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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
561

Host habitat location mediated by olfactory stimuli in anaphes iole (hymenoptera: mymaridae), an egg parasitoid of lygus hesperus (hemiptera: miridae)

Manrique, Veronica 17 February 2005 (has links)
Lygus hesperus is an important pest on different crops including cotton and alfalfa in the western U.S. Anaphes iole is a common parasitoid of Lygus spp. eggs in the U.S. and has potential as a biological control agent against L. hesperus in different crops. Its foraging behavior has been studied to a limited extent, but it is unknown whether A. iole females rely on plant volatiles to locate host habitats. L. hesperus feeding and oviposition are known to induce emission of plant volatiles in cotton and maize, but no studies have addressed the role of plant volatiles in the host searching behavior of A. iole. The objectives of this study were to evaluate the attraction of A. iole females toward volatiles derived from L. hesperus habitats and flight response of A. iole females toward cotton plants harboring L. hesperus eggs or treated with methyl jasmonate. Results from olfactometry bioassays showed that female wasps were attracted to odors emanating from different plant-L. hesperus complexes and from adult L. hesperus, while plants damaged by non-hosts or mechanically-damaged were not attractive. These findings suggested that A. iole females use specific plant volatiles released following L. hesperus feeding and oviposition to locate host habitats. In addition, in flight chamber tests A. iole females discriminated between cotton plants with moderate (41 eggs) and high (98 eggs) levels of L. hesperus infestations relative to uninfested plants, but not between plants with low (7 eggs) infestations compared to uninfested plants. In larger scale experiments conducted in the greenhouse, female wasps responded to L. hesperus-infested plants but not to methyl jasmonate-treated plants under similar conditions. Overall, results from this study revealed that A. iole females employ volatile signals to locate its host’s habitat and that they are attracted to plants damaged by L. hesperus feeding and oviposition. However, further research should seek to identify the chemical elicitors involved in the release of plant volatiles attractive to A. iole females.
562

Development of a variable-temperature ion mobility/ time-of-flight mass spectrometer for separation of electronic isomers

Verbeck, Guido Fridolin 29 August 2005 (has links)
The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to demonstrate the ability to discriminate between electronic isomers. Ion mobility allows for the separation of ions based on differing cross-sections-to-charge ratio. This allows for the possible discrimination of species with same mass if the ions differ by cross-section. Time-offlight mass spectrometry was added to mass identify the separated peak for proper identification. A liquid nitrogen-cooled mobility cell was employed for a two-fold purpose. First, the low temperatures increase the peak resolution to aid in resolving the separated ions. This is necessary when isomers may have similar cross-sections. Second, low temperature shortens the mean free path and decreases the neutral buffer gas speeds allowing for more interactions between the ions and the drift gas. Kr2+ study was performed to verify instrument performance. The variable-temperature ion mobility spectrometer was utilized to separate the distonic and conventional ion forms of CH3OH, CH3F, and CH3NH2 and to discriminate between the keto and enol forms of the acetone radical cation. Density functional theory and ab initio calculations were employed to aid in proper identification of separating isomers. Monte Carlo integration tools were also developed to predict ion cross-section and resolution within a buffer gas.
563

