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Morphological and histochemical observations of the organic components of ostrich eggshell  [cached]
P.D.G. Richards,A. Botha,P.A. Richards
Journal of the South African Veterinary Association , 2012, DOI: 10.4102/jsava.v73i1.542
Abstract: The organic component of the avian eggshell can be divided into 3 portions, the shell membranes, the matrix and the cuticle. These have been well characterised in the chicken but little has been published with regard to the ostrich (Struthio camelus). A number of recent studies have indicated that the cause of intra-shell embryonic deaths in the ostrich is similar to intra-shell embryonic deaths that occur in the chicken. These deaths in the chicken are associated with the loss of or damage to the waxy cuticle and other organic components of the eggshell, which is reported to be absent in the ostrich eggshell. In this study, preliminary morphological and histochemical analyses, at the level of the light and electron microscope, have characterised the various organic components of the ostrich eggshell. The results of the histochemical and electron microscopical analyses suggest that there mayonly be 1 shell membrane in this species, which could play a major role in the limitation of bacterial penetration to the embryonic chamber. The shell membrane has a distinct elemental profile as determined by EDSanalysis. The matrix is shown to decrease in mesh size from the mammillary layer to the vertical crystal layer. The closer packing of the mesh may indicate the presence of a morphologically discernible termination signal to calcification or the remnants of an evolutionary calcified cuticle. The matrix of the pores may also forma defensive barrier against bacterial invasion, which could be damaged as a result of dipping the eggs before incubation.
Ultrastructural characteristics of ostrich eggshell: outer shell membrane and the calcified layers  [cached]
P.D.G. Richards,P.A. Richards,M.E. Lee
Journal of the South African Veterinary Association , 2012, DOI: 10.4102/jsava.v71i2.687
Abstract: The ultrastructure of the eggshell of the domestic hen has been well researched and structural studies of other avian species, such as the ostrich, often base their interpretation of egg shell structure on that of the chicken. In the ostrich, lowered hatchability and hatching trauma may be due to shell ultrastructural abnormalities. In the present study the ultrastructure of the calcified portion, and the outer shell membrane (OSM), of domesticated ostrich eggshells was investigated using standard electron microscopic techniques. Transmission and scanning electron microscopy studies demonstrated intimate contact between cup-shaped structures present on the OSMand the mammillary layer of the calcified portion of the shell. The initial calcium carbonate growth of the calcified shell was of a dendritic nature with nucleation sites on the surface of the cup's contents. The dendritic growth gave way to a more randomly-orientated, smaller crystallite growth structure, which changed in formas it neared the vertical crystal layer (VCL). The VCL is described as being both amorphous and 'crumbly' depending on the plane of fracture. These observations suggest that firstly, initial calcification is contained within the cups and is then directed outwards to formthe shell and that secondly, the VCL may contain an evolutionary, calcified cuticular layer. These observations serve as a baseline for studies investigating the effect of shell structure and strength on hatchling trauma and the influence of maternal diet.
A preliminary study on the application of image analysis for the measurement of ostrich eggshell traits
SWP Cloete Jr, AJ Scholtz, Z Brand, SWP Cloete
South African Journal of Animal Science , 2006,
Abstract: Embryonic mortality in developing ostrich embryos has been linked to water loss in eggs during artificial incubation. Traits possibly related to water loss were assessed on shell samples obtained from 512 hatched ostrich eggs. Moderate to high repeatability estimates (0.43 to 0.86) were derived from significant between female variance components for all traits. Two-trait between female correlations were unity or near unity when the same trait was assessed at either the side or the top of individual eggshells. Recordings at either site can thus be considered as the same on the level of the individual female, implying that in future studies only one measurement is needed during the evaluation of the traits investigated in this study. South African Journal of Animal Science Vol. 36(3) 2006: 155-159
Raman spectra database of the glass beads excavated on mapungubwe hill and k2, two archaeological sites in South Africa  [PDF]
Aurélie Tournié,Linda C Prinsloo,Philippe Colomban
Physics , 2010,
Abstract: About two hundred coloured glass beads (red, yellow, green, blue, white, black, pink, plum) were selected among the thousands of beads excavated on Mapungubwe hill and at K2, archaeological sites in the Limpopo valley South Africa, and have been studied with Raman scattering. The glass matrix of the beads was classified according to its Raman signature into 3 main sub-groups and corroded glass could also be identified. At least seven different chromophores or pigments (lazurite, lead tin yellow type II, Ca/Pb arsenate, chromate, calcium antimonate, Fe-S "amber" and a spinel) have been identified. Many of the pigments were only manufactured after the 13th century that confirms the presence of modern beads in the archaeological record. This calls for further research to find a way to reconcile the carbon dating of the hill, which currently gives the last occupation date on the hill as 1280 AD with the physical evidence of the modern beads excavated on the hill.
