Дисертації з теми "HYBRID BTC"

The usefulness of interspecific crosses between Sitka spruce (Picea sitchensis (Bong.) Carr.) and interior spruce (Picea glauca (Moench) Voss, Picea engelmannii Parry and their hybrids) was investigated in one coastal environment. For height growth and bud set most of the variation was at the regional and individual cross level, but very little variation was at the subregional level. The main genetic effects, male and female, accounted for a majority of the genetic variance and additive genetic effects are interpreted as the main factor in the determination of height growth and bud set. For bud set the maternal source of variation accounted for the majority of the genetic variance and a maternal influence on bud set is suggested. Some specific cross combinations were outstanding in height growth and non-additive genetic factors are considered important in these crosses. For bud break most of the variation was due to the residual error, although regions and crosses were statistically significant sources of variation. The Female*Male term was the most important genetic source of variation although bud break is not considered to have as much genetic variation as height and bud set. Large differences were found in the pattern of cold hardiness in the fall and it is considered that photoperiod plays a much larger role than previously thought, especially for interior spruce. Most of the variation was again at the regional and individual cross level. The intermediate performance of the hybrids suggests an inheritance of cold-hardiness based on additive genetic effects. Recommendations are given in the text for the use of these hybrids as well as the areas in which further research would be desireable.
Forestry, Faculty of
Graduate

In the growing field of polycyclic aromatic hydrocarbons (PAHs), the replacement of carbon with isostructural atoms is becoming a versatile functionalisation strategy to tailor the optoelectronic properties of the materials. Among the different dopants, the substitution of C-C pairs by isoelectronic B-N covalent couples leads to isostructural molecular material bearing strong local dipole moments. This imparts a series of physical-chemical properties to the molecule, such as wider HOMO-LUMO gap, the introduction of anchoring points for gas storage and peculiar self-assembly behaviour on metal surfaces. The BN/CC isosterism concept goes back to the seminal discovery of the borazine (H3B3N3H3) by Stock and Pohland in 1926. Thus, in reference to its isoelectronic and isostructural relationship withbenzene, borazine ring is commonly known as “inorganic benzene”. Hence, borazine and its derivatives are valuable molecular modules to be inserted as doping units in graphiticbased carbon materials to tailor their physical-chemical properties. This dissertation focuses on the design, synthesis and characterisation of novel organic materials doped with borazine modules, with the aim of exploring the photophysics, electronics and self-assembly properties of hybrid boron-nitrogen-carbon (BNC)frameworks. Before addressing the detailed investigations of this thesis work, in Chapter I, a brief introduction on the past and recent achievements in the organic synthesis of borazine and its derivatives are given to the reader. This chapter also includes the main synthetic methods used for their functionalisations, as well as their chemical properties and materials applications. Chapter II addresses the design and synthesis of three-branched borazine doped polyphenylenes, in which one or more aryl units are replaced by borazine rings. Owing the possibility of functionalising the borazine ring with different groups on the aryl substituents at the N and B atoms, BNC polyphenylenes were prepared through the decarbonylative [4 + 2] Diels-Alder cycloaddition reaction. To achieve this, two types of molecular modules were synthesised: core and branching units. Therefore, having the possibility of introducing the borazine in different ratios, orientations and positions, three-branched hybrid polyphenylenes featuring controlled orientation and dosages of the doping B3N3-rings were prepared (Figure A.1). At last, the photophysical properties of borazine-doped polyphenylenes have been investigated, describing the relation between the light emission properties and the orientation / dosage doping of these hybrid materials. The second project tackled in this doctoral work is described in Chapter III. Inspiring by the local polar character of the borazine ring, B3N3 scaffold can theoretically interact with polar or polarisable gas molecules, thus making BN-materials promising candidates for tailoring the gas absorptions. In this chapter, the preparation of 3D BN metal organic framework (BN-MOF), composed by three-carboxyl borazine 3-1 as organic linker and [Zn4O(CO)6] as metal cluster is described (Figure A.2). Additionally, to evaluate the effect of the BN doping units in gas storage, the isostructural 3D C-MOF reference, in which the borazine core is replaced by the benzene unit, has been prepared (Figure A.2). The last section of the chapter is dedicated to the description of the X-ray crystal structures of the MOFs as well as their morphology, surface area and thermal stability. Finally, Chapter IV is dedicated to the investigation of three-pyridyl borazine derivatives, amenable to self-assemble and form 2D metal-organic porous network upon deposition on metal surfaces. The first part of the chapter deals with the synthesis of borazine 4-6 through a Suzuki cross-coupling reaction between borazine bearing three-OTf groups and an organoboron pyridyl moiety. The second part describes, by scanning tunnelling microscopy (STM), the tailoring of the 2D self-assembly of borazine 4-6 on Ag(100) and Cu(111) via coordination and thermal treatments. Specifically, densely packed honeycomb network on Ag(100) was observed, whereas interconnected chains were found on Cu(111). Upon deposition of additional Cu atoms at 420 K, a structural transformation can be induced on Cu(111), which leads to a fully three-fold coordinated triangular network (Figure A.3).

