A Real Story of Bioethanol from Biomass: Malaysia Perspective

Rising fossil fuel prices associated with growing demand for energy, and environment concerns are the key factors driving strong interest in renewable energy sources, particular in biofuel. Biofuel refers to any type of fuel whose energy is derived from plant materials. Biofuel which includes solid biomass, liquid fuels and various biogases is among the most rapidly growing renewable energy technologies in recently. Biofuels are commonly divided into two groups based on the technology maturity which using the terms “conventional” and “advanced” for classification. Conventional biofuel technologies include well-established processes that are already producing biofuels on a commercial scale. These biofuels, commonly referred to as first-generation, include sugar- and starch-based ethanol, oil-crop based biodiesel and straight vegetable oil, as well as biogas derived through anaerobic digestion. First generation biofuel processes are useful but limited in most cases: there is a threshold above which they cannot produce enough biofuel without threatening food supplies and biodiversity. Whereas, advanced biofuel technologies are extensions from conventional technologies which some are still in the research and development (R&D), pilot or demonstration phase and they are commonly referred to as second- or third-generation. This category includes hydrotreated vegetable oil (HVO), which is based on animal fat and plant oil, as well as bioethanol based on lignocellulosic biomass, such as cellulosic-ethanol. Although there are wide varieties of advanced biofuels conversion technologies exists today, but they are not commercially available yet. Nevertheless, the most commercializable technology and most used biofuel on the global market is bioethanol

Comparison Study Between Enzymatic Hydrolysis & Acidolysis Lignins Isolated From Oil Palm Empty Fruit Bunch Pulps

Fundamental research on paper pulp produced from oil palm (Elaeis guineensis) empty fruit bunch (EFB) fiber was carried out in this study to gain better understanding of the residual lignin’s structures. Residual lignin was isolated from EFB chemical pulps which are kraft pulp, soda pulp, kraft-anthraquinone (AQ) pulp and soda-anthraquinone (AQ) pulp. In this study, there are two methods used for the isolation of residual lignin: acidic hydrolysis in dioxane-water 82:18 (v/v) with 0.1M hydrochloric acid (HCl) under reflux and enzymatic hydrolysis by using commercial cellulolytic enzymes in an acetate buffer with pH 4.5 at 45°C under continuous shaking. The time required for enzymatic hydrolysis procedure is much greater than the acidic hydrolysis procedure. Hence, in this experiment, the structures of residual lignin by these two methods are compared. Results showed that the enzymatic hydrolysis procedure gave lignin with higher yield than acidic hydrolysis did. Most of the enzymatic residual lignin could not dissolve in the common testing solvents such as tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), acetone, chloroform and so on whereas the acidolysis residual lignin able to dissolve easily in all the testing solvents. Fourier transform infrared spectroscopy (FTIR) absorption gave almost similar band for both isolated lignin such as OH stretch, CH stretch, S unit, G unit and so on. Besides that, carbon hydrogen nitrogen (CHN) elemental analysis showed higher percentage of nitrogen for the enzymatic residual lignin compared to the acidolysis residual lignin. UV spectroscopy showed that each isolated residual lignin contained different type of phenolic hydroxyl group. Proton nuclear magnetic resonance (ˡHNMR) showed limited signal and information for both isolated lignin due to low concentration. Furthermore, pyrolysis-gas chromatography mass spectrometry (PyGCMS) was carried out to examine the changes in the residual lignin

Investigation Into The Performance Of A Desiccant Cooling System Combined With Chilled Ceiling

The heat generated within a closed space like office has increased drastically in recent years with the optimal use of the heat generated equipment such as computer, and other machines. As air conditioning is an inherently energy intensive process, so there is a need for devising more efficient system that would consume less energy while maintaining very comfortable condition for occupants inside. The desiccant air conditioning combined with chilled ceiling is a new concept of air conditioning system. This technique had been widely used in a number of European countries, however, similar the use of such system has not been reported to date in any humid tropical countries. With the aim of investigating the feasibility of such a system in Malaysian context, a climate chamber [4.25 m (L) ×3.75 m (W) × 2.7 m (H)] has been built in the Fluid Dynamic Laboratory of the Universiti Sains Malaysia wherein a desiccant dehumidifier combined with a chilled ceiling system has been installed. The system uses 100% ventilation air to maintain the freshness of air inside the chamber. The study aims at evaluating the relative performance of the above-mentioned hybrid system compared to conventional air conditioning system. The specific focus is in measuring energy consumption of the whole system. 4 experiments were conducted during the study with simulated heat loads of 0 W/m2, 25 W/m2, 62 W/m2 and 100 W/m2. The initial results show that such system is viable in Malaysia with the possibility of reduction of energy to the tune of 40% compared to the conventional system. However, more studies need to be conducted prior to large scale use

