排序方式: 共有33条查询结果,搜索用时 31 毫秒
1.
Bekun Festus Victor Alola Andrew Adewale Gyamfi Bright Akwasi Ampomah Asiedu Benjamin 《Environmental science and pollution research international》2021,28(47):66695-66708
Environmental Science and Pollution Research - In the energy-environment literature, a handful of the advanced economies, mostly the European Union countries, have met some of the national... 相似文献
2.
Gyamfi Bright Akwasi Sarpong Steve Yaw Bein Murad A. 《Environmental science and pollution research international》2021,28(9):11016-11029
Environmental Science and Pollution Research - The debate on ecological matters that relate to the biomass emissions nexus has gained prominence and different scholars have suggested various forms... 相似文献
3.
Chinazaekpere Nwani Festus V. Bekun Bright A. Gyamfi Ekpeno L. Effiong Andrew A. Alola 《Natural resources forum》2023,47(2):155-176
Sustainable use of natural resources would entail ensuring that derived economic benefits today do not undermine the welfare of generations to come. On this basis, this study examines the nexus between natural resource rents and carbon dioxide (CO2) emissions disaggregated into production and consumption-based (i.e., trade-adjusted) CO2 emissions for a selected panel of 45 developing and transition economies over the period 1995–2017. The empirical model also incorporates the impacts of population, affluence, and energy intensity. The results show that affluence increases production-based CO2 emissions by 1.407%, with the EKC's predicted inverted U-shaped curve only explaining consumption-based CO2 emissions. Economic reliance on natural resource rents and energy intensification contribute 0.022% and 0.766%, respectively, to CO2 emissions embedded in territorial production inventories and 0.035% and 0.583%, respectively, to CO2 emissions embedded in consumption inventories. The bootstrap non-causality test shows that historical data on each variable has significant predictive power for future CO2 emissions from both sources. The historical information about natural resource rents has significant predictive power over the future levels of affluence and energy intensity. Clearly, the results show that the environmental impact of natural resource rents is stronger when CO2 emissions are adjusted for trade and varies among the countries, with Bangladesh, Guinea, India, Malaysia, Mexico, Nigeria, Pakistan, Saudi Arabia, Vietnam, and Zimbabwe among the most affected countries. Overall, this study provides motivation for policies to keep the use of natural resources within sustainable limits. 相似文献
4.
Adedoyin Festus Fatai Bein Murad A. Gyamfi Bright Akwasi Bekun Festus Victor 《Environmental science and pollution research international》2021,28(31):41869-41880
Environmental Science and Pollution Research - Environmental degradation caused by various human activities has been a subject of attention over the globe. There is a concern on how to maintain a... 相似文献
5.
Asiedu Benjamin Ampomah Gyamfi Bright A. Oteng Evans 《Environmental science and pollution research international》2021,28(36):49949-49957
Environmental Science and Pollution Research - Due to various environmental degradation and natural resource depletion around the world, researchers’ and policymakers’ attention has... 相似文献
6.
Enteric viruses are a cause of waterborne disease worldwide, and low numbers in drinking water can present a significant risk
of infection. Because the numbers are often quite low, large volumes (100–1,000 L) of water are usually processed. The VIRADEL
method using microporous filters is most commonly used today for this purpose. Negatively charged filters require the addition
of multivalent salts and acidification of the water sample to effect virus adsorption, which can make large-volume sampling
difficult. Positively charged filters require no preconditioning of samples, and are able to concentrate viruses from water
over a greater pH range than electronegative filters. The most widely used electropositive filter is the Virosorb 1MDS; however,
the Environmental Protection Agency has added the positively charged NanoCeram filters to their proposed Method 1615. Ultrafilters
concentrate viruses based on size exclusion rather than electrokinetics, but are impractical for field sampling or processing
of turbid water. Elution (recovery) of viruses from filters following concentration is performed with organic (e.g., beef
extract) or inorganic solutions (e.g., sodium polyphosphates). Eluates are then reconcentrated to decrease the sample volume
to enhance detection methods (e.g., cell culture infectivity assays and molecular detection techniques). While the majority
of available filters have demonstrated high virus retention efficiencies, the methods to elute and reconcentrate viruses have
met with varying degrees of success due to the biological variability of viruses present in water. 相似文献
7.
