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91.
The Himalayan watersheds are susceptible to various forms of degradation due to their sensitive and fragile ecological disposition coupled with increasing anthropogenic disturbances. Owing to the paucity of appropriate technology and financial resources, the prioritization of watersheds has become an inevitable process for effective planning and management of natural resources. Lidder catchment constitutes a segment of the western Himalayas with an area of 1,159.38 km2. The study is based on integrated analysis of remote sensing, geographic information system, field study, and socioeconomic data. Multicriteria evaluation of geophysical, land-use and land-cover (LULC) change, and socioeconomic indicators is carried out to prioritize watersheds for natural resource conservation and management. Knowledge-based weights and ranks are normalized, and weighted linear combination technique is adopted to determine final priority value. The watersheds are classified into four priority zones (very high priority, high priority, medium priority, and low priority) on the basis of quartiles of the priority value, thus indicating their ecological status in terms of degradation caused by anthropogenic disturbances. The correlation between priority ranks of individual indicators and integrated indicators is drawn. The results reveal that socioeconomic indicators are the most important drivers of LULC change and environmental degradation in the catchment. Moreover, the magnitude and intensity of anthropogenic impact is not uniform in different watersheds of Lidder catchment. Therefore, any conservation and management strategy must be formulated on the basis of watershed prioritization. 相似文献
92.
Runa Masuma Tsutomu Okuno Mohammad Shahabuddin Kabir Choudhuri Takeshi Saito 《Journal of environmental science and health. Part. B》2013,48(6):416-421
The safety of Tinospora cordifolia and its potential to protect against ultraviolet radiation‐induced cytotoxicity and DNA damage in PC12 cells were investigated. To evaluate the safety of T. cordifolia, cell viability and agarose gel electrophoresis were carried out using PC12 cells treated with 0 to 100 μg mL?1 of methanol extract of T. cordifolia. T. cordifolia extracts did not show cytotoxicity ranging 0 to 100 μg mL?1. In addition, T. cordifolia extracts significantly increased cell viability at 1 ng, 10 ng and 1 μg mL?1 concentrations in serum‐deprived medium compared to control. To confirm the protective role against UV‐induced damage, PC12 cells alone or in the presence of 10 ng, 100 ng, or 1 μg mL?1 of T. cordifolia extract were exposed to 250, 270 and 290 nm of UV radiation, which corresponded to doses of 120, 150 and 300 mJ cm?2, respectively. Treatment with T. cordifolia extracts significantly increased the cell survival rate irradiated at 290 nm. In addition, T. cordifolia extracts significantly reduced cyclobutane pyrimidine dimer formation induced by UV irradiation at all wavelengths. In conclusion, T. cordifolia is not toxic and safe for cells. Our findings can support its application as phototherapy in the medical sector. 相似文献
93.
Mohammad Taghi Taghizadeh Reza Abdollahi Naser Sadeghpour Orang 《Journal of Polymers and the Environment》2012,20(1):208-216
The degradation of chitosan by means of ultrasound irradiation and its combination with homogeneous photocatalysis (photo-Fenton)
was investigated. Emphasis was given on the effect of additive on degradation rate constants. 24 kHz of ultrasound irradiation
was provided by a sonicator, while an ultraviolet source of 16 W was used for UV irradiation. To increase the efficiency of
degradation process, degradation system was combined with Fe(III) (2.5 × 10−4mol/L) and H2O2 (0.020–0.118 mol/L) in the presence of UV irradiation and the rate of degradation process change from 1.873 × 10−9−6.083 × 10−9 mol1.7 L s−1. Photo-Fenton process led to complete chitosan degradation in 60 min with the rate increasing with increasing catalyst loading.
Sonophotocatalysis in the presence of Fe(III)/H2O2 was always faster than the respective individual processes. A synergistic effect between ultrasound and ultraviolet irradiation
in the presence of Fenton reagent was calculated. The degraded chitosans were characterized by X-ray diffraction (XRD), gel
permeation chromatography (GPC) and Fourier transform infrared (FT-IR) spectroscopy and average molecular weight of ultrasonicated
chitosan was determined by measurements of intrinsic viscosity of samples. The results show that the total degree of deacetylation
(DD) of chitosan change, partially after degradation and the decrease of molecular weight led to transformation of crystal
structure. A negative order for the dependence of the reaction rate on total molar concentration of chitosan solution within
the degradation process was suggested. Results of this study indicate that the presence of catalyst in the reaction medium
can be utilized to reduce molecular weight of chitosan while maintaining the power of irradiated ultrasound and degree of
deacetylation. 相似文献
94.
Fatemeh Ghanbary Nasser Modirshahl Morteza Khosravi Mohammad Ali Behnajady 《环境科学学报(英文版)》2012,24(4):750-756
Titanium dioxide (TiO2) nanoparticles were prepared by sol gel route. The preparation parameters were optimized in the removal of 4-nitrophenol (4-NP). All catalysts were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). An artificial neural network model (ANN) was developed to predict the photocatalytic removal of 4-NP in the presence of TiO2 nanoparticles prepared under desired conditions. The comparison between the predicted results by designed ANN model and the experimental data proved that modeling of the removal process of 4-NP using artificial neural network was a precise method to predict the extent of 4-NP removal under different conditions. 相似文献
95.
Xiaoguang Liu Mohammad M.I. Chowdhury Masuduz Zaman Mingu Kim George Nakhla 《环境科学学报(英文版)》2019,31(8):169-178
This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants(K_(I,Ni)) for ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors(SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μ_(max), b, and K_o of AOB were 0.16 day~(-1), 0.098 day~(-1) and 2.08 mg O_2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen(DO)(7 mg/L) and long solids retention time(SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible. 相似文献
96.
