Introduction to IPv6

Size of IPv4 is 32-bits only, while IPv6 is 128-bits and it is represented in hexadecimal numbers in the form of X.X.X.X.X.X.X.X which X consists of 16-bit value. Example expression of IPv6 is 2000:0000:1234:ABCD:0000:0000:FACE:00006. This can be written as 2000:0:1234:ABCD:0:0:FACE:0006 or simplified to 2000::1234:ABCD:::FACE:6. If we find the address is 2000::A, it is also can be written as 2000:0:0:0:0:0:0:000A.

            Let’s take a look at this example of CIDR X:X:X:X:X:X:X:X/64. It means that the network is 64-bit, and we can calculate like Figure 1, and hence we get N.N.N.N.H.H.H.H. IPv6 does not have broadcast and network address translation (NAT). However, similar to IPv4, IPv6 has unicast and multicast. IPv6 is faster because of no broadcast. It can access anywhere, and everyone gets public IP. The differences between IPv4 and IPv6 are summarized in Table 1. We will discuss further the range of global unicast, link-local and multicast in the next volume.

Figure 1 CIDR in IPv6

Table 1 IPv4 vs IPv6

IPv4	IPv6
32-bit (decimal)	128-bit (hexadecimal)
Public IP	Global unicast 2000::/3
Private IP	Link local FE80::/10
Loopback 127.0.0.0 => 127.255.255.255	::1
Multicast 224-239	Multicast FF00::/8

IPv6 can be anycast i.e. one to nearest. Same IPv6 can be assigned to many hosts. Refer to the Figure 2, if we are in Malaysia and we do not have the server in Malaysia, we can anycast to the nearest, and it is Singapore server.

Figure 2 IPv6 anycast

Reference: CCNAX Training Materials

Written by SIti Sara Rais

The Untold Story in the Management of Diabetes Mellitus

Written by: Dr. Nur Syukriah Ab Rahman

Diabetes mellitus (DM) is one of the most important metabolic disease that hit the globe in the present millennium. It has been listed as one of the five leading cause of deaths and approximately six death per minute are associated to DM complications [1]. The report from National Health and Morbidity Surveys shown that there is an increasing trend in the recorded prevalence of DM for the past decades and surprisingly the overall prevalence of DM has been increased by more than doubled from 1996 to 2015 in Malaysia [2].

The earliest history recorded in the treatments of DM involved the use of plants. Metformin is one of the oral diabetic drug that is widely prescribed by the medical practitioner nowadays which is originated from the use of Galega officinalis (G. officinalis) Linn as herbal medicine in primitive Europe [3]. G. officinalis is a perennial herb with blue, white or purple flowers which is commonly found in most temperate regions and grows over three feet high.

Herbal medicine is one of the subcategories of complementary and alternative medicinal (CAM) therapies. Most of the people favor CAM over conventional therapies due to unsatisfied outcomes such as adverse side effects and higher treatment cost. Synacinn^TM  is a polyherbal formulations that consist of five herbal medicine including Cinnamomun zeylanicum, Curcuma xanthorrhiza, Syzygium polyanthum, Orthosiphon stamineus and Andrographis paniculata and has been standardized against catechin, curcumin, gallic acid, rosmarinic acid and andrographolide respectively. It is believed that each herbal present in Synacinn^TM could act through intelligent network that could produce synergistic effects to remediate DM conditions. In addition, the existing literatures and testimonials suggest promising venue for Synacinn^TM to be scientifically validated and developed as an alternative drug in the management of DM.

The scientific research on the development of Synacinn^TM as herbal medicine in the management of DM is still in progress and a group of researchers from UMT and UTM have put their blood and tears on this development. As for now, Synacinn^TM is already available on the market for example Shoppe, Lazada or can be directly purchased from NatureMedic Laboratories Sdn Bhd. It is hoped that we one fine day we found the cure for this disease.

References:

[1] Li, H., Wu, X., Davey, A. K., & Wang, J. (2011). Antihyperglycemic Effects of Baicalin on Streptozotocin–Nicotinamide Induced Diabetic Rats. Phytotherapy Research, 25(2), 189–194.

