Logistics plays a more and more important role in manufacturing company to sharp competitive in today’s supply chain integration. As the end of logistics in manufacturer, container loading intellectualization has attracted more and more focuses. Harmonious coordination between planning and execution ground high performance of the container loading. Several challenges exist in business operations. Firstly, container loading planning is time-consuming. Several case-based constraints exist in the optimization defined by different customers and the Customs. Secondly, execution driven by container loading is inefficient. Operators may use unclear or unreadable paper-based guidance during execution which is inconvenient to handle. Besides, due to various situations, shipping documentations are complex. Afterwards Order-picking, a critical part in executions, is a costly activity. Thirdly, coordination during whole container loading process is another challenge. Information sharing between planning and execution is delayed and inaccurate. The whole procedure usually cannot be monitored by managers in a remote office. Problems cannot be addressed without timely provision of data. This research targets to establish a smart container loading platform based on real life practices and constraints. Unlike common warehouse operation, warehouse executions are driven by container loading. To overcome the challenges, an integrated solution is proposed with three main parts. The first one is to establish RFID-enabled real-time smart environment where device-level data is collected timely with bidirectional communications under Wi-Fi occasionally connected situation. Secondly, Service-oriented Architecture (SOA) is applied in rule-based computation and heterogeneous information sources integration. In rule-based computation, constraint is computed and wrapped as rule. It is a kind of service which is restored in service repository according to its properties. Under different cases, several rules are addressed and invoked in a specified sequence to realize different business logics. And the platform should communicate with heterogeneous sources within short time. Systems wrap application programming interfaces (API) as web services which can be invoked flexibly at any time. Data fetch process is divided into several threads which extract data concurrently. Thirdly, container loading optimal model is provided based on practical constraints. Based on various rules, shipments are clustered as groups before loading. To load containers more equally, heuristic algorithm is provided with reducing container capacity continuously until other constraints are violated or more shipment groups are separated. Four contributions have been made in this study. Firstly, a five-layer system architecture is proposed for small and medium enterprises (SMEs) applications especially in occasionally connected network environment, rule-based computations, and efficient data exchanges. Secondly, several practical constraints of loading planning are addressed and a heuristic algorithm is designed. Shipments can be equally loaded while satisfying most conflicted constraints. Thirdly, a solution for auto-ID enabled warehouse execution is provided. The solution is driven by container loading equipped with real-time information capturing and processing. Fourthly, a guidance can be refereed for real life implementations in SME. The guidance summarizes system customization procedures with reengineered resources. / published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

