile Estimation (QE). A Chi-square goodness of fit test is then used to see how the fitted distributions compare with the empirical distribution. It is found that Weibull distributions are better fits than the Rayleigh distribution, and that the MLE estimation is the best in this respect.

The objective of this paper is to consider the use of fractal geometry as a tool for the study of non-smooth and discontinuous objects for which Euclidean coordinate is not able to fully describe their shapes. We categorized the methods for computing fractal dimension with a discussion into that. We guide readers up to the point they can dig into the literature, but with more advanced methods that researchers are developing. Considerations show that is necessary to understand the numerous theoretical and experimental results concerning searching of the conformality before evaluating the fractal dimension to our own objects. We suggested examining a cloud of points of growth of fracture surface at laboratory using CATIA - Digitized Shape Editor software in order to reconstruct the surface (CAD model). Then, the author carried out measurement/calculation of more accurate fractal dimension which are introduced by [1] in the other paper as Part II.

Polymeric membranes are widely used for gas separation purposes but their performance is restricted by the upper bound trade-off discovered by Robeson in 1991. The polymeric membrane can be glassy, rubbery or a blend of these two polymers. This review paper discusses the properties of glassy polymer membranes and their performance in gas separation. The area of improvement for glassy membrane with development of mixed matrix membrane is also highlighted.