[2] Tee, E.-S., & Yap, R. W. K. (2017). Type 2 Diabetes Mellitus in Malaysia: Current Trends and Risk Factors. European Journal of Clinical Nutrition, 71(7), 844–849. https://doi.org/10.1038/ejcn.2017.44

[3] Bailey, C. J., & Day, C. (1989). Traditional Plant Medicines as Treatments for Diabetes. Diabetes Care, 12(8), 553–564. https://doi.org/10.2337/diacare.12.8.553

Physics Law in washing machine design

Written by Siti Aishah Che Kar and Syila Izawana Ismail

Nowadays, washing machine is one of the must-have household equipments. But how does the smart machine spin and drain all the water from our clothes? Or what is actually happening during the spinning process? Here comes the scientific explanation. Centrifuge is the word or term that is used to describe the whole process. You can do a very simple experiment at home to understand the centrifuge phenomenon. Take wet clothes and turn the clothes while holding them. You can see the excess water sparking out from the wet clothes. Actually the clothes spin in circle because you force it but the water trapped in clothes retains to move in straight line. Thus the water will fly out from the wet clothes and automatically the clothes will be drier than before. [1]

Thus this concept is applied in the washing machine process. After the rinsing process, the washing machine will be in drain mode automatically where a pump is used to drain all the excess water. Then, the spin mode will take over. In top loader washing machine, the agitator which is a large plastic at the bottom of the drum will spin while in the front loader washing machine, the drum itself will spin. The drum is actually like a big basin that holds our clothes. Usually each washing machine contains two drums which are the inner drum and the outer drum. The clothes are forced to move in circle because the inner drum is spinning but the excess water in clothes still goes straight, turning into water drop. The water drop is small enough to pass through the drum’s tiny holes into the outer drum. This phenomenon is actually relevant to the Isaac’s most famous laws of motion. The First Law of motion states, “A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force.” This simply means that things cannot start, stop, or change direction all by themselves. It takes some force acting on them from the outside to cause such a change [2].

The centrifuge concept is well used in many applications especially in science laboratory as centrifuges to separate things like component in blood or any substances in liquid form. The blood sample will be spin at high speed using centrifuge to separate the blood cell such as plasma and red blood cells. NASA also uses centrifuge concept for testing their astronauts and pilots in psychology test by using human centrifuges to test whether the astronauts are fit for the space ship [3].

References:

[1] http://www.explainthatstuff.com/centrifuges.html

[2] https://www.livescience.com/46558-laws-of-motion.html

[3] https://en.wikipedia.org/wiki/Astronaut_training

Systematic Guideline for Safety Assessment based on Process Information

Written by: Muhammad Firdaus Husin

In chemical engineering, one of the targets of the process design is the creation or modification of flow diagrams capable of manufacturing the desired chemical. It is also essential to consider safety aspects when designing any new process or in the case of retrofitting. As a result, several methods have been introduced for safety assessment during process design phase [1]. To date, there are lacks of guideline in selecting an appropriate method for him/her based data availability, target of assessment and budget constraints. To fill in this gap, a heuristic framework are designed for assisting users in conducting safety assessment during chemical process design.

Figure 1 shows a summary of designing framework for process safety assessment in chemical process design methods and their strategies for minimization of hazards or risks which are based on inherent safer design (ISD) keywords [2]. For all methods, the calculated index or risk values and hazards will be compared with the respective benchmark. If the value of calculated index or risk is not acceptable, four ISD keywords (minimization, substitution, moderation and simplification) are taken-over to reduce or eliminate the hazard as much as possible. Finally, the re-assessment of hazards can be performed until the index values and all hazards are at acceptable range. The frameworks shall serve as a great help for engineers to select appropriate method for safety assessment based on the availability of process information during the chemical process design. Instead of assessing the safety level of process design phase, this framework can also be used to analyse the root of the safety problems and recommend the possible solutions.

References

 [1] Khan, F. I. and Abbasi, S. A. (1998c). Techniques and methodologies for risk analysis in chemical process industries. Journal of Loss Prevention in the Process Industries, 11(4), 261-277.

[2] Kletz, T. A. (1991). Plant Design for Safety : User-friendly Approach.

Pulsed lasers: Q-switched and Mode-locked techniques

Written by: Dr Baktiar Musa, Suziana Omar, Ir. Dr. Zulzilawati Jusoh and Norizan Ahmed

This article tries to explain about our research on Q-switched and mode-locked lasers. We begin with the definition of laser first, LASER is actually an acronym for Light Amplification by Stimulated Emission of Radiation. Historically, the first laser was realized in 1960 at Hughes Research Laboratories by Theodore H. Maiman following the theoretical work by Charles Hard Townes and Arthur Leonard Schawlow [1].