It is expected that South Africa will have to construct as much generating capacity in the next five years as has been constructed over the past 50 years. Industrialization and urbanization dictates that the larger portion of this increase will be required in the supply areas under the control of Municipal Electricity Undertakings, which means that these undertakings will have to anticipate rapid growth in their infrastructures. This will put a tremendous strain on their resources of revenue, materials and labour, and it is obvious that comprehensive and co-ordinated policies are required to be developed to enable these undertakings to deliver the electrical energy to the final consumers at the lowest possible cost. The Electricity Undertaking is a business organization with unusually difficult managerial problems in all its functional areas. Its personnel are adversely affected by the vast area of supply and by the resulting difficulty of direct supervision and control. The capital cost of electrical equipment is high, and there may be a tendency to reduce the initial cost by ignoring the long term costs associated with the selection of equipment. Electricity pricing is very difficult, as electricity is not a uniform product. The consumption patterns of the consumers causes severe peaking of loads to occur, resulting in very low utilization )f the capital equipment involved, and which can threaten to overload existing networks. These problems are compounded by the fact that the undertaking is a monopoly and as such is not driven by the free-market motivating forces, such as a profit motive and the constant need to improve to meet competition. There is thus no motive to seek optimum solutions to the many problems. It is shown that the Load Factor is an indication of the efficient use of scarce resources, and that it is similar to measurements of profitability, such as Return-on-Investment, etc. It is therefore possible to replace the missing drive for profit and product improvement by the need to constantly improve the load factor. By making this the main objective of the undertaking many of the stated problems are put in their correct perspective. Maintenance becomes important, as power failures adversely affect the load factor. More care is exercised in equipment selection, as long term energy losses are taken into account. Electricity pricing and its effect on consumer consumption patterns becomes important. The concerted effort to improve the load factor is referred to as load management. Due to the tremendous increase in electricity consumption which is expected over the next decade it is certain that load management will play an ever increasing role. Load Management is defined as the sustained attempt at modifying the load curve. Soft load management refers to pricing policies and incentive schemes designed to induce users to shift their loads .out of the peak periods. Hard load management physically switches customer loads. This thesis examines the results obtainable from various methods of load management including off-peak incentive tariffs, on-peak-reduction rebates, the use of current limiters, peak load reduction by means of voltage reduction and remote control of water heater cylinders. It is shown that whereas Sasolburg saves around R7S0 000.00 p.a. and Randburg saves over Rl,5-million p.a.,other towns such as Pretoria and Pietermaritzburg find their geyser control systems ineffective, and are phasing them out. It has hitherto not been possible to determine the actual savings which would result from the installation of a geyser control system, or to determine the optimum number of controlled geysers. The result was that some undertakings would install a control system at considerable expense which resulted in minimal savings, while other towns forego the opportunity to save hundreds of thousands of rands in reduced demand charges. In this thesis, the author develops a feasibility study model which permits the system load curve to be analysed and the viability of a geyser control system to be determined. The model was tested against the controlled and uncontrolled load curves of Somerset West, and was found to be accurate. It was shown that a geyser control scheme is a very viable proposition for those undertakings where the feasibility study shows a contribution of more than 0,5 KVA per geyser towards peak load reduction. This forms the basic guideline for the selection of an appropriate form of load mangement, and guidelines are presented to develop supporting policies in all fields of the undertakings' functions. In order to facilitate correct decision-making and to assist in the development of comprehensive policies, a database of concepts and models is presented in the various fields and various misconceptions are dicussed. The guidelines have been applied by several electricity undertakings. By using the Feasibility Study Model it was shown that the proposed installation of 4000 geyser control units at Oudtshoorn, at a cost of over RI-million, was not viable. The Feasibility Study Model permits the savings to be calculated for different numbers of geysers and it was shown that the system saturates at about 1500 controlled geysers. By reduci ng the number of controlled geysers to around 1500 the installation cost will be reduced by about R500 000.00 and the system will show a net operating savings , " of RI05 540.00 in the first year, increasing as ESCOM increases its tariffs. The application of these principles conceivably prevented the needless expenditure of RI-million on a system that would have run at an operating loss of over R17 000.00 p.a. The feasibility study model was applied to the Stanger load curve to determine the correct selection of load management. The results indicate excellent response to geyser control, and showed that a system controlling 2500 geysers, costing R498 500.00 would show a gross savings of R297 000.00 in the first year, rising to RSI0 000.00 within 5 years if ESCOM increases its tariff by 10% p.a. Based on these results and recommendations the Department of Finance gave ad hoc approval to the Borough of Stanger for the additional expenditure in the current financial year to install the control equipment. The guidelines indicated a similar result for Tongaat, where the gross savings would be R360 000.00 in the first year, increasing to R637 680.00 within 5 years if ESCOM increases its tariff by 10% p.a. The estimated cost of the control equipment is R493 649.00. In complete contrast, the feasibility studies for geyser control undertaken on the Ballito load curve showed a contribution of less than 0,5 KVA per geyser, which indicated that the alternative forms of load management should be implemented. The results are contained in the case studies. / Thesis (DBA)-University of Durban-Westville, 1986.

No description available.

Este trabalho buscou avaliar a técnica ultrassônica de Tempo de Voo da Onda Difratada (TOFD - Time-Of-Flight-Diffraction) para o monitoramento de trincas de fadiga nucleadas no interior de tubos de aço Superdúplex. Para isso, foram fabricados corpos de prova do tipo single edge bending SE(B) a partir de um tubo de aço Superdúplex sem costura. Estas amostras foram ensaiadas em fadiga, e o crescimento de trinca foi monitorado com as técnicas de TOFD, de Flexibilidade no Descarregamento (Compliance) – durante os ensaios, foram dadas sobrecargas mecânicas que causaram deformação plástica. As deformações serviram de pontos de referência para analisar o crescimento de trinca. Para aferir a validade os resultados obtidos com o TOFD nos ensaios de fadiga e fazer uma correlação com o monitoramento em campo de defeitos em tubos de aço Superdúplex, foi fabricado um padrão que simulou um tubo com defeito interno conhecido. Este padrão foi inspecionado com o TOFD, empregando os mesmos equipamentos e parâmetros utilizados nos ensaios de fadiga. Foi possível monitorar o crescimento de trinca em fadiga utilizando a técnica de TOFD e houve forte correlação entre os dados obtidos com o TOFD e o Compliance. A inspeção no tubo padrão manteve uma diferença entre a medida real e a obtida com o TOFD proporcional às encontradas durante o monitoramento dos ensaios de fadiga. / This study aimed to evaluate the ultrasonic technique Time-Of-Flight-Diffraction (TOFD) in monitoring fatigue nucleated cracks within super duplex steel pipes. In order to do it, single edge bending SE (B) specimens were manufactured using a super duplex steel seamless pipe. These samples were tested in fatigue and crack growth was monitored with two different techniques: TOFD and Flexibility in Unloading (Compliance). During the tests, it was used mechanical overloadings so deformation would be cause on the steel pipes. The deformations caused by that served as reference points to analyze the cracking growth. Thus, to assess the validity of the data obtained with the TOFD in fatigue tests, it was made a pattern that simulated a tube with known internal defect. This pattern was inspected with the TOFD, using the same equipment and parameters used in the fatigue tests. A correlation with the monitoring of defects field super duplex steel pipes was also made. The experiment has shown it is possible to monitor the cracking growth fatigue using the TOFD technique. Figures indicate, as well, there is a strong correlation between results obtained with the TOFD and Compliance. The inspection of the standard steel pipe maintained a difference between the actual measurement and obtained measurement. That difference was proportional from TOFD data and those found during the monitoring of the fatigue tests.

