Waste loading in shrimp and fish processing effluents: potential source of hazards to the coastal and nearshore environments     

Islam MS  Khan S  Tanaka M 《Marine pollution bulletin》2004,49(1-2):103-110

On average, only 30-40% of the global fishery production is consumed fresh and the rest 60-70% is processed for human consumption and other purposes. Although the proportion of the total fishery production that are processed remained relatively stable over the last decade, the total bulk of processed fishery commodity increased due to the steady increase in the total fishery production. Processing of large bulk of fish, shrimp and other aquatic organisms produces a corresponding large bulk of by-products and wastes. Although recent trend shows that much of these wastes are made into various value added products, considerable quantities are discharged as the processing effluents with large volume of waters used in processing. Reports suggest that fish and shrimp processing effluents are very high in biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fat-oil-grease (FOG), pathogenic and other microflora, organic matters and nutrients, etc. Fish and shrimp processing effluents are, therefore, highly likely to produce adverse effects on the receiving coastal and marine environments. Although substantial reduction of the waste loads is possible by applying available simple techniques, this is not in practice in most part of the world due to lack of proper managerial and regulatory approach. The present paper reviews the characteristics of fish and shrimp processing effluents as a potential source of coastal and marine pollution and, using the existing data, analyzes the global production and discharge of waste loads from the processing plants and discusses available options for waste treatment and management.  相似文献   

Estimating the size and distribution of South Asian religious populations in Britain: is there an alternative to a religion question in the census?     

Brown MS 《International journal of population geography : IJPG》2000,6(2):87-109

This paper addresses the question of whether there is an alternative to asking a direct religious question in the 2001 Census through a systematic review of alternative methods of quantifying religious populations. After establishing the limited availability of direct information on religion, the paper considers the application of an inferential method for estimating religious populations based on data from the 1994 Fourth National Survey of Ethnic Minorities (NSEM). Except for the monoreligious Pakistani and Bangladeshi populations, evidence of substantial spatial variation in the association between ethnicity and religion severely limits application of the method below national level. Using the religiously diverse Indian population of outer London as a case study, the NSEM is investigated to see whether the incorporation of other ?predictors? of religion as weighting variables improves sensitivity of the method to this variation. In a second method, logistic regression is employed to develop predictive models of religious affiliation for application to census microdata. Based on these two applications, it was concluded that very little of the variation in the religious geography of Indians in outer London can be inferred from measured characteristics in the census. However, this does not necessarily imply support for inclusion of a religion question in the 2001 Census. It was suggested that it may be more appropriate and cost effective to define and solve the need for data locally.  相似文献   

Seasonal variation of polychlorinated biphenyl concentrations in the southern part of the Baltic Sea   总被引：3，自引：0，他引：3  

Bruhn R  McLachlan MS 《Marine pollution bulletin》2002,44(2):156-163

The impact of seasonal fluctuations in forcing factors such as atmospheric concentration, temperature, and biological productivity on the concentration of polychlorinated biphenyls (PCBs) in the surface water of the southern part of the Baltic Sea was investigated. Water samples were collected on eight cruises over 2 years. A clear seasonal variability in dissolved PCB concentrations was observed with higher levels in summer than in winter and spring. This was attributed to changes in atmospheric concentrations and water temperature, based on measurements showing the PCB levels in the atmosphere and surface water to be close to a partitioning equilibrium. Concentrations in the suspended particulate material (SPM) fraction were also variable, and when the quotient of the organic carbon normalised concentration in SPM and the dissolved concentration was calculated (i.e., the bioaccumulation factor (BAF)), a seasonal pattern was observed which was consistent with kinetic limitations on partitioning into particles caused by plankton growth. However, seasonal variability in the partitioning properties of the SPM may also contribute to this variability.  相似文献   

Religious composition of Punjab's urban population, 1981     

Gill MS 《Population geography : a journal of the Association of Population Geographers of India》1986,8(1-2):38-49

The author analyzes the religious composition of the urban population in Punjab, India, for the period 1971-1981. Aspects considered include the relationship between religious composition and size-class of urban centers, changes in the size of urban religious populations, and the different spatial patterns of various religious communities.  相似文献   

二维有限差分时间域电磁偏移     

王书民 Zhda.  MS 《物探化探译丛》1998,(A04):14-18

我们已推出一种二维有限差分时间域（ＦＤＴＤ）偏移算法,有限差分方法的优点在于它能很地应用于各种电导率背景模型,比较ＦＤＴＤ算法和积分方程（ＩＥ）算法的电磁偏移计算结果表明,有限差分法结果比ＩＥ结果能更好地反映电导异常,对于含有榀 的数据也可提供稳定的图像。Ｍｉｎｄｃｏ的地球物理学家们,跨跃日本的Ａｗａｊｉ岛的Ｎｏｊｉｍａ断裂带,开展了ＴＤＥＭ法工作,并利用有限差分偏移方法测定了与断裂有关的导电破碎  相似文献   

