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Noise pollution, as an unwanted and annoying sound that can negatively impact human health and well-being, has become one of the major environmental problems in the world. This type of pollution not only disrupts peace and comfort but can also have serious consequences for human physical and mental health. Despite the importance of the issue of exposure to harmful physical factors and their impact on health, few studies have been conducted on traffic noise based on the conditions in Iranian cities. Considering the importance of urban traffic noise, the lack of domestic studies on its characteristics and how it affects the cognitive and physiological performance of exposed individuals, and its importance and decisive role in the occurrence of errors and mental functions, this research aimed to investigate the physiological and mental performance in exposure to traffic noise pollution in Sari city.

This quasi-experimental intervention study was conducted in the summer of 1401 (2023) on 40 students of Mazandaran University of Medical Sciences. To minimize confounding factors, the inclusion criteria were as follows: age range of 20-30 years, normal hearing (hearing loss less than 25 dB), and no history of taking specific medications. All experiments were conducted in an acoustic chamber measuring 3 by 2 meters with a temperature of 23°C, humidity of 50%, and illuminance of 400 lux. Physiological parameters (heart rate, blood pressure, and core body temperature) were measured in acoustic comfort and traffic noise exposure conditions. Cognitive performance was assessed using the Continuous Performance Test (CPT) in exposure and non-exposure conditions. The structural correlation of this test was estimated by the researchers to be 0.89. Data analysis was performed using descriptive and analytical tests in SPSS v24.

According to the findings, 52% of the students studied were female. The mean age of the participants was 24.23 years with a standard deviation of 4.99 years, a minimum of 19 years, and a maximum of 38 years. 76.3% of the participants were single and 23.7% were married. Based on the exposure results, the average sound pressure level of traffic noise in the exposure group was reported as 75.45±0.11 dBA. It was observed that the heart rate and core temperature of the exposure group increased significantly (P<0.05). The average error (omission and commission) between the control and exposure groups had a significant difference and the average of these variables was lower in the control group. Also, the reaction time in the exposed condition had a significant difference with the non-exposed condition (P<0.05).

With the rapid growth of urbanization and the increasing density of traffic on roads and streets, noise pollution from traffic has become an unavoidable problem in modern societies, inevitably impacting human health and safety. because of the importance of traffic noise and the inevitable encounter with it, can be considered very important in terms of health aspects and occurrence of safety consequences. Therefore, paying attention to traffic noise exposure, human performance status, and influencing factors through investigations and research is necessary.

Increasing population growth and technological advancements in cities inevitably result in rising noise pollution levels. The emergence of the coronavirus disease worldwide, including Iran, has significantly altered people's daily lives. This has presented a unique opportunity to assess changes in sound levels. Therefore, this study aims to investigate sound level variations before the outbreak and during the COVID-19 restrictions at a pivotal intersection in Mashhad.

The initial segment of this study examined the sound equivalent level in April 2018 and 2019 without considering any specific circumstances at the Shohada crossroad. In the second segment, employing SPSS22 software and the Wilcoxon test, we compared the alterations in various sound level indicators before the disease prevalence (April 2018) and during the restrictions (April 2019).

The results of the first part of the study revealed that the hourly equivalent sound level (Leq) in April 2018 and 2019 was 70.48 and 70.39 dB, respectively. The results of the second part indicated a significant difference between the two periods under investigation in terms of equivalent sound levels. The maximum and minimum sound equivalent levels (LMax, Lmin) reduction during the disease outbreak compared to the pre-outbreak period was 0.16 and 0.08 dB, respectively. Additionally, during the night curfew hours (21-03) in April 2019, the sound equivalent level decreased by 0.09 dB compared to 2018. 

The findings of this study demonstrate that the equivalent sound level at the Shohada crossroad in Mashhad exceeded national standards before the disease prevalence. However, noise pollution levels have decreased due to decreased economic activities during the outbreak and the associated restrictions. Nonetheless, the equivalent sound level still surpasses the established standards, indicating that noise pollution at the mentioned intersection persists. Further research is warranted on this subject, encompassing traffic modeling, noise pollution emission inventories, establishing links between land use patterns and noise pollution, and the influence of weather conditions on sound levels.

