Understanding nesting ecology and behaviour of green marine turtles at Setiu,Terengganu, Malaysia          下载免费PDF全文

Aini Hasanah Abd Mutalib  Nik Fadzly  Amirrudin Ahmad  Nurolhuda Nasir 《Marine Ecology》2015,36(4):1003-1012

In this paper, we emphasize the importance of understanding the nesting ecology and nesting behaviour of green marine turtles (Chelonia mydas). Data were collected from 2007 until 2012 from nesting beaches at Setiu Terengganu, Malaysia. We focused on one of the beaches, Telaga Papan, based on data collected in 2012. We recorded the distribution of nesting areas, the emergence hour and the correlation between successful nesting attempts and false crawls. Telaga Papan had a significantly higher distribution of green marine turtle nesting compared with the other five beaches (ANOVA, F_5,42 = 8.874, P < 0.01, mean = 36.750 ± 3.727). The highest number of successful nesting attempts was recorded in 2012 (mean = 28.714). A majority of the species landed between 22:00 and 23:59 h (25%). There was a strong correlation between successful nesting attempts and false crawls (r_s = 0.883, P = 0.02). Based on these findings on the nesting ecology and nesting behaviour of green marine turtles, we suggest that scientific research, strict monitoring, awareness programs and policy implementation should be carried out proactively. Such activities are necessary to reduce the anthropogenic pressures at the nesting beaches as well as to ensure more successful nesting attempts of green marine turtles in Setiu.  相似文献   

Gravitational clustering of galaxies: Derivation of two-point galaxy correlation function using statistical mechanics of cosmological many-body problem     

Farooq Ahmad  Manzoor A. Malik  M. Maqbool Bhat 《Astrophysics and Space Science》2016,361(7):223

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Dark energy in five-dimensional Brans-Dicke cosmology with dimensional reduction     

Ahmad Rami El-Nabulsi 《中国天文和天体物理学报》2011,(8)

We explore a 5D Brans-Dicke scalar cosmology by conjecturing that the four-dimensional Hubble parameter varies as H = εφs,ε∈ R and s is some unknown power index and that the extra-dimensions compactify as the visible dimensions expand as b(t) ≈ ax(t) ,x ∈ R-. We mainly discuss the case x =-1. For critical values of ε close to unity,it was observed that the acceleration of the universe occurs at redshift close to z = 0.8 which indicates that in our model,accelerated expansion of the universe began only recen...  相似文献   

D-Dimensional non-singular universe dominated by dark energy     

Ahmad Rami El-Nabulsi 《Astrophysics and Space Science》2011,332(1):37-42

We investigate the late-time dynamics of a four-dimensional universe based on the effective action of a Brans-Dicke scalar field in the presence of the matter source term, conformal coupling of the scalar curvature to the scalar field, a dynamical cosmological constant and Gauss-Bonnet higher-order terms in the scalar curvature. Many new interesting features are revealed and discussed in some details.  相似文献   

Numerical simulation of damage–Permeability relationship in brittle geomaterials     

Keyvan Maleki  Ahmad Pouya 《Computers and Geotechnics》2010

Finding a coupling model between a hydraulic parameter such as permeability and a mechanical parameter such as damage is the key element for several recent engineering problems. A review of the technical literature reveals that several mechanical constitutive laws exist which allow determining a damage tensor for a damageable porous material under loading. But the present work develops a method to deduce the permeability change due to the damage propagation.  相似文献   

Artificial groundwater recharge to a semi-arid basin: case study of Mujib aquifer,Jordan   总被引：1，自引：1，他引：0  

Tamer A. Al-Assa’d  Fayez Ahmad Abdulla 《Environmental Earth Sciences》2010,60(4):845-859

Mujib watershed is an important groundwater basin which is considered a major source for drinking and irrigation water in Jordan. Increased dependence on groundwater needs improved aquifer management with respect to understanding deeply recharge and discharge issues, planning rates withdrawal, and facing water quality problems arising from industrial and agricultural contamination. The efficient management of this source depends on reliable estimates of the recharge to groundwater and is needed in order to protect Mujib basin from depletion. Artificial groundwater recharge was investigated in this study as one of the important options to face water scarcity and to improve groundwater storage in the aquifer. A groundwater model based on the MODFLOW program, calibrated under both steady- and unsteady-state conditions, was used to investigate different groundwater management scenarios that aim at protecting the Mujib basin. The scenarios include variations of abstraction levels combined with different artificial groundwater recharge quantities. The possibilities of artificial groundwater recharge from existing and proposed dams as well as reclaimed municipal wastewater were investigated. Artificial recharge options considered in this study are mainly through injecting water directly to the aquifer and through infiltration from reservoir. Three scenarios were performed to predict the aquifer system response under different artificial recharge options (low, moderate, and high) which then compared with no action (recharge) scenario. The best scenario that provides a good recovery for the groundwater table and that can be feasible is founded to be by reducing current abstraction rates by 20% and implementing the moderate artificial recharge rates of 26 million(M)m³/year. The model constructed in this study helps decision makers and planners in selecting optimum management schemes suitable for such arid and semi-arid regions.  相似文献   

