خيارات البحث
النتائج 3271 - 3280 من 8,010
Resource recycling sustainability assessment in ready-mixed concrete manufactured on energy consumption and environmental safety in China النص الكامل
2021
Wang, Chao-qiang | Wang, Pei-xin | Zhang, Ming-tao
With the rapid development of construction industry, consumption of ready-mixed concrete has increased rapidly in China. As a kind of green building material and waste comprehensive utilization product, industrial solid waste-based ready-mixed concrete have better performance in terms of resource conservation and durability. However, some typical issues are associated with industrial solid waste resource recycling in ready-mixed concrete production process such as energy and material consumption, as well as leaching pollutant emissions. So, a “life cycle assessment” of the particular elements has been carried out, determining the resources consumption of all the processes of the ready-mixed concrete production. Through preparation of several different strength grades of concrete, the embodied energy and resources consumption indicator are quantitative evaluation. In addition, the environmental safety assessment was also proposed. The results show a certain linear relationship of concrete with various strength grade and its resources consumption, the higher strength grade, the more resources consumption potentials in the production of concrete. In this case, the linear correlation coefficient R²=0.98313 between them, and the equivalent coefficient’s order of the main resources, is as follows: the first is oil, then natural gas, iron ore, limestone, gypsum, and fly ash, and the last is coal. The more preceding shows more scarcity. Meanwhile, the general leaching of heavy metals Cu, Zn, Ni, Cr, Pb, Cd, and Ba of solid waste-based C20 concrete were also checked out. So, to further ensure the environmental safety, the potential ecological risk method was adopted to assess the heavy metal security and solid waste resource utilization.
اظهر المزيد [+] اقل [-]Occurrence of pesticides in waters from the largest sugar cane plantation region in the world النص الكامل
2021
Acayaba, Raphael D’Anna | de Albuquerque, Anjaina Fernandes | Ribessi, Rafael Luis | Umbuzeiro, Gisela de Aragão | Montagner, Cassiana Carolina
In this study, a multi-residue method was used to analyze 13 pesticides and 1 degradation product in surface and groundwater in the region with the largest sugar cane production in the world. The potential effects of individual pesticides and their mixtures, for aquatic life and human consumption, were evaluated. For the surface water, 2-hydroxy atrazine, diuron, carbendazim, tebuthiuron, and hexazinone were the most frequently detected (100, 94, 93, 92, and 91%, respectively). Imidacloprid (2579 ng L⁻¹), carbendazim (1114 ng L⁻¹), ametryn (1101 ng L⁻¹), and tebuthiuron (1080 ng L⁻¹) were found at the highest concentrations. For groundwater, tebuthiuron was the only quantified pesticide (107 ng L⁻¹). Ametryn, atrazine, diuron, hexazinone, carbofuran, imidacloprid, malathion, carbendazim, and their mixtures presented risk for the aquatic life. No risk was observed for the pesticides analyzed in this work, alone or in their mixtures for human consumption.
اظهر المزيد [+] اقل [-]Asymmetric effects of militarization on economic growth and environmental degradation: fresh evidence from Pakistan and India النص الكامل
2021
Ullah, Sana | Andlib, Zubaria | Majeed, Muhammad Tariq | Sohail, Sidra | Chishti, Muhammad Zubair
To examine the asymmetric effects of militarization on economic growth and environmental degradation, this empirical research analyzes annual data of Pakistan and India over the period 1985–2018 using the NARDL econometric model. The empirical results show significant positive militarization effects on economic growth, while non-militarization also shows positive effects on the economic growth in Pakistan and India. Estimation showed that a 1% increase in militarization (non-militarization) led to 8.818% (3.849%) increase in GDP growth, whereas a 1% increase in militarization (non-militarization) decreased carbon emissions by − 1.034% (− 0.225%) in the long run in Pakistan, while militarization has also decreased the carbon emissions − 0.337% in India in the long run. The relationship between militarization and economic growth has an asymmetry in Pakistan and India in the short and long run, while asymmetry also exists between militarization and CO₂ in Pakistan and India in the short and long run. Our findings offer significant policy implications for promoting economic growth and environmental quality in Pakistan and India.
اظهر المزيد [+] اقل [-]Air pollution and hospitalization in megacities: empirical evidence from Pakistan النص الكامل
2021
Mehmood, Usman | Azhar, Ayesha | Qayyum, Fazzal | Nawaz, Hasan | Tariq, Salman | Z̤iyāʾulḥaqq,
Air pollution has become a threat to human health in urban settlements, ultimately leading to negative impacts on overall economic system as well. Already developed nations and still developing countries both are at the risk of air pollution globally. In this scenario, this work aims to investigate the associations of asthma (AS) and acute upper respiratory infection (ARI) patients with satellite-based aerosol optical depth (AOD) and meteorological factors, i.e., relative humidity (RH), temperature (TEMP), and wind speed (WS). We applied second-generation unit root tests to provide empirical evidence. Two sets of unit root tests confirmed mix order of integration, and the other Westerlund co-integration test further showed strong linkages between estimated variables. Fully modified ordinary least square (FMOLS) and dynamic ordinary least square (DOLS) tests were applied, only to explore that TEMP and WS lower the number of AS and ARI patients, but RH and AOD increase the number of patients. Therefore, in accordance with these findings, our study provides some important policy instruments to improve the health status in megacities of Pakistan.
