This thesis is motivated by practical problems encountered in handling live products in the poultry processing industry, where live birds are manually transferred by human labors. As the task of handling live products is often unpleasant and hazardous, it is an ideal candidate for automation. To reduce the number of configurations and live birds to be tested, this thesis focuses on developing analytical models based on the Lagrange method to predict the effect of mechanical inversion on the shackled bird. Unlike prior research which focused on the effect of different inversion paths on the joint force/torque of a free-falling shackled bird, this thesis research examines the effect of kinematic constraints (designed to support the bird body) on the shackled bird. Unlike free-falling, the imposed kinematic constraints enable the shackled bird to rotate about its center of mass, and thus minimize wing flapping. In this thesis, birds are geometrically approximated as ellipsoids while the lower extremity is modeled as a pair of multi-joint serial manipulators. With the constraint equations formulated into a set of differential algebraic equations, the equations of motion as well as Lagrange multipliers characterizing kinematical constraints are numerically solved for the bird motion, specifically the position, velocity, and orientation and hence the forces and torques of the joints. The dynamic models are verified by comparing simulation results against those obtained using a finite element method. The outcomes of this thesis will provide some intuitive insights essential to design optimization of a live-bird transfer system.

A series of experiments was performed with the Texas A&M University Nuclear Science Center Reactor (NSCR) to verify ²³⁵U delayed neutron emission rates. A custom device was created to accurately measure a sample's pneumatic flight time and the Nuclear Science Center's (NSC's) pneumatic transfer system (PTS) was redesigned to reduce a sample's pneumatic flight time from over 1,600 milliseconds to less than 450 milliseconds. Four saturation irradiations were performed at reactor powers of 100 and 200 kW for 300 seconds and one burst irradiation was performed using a $1.61 pulse producing 19.11 MW-s of energy. Experimental results agreed extremely well with those of Keepin. By comparing the first ten seconds of collected data, the first saturation irradiation deviated ~1.869% with a dead time of 2 microseconds, while the burst irradiation deviated ~0.303% with a dead time of 5 microseconds. Saturation irradiations one, three and four were normalized to the initial count rate of saturation irradiation two to determine the system reproducibility, and deviated ~0.449%, ~0.343% and ~0.389%, respectively.

V této práci je představeno zařízení pro ozařování MeV ionty při tandemovém urychlovači na univerzitě v Uppsale. Jsou podány základy teorie interakce iontů s pevnou látkou a modifikace materiálu pomocí iontů s vysokou energií. Zařízení tandemového urychlovače je popsáno počínaje generací iontů a konče dopadem iontů na vzorek v hlavní komoře zařízení pro iontové ozařování. Následně jsou detailně charakterizovány modifikace systému pro přesun vzorků a popsán princip jeho funkce. Pilotní aplikace upraveného systému v oblasti materiálových modifikací je prezentována na příkladu ozařování Ge kvantových teček. Homogenita rozložení iontů na vzorku při ozařování je testována pomocí simulace elektrostatického deflektoru.

Die Arbeit beschäftigt sich mit der Untersuchung der Beanspruchungen von Staurollenketten. Zunächst wurde in den Grundlagen der Aufbau von unterschiedlichen Staurollenkettenarten dargestellt, die Eigenschaften miteinander verglichen und kategorisiert. Aufbauend auf dem anschließend geschaffenen Verständnis der wirkenden Reibpaarungen bzw. -arten wurden FEM-Analysen durchgeführt, um dadurch auftretende Spannungen zu detektieren und das thermische Verhalten der unterschiedlichen Werkstoffpaarungen zu ermitteln. Innerhalb der praktischen Versuche der Arbeit kam es zur Ermittlung der Bruch- und Dauerfestigkeiten nach ISO15654 [DIN04]. Zur Untersuchung der Eigenschaften der Ketten unter praxisnahen Randbedingungen wurde ein Versuchsstand konzipiert, welcher die Ermittlung von Kennwerten zwei unterschiedlicher Kettengrößen unter härtesten Bedingungen ermöglicht. Durch diesen Versuchsstand wurden die Staukraft, die Kettenzugkraft durch das Drehmoment am Antrieb, die Kettengeschwindigkeit, die Kettenlängung und das Temperaturverhalten dauerhaft überwacht. Im letzten Kapitel der Arbeit wurde eine Überwachungsstation für unterschiedliche Baugrößen von Staurollenketten entwickelt und die Funktionsweise durch Versuche nachgewiesen. / This dissertation is dealing with the investigation of the load behaviour of accumulation roller chains. Initially, the structures of different types of accumulation roller chains are described, properties are compared and categorised. Based on the created understanding of acting tribological pairing and friction mechanisms, FEM analysis have been performed to evaluate occurring stresses and determine the thermal behaviour of the various material combinations. Within the testing procedures, breaking strength and fatigue strength have been investigated in accordance with DIN ISO 15654 [cf. DIN04]. A test bench has been developed for practically relevant testing of the chains, where determination of characteristic values can be done under hard testing conditions for two different chain types. The test bench ensures measurement and survey of accumulation forces, tensile chain forces (by torque moment at drive), chain speed, chain elongation and chain temperature during whole testing time. The last chapter of the dissertation deals with the development of a 'control and monitoring unit' for accumulation roller chains with various dimensions including proof of function by trials.

