Comparison of SEBAL,METRIC, and ALARM algorithms for estimating actual evapotranspiration of wheat crop

Theoretical and Applied Climatology - Evapotranspiration is one of the main components of water balance and its accurate estimation is of great importance in planning and optimizing water...     

A regularization of multiple encounters in gravitationalN-body problems

A method is introduced to regularize binary collisions between one of the bodies and any number of other bodies in the three-dimensional problem ofn-bodies. The coordinates are first transformed from an inertial system to a system relative to one of the bodies. The KS dependent variable transformation and a new independent variable transformation are introduced for the regularization.     

Paleoproterozoic granitoids in the basement of Bangladesh: A piece of the Indian shield or an exotic fragment of the Gondwana jigsaw?

We present the first precise age for Precambrian basement rocks in Bangladesh. These lie within the Dinajpur block, located between the Indian Craton to the southwest and the Shillong Massif to the east. There are no surface outcrops and the rocks were intersected by drill holes. They consist of a suite of tonalitic and granodioritic rocks, variously deformed to granitic gneiss and intruded by younger monzogranite. A tonalite obtained at a depth of 227.48 m in drill hole BH-2 at Maddhapara, in northwestern Bangladesh, records a SHRIMP zircon ²⁰⁷Pb/²⁰⁶Pb magmatic age of 1722 ± 6 Ma. Paleoproterozoic rocks with similar magmatic ages are unknown in the adjacent Indian blocks of the Chotanagpur Plateau (Indian Craton) or Shillong Massif. This lack of comparable ages may be due to the paucity of precise radiometric ages from the Indian terrains or, more likely, because there are real age differences, with the buried rocks at Maddhapara representing a separate and discrete microcontinental fragment (the Dinajpur block) that was trapped by the northward migration of India during Gondwana dispersal.     

Differences in the concentrations of atmospheric trace gases in and above the tropical boundary layer

Weekly air samples were collected at Cape Kumakahi (0 km) and at nearby Mauna Loa Observatory (3.4 km) which is above the boundary layer. EC/GC and GC/FID techniques were used to measure CH₃I, CHCl₃, CO and CH₄, which are largely natural in origin, and C₂Cl₄, CCl₄, CH₃, CCl₃, CCl₃F (F-11), CCl₂F₂ (F-12), CHClF₂ (F-22) and C₂F₃Cl₃ (F-113), which are due to anthropogenic activities. It was found that all these gases are significantly (0.05) more abundant in the boundary layer than above it.     

成都平原稻田甲烷排放的实验研究

根据1996～1999年四个稻季的观测资料,分析了成都平原单季稻甲烷排放的季节变化和年际变化特征.结果表明:在水稻生长季节甲烷排放通量变化很大,在分蘖期和成熟期一般会出现峰值.年际间的通量变化也很大,其年均排放通量的变化范围在2.35～33.95mg m-2 h-1之间.4年的平均排放通量为12 mg m-2 h-1,与四川乐山的7年平均值30mg m-2 h-1相比,存在着明显的地区差异.同时分析讨论了温度、施肥、水稻品种、土壤氧化还原电位(Eh)以及稻田水位等诸多因素对稻田甲烷排放的影响.结果表明:在成都平原水稻生长季节的平均气温对CH4的平均排放通量影响不大;而气温对CH4排放的日变化有相对重要的影响,但气温对甲烷排放日变化的影响与水稻植物体的生长阶段有关;发现了水稻植物体(根、茎、叶)重量对CH4排放的重要作用.讨论了合理使用肥料和施肥量,控制水位和Eh值对稻田CH4的减排作用,提出优化组合诸影响因子,以充分发挥其减排潜力.     

Solutions for Exterior Orientation in Photogrammetry: A Review

The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term "exterior orientation"of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects.
This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first, a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point–based methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line–based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry.     

Dokhan volcanics of Gabal Monqul area,North Eastern Desert,Egypt: geochemistry and petrogenesis

The Dokhan volcanics are represented by a thick stratified lava flows succession of basalt, andesite, imperial porphyry, dacite, rhyodacite, rhyolite, ignimbrites, and tuffs. These lavas are interbanded with their pyroclastics in some places including banded ash flow tuffs, lithic tuffs, crystal lapilli tuffs, and agglomerates. They are typical calc–alkaline and developed within volcanic arc environment. All rocks show moderate enrichment of most large ion lithophile elements relative to high field strength elements (HFSE). The incompatible trace elements increase from basalt through andesite to rhyolite. The felsic volcanics are characterized by moderate total rare earth elements (REE) contents (162 to 392 ppm), less fractionated patterns {(Ce/Yb)_N = (1.24 to 10.93)}, and large negative Eu anomaly {(Eu/Eu*) = (0.15 to 0.92)}. The mafic volcanics have the lowest REE contents (61 to 192 ppm) and are relatively steep {(Ce/Yb)_N = (3.2 to 8.5)}, with no negative Eu anomalies {(Eu/Eu*) = (0.88 to 1)}. The rhyolite displays larger negative Eu anomaly (Eu/Eu* = 0.28) than those of other varieties, indicating that the plagioclase was an early major fractionating phase. The mineralogical and chemical variations within volcanics are consistent with their evolution by fractional crystallization of plagioclase and clinopyroxene.     

Automated Detection of Coronal Loops Using a Wavelet Transform Modulus Maxima Method

We propose and test a wavelet transform modulus maxima method for the automated detection and extraction of coronal loops in extreme ultraviolet images of the solar corona. This method decomposes an image into a number of size scales and tracks enhanced power along each ridge corresponding to a coronal loop at each scale. We compare the results across scales and suggest the optimum set of parameters to maximize completeness, while minimizing detection of noise. For a test coronal image, we compare the global statistics (e.g. number of loops at each length) to previous automated coronal-loop detection algorithms.     

Reproductive biology of blood cockle <Emphasis Type="Italic">Anadara granosa</Emphasis> (Bivalvia: Arcidae) in the northern region of the Strait of Malacca

A study on the reproductive cycle of the blood cockle Anadara granosa (Bivalvia: Arcidae) was conducted at three different areas in the northern region of the Strait of Malacca. A total of 1,920 samples of adult A. granosa (38–71 mm length) were collected from June 2009 until September 2010. Qualitative techniques (gonadal microscopic fresh smear test and histology analysis) as well as quantitative techniques (analysis of condition index and gonadal index) were used to predict monthly gonadal development stages of A. granosa. The gonadal index of A. granosa from Banda Aceh (Indonesia) (r = 0.469, P > 0.05) and Pulau Pinang (Malaysia) (r = 0.123, P > 0.05) did not show any correlation to their condition index, whereas the gonadal index of A. granosa from Lhokseumawe (Indonesia) (r = 0.609, P < 0.05) showed moderate positive correlation to the condition index. During the 16 month sampling period, four reproductive cycles were observed: each from three to six months. The process of releasing gametes is termed dribble spawning, and is the same in all populations. The principle component analysis (PCA) indicated that A. granosa reproduction was affected by interaction between internal physiological factors and indigenous environmental factors. In all sampling areas, phytoplankton density played a key role in the reproductive cycle in A. granosa. Information on the reproductive biology of this species is essential for species management and to improve the sustainability practices of the fisheries industry. These findings will provide basic information on the biology of the blood cockle A. granosa for stock management in the region.