اظهر المزيد [+] اقل [-]The contrasting relationships of relative humidity with influenza A and B in a humid subtropical region النص الكامل
2021
Wu, Qian | He, Jun | Zhang, Wen-Yan | Zhao, Ke-Fu | Jin, Jing | Yu, Jun-Ling | Chen, Qing-Qing | Hou, Sai | Zhu, Meng | Xu, Zhiwei | Pan, Hai-Feng
Influenza is an acute respiratory disease that seriously threatens public health. The occurrence of influenza has been proved to be related to a variety of meteorological factors. However, less attention has been paid to the effect of relative humidity (RH) on different types of influenza, especially in subtropical regions. Daily data on laboratory-confirmed influenza cases, weather variables, and air pollutants in Hefei covering the 2014–2019 period were collected. The seasonality and trend of daily influenza cases were explored by the time series seasonal decomposition method. Generalized linear model was fitted in conjunction with distributed lag nonlinear model to quantify the associations of RH with influenza A and influenza B. Subgroup analyses were conducted by sex, age (0–4, 5–17, and ≥18 years), and season (cold and warm seasons). A total of 5238 influenza cases including 2847 influenza A cases and 2391 influenza B cases were recorded. The epidemic of influenza presented a distinct seasonal pattern, and the number of daily influenza cases increased steadily since 2016. High RH was related to an increased risk of influenza A (maximum RR = 1.683, 95%CI: 1.365–2.076), especially among males, females, and school-age children. Low RH was associated with an increased risk of influenza B (maximum RR = 1.252, 95%CI: 1.169–1.340). The contrasting relationships of RH with influenza A and B remained significant in cold seasons. High RH and low RH were significantly associated with the increased risk of influenza A and B, respectively. The findings of our study may provide clues for proposing new effective interventions.
اظهر المزيد [+] اقل [-]Acrylamide-induced peripheral neuropathy: manifestations, mechanisms, and potential treatment modalities النص الكامل
2021
Bin-Jumah, May | Abdel-Fattah, Abdel-Fattah M. | Saied, Essa M. | El-Seedi, Hesham R. | Abdel-Daim, Mohamed M.
Acrylamide is a chemical monomer; its polymer compounds are used in the manufacture of plastic, papers, adhesive tapes, dyes, and food packaging. Lately, scientists found that cooking (mainly roasting, baking, and frying) yields acrylamide. In addition to fried/baked potatoes, coffee and bakery products still contain substantial amounts of acrylamide. Acrylamide has toxic effects on different body systems include genitourinary, reproductive, nervous system, along with being a carcinogenic substance. The neurotoxicity of acrylamide includes central and peripheral neuropathy. In humans, the clinical manifestations include sensory or motor peripheral neuropathy, drowsiness, or cerebellar ataxia. Likewise, it presents with skeletal muscle weakness, hindlimb dysfunction, ataxia, and weight loss in animals. The suggested mechanisms for acrylamide neurotoxicity include direct inhibition of neurotransmission, cellular changes, inhibition of key cellular enzymes, and bonding of kinesin-based fast axonal transport. Moreover, it is suggested that acrylamide’s molecular effect on SNARE core kinetics is carried out through the adduction of NSF and/or SNARE proteins. Lately, scientists showed disruption of focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) cell signaling pathways in human differentiating neuroblastoma SH-SY5Y cells, exposed to acrylamide. Different treatment modalities have been revealed to shield against or hasten recovery from acrylamide-induced neuropathy in preclinical studies, including phytochemical, biological, and vitamin-based compounds. Still, additional studies are needed to elucidate the pathogenesis and to identify the best treatment modality.