In order to understand how pulsed lasers work, we need to revisit our fundamental knowledge in physics. But explaining all those fundamentals can be tiresome, so here we just focused on differentiating pulsed laser and continuous wave (CW). CW refers to a laser that is continuously pumped and continuously emits light. The emission can occur in a single resonator mode or on multiple modes. An example of CW laser is CO₂, where initially the gas is ionized to the threshold level and then by using pulse width modulation (PWM), the laser output can be controlled. For comparison, CO₂ molecules readily lase at 10.6 µm, while neodymium-based crystals (like YAG or vanadate) produce wavelengths in the range between 1047 and 1064 nm. Each laser wavelength is associated with a linewidth, which depends on several factors: the gain bandwidth of the lasing medium and the design of the optical resonator [2]. On the other hand, a pulsed laser operates in such a way that all of its energy is dumped out in a single pulse which normally lasts from picoseconds to few nanoseconds. After that the laser output goes to zero. Again, the pulse appears at the output. This switching is done by Q switch.

Two commonly used techniques employed in producing pulsed lasers are Q-switching and mode-locking. A Q-switched laser is a laser to which the technique of active or passive Q switching is applied, so that it emits energetic pulses [3]. Typical applications of such lasers are material processing (e.g. cutting, drilling, laser marking), pumping nonlinear frequency conversion devices, range finding, and remote sensing. Q-switching technique allows the production of light pulses with extremely high (gigawatt) peak power, much higher than would be produced by the same laser if it were operating in a CW mode. Using mode-locking technique, the laser output will be pulses of light of extremely short duration, on the order of picoseconds (10⁻¹² s) or femtoseconds (10⁻¹⁵ s). Here, the laser resonator contains some kind of mode locking device – either an active element (an optical modulator) or a nonlinear passive element (a saturable absorber), which causes the formation of an ultrashort pulse circulating in the laser resonator [4]. In terms of repetition rates and pulsed durations, Q-switched lasers showed lower values compared to ones produced by using mode-locking technique.  Depending on the applications, sometimes the techniques are used together to produce pulsed lasers.

For generation of pulsed laser, a passive mode-lockers are preferred due to their simpler configuration and thus far, a variety type of saturable absorber (SA) have been proposed [3-6]. Our research focused on finding and exploring new materials that are suitable as saturable absorbers. Previously, carbon materials such as carbon nanotubes (CNTs) and graphene show promising performances as saturable absorber to achieve mode-locking in fiber lasers [5, 6]. It offers characteristics such as ultrafast recovery time and capable to achieve broadband operation. Recently, numerous novel 2D materials such as topological insulators [8,9], transition metal dichalcogenide (TMD), black phosphorus, MXene, bismuthene, metal-organic frame-works, and perovskite have demonstrated broad-band optical nonlinearities [7]. The properties of these saturable absorbers will be discussed in the next article.

1.     https://en.wikipedia.org/wiki/Laser

2.     https://www.photonics.com/Articles/Lasers_Understanding_the_Basics/a25161

3.     https://www.rp-photonics.com/q_switched_lasers.html

4.     https://www.rp-photonics.com/mode_locking.html

5.     Luo Z, Liu C, Huang Y, Wu D, Wu J, Xu H, Cai Z, Lin Z, Sun L and Weng J.  IEEE Journal of Selected Topics in Quantum Electronics 20 1-8 (2014)

6.     Bao Q, Zhang H, Wang Y, Ni Z, Yan Y, Shen Z X, Loh K P and Tang D Y.  Advanced Functional Materials 19 3077-83 (2009)

Li, L., Lv, R., Chen, Z. et al. Nanoscale Res Lett 14, 59 (2019)

Colour Development of Green Coffee Bean during Batch Roasting in Fluidized Bed Roaster

(By: Mohamad Taib Miskon & Nurul ‘Uyun Ahmad)

“While enjoying a cup of an aromatic, astonishing, hot and refreshing coffee drink.”

Roasting has been one of the most important step in a coffee production as it transforms the tasteless green coffee bean into a delicious cup of Joe. It is an act of introducing an amount of heat to a batch of green coffee bean to trigger complex chemical reaction [1] as well as colour and physical change [2]. There are various types of coffee roasting methods such as using the traditional hot pan, drum roaster and fluidized bed or hot air roaster.

