Archive for the ‘Civil Engineering’ Category

Arsenic in Wasa water supply confirmed

Thursday, June 17th, 2010

Out of 392, as many as 253 tube wells – almost 89.71 per cent – of the Water and Sanitation Agency (Wasa) are pumping out arsenic-contaminated water, posing serious health hazards to Lahorites who are unaware of the slow poison they are consuming daily, says a recent report by the Punjab Environmental Protection Department (EPD).

Sources in the EPD said that according to samples taken by the field staff, water of 253 tube wells, out of 392, was found to be contaminated with arsenic. They said the PU’s Chemistry Department also seconded the EPD’s report through Atomic Absorption Tests. The EPD would submit a complete report on the matter to the Punjab chief minister in a few days, they added.

Termed a slow poison, arsenic is present in rocks, soil, air, plants and animals and its long-term use might cause different forms of cancer. The element can not be easily detected during ingestion as it is tasteless, odorless and colorless.

Arsenic in drinking water is absorbed by the body and distributed by bloodstream. It does not enter the body through skin or by inhalation during bathing.

The body parts which accumulate arsenic the most over time are nails and hair. Though most of the element is removed through urine, skin, hair and nails also help the body get rid of it.

The permissible limit of arsenic, according to the World Health Organization (WHO) standards, is 10 parts per billion (ppb), but water of some tube wells in the city carries as much as over 50 ppb of the element.

Environmentalists say the government should declare it mandatory to carry out tests for bacteria, nitrates and organic and inorganic compounds on every tube well at least once a year. They say modern tests like Mass Spectrometry/Inductively Coupled Plasma, Electro-Thermal Atomic Absorption Spectrometric Method, Manual Hydride Generation/Atomic Absorption Spectrometric Method and Silver Diethyldithiocarbamate Method should be introduced across the province to test of presence of arsenic in water.

Dr Attiqur Rehman, assistant professor Environmental Sciences, Lahore College, who is also a visiting research fellow at the Tokyo Institute of Technology (Japan), says it is a matter of great concern that even in cities like Lahore, where the WASA claims the provision of high quality water, the level of arsenic is almost five times higher than the WHO standards. He says the government should pay immediate attention to the issue, ordering installation of arsenic filtration plants at all the sources where from water is being pumped out or stored for public supply.

He says arsenic is very harmful heavy metal and its effects on human body include loss of appetite, nausea, diarrhea, skin lesions, skin rash, chronic headaches, apathy, garlic odor on breath, a metallic taste in the mouth, a bronzing pigment of the skin resembling raindrops on a dusty road and possible damage to the liver. Arsenic and arsenic compounds are also known cancer-causing agents and have been implicated in lung and skin cancer and associated with birth defects, he adds.

When contacted, EPA director general Dr Shugufta Shahjehan said the department was working hard to identify the presence of arsenic in the province, so that necessary measures could be taken to fix the problem. To a question, she said no death had so far been reported due to arsenic poisoning in areas of high concentration. This did not mean that people were free from health hazards resulting from arsenic-contaminated water, she added.

Source: http://thenews.jang.com.pk/daily_detail.asp?id=245413, Thursday, June 17, 2010 written by Ali Raza

Tags: water quality in Lahore
Posted in Civil Engineering | 2 Comments »

Global warming and its impact on Public health

Friday, August 14th, 2009

It is good news,at last someone have realized in Pakistan to have a research on global warming with following criteria, may be helpful for policy makers and funding organizations.

“The research utilize meta analysis of existing literature on global warming and public health, the central question of what global warming is all about and how does the latter impact Pakistan’s health in accordance to literature discussion, assessment and analysis. Research objective adheres to the following salient points:  impact of environmental change on health, Pakistan context, several causes which bring the changes, how can authorities or general public tackle health related problems caused by global warming. There can be scientific consensus that greenhouse gas emissions generated by human activity will change Earth’s climate. The recent warming by 0·5°C is partly attributable to such anthropogenic emissions. Climate change will affect human health in many ways mostly adversely. The need to summarize epidemiological evidence of how climate variations and trends affect various health outcomes.

