Monday, 30 January 2017

Ballpoint pens are are not recycled, use pens that can be refilled with ink

Throwaway ballpoint pens pose a serious environment problem. Billions are used and thrown away every year. These pens, and refills, are not recycled since it is difficult to separate the metal nib and ink from the plastic.

It isn't a secret that the ballpoint pen is the most popular type of pen. It uses a thick, oil-based ink that is dissolved in alcohol. As soon as you write, the alcohol evaporates, and so the ink dries up quickly. The ink does not bleed through paper and lasts long. But since the ink is thicker, the pen must be pressed harder on paper leading to greater stress on the hand and slower writing.

Fountain Pen


An environment-friendly alternative to ballpoint pen is the fountain pen - it is commonly available too. Some kids may find it difficult to write with the traditional nib since its angle with the paper must remain the same to ensure smooth writing. To get around this, use fountain pens that have roller balls at the tip instead of nibs. (Ballpoint pens too use roller balls; however, the ink used by roller ball  pens is thinner and so the flow is better.)

Fountain pen with nib (Wikipedia)
Roller ball pens use either water-based ink or a thicker gel ink (pigments on a water-based gel). Gel ink dries quicker. It also writes thicker but may skip/slip occasionally and bleed more.

Close-up shot of roller ball at the tip
(Wikipedia)
Some pens use removable cartridges that hold ink - the advantage is that students can carry a spare cartridge to school instead of an ink pot. When the cartridge in the pen runs out of ink, it can be replaced with the spare one. The empty cartridge can be refilled later at home. Throwing away a cartridge after using it once defeats the purpose of using refillable ink pens. (Also, don't buy pens with cartridges that cannot be refilled.)

If you travel by air with a fountain pen, the guaranteed way to prevent leakage is to empty the ink tank. Or, fill it up and keep it upright.  To use the pen, wait till the flight takes off and reaches 6000 feet, which is when cabin pressure is increased to match the pressure at ground level (the air trapped in the ink tank is at the pressure at ground level; if the pen is opened before the cabin is pressurized, the higher pressure of air in the tank will push out the ink since the pressure in the cabin would be lesser).

Saturday, 6 February 2016

Spectacles: plastic lens or polycarbonate lens?

Specs
When shopping for a pair of spectacles, people are not usually not aware of lens materials and may be baffled by the sales pitch and the options available at the store.

Optical quality is the most important point to consider when buying spectacles. Glass has the best optical quality, followed by plastic lens and polycarbonate lens. However, glass is not commonly sold by retailers since it breaks easily and is heavier if the power is higher e.g. more than +2 dioptres.

When CR39 was the only type of plastic lens available, polycarbonate had a couple of advantages. But with the advent of plastic lens like MR8, MR174 etc., polycarbonate is not required for low, mid or high power.

In a nutshell,
  • Plastic lens has better optical quality.
  • Plastic lens is strong and can be cracked or broken only with great force.
    • CR39 plastic lens is good enough for most people.
    • If the lens must be stronger than CR39, consider MR8 - it is as strong as polycarbonate.
  • Polycarbonate lens is sold at a premium, which is why stores recommend it over CR39 for low power.

Buying spectacle lens

The following indication is general and simple, there are a few variables to consider. Armed with the details here and some research based on your prescription, you would be able to handle well the conversation with your optician.
  • Lower power/index: 
    • Get CR39 plastic lens (or any alternative entry-level plastic lens) 
    • Get Ultraviolet and anti-reflective coating applied. 
    • Make the lens photochromic, if required. 
  • Higher power/index lens, high impact sports: 
    • Get stronger plastic lens like MR8. 
  • Frame: 
    • For half-rim frame, CR39 is fine (recommended) 
    • For rimless frame, get MR8 plastic lens since CR39 lens will crack when screws are drilled. 
  • Bifocals: 
    • The type with Line in the middle where bottom half is for reading. Especially useful if the glass is only for reading. May avoid tilting up head when reading. Check if this type of lens obstructs long distance (non-reading) vision.
    • If the above type obstructs your long distance vision, go for D-shape or circular portion (Kryptok) at the bottom of lens.
  • Special cases: 
    • Please consult an expert in optics. The MR series has other types of lens.

Sunday, 31 January 2016

Library Management Systems - free software

This is a brief overview of free Library Management Systems (LMS) that educational and other institutions can make use of.

Some of the free ones are open source software (OSS), meaning their code too is available for modification and use.

Main features of an LMS


  • Acquisitions (buy books etc.)
  • Cataloguing (classify and index books etc.)
  • Circulation (lend and receive)
  • Serials (track periodicals like magazines)
  • Online Public Access Catalog or OPAC (online access for library members)


LMS - products


The software listed below have been selected from the many that are available. Products were left out for reasons like: they were not being actively developed or did not have strong backing of a community or organizations, have outdated technology and are not suitable for use etc.

DIY or find a service provider


The software may be installed on your own server or on cloud. This would be cheaper - however, depending on your choice, it needs ongoing maintenance of software and hardware (apply software updates, fix security issues, upgrade hardware etc.). This option can be considered if you have a couple of people in your organization who are familiar with the relevant technology and can handle ongoing maintenance.

Alternatively, there are (third-party) service providers who take care of the software and hardware, maintenance etc. While the cost for this option would be higher, it is useful if you do not have people with technical knowledge, or if you need to save their time. The main thing here would be to find a good, reliable service provider. A trial period would help you to check out their service. Talking to an existing customer would help.

Table for comparison of LMS products


To start with, it would be a good idea to list your requirements at a high level. Then, use a table, with columns like those below, to compare the available software systems.

  • Product (linked to home page)
  • Target (targeted for specific types of libraries? e.g. K12, scientific etc.)
  • Unique features
  • Standards for communication: MARC, Z39:5. Modern alternatives to these.
  • Authentication standards: LDAP
  • Interfaces for staff, members: browser-based software is better
  • Offline usage (when connectivity to LMS server is not available)
  • Number of Installations, worldwide and specifically in your country.
  • Contributors: community or company. Is community active and dedicated?
  • Operating Systems supported: Hosting on Linux may cost less. Mention if software package has to be built by ourselves.
  • Hosting service providers: cost, extent of technical support, whether they offer help in initial setup, backup and restore procedures, support hours, on-premise support etc.
  • Total cost to institution
  • Year it began: product might be more stable, but check if technology is outdated and hampers usage.
  • Technology stack: to evaluate if your organization has in-house expertise, is the stack outdated and hampers usage or finding expertise.

Usage in India


Koha seems to be popular choice in India. (LibSys, a commercial LMS, is also popular in India.)

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