Este trabalho buscou avaliar a técnica ultrassônica de Tempo de Voo da Onda Difratada (TOFD - Time-Of-Flight-Diffraction) para o monitoramento de trincas de fadiga nucleadas no interior de tubos de aço Superdúplex. Para isso, foram fabricados corpos de prova do tipo single edge bending SE(B) a partir de um tubo de aço Superdúplex sem costura. Estas amostras foram ensaiadas em fadiga, e o crescimento de trinca foi monitorado com as técnicas de TOFD, de Flexibilidade no Descarregamento (Compliance) – durante os ensaios, foram dadas sobrecargas mecânicas que causaram deformação plástica. As deformações serviram de pontos de referência para analisar o crescimento de trinca. Para aferir a validade os resultados obtidos com o TOFD nos ensaios de fadiga e fazer uma correlação com o monitoramento em campo de defeitos em tubos de aço Superdúplex, foi fabricado um padrão que simulou um tubo com defeito interno conhecido. Este padrão foi inspecionado com o TOFD, empregando os mesmos equipamentos e parâmetros utilizados nos ensaios de fadiga. Foi possível monitorar o crescimento de trinca em fadiga utilizando a técnica de TOFD e houve forte correlação entre os dados obtidos com o TOFD e o Compliance. A inspeção no tubo padrão manteve uma diferença entre a medida real e a obtida com o TOFD proporcional às encontradas durante o monitoramento dos ensaios de fadiga. / This study aimed to evaluate the ultrasonic technique Time-Of-Flight-Diffraction (TOFD) in monitoring fatigue nucleated cracks within super duplex steel pipes. In order to do it, single edge bending SE (B) specimens were manufactured using a super duplex steel seamless pipe. These samples were tested in fatigue and crack growth was monitored with two different techniques: TOFD and Flexibility in Unloading (Compliance). During the tests, it was used mechanical overloadings so deformation would be cause on the steel pipes. The deformations caused by that served as reference points to analyze the cracking growth. Thus, to assess the validity of the data obtained with the TOFD in fatigue tests, it was made a pattern that simulated a tube with known internal defect. This pattern was inspected with the TOFD, using the same equipment and parameters used in the fatigue tests. A correlation with the monitoring of defects field super duplex steel pipes was also made. The experiment has shown it is possible to monitor the cracking growth fatigue using the TOFD technique. Figures indicate, as well, there is a strong correlation between results obtained with the TOFD and Compliance. The inspection of the standard steel pipe maintained a difference between the actual measurement and obtained measurement. That difference was proportional from TOFD data and those found during the monitoring of the fatigue tests.

Thesis advisor: John E. Ebel / Thesis advisor: Mark D. Behn / On January 12, 2015, a magnitude 3.1 mainshock occurred in Plainfield, Connecticut near Wauregan Tilcon Quarry, causing modified Mercalli II-IV intensities. Shortly after the event, a team from Weston Observatory installed portable seismographs in the epicentral area. The portable array detected hundreds of small earthquakes from around the quarry, with 26 events that were accurately located. P-wave first motion directions obtained from readings of the mainshock suggest a thrusting focal mechanism on a NNE-SSW trending fault. In this research, we collected 113 gravity measurements in the proximity of the quarry to verify and correct local fault geometry proposed by historic aeromagnetic and geologic mapping. Interpretations of the computed simple Bouguer anomaly are consistent with historic mapping, with a few exceptions. The gravity survey constrains a NNE-SSW trending fault that dips west underneath the quarry, inferred to be the Lake Char-Honey Hill Fault, and reduces ambiguity in the position of an undefined ESE-WNW trending fault, which appears to be on strike to intersect the quarry. A 3D boundary element program (3D~Def) is used to simulate quarry-induced stress changes on these faults in order to analyze the possibility of inducing seismicity through crustal unloading in the region. Quarry operations resulted in the removal of mass from the crust, which decreased lithostatic load. In a setting confined by a maximum horizontal compressional stress, decreasing the lithostatic load, orminimum principal stress (σ3), shifts a Mohr-Coulomb diagram toward failure. The boundary element model shows that following the excavation of materials at the quarry, positive Coulomb failure stress changes occur on the west dipping Lake Char-Honey Hill Fault. In agreement with past studies, our results suggest that quarrying operations can trigger seismic activity in specific settings with stress regime, fault orientations, and rock characteristics such as those that exist in the northeastern U.S. In order to mitigate the risk for future earthquakes related to quarrying operations, these factors must be considered before operations begin. / Thesis (MS) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