Assess evidence there is that global warming affected Pakistan health, reviewing published estimates of impeding health effects of climate change at present times. Researches have focus on thermal stress, extreme weather events, and infectious diseases, with some attention to estimates of regional food yields and hunger prevalence. An emerging broader approach address wide spectrum of health risks due to social, demographic and economic disruptions of climate change. Evidence and anticipation of adverse health effects will strengthen Pakistan based case for pre-emptive policies, will guide priorities for planned adaptive strategies. Indeed, environmental change and pollutants stress individuals and populations, and may be reflected in the global resurgence of infectious disease as these stresses cascade through the community assemblages of species.

Research will suggest framework for integrating surveillance of Pakistan health outcomes with climatic monitoring. Thus, initial concern about the possible effects of global warming have declined with realization that the spread of tropical diseases is likely to be limited and controllable. However, direct effects of heat causes substantial numbers of deaths among vulnerable people such as during summer. Action to prevent deaths from rising is obvious medical challenge presented by global rise in temperature. For example, air conditioning has reduced them in the United States and technologies such as fans, shade and buildings designed to keep cool on hot days have generally done so in Europe as the energy requirements of air conditioning accelerate global warming, combination of the older methods, backed up by use of air conditioning when necessary, can provide the ideal solution.

Despite availability of technologies, occasional record high temperatures still cause sharp rises in heat related deaths as the climate warms such action at home can be effective than transporting the patient to hospital, even in tropical regions. The aggregate human impact on the environment now exceeds the limits of absorption or regeneration of biophysical systems. The resultant global environmental changes include altered atmospheric composition, widespread land degradation, depletion of fisheries, freshwater shortages and biodiversity losses. The drive for further social and economic development, plus an unavoidable substantial increase in population size will tend to augment these large-scale environmental problems. Overall, large scale environmental changes are likely to increase the range and seasonality of various infectious diseases, food inscurity, water stress, population displacement with adverse health consequences (2000).

Most directly, it can generate more, stronger and hotter heat waves, which will become especially treacherous if the evenings fail to bring cooling relief, lack of nighttime cooling seems to be in the cards; the atmosphere is heating unevenly and is showing the biggest rises at night, in winter and at latitudes higher than about 50 degrees. Prolonged heat can enhance production of smog and the dispersal of allergens and linked to respiratory symptoms. Human infections are intricately linked to the global environment by altering this environment, global warming has significant potential to intensify selected infectious diseases ( 2000). Thus, climatic effects are predicted to include crowding, famine, water contamination, human migration, and alterations in vector ecology, all of which increase infectious diseases. Global warming will cause economic strain that may divert public health resources from existing infections. Through planning and research, there can mitigate health effects of global warming by means of policy, politics, and global cooperation, Pakistan may reduce the environmental problems that cause global warming.

Global warming has serious implications for human life, effect of global warming depends on the complex interaction between the human host population and the causative infectious agent, changes in the environment may trigger human migration, causing disease patterns to shift ( 2005 ). Disease transmission may be enhanced through the scarcity and contamination of potable water sources. Importantly, significant economic and political stresses may damage the existing public health infrastructure, leaving mankind poorly prepared for unexpected epidemics.

Global warming will certainly affect the abundance and distribution of disease vectors, altitudes that are cool to sustain vectors will become more conducive to them for instance, Malaria, dengue, plague, and viruses causing encephalitic syndromes are likely to be affected. Some models suggest that vector-borne diseases will become more common as the earth warms, although caution is needed in interpreting these predictions (2005). Clearly, global warming will cause changes in the epidemiology of infectious diseases as the ability of mankind to react or adapt is dependent upon the magnitude and speed of the change. Research will depend on ability to recognize epidemics early, to contain them effectively, to provide appropriate treatment, to commit resources to prevention and further investigation.”

http://ivythesis.typepad.com/term_paper_topics/2009/08/global-warming-and-its-impact-on-public-health.html

Tags: global warming
Posted in Civil Engineering | No Comments »