اظهر المزيد [+] اقل [-]Another insight into the contamination levels at Ogoniland in Niger Delta, Nigeria, with focus on Goi Creek النص الكامل
2021
Nnoli, Nkechi Gloria | Olomukoro, John Ovie | Odii, Elijah Chibueze | Ubrei-Joe, Maimoni Mariere | Ezenwa, Ifeanyi Maxwell
Environmental pollution arising from crude oil exploratory activities has adversely impacted both the living and non-living components of the ecosystem. An insight into the impact of such activities with focus on Goi Creek in Ogoniland was provided in this study. We generated reliable data for physicochemical, heavy metal, and total hydrocarbon levels in the creek via a total of 40 samples collected across 4 stations designated within the creek in a duration of 10 months. With the exception of temperature, total dissolve solid, dissolved oxygen, chloride, sulfate, nitrate, zinc, and vanadium, the levels of other regulated parameters in the samples were not compatible with the national and international guidelines and standards for surface water quality including Federal Ministry of Environment Guidelines and standards for water quality in Nigeria and Environmental Protection Agency National recommended water quality criteria, respectively. The principal components (PCs) 1 and 2 of principal component analysis biplot revealed that the concentrations of the physicochemical parameters showed a mixed distribution among the stations; however, the heavy metals were more localized to station 4. Moreover, the dataset was subjected to water quality index (WQI), contamination index (Cd), heavy metal evaluation index (HEI), trace element toxicity index (TETI), and environmental water quality index (EWQI) to determine the extent of contamination. The result showed poor WQI, high contamination for Cd, and low-to-medium contamination for HEI. Although, there were variations among the stations on the contamination level, uniform remediation method should be adopted due to the similarity of the contaminants in all the stations.
اظهر المزيد [+] اقل [-]Disease recognition in philodendron leaf using image processing technique النص الكامل
2021
Muthukrishnan, Viswanath | Ramasamy, Seetharaman | Damodaran, Nedumaran
Numerous disease recognition techniques are available to identify diseases in plant leaves. Assignment of spherical polar coordinate treated equivalent to hue, saturation, and intensity helps for disease recognition in Philodendron leaf which was identified as specks. Black vision, white vision, and color vision for the eye are possible with photopigments present in rods and cones in the retina. The highlight of this paper is converting the Philodendron leaf in natural color to grayscale and applying the technique of hue, saturation, and value to the gray image. Then running iteration for the double-sized image by allowing for the simultaneous recognition of the diseased part helps for the identification of the spots present in the leaf. This focuses specks on a brighter scale.
اظهر المزيد [+] اقل [-]Influences of offshore background wind on the formation of sea-land breeze and the characteristics of pollutant diffusion النص الكامل
2021
Xu, Jiajia | Jia, Hongwei | Zhou, Huayuan | Kang, Yanming | Zhong, Ke
The formation of sea-land breeze (SLB) is primarily affected by background wind and temperature difference between the sea and nearby land. Because the intensity of sea breeze is significantly stronger than that of land breeze, land breeze may result in more accumulated pollutants under the condition of offshore background wind (OBW) than under the condition of no OBW in coastal areas. The formation process of sea-land breeze and the dispersion trajectory and accumulation effect of pollutants are studied under different velocities of OBW with the same sea-land temperature difference by employing computational fluid dynamics (CFD). The results reveal that the depth and the duration of sea breeze decrease with the increase of the velocity of OBW. The most unfavorable velocity of OBW (0.2 m s⁻¹) exists when the concentration affected by OBW is higher than that by no OBW in coastal areas. The pollutants close to the ground will be blown to the inland by sea breeze when the velocity of OBW is less than 1.0 m s⁻¹. When the velocity of OBW is larger than 2.0 m s⁻¹, the pollutants will not occur on the inland due to the influence of OBW.
اظهر المزيد [+] اقل [-]The first detection of SARS-CoV-2 RNA in the wastewater of Tehran, Iran النص الكامل
2021
Tanhaei, Mohammad | Mohebbi, Seyed Reza | Hosseini, Seyed Masoud | Rafieepoor, Maedeh | Kazemian, Shabnam | Ghaemi, Amir | Shamloei, Sharareh | Mirjalali, Hamed | Asadzadeh Aghdaei, Hamid | Zali, Mohammad Reza
Following the official announcement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide pandemic spread by WHO on March 11, 2020, more than 300,000 COVID-19 cases reported in Iran resulting in approximately 17,000 deaths as of August 2, 2020. In the present survey, we investigated the presence of SARS-CoV-2 RNA in raw and treated wastewater samples in Tehran, Iran. Untreated and treated wastewater samples were gathered from four wastewater treatment plants over a month period from June to July 2020. Firstly, an adsorption-elution concentration method was tested using an avian coronavirus (infectious bronchitis virus, IBV). Then, the method was effectively employed to survey the presence of SARS-CoV-2 genome in influent and effluent wastewater samples. SARS-CoV-2 RNA was found in 8 out of 10 treated wastewater samples utilizing a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) test to detect ORF1ab and N genes. Moreover, the rate of positivity in wastewater samples increased in last sample collection that shows circulation of SARS-CoV-2 was increased among the population. In addition, the high values detected in effluent wastewater from local wastewater treatment plants have several implications in health and ecology that should be further assessed.
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