An engraved artifact from Shuidonggou, an Early Late Paleolithic Site in Northwest China
Fei Peng,Xing Gao,HuiMin Wang,FuYou Chen,DeCheng Liu,ShuWen Pei
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5317-6
Abstract: Cognition and symbolic thinking are viewed as important features of modern human behavior. Engraved objects are seen as a hallmark of cognition and symbolism, and even as evidence for language. Accumulated evidences including engraved bones, ochre, ostrich eggshells and stone artifacts were unearthed from Africa, Europe, Levant even Siberia Paleolithic sites. But the archaeological evidence for this, including beads, ornaments, burials, performed objects and engraved objects, is rarely discovered in the Pleistocene of East Asia. The present paper reports an engraved stone object unearthed in the Early Late Paleolithic levels about 30 ka BP at the Shuidonggou site (SDG) in northwestern China. It was unearthed in the 1980’s excavation from Lower culture unit of SDG1 but was identified in 2011 when the first author of this article observed the collection from the 1980’s excavations stored in the Institute of Archaeology of Ningxia Hui Autonomous Region for further detailed lithic analysis. This lithic artifact is the first engraved non-organic object of the Paleolithic period found in China. In order to clarify the details of the incisions and to document the human intentional modifications, we used a KEYENCE VHX-600 Digital Microscope to measure and observe all the incisions in 3-dimensional perspective. Comparing the natural cracks and analyzing many details of the incisions, we argue that incisions on this stone artifact are the result of intentional behaviors by ancient humans. Also, we exclude the possible other causes including animal-induced damages, post-depositional phenomenon and unintentional by-products. Combining all these features, we suggest that the incisions were made by an intentional behavior and were probably of a non-utilitarian character. Because the nature of most other engraved objects in China is debate, we cannot get a clear scenario of the emergence and progress of modern human behavior in North China. But we infer the possible existence of a counting or recording system, or other symbolic behaviors, which reflect considerably evolved cognitive capacities or modern human behavior in the Early Late Paleolithic of East Asia.
The Significance of the Earliest Beads  [PDF]
Robert G. Bednarik
Advances in Anthropology (AA) , 2015, DOI: 10.4236/aa.2015.52006
Abstract: This paper attempts to explore beyond the predictable and banal archaeological explanations relating to early beads and pendants. It recounts replication experiments to establish aspects of technology so as to better understand what can be learnt from the quantifiable properties of these artifacts. The article also scrutinizes the available empirical record in the light of taphonomic logic to translate the known spatial and temporal distributions of such remains into epistemologically meaningful pronouncements about the significance of the primary evidence. It is shown that numerous reasonable deductions become possible by engaging such avenues of inquiry. For instance some beads, in which production has been pushed to the limits allowed by the medium, seem to express a sense of perfection, and it is contended that beads are among the most informative forms of exograms that could possibly have survived from these very early times. A key requisite for the use and appreciation of all beads and pendants is a level of hominin self-awareness that essentially expresses full cognitive modernity.