Using a hearing protection device is one of the ways to control noise pollution in the industry. The purpose of the present study is to evaluate the changes in the sound absorption coefficient of some commonly used earmuffs in laboratory conditions at various sound levels and frequencies.

In this study, four earmuff models, including TASCO2550, AKHAVAN (VENUS-740), 3M optime98, and Parkson ABZ, were prepared. The absorber of the earmuffs was then cut to a diameter of 3 cm and a thickness of 1.2 cm. The absorption coefficient of each sample was measured using an impedance tube and VA-Lab4 software at three sound levels of 75, 85, and 95 dB. Finally, the data were analyzed using SPSS software.

There was no significant difference in the average absorption coefficient between sound levels of 75, 85, and 95 dB. However, in middle and high frequencies, the average absorption coefficient increased. TASCO2550 earmuff absorbent samples showed the highest absorption coefficient at frequencies of 2000-2500 Hz. While AKHVAN (VENUS-740) and 3M optime98 absorbent samples showed the highest average absorption coefficient at the frequency of 4000 Hz. Also, The Parkson ABZ absorbent sample had the highest average absorption coefficient at a frequency of 5000 Hz. In general, The TASCO2550 earmuff absorbent sample showed the highest absorption coefficient, while the 3M optime98 absorbent sample showed the lowest absorption coefficient.

By selecting an earmuff with efficient absorber, we can increase sound absorption rate to achieve the desired results of reducing noise pollution.

Traffic noise is one of the most important causes of noise pollution and also one of the environmental problems in today's societies. According to the World Health Organization, traffic noise is the cause of physiological and psychological disorders. Psychological disorders include impaired mental function, disruption of daily activities, increased rates of traffic accidents, and decreased concentration. Physiological disorders include sleep disorders, hearing loss, hypertension, gastrointestinal disorders, and effects on job performance. Accordingly, the purpose of this study was to determine the relationship between mental performance of introverts and extroverts in the face of traffic noise.

This study was performed on 40 students of Alborz University of Medical Sciences. The Mental Health Questionnaire were administered to all individuals. Also, traffic noise was recorded by a tape recorder for 15 minutes. Then, the participants were exposed to traffic noise in two modes of calm environment, and in both modes, a strope test was performed while playing the recorded sound. Finally, statistical analysis was performed to find the relationship between exposure to traffic noise and changes in mental function.

The results showed that after playing the sound in all participants, the mean consonant time decreased (p = 0.143), while the number of correct consonant responses increased after exposure to sound. (p=0.640)

Conclussion: 

The results of this study showed that traffic noise does not have different effects on the mental function parameters, and there is no significant relationship between voice and age, as well as voice and gender.

 Noise is the industry's most common occupational harmful factor. Therefore, the present study aimed to identify and prioritize occupational groups exposed to noise in an oil field.

 This cross-sectional study was started in the winter of 2021 by examining the job description of employees and performing dosimetry using the CEL-360 device. The sound pressure level distribution was measured using the Casella CEL device and based on ISO 9612-2009 (E). Using Surfer 21 and AutoCAD 2020 software, an isotonic map was prepared, and priority occupational groups and primary noise sources were identified using Noise Control Priority Index (NCPI). In stations with more than 85 dB sound pressure levels, noise frequency analysis was performed, and in the last stage, appropriate corrective action was presented according to the production process.

 The findings of this study showed that 16% of the area has the priority for control measures in the danger area, and 23.56% is located in the precautionary area. Operations were identified among the occupational groups with the highest NCPI score (1.5) to be prioritized in the hearing protection program.

 The present study results show that the combined sound pressure level, duration, and the number of exposed people can provide a suitable model for prioritizing voice control and identifying occupational groups in need of care in the hearing protection program.