Thermal Mass Explained

Saturday, May 23rd, 2009
The potential of using a building’s thermal mass to reduce its ongoing heating and cooling energy requirements is being increasingly recognised. How to successfully realise this potential is often less understood but is explained in new technical guidance from The Concrete Centre.
Until recently, the use of thermal was often disregarded in favour of a largely services-based solution for the heating and cooling of buildings. However, the wish to reduce the on-going energy consumption of buildings both in terms of carbon dioxide emissions and energy bills has led to a re-evaluation of the contribution that thermal mass can help to achieve a more sustainable built-environment.
“Exploiting thermal mass so that it helps to reduce heating requirements in the winter and cooling requirements in the summer is not difficult. However, it does need to be considered at the outset of the design process when the building’s form, fabric and orientation requirements are being determined”, said Tom de Saulles, building physicist, at The Concrete Centre and author of the report ‘Thermal Mass Explained’. “Get it right and you can have significant energy savings and carbon savings over the life of a building with less need for expensive low carbon technologies”.
Thermal mass, in the most general sense, describes the ability of a material to store heat. For a construction material to provide a useful level of thermal mass it must have a high specific heat storage capacity, be of high density and have moderate thermal conductivity so that heat conduction is roughly in synchronisation with the daily heat flow in and out of the building.
Timber has a high heat capacity but a low thermal conductivity. This limits the useful heat absorption rate and so provides a low thermal mass. Steel also has a high heat storage capacity but it also has a very high rate of thermal conductivity which means that heat is absorbed and released too quickly for any meaningful thermal mass efficiency. Concrete and masonry, with their high heat capacity and density but moderate thermal conductivity offers a good balance. They steadily absorb heat and store it until the ambient temperature drops causing stored heat to migrate back to the surface from where it is released. Heat moves in a wave like motion alternatively being absorbed and released in response to the variations in day and night-time conditions.
“The absorption and release of heat enables buildings with thermal mass to respond naturally to changing weather conditions, helping to stabilise the internal temperature and provide a largely self-regulating environment”, explained de Saulles. “This action helps to prevent summer overheating and reduces the need for air conditioning. It can also reduce the need for heating during the winter by capturing and later releasing solar and internal heat gains”.
During warm weather, much of the heat gain in heavyweight buildings is absorbed by the thermal mass in the floors and walls thereby reducing the risk of overheating. This heat is then removed by allowing cool night-time air to ventilate the building. This daily heating and cooling of the thermal mass works relatively well in the UK as the air temperature at night is typically 10 degrees less than peak daytime temperatures during the summer.
“The benefits of thermal mass, which is well understood in warmer parts of Europe, will become increasingly recognised in the UK as climate change results in hotter summer temperatures”, said de Saulles. “As well as cooler internal temperatures, these benefits also include reduced heating bills in the winter as instead of purging the day-time heat gains with night-time air, the stored heat is allowed to radiate back into the building”.
For the winter, thermal mass works best when it is used as part of a passive solar design strategy (PSD). This approach seeks to maximise the benefit of solar gain in the winter, using thermal mass to absorb gains from south facing windows, as well as internal heat gains from electrical equipment, cooking and lighting. These gains are slowly released overnight as the temperature drops so helping to keep the building warm and reducing the need for supplementary heating. Applying simple passive solar design techniques can result in fuel savings of up to 10 per cent. This saving can increase to 30 per cent if more sophisticated passive solar techniques such as sunspaces are adopted.
“The need to design and build for higher levels of energy efficiency and to mitigate the effects of climate change means that the performance requirements of building materials continue to increase. Meeting these challenges requires a whole-building approach where the materials, structure and systems work in unison to maximise the building’s overall performance. The thermal mass of concrete provides a useful constituent of this whole building approach”, said de Saulles. “Efficient use of thermal mass used in conjunction with orientation, solar gain, ventilation and shading can do much to reduce the whole-life carbon footprint of buildings”.

http://www.concretecentre.com

Posted in Civil Engineering | No Comments »

Engineering Education in Pakistan

Monday, May 4th, 2009

Developing countries are facing many challenges in Engineering Education and one of the key issues is the question of curriculum adaptability to the growing needs in the concerned sector relevant to developmental process. For example the civil engineering curriculum equally revolves around structures and surveying.

During the last three decades, engineering and technical education in Pakistan has witnessed large growth. Setup of new engineering universities and other institutes of higher education have relatively good infrastructure with qualified teaching staff.

But there is need to focus in engineering education more on teaching the basics of technology (from textbooks). The subjects covered in universities are not up to that level which is studied in European Universities. It may be some institutes have the offer to its student knowledge pertinent to the needs of industry as a part of the curriculum but what has been examined in reference to developed countries institutes, some faculties of engineering are still to be modernized. For example some subjects like environment engineering, construction law and arbitration subjects are required to be introduced within their curriculum. Some faculties lack a clear vision regarding strategies needed to inform their students about the future technologies and demand of the industry. Thus, there is an urgent need for an important change in perspective and in the model used of for establishing new curricula.