Build Special Restaurant's Management Flight Simulator by System Dynamics

Huang, Tzu-Wen 22 July 2008 (has links)
This research is an empirical study on the kind of special restaurants, aiming at understanding the growth strategy in food and beverage industry by means of system dynamics and building the management flight simulator for the research object. Based on several times of interviewing an Italian restaurant, the research model is built and composed of five major parts, which are ¡§Subsystem of customer and market,¡¨ ¡§Subsystem of employee,¡¨ ¡§Subsystem of capacity,¡¨ ¡§Subsystem of service quality and satisfaction¡¨ and ¡§Subsystem of finance.¡¨ Under the property of low repurchasing in this kind of restaurant, conclusions below are found after policy simulating: 1. Strategy of high-price with high-cost is suitable for this kind of restaurant¡¦s long-term management. Though the cost is higher, high-price strategy results in high customer satisfaction. With high revenue and steady customers, the possibility of insufficiency of growth and investment decreases. 2. Even if a restaurant has high customer satisfaction and sufficient capital, growing too fast will fail it easily. Growing too fast will fail a restaurant because of insolvency, especially the kind of special restaurant, of which the frequency of patronage is not as high as that of common restaurants. Therefore, quick expansion will bring out huge expenditure; thus, fails a restaurant even if there is high service quality and high satisfaction. 3. Advertisement makes future customers patronize earlier. Maintaining frequent customers is a better strategy. Advertisement makes future customers patronize earlier, but its effect does not last as long as word-of-mouth effect. 4. Business environment is better when all competitors compete with each other by means of high-price strategy. By adopting low-price strategy, a restaurant will draw lots of customers and need to expand itself. Quick expansion, however, reduces customer satisfaction and leads to fail eventually. Instead, managers who adopt high-price strategy run business better. As a result, business environment is better when market players adopt high-price strategy.
564

none

Chien, Lien-yin 25 July 2008 (has links)
This article is about building a dynamic model of an Italian food restaurant in Kaohsiung, Taiwan. The model contains six sectors, including human resource sector, kitchen sector, quality sector, training sector, market sector and the financial sector. Depending on these six sectors we build a computer simulation model. With this computer simulation model can help people get better understanding of the real operational system and can have better insights of the restaurant management. In this article, we found out that the restaurant manager needs to emphasize the quality and training of their employees. If the restaurant grows without enough qualified employees, the growth will meet its limit and has problems like quality decline, working overtime, high turnover rate, customer base decline and may cause the restaurant to close up. In this article, we also found out that the training must both emphasize the professional training and ethic training and it is better to emphasize a little more on the ethic training. If the restaurant managers focus only on the professional training, it will bring serious problems. Since it has many conflicts during the work, the ethic training can help employees having more stable, social emotions for better customer service and build a trust and harmonious working atmosphere. Otherwise, the conflicts between the coworkers may cause service delay, service mistakes, increasing cost and high turnover rate. All these problems will affect the operation of the restaurant management in long term. In this article, the dynamic model contains many soft variables of the restaurant management. It can provide the learner of dynamic model building to learn about the soft variables modeling.
565

None

Chen, Ying-ting 01 August 2008 (has links)
This research tries to observe an advertizing printing company¡¦s business model and understand the interaction between different policies implemented on the company by System Dynamics. Futhermore, building Management Flight Simulatior can let one simulate the situation and policies to find the effective policies. After the simulation and the evaluation, we find that if the company only pays attention to marketing but didn¡¦t make efforts on the employees¡¦ training, it will block the company¡¦s growth, and the manager always ignored this problem. However, if we only make efforts on training the employees or hiring new employees, it will be just a waste of money in the long run. Therefore, the manager should enlarge his thinking boundary, and considerate not only marketing but training, and even many other policies, and the most important is their interaction, at appropriate time.
566

Aerodynamic and Flight Dynamic Simulations of Aileron Characteristics

Soinne, Erkki January 2000 (has links)
No description available.
567

Surface induced dissociation of small molecules and peptides utilizing delayed extraction with tandem time-of-flight mass spectrometery [sic] /

Haney, Lisa L. January 1999 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
568

Surface induced dissociation of small molecules and peptides utilizing delayed extraction with tandem time-of-flight mass spectrometery [sic]

Haney, Lisa L. January 1999 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.
569

Micro-and pulsed-plasmas fine tuning plasma energies for chemical analysis /

Moser, Matthew A. January 2002 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 99 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
570

Performance advantages of maximum likelihood methods in prbs-modulated time-of-flight electron energy loss spectroscopy /

Yang, Zhongyu, January 2003 (has links) (PDF)
Thesis (Ph. D.) in Physics--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 153-158).

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