One of the complications of transportation in cities is noise pollution caused by vehicles. Today, noise in urban environments is an important issue in the field of public health. Due to the negative effects of noise pollution on human health and well-being, it is necessary to identify and understand these effects on the health of exposed people. In this study, the type of traffic axis composition of the highway was identified and the type of traffic information required was identified by identifying the locations for the sound station along the highway axis and preparing sound data and identifying the factors affecting sound propagation. At each sampling station, the required variables in the intervals of 7: 30-9: 30, 12: 30-14: 30, 18: 30-20: 30, 23: 30-1: 30 And 3: 30-5: 30 and different seasons of the year were measured and recorded for modeling. The results show that the comparison of the average parameters of noise pollution in different stations of Shahid Kalantari Highway at a significant level of 5% showed that the highest amount of noise and sound indicators measured are related to the first station of Abadgaran with the amount of deci, respectively. Bell is 79.61 dB, the entrance road to Kuhsangi is about 80 dB and the lowest station of Hafez Square is about 58 dB. The parameters Lmax, Leq, L10, L50 and L90 are visually uniform distribution of results in the fit line range. According to the results of this study, it is announced that in all seasons of the year, the average equivalent sound level in all stations studied is higher than the recommended daily ambient sound level in the Iranian open air sound standard. While the standard sound level in residential areas is 55 decibels during the day and 45 decibels at night.

Cognitive performance in workplace encompasses a wide range of work-related psychological activities. Meanwhile, personality traits as a mediating variable has a determining role in mental functions and occurrence of errors. The aim of this study was to investigate the effect of urban traffic noise pollution on working memory and sustained attention considering personality features in university students.

This interventional laboratory study was performed in 70 students. Urban traffic noise (Sari, north of Iran) was recorded and then the Cool Edit Pro software was used to check, edit the recorded noise, and prepare an audio clip. The students' cognitive performance were assessed using working memory (n-back task) and psychomotor consciousness task (PVT).

The mean ages of male and female students were 23.63±3.15 and 24.17±4.23, respectively. According to the Wilcoxon test, a significant relationship was seen between cognitive performances before and after exposure to urban traffic noise (P<0.05). In fact, after exposure to traffic noise, the mean reaction time, response time, and the number of incorrect answers in cognitive tests increased by 8.54%, 9.11%, and 60.61%, respectively. Also, there was an inverse significant correlation between neuroticism and reaction time and accuracy (percentage of correct answers) in students' cognitive performance associated with working memory and sustained attention (P<0.05).

Current study can be effective in improving cognitive performance, adopting management strategies in selection of individuals, and establishing a balance between traffic noise and cognitive features in the workplace.

The interior of airport lounges is often exposed to a lot of noise, which can increase the risk to human health. Due to the dangers of high noise pollution for airport users, the present study was conducted to reduce noise pollution in the transit lounges of Ahvaz International Airport.

This study is considered interdisciplinary and applied research and its method is a combination of experimental, simulation and case study methods. firstly, the acoustic status of Ahwaz International Airport was obtained experimentally by measuring the amount of noise pollution during the test period (8 AM to 2 PM) by the Brüel & Kjær sound level meter model 2260 B&K in twelve places. Then the sound absorbing plates were tested with different geometric models. After proving the validity and reliability of the research, the experiments were performed by simulation using EASE 4.4 software.

In this study, the noise level of the airport lounge is considered as a dependent variable and four sound indices including, reverberation time (RT) (main index), indirect sound index (STI), total sound pressure level (SPL) and auditory error coefficient (〖AL〗_CONSE ) were evaluated according to the international standards ISO3382 and ISO 3382-1.

After the simulation, it was found that the use of raster pattern sound-absorbing plates (Model A in research) in walls and ceilings with different frequencies has the lowest sound pressure and the above-studied indices are at a desirable level. As a result, Model A has the greatest effect on reducing noise in the tested space.

Conversion of houses into residential towers in worn-out urban textures increases population. Schools of the vicinity would face with multiplicity and limited space for students, leading to noise pollution. The purpose of this study was to evaluate the noise levels during morning and afternoon shifts among two primary schools in Zanjan.

Measurements had been done using sound level meter, KIMO DB100. The equivalent noise level (Leq) measured during school year (2018-2019) in 10 stations. The measurements were done in three seasons (autumn, winter and spring) and in each season for two weeks. The data of the two schools were used for drawing charts and zoning by ArcGIS using IDW method. In addition, questionnaires were distributed among the teachers and school’ neighbors. The data were analyzed by SPSS software.

The results showed that all the stations were tackled with noise pollution. The highest levels were related to school’s shift change and break times. The morning shift schools experienced higher levels of noise in comparison to the afternoon ones (1.87 and 2.1 dB, respectively for boys and girls). Leq values for boys’ school was 2 dB higher than that of the girls’. The noise level in the schools were 72 dB, which is 17 dB higher than the standard level 55 dB.

