Uditha's Blog

Android

2010-09-22T01:32:00.000-07:00

Android is a mobile operating system developed by Google and is based upon a modified version of the Linux kernel. It was initially developed by Android Inc. (a firm purchased by Google) and later positioned in the Open Handset Alliance. According to NPD Group, unit sales for Android OS smartphones ranked first among all smartphone OS handsets sold in the U.S. in the second quarter of 2010, at 33%. BlackBerry OS is second at 28%, and iOS is ranked third with 22%.

Android has a large community of developers writing application programs ("apps") that extend the functionality of the devices. There are currently over 70,000 apps available for Android with some estimates saying 100,000 have been submitted, which makes it the second most popular mobile development environment. Developers write managed code in the Java language, controlling the device via Google-developed Java libraries.

The unveiling of the Android distribution on 5 November 2007 was announced with the founding of the Open Handset Alliance, a consortium of 78hardware, software, and telecom companies devoted to advancing open standards for mobile devices. Google released most of the Android code under the Apache License, a free software and open source license.

The Android operating system software stack consists of Java applications running on a Java based object oriented application framework on top of Java core libraries running on a Dalvik virtual machine featuring JIT compilation. Libraries written in C include the surface manager, OpenCore media framework, SQLite relational database management system, OpenGL ES 2.0 3D graphics API, WebKit layout engine, SGL graphics engine, SSL, andBionic libc. The Android operating system consists of 12 million lines of code including 3 million lines of XML, 2.8 million lines of C, 2.1 million lines ofJava, and 1.75 million lines of C++.

Blackberry Curve

2009-08-26T03:25:00.000-07:00

The Blackberry Curve 8310 and 8320 are the newest smartphones in the Blackberry portfolio. Both offer dynamic satellite navigation and impressive mobile multimedia communications. With email, Internet, GPS and a 3 megapixel camera, the Curve is a device that will impress both the business savvy and general consumer. Its feature rich applications, email communications and 3G Internet capabilities are flawless, and the GPS connectivity is hugely impressive, offering precise location pickup, signal strength, and satellite navigation.

The Curve 8310 also delivers an exceptional interface which makes this an impressive device for the road warrior, those who use the underground / subway, or frequently visit back waters. Menu navigation is slick, the full QWERTY keyboard is easy to operate, and applications launch with neat precision. The Blackberry Curve also looks and feels the part, housing an impressive screen that projects brilliant imagery both inside and outdoors.

High-Fibre Banana Powder.

2009-07-11T06:16:00.000-07:00

The researchers applied starch liquefaction to eliminate the high starch content present in the fruit and thereby produce a fibre-rich powder capable of being formulated in a variety of diverse functional foods.

Using commercial unripe (hard green) bananas, the liquefied slurry was then mixed with an alpha-amylase enzyme for three hours. After this time, the enzyme was inactivated, and the material centrifuged and dried to obtain the fibre-rich powder.

Compared to normal banana flour, the researchers report that the fibre-rich powder of banana flour contained 200 per cent more total dietary fibre, 32 per cent less starch, 88 per cent less resistant starch, and 32 per cent less available starch.

Moreover, the insoluble indigestible fraction was higher in the fibre-rich powder, compared to the plain banana flour (61 versus 44 grams, respectively).

The researchers also report that the powder contained high levels of extractable polyphenols that exhibited antioxidant activity similar to that of apple fibre

"A very fast reduction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was observed in the presence of fibre-rich powder (FRP), indicating that polyphenols in this preparation efficiently quench free radicals," they wrote.

"FRP might be a potential ingredient for development of products with high total dietary fibre and indigestible fraction contents, as well as important antioxidant capacity," they concluded.

Only recently, researchers from Nova Scotia Agricultural College in Canada reported that apple skin, an under-utilised food-processing by-product, could offer the food industry a novel and healthy-boosting source of fibre for bakery.

Incorporation of apple skin powder into muffins were found to be higher in fibre and have a higher antioxidant content than standard muffins, they reported in Food Chemistry.

Insoluble fibre contains cellulose, hemicellulose and lignin and cannot be dissolved in water, unlike soluble fibre. It is found in wheat or cereal bran and in most vegetables and fruits.

Consumption of insoluble fibre has previously been associated with a reduced risk of obesity and diabetes.

Product Description

Banana powder processing line, the craft procedure:

1. Raw material chosen
2. Color protection
3. Pulping
4. Homogenizer
5. Heating
6. Spray and drying
7. Packaging
8. Finished products

Banana Paper

2009-07-06T07:48:00.000-07:00

Banana paper is used in two different senses: to refer to a paper made from the bark of the banana plant, mainly used for artistic purposes, or paper made from banana fiber, obtained from an industrialized process, from the stem and the non utilizable fruits. This paper can be either hand-made or made by industrialized machine.

