This paper is to advance some relevant techniques to set up a three-dimensional industrial surveying system of “building blocks type”, making use of the electronic theodolite, standard ruler and portable computer.
The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The parti...The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The particular issue of plot size is a crucial factor in the whole housing policy as it directly affects the urban land use and consumption and extends its influence far into sustainability and affordability issues and the whole housing policy and supply process. The article, analysing the applied standards, argues that plot subdivision can substantially contribute to providing more access of housing to the low-income groups. Large plot sizes can be subdivided driven by the need to realize security of tenure, doubling the owner-occupier housing stock which is the base issue of self-help housing, increases housing finance, provides variety of housing choices and behind all it conforms to the legacy principles and some cultural attributes of the local community. The article underlined existence of a cumbersome regulatory system, subdivision procedures and development controls which need to be reformed.展开更多
The paper develops a methodology for the optimal sizing of a generic wind farms, focusing primarily on reliability aspects, besides the traditional economic ones. A specific objective function is proposed in order to ...The paper develops a methodology for the optimal sizing of a generic wind farms, focusing primarily on reliability aspects, besides the traditional economic ones. A specific objective function is proposed in order to select the better wind farm configuration, based upon the profits related to the economic trading in the deregulated electric market and the costs due to investment, operation ＆ management, and to system unavailability. This objective function is accurately investigated as a function of the turbines number in order to derive the most convenient alternative, which implies also the optimal choice of the single wind generators size. The ranking coming out from this assessment is then compared with that one established in terms of expected load not supplied. A compromise choice, between the best alternatives provided by the two criteria has finally adopted. A simple numerical application is reported in the last part of the paper for testing the validity of the proposed approach. Also uncertainty aspects in the basic input parameters are taken into account and possible way of dealing with them is briefly illustrated.展开更多
The indentation test is a localized testing technique;therefore,the role of the material size-effect and local non-uniformity is of much importance.The influence of the heterogeneity in size-independent materials has ...The indentation test is a localized testing technique;therefore,the role of the material size-effect and local non-uniformity is of much importance.The influence of the heterogeneity in size-independent materials has been studied previously.The present work detailedly investigated the influence of the material size-effect and heterogeneity(inclusions near the indenter tip)on the indentation hardness using a size-dependent strain gradient plastic theory.And it was found that when considering the material size-ffect,shallow hard inclusions in the heterogeneous materials more significantly enhance the material indentation hardness compared with the size-independent materials which are based on the conventional plastic theory.This hardening effect is be-lieved to be related to the elevation of the load and local constraints of large deformation.The effect of material inhomogeneity mainly comes from the non-uniformity of the structure rather than the inclusion modulus itself especially when the size-effect is involved,and the transition range of the inclusion modulus'influence is pretty narrow.The effect of non-uniformity becomes negligible after the initial inclusion depth is larger than its diameter.The horizontal offset of the indenter from the inclusion is also of much sensitivity to the influence of the heterogeneous indentation.This paper focuses on the scaling relationships in micro-and nanoindentation,the influence of non-uniformity in microscopic materials is studied and supplemented as well.展开更多
文摘This paper is to advance some relevant techniques to set up a three-dimensional industrial surveying system of “building blocks type”, making use of the electronic theodolite, standard ruler and portable computer.
文摘The article discusses plot size standards applied in the government sites-and-services projects in Khartoum and probes into the possible alternative ways of re-establishing solid grounds for those standards. The particular issue of plot size is a crucial factor in the whole housing policy as it directly affects the urban land use and consumption and extends its influence far into sustainability and affordability issues and the whole housing policy and supply process. The article, analysing the applied standards, argues that plot subdivision can substantially contribute to providing more access of housing to the low-income groups. Large plot sizes can be subdivided driven by the need to realize security of tenure, doubling the owner-occupier housing stock which is the base issue of self-help housing, increases housing finance, provides variety of housing choices and behind all it conforms to the legacy principles and some cultural attributes of the local community. The article underlined existence of a cumbersome regulatory system, subdivision procedures and development controls which need to be reformed.
文摘The paper develops a methodology for the optimal sizing of a generic wind farms, focusing primarily on reliability aspects, besides the traditional economic ones. A specific objective function is proposed in order to select the better wind farm configuration, based upon the profits related to the economic trading in the deregulated electric market and the costs due to investment, operation ＆ management, and to system unavailability. This objective function is accurately investigated as a function of the turbines number in order to derive the most convenient alternative, which implies also the optimal choice of the single wind generators size. The ranking coming out from this assessment is then compared with that one established in terms of expected load not supplied. A compromise choice, between the best alternatives provided by the two criteria has finally adopted. A simple numerical application is reported in the last part of the paper for testing the validity of the proposed approach. Also uncertainty aspects in the basic input parameters are taken into account and possible way of dealing with them is briefly illustrated.
基金the National Natural Science Foundation of China(Grant Nos.11890681,12032001,and 11521202).
文摘The indentation test is a localized testing technique;therefore,the role of the material size-effect and local non-uniformity is of much importance.The influence of the heterogeneity in size-independent materials has been studied previously.The present work detailedly investigated the influence of the material size-effect and heterogeneity(inclusions near the indenter tip)on the indentation hardness using a size-dependent strain gradient plastic theory.And it was found that when considering the material size-ffect,shallow hard inclusions in the heterogeneous materials more significantly enhance the material indentation hardness compared with the size-independent materials which are based on the conventional plastic theory.This hardening effect is be-lieved to be related to the elevation of the load and local constraints of large deformation.The effect of material inhomogeneity mainly comes from the non-uniformity of the structure rather than the inclusion modulus itself especially when the size-effect is involved,and the transition range of the inclusion modulus'influence is pretty narrow.The effect of non-uniformity becomes negligible after the initial inclusion depth is larger than its diameter.The horizontal offset of the indenter from the inclusion is also of much sensitivity to the influence of the heterogeneous indentation.This paper focuses on the scaling relationships in micro-and nanoindentation,the influence of non-uniformity in microscopic materials is studied and supplemented as well.