The residents living close to the schools were exposed to noise pollution for almost 10 hours a day. This could be regarded as harmful. The zoning maps showed that southwest side of the yard, adjacent to the neighboring residential buildings, had the highest levels of noise. This study demonstrated the site selection for the schools were not properly done.  Having a control strategy is needed.

Population growth and the increase in urban migration in the past decades have led to an increase in population density and size of major cities. Unfortunately, this kind of pollution has mostly gone under-noticed. The purpose of this research was to model the correlation between noise pollution level and landscape metrics of urban structures and vegetation. To do so, 67 stations were selected in different parts of Isfahan and noise parameters were measured at peak traffic hours (16 to 19) during the fall season. Sampling stations were located through a systematic-random method based on the amount of construction, green spaces and structural diversity. There were 27 types of landscapes and three stations were randomly selected in each. In most stations, the noise level was above the permitted level(Residential 45-55, Residential-Commercial 50-60). The advanced regression method of random forest was used for the analysis. Through this method, the most effective metrics identified in different buffers were IJI index, FRAC_MN index, CLUMPY index, CONTIG_MN index, SHAPE_MN index, ENN_MN index. Also, checking of the first six metrics in each of the buffers and land uses showed the importance of the metrics is different. Identification of important metrics in each buffer and land use helps better design urban blocks and their arrangement.

Noise is one of the most harmful physical issues in the workplace that may turn into a stressor. Transit bus drivers are exposed to noise caused by the environment as well as buses that can result in stress among bus drivers. Thus, this study was conducted in order to determine the effect of noise exposure on occupational stress of Bojnourd’s transit bus drivers in 2018.

This descriptive study is conducted by cross-sectional method. In this study, 110 bus drivers of Bojnord city were surveyed. The job stress questionnaire of Philip L. Rice (1992) was used to evaluate occupational health along with a sound level meter (971-SVANTEK) to measure the amount of exposure to noise. Finally, SPSS.20 software and descriptive statistics (mean and standard deviation) and correlation tests were used for data analysis.

Findings on occupational stress indicated that the stress was high in 102 cases (92.7%); there was moderate stress in 4 cases and low stress in 4 cases. Sound measurement results demonstrated that the exposure level was standard in all cases. The equivalent continuous sound pressure level (LAeq) was 75.43 dB with a standard deviation of 2.74. There was no significant relationship between equivalent continuous sound pressure level and the stress experienced by the drivers. However, there was a significant relationship between equivalent continuous sound pressure level and occupational interest subtest (p<0.01).

Occupational stress was high in Bojnord city’s transit bus drivers and noise exposure was lower than the threshold. Since statistical analysis did not show a significant relationship between occupational stress and noise exposure, this finding is considered acceptable given the low noise exposure level among drivers.

 

Workplace noise is one of the occupational hazards in the ceramic industry, which can cause noise annoyance to workers. The aim of the present study is to investigate the relationship between indicators of Noise annoyance and job burnout in the ceramic manufacturing industry.

A descriptive-analytical study was performed on 100 male workers. The inclusion criteria for participating in this study were: filling informed consent, having age less than 50 year, and work experience of at least 6 months, as well as not having cardiovascular disease, diabetes, and not taking any antidepressant medication. According to the measurement of environmental noise, individuals were divided into control group (50 people) and exposure on (50 people). noise dosimetry was performed for all participants. Two questionnaires on noise annoyance and job burnout were used for this purpose. the results were analyzed with spss19 software.

The results showed that 8- hour time weighted average – noise exposur level for the exposure and control groups for shift was calculated 86 dBA, 59 dBA respectively. The mean noise annoyance in the exposed and control group, was 70.79 and 20, respectively, and the mean burnout score was obtained 82.36 in the exposed and 36.62
in the control group. The results of the Spearman correlation test showed a positive and significant relationship between the dimensions of burnout and noise annoyance score(p <0.05). The results showed a significant relationship between the noise exposure level and the incidence of its annoyance and as well as job burnout (p <0.05)

The results showed a positive and significant relationship between noise annoyance and job burnout. It is recommended to adopt the appropriate noise control measures like engineering methods.

Noise is one of the most important pollutants in worksites. Hospitals are imposed to noise pollution.  Considering lack of research in Sari educational hospitals and applicability of noise control by engineering controls and education, we proposed this research to evaluate the sound pressure level (SPL) in three educational hospitals of Sari, Iran.