Effects of natural and calcined oyster shells on Cd and Pb immobilization in contaminated soils   总被引：5，自引：0，他引：5  

Yong Sik Ok  Sang-Eun Oh  Mahtab Ahmad  Seunghun Hyun  Kwon-Rae Kim  Deok Hyun Moon  Sang Soo Lee  Kyoung Jae Lim  Weon-Tai Jeon  Jae E. Yang 《Environmental Earth Sciences》2010,61(6):1301-1308

In Korea, soils adjacent to abandoned mines are commonly contaminated by heavy metals present in mine tailings. Further, the disposal of oyster shell waste by oyster farm industries has been associated with serious environmental problems. In this study, we attempted to remediate cadmium (Cd)- and lead (Pb)-contaminated soils typical of those commonly found adjacent to abandoned mines using oyster shell waste as a soil stabilizer. Natural oyster shell powder (NOSP) and calcined oyster shell powder (COSP) were applied as soil amendments to immobilize Cd and Pb. The primary components of NOSP and COSP are calcium carbonate (CaCO₃) and calcium oxide (CaO), respectively. X-ray diffraction, X-ray fluorescence and scanning electron microscope analyses conducted in this study revealed that the calcination of NOSP at 770°C converted the less reactive CaCO₃ to the more reactive CaO. The calcination process also decreased the sodium content in COSP, indicating that it was advantageous to use COSP as a liming material in agricultural soil. After 30 days of incubation, we found that the 0.1 N HCl-extractable Cd and Pb contents in soil decreased significantly as a result of an increase in the soil pH and the formation of metal hydroxides. COSP was more effective in immobilizing Cd and Pb in the contaminated soil than NOSP. Overall, the results of this study suggest that oyster shell waste can be recycled into an effective soil ameliorant.  相似文献   

Rancher and farmer perceptions of climate change in Nevada, USA   总被引：1，自引：1，他引：0  

Zhongwei Liu  William James Smith Jr.  Ahmad S. Safi 《Climatic change》2014,122(1-2):313-327

Farming and ranching communities in arid lands are vulnerable to the adverse impacts of climate change. We surveyed Nevada ranchers and farmers (n?=?481) during 2009–2010 to assess climate change related knowledge, assumptions, and perceptions. The large majority of this group agreed that we are in a period of climate change; however, only 29 % of them believed that human activity is playing a significant role. Female ranchers and farmers hold more scientifically accurate knowledge about climate change than do their male counterparts, regardless of Democratic or Republican affiliation. Partisan affiliation, political ideology, and gender have strong impacts on climate change knowledge and perceptions. Republican, conservative and male rural residents view climate change as a low national priority, less important to themselves, and less harmful to their communities. Female ranchers and farmers are more concerned about the negative impacts of climate change. We found that only 4 % of our subjects (n?=?299) attribute local environment changes to climate change or global warming. The knowledge gained from this study will help researchers and natural resource managers understand how to best communicate about climate change with rural communities, and support policy makers in identifying potentially effective adaptation and mitigation policies and outreach programs.  相似文献   

Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water   总被引：2，自引：0，他引：2  

Yaser A. Almaroai  Adel R. A. Usman  Mahtab Ahmad  Deok Hyun Moon  Ju-Sik Cho  Young Kyoo Joo  Choong Jeon  Sang Soo Lee  Yong Sik Ok 《Environmental Earth Sciences》2014,71(3):1289-1296

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.  相似文献   

Weathering and anthropogenic influences on the water and sediment chemistry of Wular Lake,Kashmir Himalaya   总被引：1，自引：1，他引：0  

Javid A. Sheikh  Gh. Jeelani  R. S. Gavali  Rouf Ahmad Shah 《Environmental Earth Sciences》2014,71(6):2837-2846

This paper presents a study on the Wular Lake which is the largest fresh water tectonic lake of Kashmir Valley, India. One hundred and ninety-six (196) water samples and hundred (100) sediment samples (n = 296) have been collected to assess the weathering and Anthropogenic impact on water and sediment chemistry of the lake. The results showed a significant seasonal variability in average concentration of major ions being highest in summer and spring and lower in winter and autumn seasons. The study revealed that lake water is alkaline in nature characterised by medium total dissolved solids and electrical conductivity. The concentration of the major ion towards the lake central showed a decreasing trend from the shore line. The order of major cations and anions was Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ and HCO₃ ^? > SO₄ ^2? > Cl^?, respectively. The geochemical processes suggested that the chemical composition lake water is mostly influenced by the lithology of the basin (carbonates, silicates and sulphates) which had played a significant role in modifying the hydrogeochemical facies in the form of Ca–HCO₃, Mg–HCO₃ and hybrid type. Chemical index of alteration values of Wular Lake sediments reflect moderate weathering of the catchment area. Compared to upper continental crust and the post-Archean Shale, the sediments have higher Si, Ti, Mg and Ca contents and lower Al, Fe, Na, K, P, Zn, Pb, Ni, Cu content. Geoaccumulation index (Igeo) and US Environmental Protection Agency sediment quality standards indicated that there is no pollution effect of heavy metals (Zn, Mn, Pb, Ni and Co).The study also suggested that Wular Lake is characterised by both natural and anthropogenic influences.  相似文献