Flow And Turbulence Characteristics Through A Vertical-Axis Wind Turbine Using Eddy Covariance Method

Turbin angin berjenis paksi menegak (VAWT) dipercayai berkesan dalam keadaan kelajuan angin rendah. Objektif kajian ini adalah untuk menilai ciri-ciri pergolakan dan aliran di depan dan belakang VAWT berdasarkan kelajuan aliran yang berbeza, untuk menentukan profil sisi dan menegak bagi di depan dan belakang VAWT, dan untuk menentukan ciri-ciri spektrum pergolakan di aliran belakang VAWT dengan menggunakan kaedah “kovarians eddy” untuk menentukan ciri-ciri aliran dan pergolakan bagi VAWT. Kajian dijalankan di makmal tertutup untuk mengelakkan pembolehubah yang kompleks yang hadir dalam angin di luar. Tiga 26" kipas angin industri yang diatur sebaris boleh beroperasi pada kelajuan berlainan digunakan untuk menjana sumber aliran. Naik turun pergolakan dalam tiga dimensi diukur oleh satu ultrasonik anemometer pada 10 Hz untuk memastikan kebanyakan daripada skala pergolakan dirangkumi. Kajian awal menunjukkan siri masa halaju aliran adalah sama dengan keadaan pergolakan di luar. Vertical-axis wind turbine (VAWT) is claimed to be effective in low wind speed conditions. The objectives of this research are to assess the turbulence and flow characteristics of upwind and wake of a VAWT based on different flow speeds, to determine the lateral and vertical profiles of upwind and in the wake of a VAWT and to determine the spectral characteristics of turbulence in the wake of VAWT using the eddy covariance method. To characterize the flow and obtain direct measurements of turbulence of a VAWT, the experiment is conducted in a controlled indoor laboratory to avoid the complex nature of outdoor wind. The flow source was simulated by three 26" industrial standing fans arranged in a row at different speed settings. The three dimensional flow velocities fluctuations were measured by an ultrasonic anemometer at 10 Hz in order to cover most turbulence scales. A preliminary study showed that the time series of flow velocities were similar to the outdoor turbulence condition

Prediction Of Leaf Mechanical Properties Based On Geometry Features With Data Mining

The leaf mechanical properties are typically determined by mechanical tests to study the leaf‟s lifespan, its anti-herbivore defences and the ecological functions. The influences of habitats, environmental resources such as nutrient, light, and water, and species diversity on the leaf anatomies and their chemical compositions were previously considered. However, the mechanical properties of the leaves from the geometry and morphology aspects are still vague. The main goal of this study is to examine the effect of various geometrical attributes to predict the leaf mechanical properties based on four different indicators using data mining approach. An experimental study involving 20 different species of the terrestrial plants were conducted. A total of 600 x 23 features attributes comprising of leaf geometrical features, discriminant features and its derived quantities were collected by measurements, field observations and the tearing test performed using the Universal Testing Machine (UTM). The recorded data were screened on data normalization while the outliers were discarded prior to regression analysis aided by the Waikato Environment for Knowledge Analysis (WEKA) tool. The leaf mechanical property indicators: Tearing Force (FT), Tearing Strength (ST), Work-to tear (WT), and Specific Work-to-tear (SWT) identified were predefined as the numeric class attribute. The leaf mechanical properties indicators were predicted using the GaussianProcess, LinearRegression, MultilayerPerceptron (MLP), SMOreg, M5P and REPTree algorithms of WEKA tool, verified on Root Relative Squared Error (RRSE) evaluation index. Findings showed that the numerical predictions on FT and ST (RRSE ~ 25%) were about two folds better than the WT and SWT (RRSE ~50%) in the six algorithms tested. The best prediction performance was gained on FT indicator using the M5P algorithm (RRSE = 22.44%). The linear models and rules developed from the M5P algorithm were adopted for the FT indicator prediction modelling of 14 attributes. The „Species‟ attribute contributes the most for the M5P regression model. Findings also indicate that leaf mechanical properties were insufficient to be represented by its geometry features alone. The M5P regression model was further simplified into 9 attributes showing insignificant difference determined on the paired T-test between the RRSE achieved by M5P regression and the simplified model (RRSE = 21.37%)