In a descriptive-analytical study, the SPL of three hospitals was evaluated using sound level meter (model; CACELLA CELL-490, made in England). The evaluation was performed in 1.5 meter height, in three shifts, and in three days of the week. Data were analyzed using descriptive statistic methods and SPSS software version 24.  For assessing the rate of effective factors, the GEE (Generalized estimating Equation) methods were used.

According to the results, the mean SPL was 63.30 ± 7.33 dB and a significant difference was observed between the mean SPL and the standard (35 dB) (p <0.001). Moreover, the highest mean of sound in hospitals was observed in Fatemeh Al-Zahra Hospital. Considering the week days, Saturday and among shifts, the night shift had the highest mean SPL.

The findings showed that SPL was higher than the Iranian National Construction Regulations and World Health Organization (WHO) standards in all evaluated places. So, the noise control programs should be considered seriously.

Noise exposure, risk exposure in a wide range of work station, especially oil and gas industry and related companies is considered. This study was carried out to evaluate the noise before and after corrective action in 11 operational units of tanks and transportation in Abadan oil refining company.

First, the basic information including the location of noise sources and operating conditions of the equipment was collected. noise measurements was performed based on ISO 9612 standard before and after implementation of corrective actions, including repair or replacement of defective and worn out Parts or lubrication of moving parts  and using SLM CEL 490 mode calibrated with CEL-110/1  of casella  company was performed.

According to the results, the NTA has the highest amount of noise (97 dB) and spherical tanks with the lowest noise (82 dB). In this study, measured total 523 stations, 115 stations with noise levels over 85 dB, 373 stations between 65 and 85 dB sound pressure level and sound pressure level less than 65 dB in 30 stations. After carrying out corrective measures to reduce noise measurements, result showed that reduction of average sound pressure level of unit 1 of oil pumping with the 2/39 dB, 1.7 dB with a unit of Control Center, pus oil pumping unit with 0.98 dB and NTA unit with 0.08 dB, carried out respectively.

Noise measurements showed that the NTA unit was one of the severest conditions from the viewpoint of noise pollution among the other units. This study confirms the need to identify the main sources of sound and prioritize different parts of the industrial unit in order to implement control schemes engineering.

Noise pollution can exert negative effects on mental health. In this regard, the present study aimed to evaluate the noise levels in sugar factory of Debal Khozaei agro-industry complex in 2018.

For the current study, sound and audio parameters were measured using a sound meter. These audio parameters included sound pressure level and minimum and maximum values measured in 9 units located in the interior space of the factory entailing 38 study stations  with 30 points in open space. It is worthy to note that sound measurements were performed twice a week in morning and afternoon shifts at time intervals of 15 min. Data were analyzed in SPSS software (version 16) using the ANOVA test.

Based on the results, the maximum and minimum sound pressure levels of power plants and white sugar warehouse were 0.86 ± 91.10 and 0.44 ± 91.10 dB, respectively. Additionally, the comparison of the average sound pressure level at different stations in the power plant and raw sugar production units, as well as some stations in the sugar refinery, lime kiln, and boiler exceeded the standard limit of 85 dB. However, this value was found to be below standard in the open space of the factory.

The ongoing monitoring along with the application of noise reduction techniques is recommended due to the excessive noise levels in some parts of the factory.

The use of new technologies has positive and negative effects on human society. Loudspeakers and sound systems can also make harm to humans and noise pollution. Shiite religious ceremonies have special religious occasions in addition to the five prayers and religious lectures. The high performance of audio systems in mourning applications requires proper use of this technology. The purpose of this study was to determine the sound pressure level in religious centers and on various religious occasions in mosques and chapels of Mashhad University of Medical Sciences.

In this descriptive-analytical study, the sound pressure level was surveyed in all active mosques and chapels at Mashhad University of Medical Sciences in 2016. To determine the sound pressure level distribution, TES 1358 was used to measure the noise level.

The mean sound pressure levels in the endowment, lecture, and mourning ceremonies were 87.14, 90.31 and 93.91 dB respectively. Comparison of the sound pressure level in the A-weighting network in a  mourning ceremony with the US Environmental Protection Agency and the World Health Organization standards showed a significant difference (P-value = 0.013).

