The effects of open-plan office noise levels on annoyance in Egypt were studied. More than 200 respondents from 10 Egyptian open-plan office sites representing different functions were evaluated. The goals of this study are to carry out measurements to evaluate open-plan office noise levels, to determine if these levels exceeded the permissible levels set by Egyptian noise standards and policy to protect public health, to examine respondent’s attitudes towards open-plan office noise, and to determine the relationship between open-plan office noise levels and degree of annoyance. Results of measurements showed that equivalent continuous noise levels varied from 72 dB to 93 dB. Results of experiments showed that open-plan office noise reduced by 11 dB when users kept their conversations quiet, 6 dB when operating conditions of air conditioners (split units) were changed from high to low, and reduced by 5 dB when partial height „1.5 m… partitions made of plastic sheets with thickness of 6 mm were used. There was a strong relationship between open-plan office noise levels and percentage of highly annoyed respondents. There were a 10% increase in highly annoyed respondents per 4 dB increase in noise levels. Perception of unwanted speech conversations should be reduced. © 2011 Institute of Noise Control Engineering.

Annoyance and increase of accident risk of workers from industrial noise levels in Egypt were studied. 683 workers from 15 Egyptian sites of industry, ranging from food to metal industry were evaluated. The goals of this study are to carry out measurements to evaluate industrial noise levels, are these levels exceeded the permissible levels set by Egyptian noise standard and policy to protect public health of workers?, to examine worker’s attitudes towards industrial noise, to know the relationship between industrial noise levels and degree of annoyance. Results showed that equivalent continuous noise levels ranged from 70 to 100 dB (A). Annoyance of respondents showed that 47.1% were highly annoyed, 5.8% their hearing were harmed. There was a strong relationship between industrial noise levels and percentage of highly annoyed respondents. By increasing industrial noise level possibility of workers to make accident was also increased. Respondents suggest less maximum daily exposure duration than those set by Egyptian law.

Every day, approximately half a million workers in the construction sector in Egypt are exposed to excessive noise. Noise is one of the most prevalent physical contaminants in the construction sector. The most negative effects of noise exposure are related to the hearing system and may produce occupational deafness or even permanent deafness. These effects have a very important influence on people’s health and well-being. The goals of this study are to carry out measurements to evaluate construction noise levels, which exceed the permissible level set by Egyptian noise standards and policy to protect the public health of workers, to assess noise exposure, and to develop controls for proposing preventive solutions. The noise levels to which the workers in the construction sector are exposed have been studied. A number of representative measurements have been carried out using a sound level meter and a dosimeter to collect data from workers devoted to different tasks in the construction process. The most important levels and indexes have been analyzed with those data.

This study concerns road traffic noise in Alexandria, the second biggest city in Egypt. Goals of this study are to carry out measurements to evaluate road traffic noise levels, are these levels exceeded permissible noise levels set by Egyptian noise standard and policy to protect public health. To carry out restrictions to reduce noise levels for improving environmental conditions. Measurements taken for traffic noise levels, indicates that noise levels are higher than those set by Egyptian noise standards. Ldn = 80 dB and higher were recorded, while maximum permissible level is 60 dB. Ldn are calculated for 22 locations spread over different urban zones of city. It was found out that 95.5 % out of locations display Ldn are over 65 dB. 86.4 % out of total number of locations their Ldn are over 70 dB. Results of restrictions found that (i) in absence of horns, Ldn decreased at all sites reduction was 11.2 dB occurred in downtown area. (ii) In absence of horns, trucks and buses reductions in Ldn range between 6.2 to 14.3 dB. This shows that town planner can use various strategies to change traffic composition in order to achieve quieter city environments.

Cairo is the eleventh biggest city in the world and the capital of Egypt. Annoyance of workers from Cairo international airport noise levels was studied. 260 workers at 20 selected locations with different noise levels in offices, arrival, and departure halls were evaluated. The goals of this study are to carry out measurements to evaluate noise levels within airport, are if these levels exceeded the permissible levels set by Egyptian noise standard and policy to protect public health of workers?, to carry out experiments to reduce airport noise levels as: effect of distance from runway, numbers of movements, and types of aircrafts, to examine worker's attitudes towards airport noise, to know the relationship between airport noise levels and degree of annoyance. The results of the measurements showed that aircraft noise level inside building were 84 dB. Annoyance of respondents showed that 42.8 % were highly annoyed, 4.6 % their hearing were harmed. There was a strong relationship between airport noise levels and percentage of highly annoyed respondents. By increasing airport noise level possibility of workers to make mistake in their work was also increased

ecently, it is predicted that the fossil fuels will be sufficient for a few decades at the present extraction rates. So, the performance studies of the internal combustion engines play an important role to achieve the best operating point at different weather temperatures. In the present study, the effects of the inlet air temperatures on the engine performance characteristics were studied at different cooling loads. Several experiments were carried out on a single cylinder diesel engine (SCDI). The performance characteristics of SCDI included: brake power, specific fuel consumption, brake thermal efficiency and exhaust emissions (carbon dioxide, CO2, carbon monoxide CO, and hydrocarbon HC). The findings show that the inlet air temperature and cooling conditions have appreciable effect on the performance characteristics of the SCDI especially at low cooling rate. It can be concluded that the high cooling rate leads to the enhancement in the brake thermal efficiency, the b.s.f.c, and the emitted CO2, CO, and HC. On the other hand the high cooling rate leads to the decrease in the volumetric efficiency. So, a compromising between the inlet air temperature and the cooling rate should be recommended for the engine best performance.