间歇过程动态SDG建模  [PDF]
张贝克,郑然,马昕,吴重光
化工学报 , 2008,
Abstract: 目前用于间歇过程的SDG建模方式不能达到计算机辅助HAZOP的要求,本文在现有SDG-HAZOP理论基础上提出了面对间歇过程的动态SDG建模理论,并详细阐述了如何运用SDG对间歇过程进行建模的思路和方法,并运用该方法对一个煤制油流程的除灰工序进行建模和分析,同时解决了间歇过程SDG建模的模型接续性与故障和危险覆盖面最大化两方面问题。
Development of Polyester/Eggshell Particulate Composites
S.B. Hassan,V.S. Aigbodion,S.N. Patrick
Tribology in Industry , 2012,
Abstract: The development of Polyester/Eggshell particulate composites has been carried out. Uncarbonized and carbonized eggshell particles were used as reinforcement in polyester matrix. 10 to 50 wt% eggshell particles at intervals of 10 wt% were added to polyester as reinforcement. The microstructural analyses of the polyester/eggshell particulate composites were carried out using SEM and EDS. The mechanical properties and density were carried out by standard methods. The results showed that the density and hardness values of the polyester/eggshell particulate composite increased steadily with increasing eggshell addition. The tensile strength increased from 15.182 N/mm2 at 0 wt% eggshell addition to a maximum of 23.4 N/mm2 at 40 wt% eggshell addition for uncarbonized eggshell; while it increased to a maximum of 28.378 N/mm2 at 20 wt% eggshell addition for carbonized eggshell. Compressive strength increased steadily from 90.3 N/mm2 at 0 wt% eggshell additions to a maximum of 103.6 at 50 wt% eggshell addition for uncarbonized eggshell and 116.5N/mm2 at 50 % eggshell addition for carbonized eggshell. Hardness value increased from 91 HRF at 0 % eggshell addition to a maximum of 120.05HRF at 50 wt% eggshell addition for uncarbonized eggshell and 149.45HRF at 50 wt% eggshell for the carbonized eggshell. Flexural strength increased from 76.06 N/mm2 at 0 wt% eggshell addition to a maximum of 97.06 N/mm2 at 40 wt% eggshell addition for uncarbonized eggshell; however, it increased to a maximum of 106.66 N/mm2 at 20 wt% eggshell addition for the carbonized eggshell. The impact energy also increased from 0.1 Joules at 0 wt% eggshell addition to a maximum of 0.35 Joules at 30 wt% eggshell addition for uncarbonized eggshell; it however increased to a maximum of 0.45 Joules at 20 wt% eggshell addition for the carbonized eggshell. Hence the development of polyester/eggshell particulate composites material with good mechanical properties and light weight which is relevant to the electronics, auto and building industries has been achieved.
Fertility Recognition of Ostrich Egg Using Physical Properties  [PDF]
M.H. Abbaspour-Fard,B. Emadi,M.H. Aghkhani
Journal of Applied Sciences , 2010,
Abstract: The aim of this study was to investigate some physical properties of ostrich egg, including eggshell porosity, dimensional and gravimetric properties which were nondestructively measured to find any probable correlation between these properties and egg fertility. Currently one of the blockade problems in ostrich egg production industry is the impossibility of egg candling prior to hatching. Therefore, fractions of the hatcher are occupied by infertile eggs and soon fall to decay without any economical use. Totally 301 eggs were sampled during three consecutive weeks of June. The results showed overall, about 63% of the eggs were fertile and among these eggs, 7% were not hatched successfully. No significant correlation observed between physical properties of eggs and fertility. However, the data analysis on frequency of fertile and infertile eggs of different categorized properties indicated that some groups of eggs might have a higher fertile eggs frequency than infertile eggs. In general, the groups of eggs with aspect ratio about 1.2, weight of 1500 g, density of 1.15 g cm -3 and average shell pore diameter of less than 750 μm had a higher fertile egg frequency than infertile egg frequency. On the other hand, egg volume and dielectric properties had the least impact on egg fertility. Image processing of the eggshell pigment and thermal photography are recommended for further investigations.
基于开源组件的SDG推理平台  [PDF]
王杭州,陈丙珍,何小荣,赵劲松,邱彤
化工学报 , 2010,
Abstract: 符号有向图(SDG)是定性研究化工过程中变量间关系的有力工具,利用SDG的正向反向推理机制可以快速发掘出系统中变量之间影响的因果关系,不仅可以用于在线的故障诊断,还可以用于离线的危险和可操作性(HAZOP)分析。近年来,随着计算机和信息技术的发展,人们利用GensymG2或者C++开发了一些针对特定研究体系的SDG模型的计算机辅助推理系统,但是,目前还没有一个通用的SDG推理平台。为促进SDG在科研和教学中的广泛应用,本文介绍了通过公共组件来搭建的一套开放体系的SDG推理平台系统,这是服务器/浏览器结构的推理平台,使用方便,维护便捷。使用这套系统,可以方便地绘制特定研究体系的SDG模型的图形;可以快速建立针对特定研究体系的SDG系统并且进行相应的推理分析。本文通过一个例子演示了如何在SDG推理平台上建立特定SDG推理系统的方法,之后通过对两个研究体系建立SDG推理系统来展现该平台的有效性。
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