<p>Real-time hybrid simulation (RTHS) has demonstrated certain advantages over conventional large-scale testing. In an RTHS, the system that is under study is partitioned into a numerical and a physical substructure, where the numerical part is comprised of those elements that are easier to model mathematically, while the physical part consists of those that present a complex behavior difficult to capture in a numerical model. The most complex part of this study is the isolation system, a technology used to protect structures against earthquakes by modifying how they respond to ground motions. Unbonded Fiber Reinforced Elastomeric Isolators (UFREIs) are devices that can accomplish this task and have gained attention in recent years because of their modest but valuable features that make them suitable for implementation in low-rise buildings and in developing countries because of their low cost. Our end goal for this work is to enable the testing of scaled versions of these elastomeric isolators to understand their behavior under shear tests and realistic loading. </p> <p>A testing instrument was designed and constructed to apply a uniaxial compressive force up to 22kN and a shear force of 8kN simultaneously to the specimens. A testing program was conducted where four primary sources of signal distortion were identified as caused by the servo-hydraulic system. From these results, a mechanics-based model was developed to understand better the dynamics that the sliding table can introduce to the measured signals accounting for inertial and dissipative forces. Two Bouc-Wen models were implemented to simulate the behavior of the UFREIs. The first only accounts for the hysteretic behavior of the isolator, and the second accounts for the additional nonlinearities found in the isolator’s behavior. These models were assembled in a virtual RTHS which is available to users interested in learning the applications of RTHS of a base-isolated structure with a nonlinear component.</p> <p>An RTHS experiment was conducted in the IISL where the control system comprised a delay compensator and a proportional-integral controller, which exhibited a good tracking performance with minimal delay and low RMSE. However, it can increase the distortion of the oil-column resonance in the measured signals. The simulation captures the behavior of the isolated structure for small displacements. However, it underestimates the displacement of the full-scale specimen for large displacements. The RTHS showed a better approximation of the displacement of the full-scale structure than the theoretical behavior approximated by the Bouc-Wen models.</p>

No description available.

Nous avons développé un système de transfert des surfaces monocristallines préparées sous ultra-haut vide (UHV) vers un milieu électrolytique pour effectuer des mesures voltampérométriques. Ce système original très compact comprend une valise sous vide et une cellule électrochimique dédiée. Le système a été testé avec succès sur des surfaces monocristallines de platine, en particulier la surface Pt(111) très sensible à la qualité de la préparation sous UHV. Puis nous avons utilisé ce système pour caractériser les propriétés électrochimiques du système Pt/W(111) avec d'une part l'effet des contraintes élastiques pour les couches ultra-minces planaires de Pt épitaxié ainsi que la stabilité en milieu électrolytique de nano-pyramides obtenues par déstabilisation en température des surfaces Pt/W(111). Ce travail ouvre des perspectives intéressantes pour l'étude électrochimiques des surfaces modèles préparées sous UHV. / In this work, we developed a system for transferring single crystal surfaces prepared in ultra-high vacuum (UHV) to an electrolytic medium where voltammetric measurements are carried out. This unique system includes a compact vacuum chamber and its dedicated electrochemical cell. The system was successfully tested on platinum single-crystal surfaces; in particular the Pt (111) surface which is well known for it's sensitive to the quality of the preparation under UHV. Then we used this system for characterizing the electrochemical properties of the Pt / W (111) system, both the effect of elastic strain of ultrathin epitaxial planar Pt films and the stability of nano-pyramids obtained after a temperature annealing of the planar Pt / W (111) system. This work opens up interesting perspectives for the study of electrochemical model surfaces prepared in UHV.

