Apr 192013

Scanner is the input device which helps to convert a hard copy data into a soft copy data and send them to the computer. ScannerAll scanners work on the same principle of reflectance or transmission. The image is placed before the carriage, consisting of a light source and sensor.

To direct light from the bulb to the sensors that read light values, CCD (Charge-coupled Device) scanners use prisms, lenses and other optical components.

The amount of light reflected by or transmitted through the image and picked up by the sensor, is then converted to a voltage proportional to the light intensity – the brighter the part of the image, the more amount of light is reflected or transmitted, resulting in a higher voltage. The analogue-to-digital conversion (ADC) is a sensitive process, and one that is susceptible to electric interference and noise in the system. In order to protect against image degradation, an electrically isolated analogue-to-digital converter that processes data away from the main circuitry of the scanner is used. However, this introduces additional costs to the manufacturing process; so many low-end models include integrated analogue-to-digital converters that are built into the scanner’s primary circuit board.

The sensor component itself is implemented using one of the three different types of technology:

  • PMT (Photo-Multiplier Tube): It is a technology inherited from the drum scanners of yesteryear.
  • CCD (Charge-Coupled Device): It is the type of sensor used in desktop scanners.
  • CIS (Contact Image Sensor): It is a newer technology which integrates scanning functions into fewer components, allowing scanners to be more compact in size.
Apr 192013

In this modern age, the process of urbanization is also growing along with the process of industrial development. A view of UrbanizationUrbanization can simply be defined as the act of establishing urban areas by substituting the rural areas. A country can be divided into urban and rural areas on the basis of residence. The residence status and facility greatly differ between these areas. In our country Nepal, urban area is identified as municipality, sub-metropolitan (Lalitpur, Pokhara, Birgunj, Biratnagar) city and metropolitan city (Kathmandu). Urban area is a limited area where certain population (more than twenty thousand), dense settlements, small to big markets, wide road, huge buildings, transportation, communication, health services, good opportunity of education, recreational facilities etc. are available. The rural area has very few physical facilities and hence, the population pressure is also very low.

The development in population pressure causes the surrounding areas of town and the areas change into urban areas. Hence, urbanization includes the urban area and the growth of population living there. Therefore, urbanization not only denotes the growth of area of towns but also the growth of population there. In municipality and metropolitan city, there must be basic physical facilities like electricity, road , drinking water, communication, health and education.

Unplanned Urbanization and its effects

The process of urbanization needs proper planning. About half of the world population has been residing in urban areas. Migration from rural areas to urban areas is on increasing trend. Not only economic but also social aspect should be developed for urbanization. If there is unplanned building construction and settlement extension, mismanagement of sewage and garbage, lack of drinking water and electricity, the process of urbanization is unplanned. Because of the rapid growth of the urban area, the required facilities cannot be made available. If the population pressure in the city continues to grow without fulfilling basic needs and infrastructure of urbanization, the city extends with inadequate means and sources. It results in unorganized urbanization, which is unfavourable for the environment. There are adverse effects on the environment. Some prominent effects of unorganized urbanization on environment and the ways to check them are given below:

  • Lack of Facilities: In the planned urban area, facilities of drinking water, health service, transport, electricity, communication, employment are available. But in the unorganized urban area, the above-mentioned facilities which are essential for healthy and happy life are lacking.
  • Unhealthy Settlement: Healthy settlement is one which is neat and clean. Open space, greenery, proper drainage system, clean water etc. make the residence pleasant. The residence area becomes unhealthy if the urbanization is growing in an unplanned way and a lot of people migrate there for facilities. Unorganized urbanization results in an unhealthy residence area.
  • Unequal Distribution of Population: Facilities as well as means and sources are not adequate in unplanned urbanization. The population pressure is high there. The limited space is much crowded. Consequently, population pressure in some places in the world is very great while it is very low in some places. The unequal distribution of population disturbs the balance of the environment.
  • Social Disorder: High population pressure is found in unplanned urban area. Employment, health facility, transport, communication etc. cannot be provided properly. Consequently, there is struggle of people for means and sources which are limited. Deformities like dispute, thefts etc. grow. There is no discipline in the society. So unhealthy social environment is created.
  • Degradation in Environment: Land, water, forest etc. are excessively used due to unorganized urbanization. They try to meet their requirements in whatever way they can. Garbage increases due to thick and unplanned settlement. The environment is polluted. Due to air, land and water pollution, there is decline in the qualitative aspect of the environment.
  • Adverse Effect on Health: Because of unorganized urbanization, there is no efficient management of the settlement. Drainage system, drinking water management, road control etc. are not adequate. People are forced to live on limited means of life. The adverse effects cause diseases. The health of the people is impaired and their life is full of sufferings.

Mitigating Measures of Unplanned Urbanization

The prominent measure to control the effects of unplanned urbanization is the introduction of planned urbanization. However, the following means can be applied to check the unplanned urbanization:

  • Development of Rural Area: Basic facilities like drinking water, electricity, health service, communication, education etc, should be provided in the rural areas. When the people get these facilities in their villages, they will no more be attracted to cities. The development of the rural area can help to control the extension of unorganized urbanization. It will restrain the effects of unorganized urbanization.
  • Employment Opportunity in Rural Areas: Trade, industry, construction work provide employment opportunities. These job-providing and income-generating projects should be conducted in the rural areas so that the villagers will get employment and will not migrate to urban areas.
  • Balanced Development: Development policy should be formulated considering the geographical situation of the country. A strategy should be adopted to start developmental activities in all the geographical regions. It will bring balance in the use of natural resources. There will be equal utilization of land in all regions. There will be people’s participation in development activities in every region. These efforts will assist to curb the expansion of unorganized urbanization and its unfavourable effects.
  • Development of semi-urban areas: Development of semi-urban areas helps to check unplanned urbanization. It is wise to set up middle class towns according to the geographical situation and rural areas. Employment and labour-oriented projects focusing youths should be conducted. The change of such places into town will control the growth of unplanned urbanization.