Jeris A. Danielson A. Raziq Qazi 《Journal of the American Water Resources Association》1972,8(2):359-366
The agricultural production from the Lower South Platte Basin in Colorado represents a significant portion of the state economy. Until the early 1950's the production had developed almost exclusively by use of river water. Drought conditions combined with improved well technology resulted in an inordinate amount of well development in the valley during the period 1952-56. These wells were used for supplemental supply in many cases, but the application of sprinkler irrigation brought many acres of here-to-fore dry land into irrigated production. As a result of the vast amounts of groundwater withdrawal by the newly developed wells, senior surface appropriators found a decreasing amount of water available for use in the streams. The legislature, observing the doctrine of prior appropriation, ruled that all surface and ground water in a tributary would be treated and administered as one resource. This, of course, spelled doom for the well-oriented segment of the economy. Analysis of a segment of the river on an inflow-outflow basis was made with careful determination of all inflow-outflow in the study reach to include correlations required to determine ungaged side-channel in-flow and unmetered irrigation wells. Results indicate that wells have intercepted normal return flows to the river resulting in a decreased amount of surface water during the irrigation season. Stream depletion appears to equal the expected consumptive use of well water which ranged between 40% to 50% of the groundwater extraction. 相似文献
97.
Patsy Healey Mohammad Chowdbury John Olaniyan 《Journal of Environmental Planning and Management》1988,31(2):126-128
Planning in the Public Domain: From Knowledge to Action
John Friedmann. Princeton University Press, 1987, 501pp.
New Communities for Urban Squatters: Lessons from the Plan that Failed in Dhaka, Bangladesh
Charles L. Choguill, Plenum Press, New York 1987, pp. 213.
Models of Urban and Regional Systems in Developing Countries
George Chadwick, Oxford, Pergamon Press, 1987, xv +320pp.
Price: £17.50. 相似文献
98.
Mahmood Bakhtiyari Ali Delpisheh Sayyed Mohammad Riahi Arman Latifi Farid Zayeri Masoud Salehi Hamid Soori 《Safety Science》2012,50(7):1480-1484
Work-related accidents are considered as a major health problem worldwide. The aim of present study was to determine the epidemiological pattern of occupational accidents among workers insured by the Iranian Social Security Organization (ISSO) between 2001 and 2005.Subjects consisted of all workers and drivers who had a work-related accident during 2001–2005 and were registered in the Iranian Social Security Organization (ISSO) database according to the inspection reports. An ordinal logistic regression model (proportional odds regression model) was used to assess the concurrent effects of independent variables on accident outcomes.Overall, 86,437 work-related accidents were investigated. The accidents were more frequent in metal workplaces and electrical industries, respectively. More than half of the accidents were due to incautious activities. Workers’ age (age at the time of accident) (OR = 0.99, CI: 0.989–0.994), gender (OR = 1.3, CI: 1.191–1.683), marital status (OR = 1.25, CI: 1.143–1.675) as well as accident setting (OR = 1.88, CI: 1.728–1.975) had significant effect on accident outcomes. Pattern of occupational injuries in Iran was consistent with the global pattern for accident outcomes. 相似文献
99.
Mohammad Vaez Abdolsamad Zarringhalam Moghaddam Niyaz Mohammad Mahmoodi Somayeh Alijani 《Process Safety and Environmental Protection》2012,90(1):56-64
This paper addresses the decolorization and degradation of acid dye by a heterogeneous photocatalytic process using immobilized nano-sized TiO2 particles as the photocatalyst. Sackcloth fiber was used as a support to immobilize the nano-sized TiO2 photocatalyst. The structural properties of the immobilized photocatalyst were characterized by XRD, SEM and EDX. UV–Vis absorption spectroscopy and the measurement of the chemical oxygen demand (COD) were also used for the process performance studies. The XRD results did not show significant changes in the structure of P25 as a consequence of the immobilization procedure. The formation of titania crystallites in the sackcloth fiber was confirmed by SEM/EDX. The photocatalytic activities of TiO2-coated sackcloth fiber catalyst were evaluated using Acid Black 26 as a model organic contaminant and using UV-A radiation. Experimental results showed that after 60 min, the degradation of Acid Black 26 with the immobilized TiO2 particles was higher than that with plain TiO2. Based on the COD results, after 3 h, the TiO2-coated sackcloth fiber effectively decomposed all of the organic compounds present in dye solution under the studied experimental conditions. The effects of the oxidant H2O2, initial dye concentration and pH on the photocatalytic degradation were also investigated. The presence of CO32? as a dissolved inorganic anion had the highest inhibitory effect on the decolorization of the dye, when compared with the other anions investigated. Kinetics analysis indicates that the photocatalytic decolorization rate of Acid Black 26 can be described by a pseudo-first-order model. 相似文献
100.
Sharafi Zeynab Ehrampoush Mohammad Hassan Salehi-Abargouei Amin Sakhvidi Mohammad Javad Zare Askarishahi Mohsen Mirzaei Masoud Mehrparvar Amir Houshang Fallahzadeh Hossein Dehghani Ali Dalvand Arash 《Environmental science and pollution research international》2021,28(32):43394-43401
Environmental Science and Pollution Research - This study aimed to investigate the effect of exposure to pesticides and the prevalence of type 2 diabetes (T2D). In a cross-sectional study with a... 相似文献