Since the average time for holding religious ceremonies and celebrations is up to 2 hours, the audio players and design of the interiors should be adjusted to a maximum sound pressure level of 80 dB. Keywords:Sound Pressure Level, Mosques, Religious Ceremonies, University of Medical Sciences

Paying attention to the comfort of the patient during hospitalization is very important. Noise pollution can exacerbate a person's illness. Additionally, if the noise pollution exceeds the threshold limit, it will have negative effects on the staff and appropriate services. The aim of this study was to identify the sources and the level of noise pollution in the emergency and emergency care units and outside areas of educational hospitals at the 1st district of Tehran, in the winter of 2017. In this descriptive study, measurement of noise pressure level in emergency department, emergency care units and outdoors in four hospitals in working days and holidays was carried out at three times in the morning, noon and evening by the TES-1358 sound analyzer device. Data was analyzed using one-way ANOVA. According to the results, the average and standard deviation of noise level in different sections of the hospitals on Saturday and Friday were respectively 62.79±7.32 and 57.98±6.43 dB during the morning shift, 66.15±8.09 and 65.16±7.82 dB during afternoon shift, 64.26±6.69 and 63.19±5.42 dB during the evening shift. There was no significant difference between the sound pressure levels on Friday and Saturday, among the rounds of measurements (morning, afternoon and evening) and among sections (the emergency department and the emergency care unit)(p>0.05). The results of the study showed that the rate of noise pollution in some parts of educational hospitals is higher than national and international standards. The necessary actions are recommended to be taken in order to decrease the noise and its causative factors for creating a more quiet environment for patients.

Noise pollution is becoming a severe issue for the patients admitted in intensive care units (ICUs). For the reduction of noise pollution in hospitals, researchers recommend proper training and adherence to protocols. The present study aimed to assess the effect of the training of nurses on the reduction of noise pollution in ICUs. This clinical trial was conducted at Tehran University of Medical Sciences and Iran University of Medical Sciences, which were randomly selected as the intervention and control groups, respectively. Before the intervention, noise intensity was measured at four locations inside the ICUs of the selected universities (entrance and exit, nursing stations, center of the department, and patients' bedside). Afterwards, methods for the control of noise pollution were introduced to the nurses in the intervention group in the form of a training workshop. Two months after the intervention, noise intensity was measured in the selected locations in the intervention and control groups. Noise intensity was measured using a sound meter in decibels (dB), and the dB-scale sound pressure level in LA networks (corresponding to the hearing of humans) was measured every two hours for three consecutive days.  According to the results of paired t-test, the intra-group effects of training regarding the correlation of the mean and standard deviation of the sound pressure level was estimated at 55.37±5.43 and 57.79±4.96 in the intervention group before and after the intervention, respectively, which indicated a significant difference in this regard (P<0.001). In addition, comparison of the intervention and control groups using independent t-test indicated a significant difference between the groups before and after the intervention (P<0.001). Also, the result of covariance test was not significant in intervention group and control group. According to the results, the training of nurses on the control of noise pollution was effective in the reduction of this issue. Therefore, it is recommended that noise pollution in hospitals be reduced through implementing in-service training workshops for nurses, asking nurses to be quite and promote sleep, and exploit silence signs in ICUs.

Since noise pollution as an important environmental problem, affects people’s health, the present study aimed at evaluating noise pollution level and the pattern of its changes in the area. In the present cross-sectional study, the equilibrium sound levels (Leq) were measured in 16 stations, during fall-winter of 2016 and spring-summer of 2017, in the morning and evening peak traffic times at all weekdays using the KIMO-DB100 Sound Level Meter. The data were analyzed using the Geostatistical Analyst tool and based on Inverse Distance Weighting (IDW) interpolation method. The results showed that the highest and lowest Leq were related to working days and Friday, respectively. The equivalent sound level in winter is as a minimum 1 dB higher and in summer as a minimum 1.5 dB lower than the other seasons. The minimum equivalent sound level was 56.1 dB throughout the sampling period and the maximum was 86.75 dB. The extents of equivalent sound in all stations were more than standard limit of residual areas (55 dB). According to the results, noise pollution is spread almost in all areas and hours of Zone 1-Region 6 of Tehran. This issue illustrates the necessity of applying noise pollution control technologies in this region.