PW Kok HY Ong MK Wong WK Au KT Tan WH Phoon CN Ong 《Environmental monitoring and assessment》1997,44(1-3):425-431
Occupational exposure to benzene was measured in two gasoline marketing terminals and five major refineries in Singapore. A total of 280 workers were monitored over two years. This assessment was carried out with two primary objectives: (1) To find out the extent of occupational exposure to benzene in the petroleum industry in Singapore, (2) To identify suitable biomarkers for monitoring of low levels of benzene exposure. The exposure was measured in five different categories of petroleum and petrochemical workers, i.e., truck drivers, despatch assistant, process operators, oil movements operators and laboratory technicians. The results revealed wide variations in exposure, from 0.01 to 13.6 ppm for personal time weighted average (TWA) exposure over the whole workshift. The exposure of truck drivers appeared to be the highest, with geometric mean (GM) of 1.98 ppm (ranged from 0.25 to 13.6 ppm). The average benzene exposure for process operators was relative low with a GM of 0.04 ppm. Lowest benzene exposure was found in the laboratory technicians, with a GM of 0.02 ppm. As cigarette smoking is known to affect metabolism of benzene, data analyses on the relationships with environmental exposure were conducted only on the 190 nonsmokers. The results showed that urinary trans, trans-muconic acid (ttMA), unmetabolized benzene in urine (UBZ) and benzene in blood (BBZ) were better biomarkers for low level benzene exposure as compared to urinary phenolic metabolites in urine, such as hydroquinone, phenol and catechol. 相似文献
8.
An autoradiographic examination of carbon fixation, transfer and utilization in the Riftia pachyptila symbiosis 总被引:4,自引:0,他引:4
Riftia pachyptila, the giant vestimentiferan tubeworm from the East Pacific Rise, harbors abundant chemolithoautotrophic, sulfide-oxidizing
bacteria in an internal organ, the trophosome. Several facts, such as the lack of a digestive system in the host, stable carbon
isotope values and net carbon dioxide uptake all suggest that the tubeworms obtain the bulk of their nutrition from their
symbionts. Using tissue autoradiography, we investigated the mode of nutritional transfer between symbionts and host, and
the site of early incorporation of symbiont fixed-carbon in the host. Fast labeling in the trophosome clearly demonstrates
that the symbionts are the primary site of carbon fixation. Appearance of label in some symbiont-free host tissues in as little
as 15 min indicates that the symbionts release a significant amount of organic carbon immediately after fixation. The organic
carbon is largely incorporated into specific, metabolically active host tissues such as fast-growing body regions in the trunk
and plume, and into tube-secreting glands. In addition to immediate release of fixed carbon by the symbionts, there is evidence
of a second possible nutritional mode, digestion of the symbionts, which is consistent with previous suggestions based on
trophosome ultrastructure. Results suggest that symbiont-containing host cells migrate in a predictable pattern within trophosome
lobules and that symbiont division occurs predominately in the center of a lobule, followed eventually by autolysis/digestion
at the periphery of the lobule.
Received: 1 July 1999 / Accepted: 30 December 1999 相似文献
9.
How population dynamics shape the functional response in a one-predator-two-prey system 总被引:1,自引:0,他引:1
The type III functional response has historically been associated with switching predators; when there is a choice of prey the predator favors the more abundant prey type. Although this functional response has been found in experiments where both prey densities are manipulated, in real world studies the type II functional response is more commonly found. In modeling, the type III functional response is often used in systems where the second prey type is, implicitly, assumed to be constant. Here we define a functional response that takes into account both prey densities. This causes the functional response to show both type II and type III behavior, dependent on the interaction between the two prey densities. If we take into account population dynamics, we find a type II functional response in most cases, because predation regulates the relative prey densities. This explains why type III functional responses are found in experiments where both prey densities are manipulated, but type II functional responses occur when the feedback of population dynamics on the functional response is important. Furthermore, the results show that switching can have a stabilizing or destabilizing effect and can even lead to predator extinction. 相似文献
10.
Environmental Management - The population in the American West has been increasing at a rapid rate and is predicted to continue growing. As a result, the availability, use, and allocation of water... 相似文献