In my opinion, universities in Pakistan should also offer courses based on e-learning formats using web-based tools and practicing engineers should take them “on a need basis” consideration the specific requirements for new knowledge and skills.

The engineers in all departments must have exams based on experience and skill minimum after 2-3 years and CPD points should be counted while promoting to higher posts. To be a member of Pakistan Engineering Council is not enough, engineers should prove themselves the engineers, not good clerks who only sign the bills and forward the files in government departments. The competency profile of engineers is changing dramatically in this age and it is essential to establish a close cooperation between faculties of engineering, industry and engineering council in order to participate in the formation of engineers.

The future engineering education must take the following into consideration while planning their courses and Pakistan Engineering Council should watch it in the scenario of other developed countries demand and environments:

  • Offer modular and flexible programs.
  • Redesign curricula and involve industry in the development of these new curricula.
  • Use of advanced lecture delivery tools such as projection systems, e-learning via intranet and internet.
  • Offer collaborative learning environment by tying up with leading foreign.

The engineering educational programs must prepare engineers capable to fulfil the demand of industry and standard of education and be fully aware of some important facts such as.

  • Understand that employers of engineers are multi-national companies with wide geographical spread and conduct business across international boundaries.
  • Engineers must deal with varied cultures, customs and languages and must be capable of working in global rather than local environments.
  • Engineering work must adhere to a variety of statutory and regulatory requirements.
  • Engineering designs need to address both local and international requirements, and in particular, environmental regulations.
  • Developed products must address a variety of customers and consumer preferences.

And new engineering curricula must address the following:

  • Clarify the impacts of technological change on societies.
  • Stress the need to make information technology part of engineering education.
  • Offer basic foundations of science and mathematics and offer opportunities for the inclusion of biology, energy and water technologies.
  • Offer opportunities for specialized knowledge without ignoring multi-disciplinary content of the curriculum.
  • Teach engineering students the real value of teamwork and stress the need for clear communication/soft skills including verbal, written and visual.
  • Teach engineering student basic elements of business, finance, management and quality.

In conclusion, developing countries should be committed to retaining high-level scientists, stimulating them, and providing funds and other support to encourage and maintain their productivity.

Abstracts from: http://www.arabrise.org

Tags: engineering education, future of engineering education in pakistan, technical education in Pakistan
Posted in Civil Engineering | 1 Comment »