This article presented the colour development of green Ethiopian coffee bean during roasting in a Fresh Roast SR500 coffee roaster with Artisan Roaster Scope. Figure 1.0 depicted the colour changes of the bean over temperature progression during the roasting process. The process took about 15 minutes and it can be divided into six key stages;

Stage 1: Drying (at minutes: 0 – 2.15)

The roasting process started with the bean temperature at 33°C and it endured the drying phase for about 2.15 minutes as the beans’ colour changed from green to yellow. During this stage, the beans were absorbing heat from the hot air or also known as an endothermic process. 

Stage 2: Yellowing (at minutes: 2.15 – 6.33)

At this stage, more water was removed from the bean and the bean colour was changing from yellow to brown. The size of the bean was also expanding rapidly due to the build-up of gas pressure inside the bean [3].

Stage 3: First Crack (at minutes: 6.33 minutes)

The first crack was determined by the audible popping sound, indicating the beginning of the beans’ exothermic reaction.

Stage 4: Roast development (at minutes: 6.33-9.09)

At this stage, the beans’ flavour and sweetness started to develop [4] and the process continued for about 3 minutes.

Stage 5: Second Crack (at minutes: 9.27)

The second crack occurred at minutes of 9.27 and the heater was turned off shortly after to allow the execution of the cooling phase.

At this stage, the bean experienced the second crack whereby the oil’s bean were encapsulated to the surface of the bean. The bean produced was less acidic, smoky yet aromatic, and the authentic flavour has developed.

Stage 6: Cooling (at minutes: 9.36-15.00)

The bean must be cooled quickly to stop the roasting process.

[1]       A. N. Gloess et al., “Evidence of Different Flavour Formation Dynamics By Roasting Coffee From Different Origins: On-Line Analysis With PTR-ToF-MS,” Int. J. Mass Spectrom., vol. 365–366, pp. 324–337, 2014.

[2]       J. Daniel Bustos-Vanegas et al., “Developing Predictive Models For Determining Physical Properties of Coffee Beans During The Roasting Process Kinetic Charcoal Cooling: Computer Simulation and Technological Applications View Project Harvest Process View Project Developing Predictive Models For Determining Physical Properties Of Coffee Beans During The Roasting Process,” Ind. Crop. Prod., vol. 112, pp. 839–845, 2018.

[3]       R. Eggers and A. Pietsch, “Technology I: Roasting,” Coffee Recent Dev., pp. 90–107, 2008.

[4]       L. Poisson, I. Blank, A. Dunkel, and T. Hofmann, The Chemistry of Roasting-Decoding Flavor Formation. Elsevier Inc., 2017.

Overview of Protein Structure Prediction

 Written by: Fatahiya Mohamed Tap

Based on structural perspective, protein is an ordered structure of the unique linear chain of amino acids.  The tertiary structure of protein is represented by the distribution of secondary structures.  The secondary structure is defined by the presence of hydrogen bond patterns between hydrogen atoms of the amino acid and the oxygen atom of the carboxyl groups in the polypeptide chain.  The functional properties of the protein can be determined from the known tertiary structure of the protein.  Thus, the generation of this tertiary structure is vital in understanding the functional and structural properties of a protein.

Structural bioinformatics is an important area in the field of computational biology.  It focuses on the prediction and analyses of structures which are mainly protein and DNA [1]  Conventionally, the tertiary structure information of protein is obtained through experimental methods such as protein crystallography (X-ray diffraction), and nuclear magnetic resonance (NMR).  The structures obtained from these methods can be further used to investigate the protein folds, evolution, and structure-function relationship.

However, the determination of protein structure through experimental approach is expensive and time-consuming [1].  The difficulty in finding the structure of a protein has generated a large gap between the number of sequences of amino acids and the number of tertiary structures of proteins.  Only a small number of amino acid sequences have their tertiary structures solved using the experimental method.  Thus, this gap motivated the researchers to predict the tertiary structure of proteins using computational approaches [2].  Computational approaches are fast and non-expensive compared to the experimental approaches.  Thus, several computational methods have been developed in order to predict the tertiary structure of proteins.  These methods are:

i           Homology modelling/Comparative modelling

ii          Fold recognition

iii         Ab initio

The threading and comparative modelling methods are the fastest and effective approaches in predicting the structure of protein because these two methods are based on known template structures with the availability of fold library [3], [4].  These methods can predict the tertiary structures of proteins with high accuracy. The models can be applied in the field of drug design, virtual screening and site-directed mutagenesis [5].