我國為配合加入WTO，紓緩日後大量農產品開放進口，對本土農地利用管理與農業生產所帶來的衝擊，政府乃大幅度修正農業發展條例（以下簡稱農發條例），以為因應。該條例及配套法案業於民國八十九年一月四日、六日及十三日經立法院三讀通過，並由總統於同年一月二十六日公布施行。本次農發條例之修正要點，在農地政策方面，主要側重於農地合理的利用、有效地管理與適當的釋出，其中最大的轉變在於調整為「放寬農地農有，落實農地農用」原則，不再限制農地移轉承受人之身份與資格，並有條件地許可農企業法人承受農地。這樣的變革，旨在建立更為開放競爭的耕地買賣市場，增進耕地的流動性，以利農業經營者取得耕地，調整農業經營結構，應值贊同。然而，條文內容有無疏漏不妥？仍有待深入檢討；條文原則性的規定能否落實？尚待相關法令的配合修訂，方能儘速建立合理農地利用、管理與釋出機制，以確保我國的農業發展。 　　緣此，本研究乃就農發條例之研修條文內容，深入探析農地政策與移轉規定之轉變，同時藉由實地調查（問卷調查與深度訪談）及拜訪農政等單位，以瞭解移轉制度變遷之實施現況及其對農業經營之影響程度，並訪察農業經營者之意向及博採各方之想法，據以確實地檢視現行農地移轉制度有關之爭議與問題，再提出研修現行條文、修訂行政命令及研議配合措施等改進意見，冀能有助於促進農地合理利用，並供後續法律修正、執行之參考。最後，再綜合本研究之成果，推衍以下結論： 　　一、調整農地農有制度係時勢潮流，農地農用管理機制應詳加落實。 　　二、實證調查發現，受訪者大抵認同目前農地移轉制度之變革規定，惟對促進農地流動及帶動農業升級助益不大。 　　三、引進農企業法人承受耕地之成效不彰，且牽涉法令繁多，亟待整合修訂。 　　四、制度規則未能公平提供誘因，且未能有效減低執行面之不確定性，應儘速檢討改進並確實執行之。 　　五、農民與農企業法人普遍欠缺對相關法令資訊的瞭解，應加強相關人員之專業訓練與宣傳輔導。 　　此外，在研究過程中，發現仍有相關課題有待未來後續研究，以促使農地更有效利用管理，並能確保農業永續發展，建議如下： 　　一、健全農企業法人承受耕地之管理制度。 　　二、建構重要農業區之區分與保護機制。 　　三、進一步研究農業產銷班與農地利用之關聯性。 / For joining WTO and moderating the impact of the import of agricultural products on agricultural lands use and, management and production, our government reacted by revising the Agricultural Development Act (ADA). The ADA has been revised by the Legislative Yuan on January 4 and promulgated by the Presidential Decree on January 26, 2000. The main point of the revision is to emphasis on reasonable farmland uses, effective management and adequate release of the land regulations in the agricultural policy. The main change is to adjust ADA’s principle from “the right to own and use farmland to be limited to the farmer” to “the release of the restriction on farmland transferee and realization of the substantial farmland uses.” The revision does no longer set a limit to the status and qualification of transferees and permits the transferable rights of agribusiness on some certain conditions. It is approved that the revision is to establish a more open and competitive arable land market, to improve the liquidity of arable lands, to facilitate the acquirement of arable lands for agribusiness, and to adjust the agricultural production structure. However, we should review the completeness and realization of the revised ADA after the promulgation in order to assure the agricultural development. 　　Therefore, the main purpose of this thesis is to probe into the change of the agricultural land policy and transfer regulation from the provisions of the revised ADA, examine the exercising of transfer system change and its influence on agricultural operation, investigate the intention of agricultural managers for reviewing the relative debates and issues, and then offer some advice as references of revision in the future. The conclusion is described as follows: 　　1.It is a trend of the times to adjust the transfer system that the right to own and use farmland is limited to the farmer, and the mechanism of assuring the substantial farmland uses should be realized. 　　2.From empirical research, the interviewees almost agree to the new agricultural land transfer system, but think that it is not useful for accelerating the liquidity and promoting the level of agricultural industry. 　　3.It is not significant on introducing agribusiness to be the transferee of arable lands, and it is necessary for our government to integrate too many relative and complicated laws. 　　4.We should review and implement the revised ADA because the rules themselves cannot provide fair incentives and effectively reduce the uncertainty from exercising it. 　　5.Farmers and agribusinesses lack the knowledge of relative laws, so the government should enhance them the professional training and give them consultant service. 　　In addition, from this research, we also found that some issues need to be studied for effective management of agricultural lands and sustainable development of agricultural industry in the future. 　　1.How to sound the management institution when agribusinesses want to be the transferee of arable lands. 　　2.How to designate important agricultural zones and establish protection mechanism. 　　3.Study the correlation between the agricultural product marketing class and agricultural land uses.