Reducing C02 Emissions and the Potential for Fuel Poverty

Thursday, March 26th, 2009
Thermal mass, particularly when used as part of a passive solar design strategy, is increasingly being used to reduce heating and air conditioning energy consumption and bills. Both benefits are of interest to housing associations wanting to build sustainable homes that reduce both their environmental impact and the potential for fuel poverty.
The ability of thermal mass to reduce overheating problems is increasingly recognised. Perhaps less appreciated is its ability to save heating energy when used in passive solar design (PSD). Consequently, it is possible for concrete, masonry and other heavyweight dwellings to exploit their inherent thermal mass on a year-round basis. During the summer, heat is absorbed on hot days, helping to cool the internal temperature and prevent overheating problems. The stored heat is then removed by night ventilation. During the winter, the thermal mass will absorb solar gains through south facing windows, and slowly releases the heat at night. This process is effectively the same as that which occurs on summer nights, the only difference being that during the winter the stored heat is beneficial, so windows and openings are kept shut to minimise heat loss. Shutters and blinds used to prevent overheating in the summer can also help minimise heat loss during the winter.
Useful levels of thermal mass are found in medium and heavyweight construction, which in practice is most easily provided by concrete in the form of blocks and precast or in-situ floors and panels.
The use of concrete often raises questions regarding its embodied CO2, which can be slightly higher than that associated with alternative materials, but in reality the difference is relatively small when compared to lightweight systems. And, when you evaluate this in whole-life terms, the operational CO2 savings provided by the heavyweight solution is actually much more significant over the long-term. This point can sometimes be overlooked in the drive to specify the greenest materials available, but should to some extent be redressed in the forthcoming revisions to Part L1 of the Building Regulations, which will take greater account of thermal mass in the Standard Assessment Procedure (SAP) calculation.
To establish the facts of embodied versus operational CO2, The Concrete Centre commissioned research to examine the embodied and operational CO2 emissions of a simple semidetached house built using a typical lightweight frame, with that of several heavyweight versions built using varying levels of thermal mass. The embodied CO2 for each option was calculated and thermal modelling was undertaken to see how each performed across the 21st century, taking account of the likely impacts of climate change. The results showed that a typical masonry house with a medium level of thermal mass, has around 4% more embodied CO2 than an equivalent lightweight frame construction, but that this could be offset in as little as 11 years due to the energy savings provided by its thermal mass. Increasing the mass through additional concrete elements, such as precast upper floors, resulted in a longer offset period, but ultimately led to the lowest whole life CO2 emissions of all the options, with a saving in CO2 over the 21st century approximately six times greater than the difference in its embodied CO2 when compared to the lightweight frame solution.
Due to the predicted increase in summer temperatures resulting from climate change, the lightweight home was found to need air-conditioning by 2021. This compared with 2041 for the medium-weight home and 2061 for the medium-heavy and heavyweight homes.
Thermal mass is of course only one of the steps needed to adapt homes to a warming climate. Effective ventilation and shading are also of great importance in all types of housing, particularly in the south of the UK where overheating is likely to be greatest. Traditionally, shading has not been a major feature of UK housing. However, this is likely to change, particularly if tougher overheating rules appear in the Building Regulations. There are many shading options, but the most effective at minimising solar gains are externally located, such as overhangs and louvered shutters. The latter has the advantage of also providing secure night time ventilation in the summer.
In addition to having a medium to high level of thermal mass the key design requirement for capturing solar gains during the winter is to locate a large proportion of the glazing on the south elevation, or within about 30° of south. This will allow the low winter sun to shine directly into the home, passing underneath any fixed external shading overhangs. There are no hard and fast rules for window size in passive solar design; the objective is to optimise solar gains during the winter without incurring summertime overheating problems. This typically leads to a glazed area that between approximately 20 and 40% of the façade area. Glazing on the north façade should be restricted to the minimum area needed for adequate daylighting, since over the course of a year this will have a net heat loss.
Incorporating these all design features can help to maximise a home’s year-round passive thermal performance thereby reducing both CO2 emissions and energy bills.

Tags: Carbon Emissions, CO2, reducing carbon emissions
Posted in Civil Engineering | No Comments »

Concrete as a leader of sustainable construction

Thursday, March 26th, 2009

Jonathon Porritt, Founder Director of Forum for the Future, has applauded the concrete industry for its initiative and commitment to become a leader for sustainable construction.

Speaking at the launch of ‘The Concrete Industry Sustainability Performance Report’, Porritt commended the industry saying that: “I am genuinely impressed at the progress that has been made and the quality of the leadership shown. The industry is to be congratulated upon the journey that it is taking”.

Forum for the Future has been working with the concrete industry to develop and implement a sustainability strategy. The launch of the first industry-wide Performance Report marks a milestone for the concrete industry. It examines the challenges being faced and provides a statement of achievement. Importantly, the report provides industry data across 14 performance indicators against which the concrete sector has committed to be benchmarked against and to improve upon.

The performance indicators are wide ranging and include the implementation of environmental management systems, reduction of waste and carbon emissions, improved energy efficiency and the provision of locally sourced materials. In addition, there are commitments to enhance the environment and create sustainable communities. The report will be followed up on an annual basis so that ongoing sustainability improvements can be measured.

To download the report, visit www.sustainableconcrete.org.uk

Tags: sustainability of concrete
Posted in Civil Engineering | No Comments »

Construction Law in Pakistan

Tuesday, December 30th, 2008

I am not sure that in Pakistan, any university have the facility to teach the civil engineering students, Construction Law and Arbitration, subject which, I think is a fundamental for engineering students. The Civil Engineers should have the knowledge of the value of contract, its terms, clauses and terminology. When the contracts are awarded, what terms should be inserted and should be careful while inserting some clauses. The Arbitration clause is very important. If it is not well construed, the problems faced by either property during the contract may delay the project.

Similarly as I know , there are no typical contracts published by any body like in UK, where JCT Forms, NEC Contract document etc are published by IBA and ICE as a guide lines to landlords and contractors, an exemplary documents.

Can anyone comment on “Construction law and Arbitration” in Pakistan in these pages?

Tags: construction law
Posted in Civil Engineering | No Comments »