References

[1]       M. Dorn, M. B. e Silva, L. S. Buriol, and L. C. Lamb, “Three-dimensional protein structure prediction: Methods and computational strategies,” Comput. Biol. Chem., vol. 53, no. Part B, pp. 251–276, 2014.

[2]       H. Deng, Y. Jia, and Y. Zhang, “Protein structure prediction,” Int. J. Mod. physics. B, vol. 32, no. 18, p. 1840009, Jul. 2018.

[3]       V. K. Vyas, R. D. Ukawala, M. Ghate, and C. Chintha, “Homology Modeling a Fast Tool for Drug Discovery: Current Perspectives,” Indian J. Pharm. Sci., vol. 74, no. 1, pp. 1–17, Jun. 2012.

[4]       S. D. Lam, S. Das, I. Sillitoe, and C. Orengo, “An overview of comparative modelling and resources dedicated to large-scale modelling of genome sequences,” Acta Crystallogr. Sect. D, Struct. Biol., vol. 73, no. Pt 8, pp. 628–640, Aug. 2017.

[5]       T. Schmidt, A. Bergner, and T. Schwede, “Modelling three-dimensional protein structures for applications in drug design,” Drug Discov. Today, vol. 19, no. 7, pp. 890–897, Jul. 2014.

WHAT ARE THE COMPONENTS INSIDE FERTILIZER?

Written by Shaiful Bakhtiar Hashim, Norhidayatul Hikmee Mahzan, Dr Sukreen Hana Herman, Dr Zurita Zulkifli.

Agriculture is an important sector in Malaysia. For many years, this sector has been the backbone of Malaysian economy by producing agricultural products for domestic consumption, as the earner of foreign exchange. Agriculture also contributes to the national Gross Domestic Products (GDP). It provides major employment for the people, especially from the rural areas.

Fertilizer is a component applied to the soil or plant in order to add more plant nutrients essential for growth of the plant. The good productivity of crops is directly dependent on soil fertility. Basically, Nitrogen (N), phosphorus (P) and potassium (K) are the macronutrients present in all fertilizers and represent the most important nutrients in agriculture. N, P and K elements in fertilizer is a complex comprised primarily of the [i]three primary nutrients which is required for healthy plant growth.

These three elements nutrients promote the growth of the plant in different ways which N promotes the growth of leaves and vegetation, P promotes root and growth and K promotes flowering, fruiting and keeps regulation of nutrient and water in plant cell. To improve the quality and quantity of crops and to get a good crop, one of the important things that the land or soil has is an adequate fertilizer and also contain sufficient nutrients.

Soils that lack of these three nutrients, either naturally or because of cultivation will affect the plant growth. In cases where soils are lacking, nutrients must be put back into the soil in order to create the ideal environment for optimal plant growth. Each of the primary nutrients is essential in plant nutrition, serving a critical role in the growth, development, and reproduction of the plant.

In agricultural technology, a variety of tools have been created to help farmers make their agricultural activities and get a good crop. Previous researchers have developed detection of N, P and K devices in soil from various methods, including optical, acoustic, electrical and electromagnetic, mechanical and electrochemical [1-3].

References

[1]    M. Y. Kulkarni, K. K. Warhade, and S. Bahekar, “Primary Nutrients Determination in the Soil Using UV Spectroscopy,” Int. J. Emerg. Eng. Res. Technol., vol. 2, no. 2, pp. 198–204, 2014.

[2]    M. Joly, L. Mazenq, M. Marlet, P. Temple-Boyer, C. Durieu, and J. Launay, “All-solid-state multimodal probe based on ISFET electrochemical microsensors for in-situ soil nutrients monitoring in agriculture,” TRANSDUCERS 2017 - 19th Int. Conf. Solid-State Sensors, Actuators Microsystems, vol. 1, no. 10, pp. 222–225, 2017.

[3]    M. A. Ali, K. Mondal, Y. Wang, N. K. Mahal, M. J. Castellano, and L. Dong, “Microfluidic detection of soil nitrate ions using novel electrochemical foam electrode,” Proc. IEEE Int. Conf. Micro Electro Mech. Syst., pp. 482–485, 2017.

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