The banana agro-industry processes each year 42 million tons of bananas with 20,000 square kilometres planted.This industry generates numerous wastes such as: the plastic that wrap the bananas, plastic cords to tie the wrapping, damaged bananas and the pinzote (stems). An alarming quantity of over 10 million metric Tons of pinzote is thrown in landfills or even worse in local rivers. The pinzote is composed 92% of water, 3% of resins and 2% glucose, the rest is vegetal fiber. This particular composition makes it decompose with the solid component not getting destroyed. This causes a severe impact on the surrounding ecosystems, the detriment of river sand underground waters, also the massive reproduction of flies and nauseous smells. Agro-industrial fibers come from the waste of processing common agricultural products.

Firetube Boiler Technology

2009-04-22T09:39:00.000-07:00

Introduction

Boilers are used to turn the energy originating from a combustion process to usable heat and/or power. If electrical power is required, the boiler will produce steam (or an organic vapour if the working fluid is not water) which will undergo a thermodynamic cycle and power a turbine coupled to a generator. If only heat is required, steam (organic vapour) generation is not necessary and hot water production will be sufficient. This is the case when it comes to small-scale heating. Therefore, only hot water boilers will be dealt with here.

Two main boiler technologies are currently available on the market: watertube and firetube boilers. In watertube boilers, the water is heated by circulating in tubes around which the hot combustion gases flow. In firetube boilers, the hot combustion gases flow through tubes immersed in a tank filled (or partly filled if steam generation is required) with water.

Very large boilers with high ratings usually involve high water temperatures and pressures. Given these operating conditions, watertube designs are more convenient since only the water tubes should be designed to withstand such high pressures and temperatures. At lower power, firetubes designs are usually cheaper. If the output of the boiler does not exceed 20 MW and the pressure 20 bars which is the case for this feasibility study, a firetube boiler is the most adapted technology.

Description of the firetube boiler technology

1.The Furnace

In a firetube boiler, the combustion takes place in the furnace. This furnace, usually cylindrical, can either be covered with refractory material like ceramic (dryback furnace) or be in contact with the boiler's water (wetback furnace) which significantly increases the heat-exchange surface. The end of the furnace is called the reversal chamber since the hot gases make a U-turn and are fed into the first tube-pass. At the end of the reversal chamber, the gas' temperature must be sufficiently low to avoid excessive thermal stress on the tubes. The reversal chamber may be equipped with a drain to collect the water condensing on its sides (the hot combustion gas usually contain a fraction of water vapour). Even though the furnace and the reversal chamber only represent 10% of the exchange surface, they account for 40-50% of the heat exchange (mainly through radiation) given the very high gas temperatures. Some biomass boilers include two furnaces to make sure that the combustion is as complete as possible. In this case, a secondary air supply must be included in the design of the boiler.

2. The Tube Passes

The first tube-pass is entirely immersed in the water and goes from one end of the boiler to the other. Depending on the boiler's design there might be a second tube-pass (also fully immersed) in which case the boiler is called a "three pass" model (since the furnace is counted as the first pass). The diameter of the tubes has an important impact on the heat recovery performance. Clearly, for the same overall cross-section, a number of narrow tubes will be more efficient than one large tube since the heat exchange surface will be much greater. However, this multi-tube layout will be more expensive and small tubes are more likely to be blocked so maintenance costs will also be greater. The heat-exchange takes place mainly through a convective process with a limiting heat resistance on the dry side of the tubes.

3. Combustion Gas Circulation

Firetube boilers represent a significant resistance to gas flow: the combustion gas circulation is made possible by the use of a fan. Typically, pressure losses are low in the furnace given its large cross section but are significant in the reversal chambers (the gas undergoes a U-turn) and in the tube passes (large gas velocity). The so-called "draught loss" must be calculated (many correlations are available in the literature) and the fan power deduced.

4. The Water Tank

Contrary to firetube boilers designed for steam generation where a steam disengagement surface must be provided, the water tank of hot water firetube boilers is completely filled with water.

Typical firetube boiler

1. Furnace

2. Reversal chamber

3. Second tube pass

4. Front smoke box

5. Third tube pass

6. Gas outlet

Nanotechnology

2009-02-26T07:16:00.000-08:00

Nanotechnology, which is sometimes shortened to "Nanotech", refers to a field whose theme is the control of matter on anatomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller, and involves developing materials or devices within that size.

Nanotechnology is extremely diverse, ranging from novel extensions of conventional device physics, to completely new approaches based upon molecular self-assembly, to developing new materials with dimensions on the nanoscale, even to speculation on whether we can directly control matter on the atomic scale.

There has been much debate on the future of implications of nanotechnology. Nanotechnology has the potential to create many new materials and devices with wide-ranging applications, such as in medicine, electronics, and energy production. On the other hand, nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.