In the field of civil engineering, particularly structural foundations, low-cost options and time saving construction methods are important because both can be a burden on the public. Drilled shafts have proven to both lower cost and shorten construction time for large-scale projects. However, their integrity as load-carrying foundations has been questioned. The statnamic load test was conceived in the 1980s as an alternative method of testing these larger, deeper foundation elements. Performing a load test verifies that the load carrying capacity of a foundation is agreeable with the estimated capacity during the design phase and that no significant anomalies occurred during construction. The statnamic test, however, is classified as a rapid load test and requires special data regression techniques. The outcome of available regression techniques is directly related to the available instrumentation on the test shaft. Generally, the more instrumentation available, the more complete results the regression method will produce. This thesis will show that a proposed method requiring only basic instrumentation can produce more complete results using a predictive model for side shear development with displacement during the statnamic test. A driven pile or drilled shaft can be discretized into segments based on the load shed distribution model. Each segment can be analyzed as a rigid body. The total static capacity is then the summation of each segments’ contribution. Further, a weighted acceleration can be generated and used to perform an unloading point analysis.

The problems with the crack length determination by the unloading compliance method are well known for Charpy size specimens. The final crack lengths calculated for bent specimens do not fulfil ASTM 1820 accuracy requirements. Therefore some investigations have been performed to resolve this problem. In those studies it was considered that measured compliance should be corrected for various factors, but satisfying results were not attained. In the presented work the problem was attacked from the other side, the measured specimen compliance was taken as a correct value and what had to be adjusted was the calculation procedure. On the basis of experimentally obtained compliances of bent specimens and optically measured crack lengths the investigation was carried out. Finally, a calculation procedure enabling accurate crack length calculation up to 5mm of plastic deflection was developed. Applying the new procedure, out of investigated 238 measured crack lengths, more than 80% of the values fulfilled the ASTM 1820 accuracy requirements, while presently used procedure provided only about 30% of valid results. The newly proposed procedure can be also prospectively used in modified form for the specimens of different than Charpy size.

Extended periods of mechanical unloading are known to be detrimental to bone health. Astronauts who spend months in microgravity aboard the International Space Station (ISS) are at particular risk. It is anticipated that NASA will not drastically increase the size of the astronaut corps, and this will mean increased likelihood of repeat missions for more astronauts. Thus, it is important to better understand the effects that prolonged, multiple bouts of unloading have on bone. This study utilized the hindlimb unloaded (HU) rat model to examine bone loss and recovery for single and double unloading bouts. Adult male Sprague-Dawley rats (6 months old) were randomized into the following groups: baseline (sacrificed at 6 months), 1HU7 (unloaded for 1 month, weight-bearing recovery for 3 months), 2HU10 (unloaded for 1 month, recovered for 2 months, unloaded for another month, and then recovered 2 months), 1HU10 (normal cage activity until 1 month HU ending at month 10, 2 month recovery followed), and aging controls (remained ambulatory throughout experiment). Every month (28 days), animals were terminated and the left femurs were excised, resulting in n=15 per group for each time point. Mineral and geometric properties were measured using peripheral quantitative computed tomography (pQCT) at the distal femur metaphysis, and quasi-static reduced platen compression (RPC) was used to estimate the mechanical properties of cancellous bone. Strength indices based on pQCT parameters were calculated as predictors of mechanical properties. Bone mass properties decreased due to HU and recovered within 2-3 months post-HU. A combination of increased periosteal apposition and endocortical resorption also occurred during HU. The initial HU bout suppressed normal age-related increases in mechanical properties and recovered within 1-2 months. Cancellous compressive strength index (CSI) most closely matched changes in mechanical properties. A second HU bout after two months recovery had a less detrimental effect on pQCT parameters but a greater negative impact on mechanical properties, when compared to pre-HU values. The opposite is true for mechanical properties if loss is characterized relative to aging controls. Recovery after the second HU period did not appear to be significantly affected by a previous bout of HU.