The dust coma of Comet P/Giacobini-Zinner in the infrared     

Hanner MS  Veeder GJ  Tokunaga AT 《The Astronomical journal》1992,104(1):386-393

We present 1-20 micrometers photometry of P/Giacobini-Zinner obtained at the NASA Infrared Telescope Facility, during 1985 June-September (r = 1.57-1.03 AU). A broad, weak 10 micrometers silicate emission feature was detected on August 26.6; a similar weak emission feature could have been hidden in the broadband photometry on other dates. The total scattering and emitting cross section of dust in the inner coma was similar to that in other short-period comets, but a factor of 10 (r = 1.56 AU) to 100 (r = 1.03 AU) lower than the amount of dust in Comet Halley. The thermal emission continuum can be fit with models weighted toward either small or large absorbing grains. The dust production rate near perihelion was approximately 10(5) g/s (small-grain model) to approximately 10(6) g/s (large-grain model). The corresponding dust/gas mass ratio on August 26 was approximately 0.1-1. A silicate-rich heterogeneous grain model with an excess of large particles is compatible with the observed spectrum of Giacobini-Zinner on August 26. Thus, weak or absent silicate emission does not necessarily imply an absence of silicates in the dust, although the abundance of silicate particles < or = 1 micrometer radius must have been lower than in Comet Halley.  相似文献   

The organochlorine contamination history of the Mersey estuary, UK, revealed by analysis of sediment cores from salt marshes   总被引：2，自引：0，他引：2  

Fox WM  Connor L  Copplestone D  Johnson MS  Leah RT 《Marine environmental research》2001,51(3):213-227

Sediment profiles in the Banks, Ince and Widnes Warth salt marshes in Northwest England contain a mappable record of historic pollution. For persistent organochlorine compounds this stretches back over 90 years. The PCB and HCH profiles can be successfully rationalised by dating methods, and they can be related to the dates of initial production and subsequent withdrawal from use of these chemicals as a result of restrictive environmental legislation. HCB has a more complex pollution profile as it has been manufactured in Northwest England, both deliberately as a pesticide and accidentally as a by-product of several chlorination processes, dating back to the start of the 20th century. The concentrations of degradation products of DDT are relatively constant through the sediment profile and are dominated by op'- and pp'-DDD with only minor contributions from the most toxic species, pp'-DDT. The quantities of these compounds resident in the reservoir of pollutants under these marshes have been calculated, and have fallen progressively in the last 30-50 years.  相似文献   

Inference of a 7.75 eV lower limit in the ultraviolet pumping of interstellar polycyclic aromatic hydrocarbon cations with resulting unidentified infrared emissions     

Robinson MS  Beegle LW  Wdowiak TJ 《The Astrophysical journal》1997,474(1):474-478

The discrete infrared features known as the unidentified infrared (UIR) bands originating in starburst regions of other galaxies, and in H II regions and planetary nebulae within the Milky Way, are widely thought to be the result of ultraviolet pumped infrared fluorescence of polycyclic aromatic hydrocarbon (PAH) molecules and ions. These UIR emissions are estimated to account for 10%-30% of the total energy emitted by galaxies. Laboratory absorption spectra including the vacuum ultraviolet region, as described in this paper, show a weakening of the intensity of absorption features as the population of cations increases, suggesting that strong pi* <-- pi transitions are absent in the spectra of PAH cations. This implies a lower energy bound for ultraviolet photons that pump infrared emissions from such ions at 7.75 eV, an amount greater than previously thought. The implications include size and structure limitations on the PAH molecules and ions which are apparent constituents of the interstellar medium. Also, this might affect estimations of the population of early-type stars in regions of rapid star formation.  相似文献   

藏南冈底斯带西段铁矿找矿工作新进展     

张振利张计东  李广栋孙肖邓绍颖  郭金城冯桂兴 专少鹏 《地质通报》2006,25(5):544-548

通过1:25万区域地质调查,在冈底斯带西段革吉县南部地区新发现了具有进一步工作价值的铁矿及含铜铁矿点4处、银铜多金属矿点2处.重点对桑穷勒磁铁矿、含铜磁铁矿及列马镜铁矿进行了初步评价.其中前者磁铁矿矿石资源量为401.59Mt,后者镜铁矿矿石资源量18.50Mt.这是冈底斯带西段铁矿等找矿工作的重要新进展.  相似文献   

OPTIMAL MODE OF SEDIMENT TRANSPORT BY SHALLOW FLOWS IN UPLAND AREAS     

D. PAL  S. N. PRASAD 《国际泥沙研究》2000,(2)

lNTR0DUCTI0NThemechanismofsedimenttransp0rtinshall0wchanneIfiowscanbequitec0mplicateddependingupona)themechanismofsoildetachment,b)thesizeandshaperanges0ftheavailablesediment,c)thesedimentc0ncentrati0n,d)theenergeticc0nditi0n0ftheflow,e)thechannelsurfacec0nditi0n,Dtherateofwaterinfiltrati0nandg)thechemicalc0nstituentspresentinthes0ilandthesurfacewater.Th0ughthedetachment0fs0ilparticlesbyrainfallistheprimarys0urce0favailablesediment,theeffect0fdynarnicwaterwavesandwind-gustsals0playasignifi…  相似文献