One nanometer (nm) is one billionth, or 10^-9, of a meter. By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12-0.15 nm, and a DNA double-helix has a diameter around 2 nm. On the other hand, the smallest cellular lifeforms, the bacteria of the genus Mycoplasma, are around 200 nm in length.

To put that scale in another context, the comparative size of a nanometer to a meter is the same as that of a marble to the size of the earth. Or another way of putting it: a nanometer is the amount a man's beard grows in the time it takes him to raise the razor to his face.

Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control.

History of Java

2009-02-03T20:16:00.000-08:00

James Gosling initiated the Java language project in June 1991 for use in one of his many set-top box projects. The language, initially called Oak after an oak tree that stood outside Gosling's office, also went by the name Green and ended up later renamed as Java, from a list of random words. Gosling aimed to implement a virtual machine and a language that had a familiar C/C++ style of notation.

Sun released the first public implementation as Java 1.0 in 1995. It promised "Write Once, Run Anywhere" (WORA), providing no-cost run-times on popular platforms. Fairly secure and featuring configurable security, it allowed network- and file-access restrictions. Major web browsers soon incorporated the ability to run secure Java applets within web pages, and Java quickly became popular. With the advent of Java 2 (released initially as J2SE 1.2 in December 1998), new versions had multiple configurations built for different types of platforms. For example, J2EEtargeted enterprise applications and the greatly stripped-down version J2ME for mobile applications. J2SE designated the Standard Edition. In 2006, for marketing purposes, Sun renamed new J2 versions as Java EE, Java ME, and Java SE, respectively.

In 1997, Sun Microsystems approached the ISO/IEC JTC1 standards body and later the Ecma International to formalize Java, but it soon withdrew from the process. Java remains a de facto standard, controlled through the Java Community Process. At one time, Sun made most of its Java implementations available without charge, despite their proprietary software status. Sun generated revenue from Java through the selling of licenses for specialized products such as the Java Enterprise System. Sun distinguishes between its Software Development Kit (SDK) and Runtime Environment (JRE) (a subset of the SDK); the primary distinction involves the JRE's lack of the compiler, utility programs, and header files.

On 13 November 2006, Sun released much of Java as free and open source software under the terms of the GNU General Public License (GPL). On 8 May 2007 Sun finished the process, making all of Java's core code free and open-source, aside from a small portion of code to which Sun did not hold the copyright.

JavaME

2009-01-19T06:10:00.001-08:00

An Introduction about JavaME......

In computing, the Java Platform, Micro Edition or Java ME (still commonly referred to by its previous name: Java 2 Platform, Micro Edition or J2ME) is a specification of a subset of the Java platform aimed at providing a certified collection of Java APIs for the development of software for tiny, small and resource-constrained devices based on microcontrollers such as ARM7, ARM9, AVR32, ... Target devices are from many industries: Home appliances, Security, Defense, Automotive, Industrial, Handsets, Industrial Control, Multimedia, Communication, ... cell phones , PDAs and set-top boxes are some well known samples.

Java ME was designed by Sun Microsystems and is a replacement for a similar technology, PersonalJava. Originally developed under the Java Community Process as JSR 68, the different flavors of Java ME have evolved in separate JSRs. Sun provides a reference implementation of the specification, but has tended not to provide free binary implementations of its Java ME runtime environment for mobile devices, rather relying on third parties to provide their own.

As of 22 December 2006, the Java ME source code is licensed under the GNU General Public License, and is released under the project name phoneME.

As of 2008, all Java ME platforms, even up to BD-J, are currently restricted to JRE 1.3 features and uses that version of the class file format (internally known as version 47.0). Should Sun ever declare a new round of Java ME configuration versions that support the later class file formats and language features, such as those corresponding JRE 1.5 or 1.6 (notably, generics), it will entail extra work on the part of all platform vendors to update their JREs.

What is Chemical Engineering....?

2009-01-16T20:17:00.000-08:00

Chemical engineering is the branch of engineering that deals with the application of physical science (e.g. Chemistry and physics), with mathematics, to the process of converting raw materials or chemicals into more useful or valuable forms. In addition to producing useful materials, chemical engineering is also concerned with pioneering valuable new materials and techniques, an important form of research and development. A person employed in this field is called a chemical engineer.

Chemical engineering largely involves the design and maintenance of chemical processes for large-scale manufacture. Chemical engineers in this branch are usually employed under the title of process engineer.

Applications

Chemical engineering is applied in the manufacture of a wide variety of products. The chemical industry proper manufactures inorganic and organic industrial chemicals, ceramics, fuels and petrochemicals, agrochemicals (fertilizers, insecticides, herbicides), plastics and elastomers, oleochemicals, explosives, detergents and detergent products (soap, shampoo, cleaning fluids), fragrances and flavors, additives, dietary supplements and pharmaceuticals. Closely allied or overlapping disciplines include wood processing, food processing, environmental technology, and the engineering of petroleum, glass, paints and other coatings, inks, sealants and adhesives.