An innovative modification of the retrograde approach to angioplasty and recanalization of the superficial femoral artery

Endovascular therapy has been performed for chronic limb ischemia since 1964, with intraluminal and subintimal angioplasty of the superficial femoral artery (SFA) gaining popularity in the last decade (1). SFA occlusions can be managed by retrograde contralateral or antegrade ipsilateral approaches (2, 3); when these approaches fail, some practitioners resort to using a re-entry device (4, 5). The retrograde popliteal approach was initially fraught with limitations and served as a backup option (1, 4, 6). However, refinements to this technique have made this an enticing option (2–7), and it has been advocated as a first-line treatment in select patients (3). We herein describe another modification of this method

Look who’s TORking: mTOR-mediated integration of cell status and external signals during limb development and endochondral bone growth

The balance of cell proliferation and size is key for the control of organ development and repair. Moreover, this balance has to be coordinated within tissues and between tissues to achieve robustness in the organ’s pattern and size. The tetrapod limb has been used to study these topics during development and repair, and several conserved pathways have emerged. Among them, mechanistic target of rapamycin (mTOR) signaling, despite being active in several cell types and developmental stages, is one of the least understood in limb development, perhaps because of its multiple potential roles and interactions with other pathways. In the body of this review, we have collated and integrated what is known about the role of mTOR signaling in three aspects of tetrapod limb development: 1) limb outgrowth; 2) chondrocyte differentiation after mesenchymal condensation and 3) endochondral ossification-driven longitudinal bone growth. We conclude that, given its ability to interact with the most common signaling pathways, its presence in multiple cell types, and its ability to influence cell proliferation, size and differentiation, the mTOR pathway is a critical integrator of external stimuli and internal status, coordinating developmental transitions as complex as those taking place during limb development. This suggests that the study of the signaling pathways and transcription factors involved in limb patterning, morphogenesis and growth could benefit from probing the interaction of these pathways with mTOR components

Torrefaction treatment on fuel properties of bambusa vulgaris and Gigantochloa scorthecinii

There is a great potential for bamboo to be applied as a biofuel for the future due to its good fuel properties with low alkali index and fast growth rate. Torrefaction treatment can increase the fuel quality of biomass in terms of the calorific value, energy density and storability. The aim of this research was to explore the effect of torrefaction temperature and reaction time on the fuel properties of B. vulgaris and G. scorthecinii. The bamboos were treated at varioustorre faction temperatures (200, 250 and 300 ̊C) and reaction time (15, 30, 45 mins). In overall, the highest higher heatingvalue was obtained from bamboos torrefied at 300ºC for 45 mins. In general, the temperature used in torrefaction has a relatively stronger effect on the higher heating value while the impact of the residence time was considerably lesser

Selective Harmonic Elimination Pulse Width Modulation for Five-Level Cascaded Inverter

This paper presents an efficient selective harmonics elimination method for a five-level cascaded inverter by using the Newton-Raphson method. The aim of this project is to eliminate selected low-order harmonics by solving non-linear equations using the programming developed based on NewtonRaphson method. Meanwhile, at the same time, the fundamental component is retained efficiently. Instead of single switching, multiple switching in quarter cycles has been introduced to increase the number of harmonic orders that should be eliminated. In addition, the low-order harmonics up to the 5th order for single switching and 17th order for multiple switching are eliminated from the inverter output voltage waveform for entire modulation index. The calculated switching angles have been inserted into the simulation model of the five-level inverter by using PSIM software. Moreover, the calculated switching angles for single and multiple switching are then tested by using a prototype of a five-level inverter that has been built in the laboratory. The simulation results are verified with the experimental results for single and multiple switching