Thesis advisor: Dunwei Wang
Water splitting has been recognized as a promising solution to challenges associated with the intermittent nature of solar energy for over four decades. A great deal of research has been done to develop high efficient and cost-effective catalysts for this process. Among which tantalum nitride (Ta₃N₅) has been considered as a promising candidate to serve as a good catalyst for solar water splitting based on its suitable band structure, chemical stability and high theoretical efficiency. However, this semiconductor is suffered from its special self-oxidation problem under photoelectrochemical water splitting conditions. Several key unique properties of graphitic carbon nitride (g-C₃N₄) render it an ideal choice for the protection of Ta₃N₅. In this work, Ta₃N₅/g-C₃N₄ hybrid photoanode was successfully synthesized. After addition of co-catalyst, the solar water splitting performance of this hybrid photoanode was enhanced. And this protection method could also act as a potential general protection strategy for other unstable semiconductors
Thesis (MS) — Boston College, 2018
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Thesis advisor: Jeffery A. Byers
Thesis advisor: Chia-Kuang Tsung
Homogeneous catalysts are advantageous in selective catalysis due to the well-defined active site at the molecular level. The poor recyclability, bimolecular aggregation, and undesired poison resistance of homogeneous catalysts hinder further industrial application despite the controlled reaction pathway due to the homogeneous environment. On the other hand, heterogeneous catalysts are preferred in industry due to their high recyclability and high activity. Yet, poor selectivity due to undefined active sites is a drawback. The construction of a host-guest system where a molecular level catalyst is incorporated into the Metal-Organic Framework (MOF) provides a promising solution to bridge those two fields. This composite maintains the advantages of homogeneous and heterogeneous catalysts and overcomes the disadvantages. However, finding an incorporation method that is versatile with minimum synthetic modification of the host and guest remains one of the challenges. In the first part of this dissertation, a new concept called “aperture-opening encapsulation’’ is introduced for incorporating large and diverse guest molecules into MOFs without changing the identity of either the guest or MOF. The approach capitalizes on the existence of linker exchange reactions, which, as our kinetic studies show, proceed via competition between associative and dissociative exchange mechanisms. The second part describes how this method is applied to incorporate a molecular catalyst into the cavity of UiO-66 for the hydrogenation of carbon dioxide to formate, which is a useful application for energy related industry. The developed hybrid composite showed the ability to be recycled, showed no evidence of bimolecular catalyst decomposition, and was less prone to catalyst poisoning. These results demonstrate for the first time how the aperture-opening process resulting from linker dissociation in MOFs can be utilized as a strategy to synthesize host-guest materials useful for chemical catalysis. After the establishment of the hybrid catalyst, the last part of the dissertation describes our efforts into the investigation of mass transport in catalysis. The understanding of the interaction between the host-guest is beneficial for the development of biological analogs in the future
Thesis (PhD) — Boston College, 2019
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Municipal housing companies (MHCs) can be seen as hybrid organizations, operating under multiple institutional logics that are likely in tension with each other. Measuring the performance of hybrid organizations is a much harder exercise than measuring the performance of pure public or pure private entities. There is a lack of research in this area. To fill this gab van Helden and Reichard’s (2016a) proposed a framework that assigns typical characteristics to PMS in hybrids. The authors call for empirics to test the framework. Accordingly, the first purpose of the thesis is to test the hypotheses of this framework in practice, using a case study approach of two MHCs, MKB AB and LKF AB. The second purpose is to shed light on challenges, conflicts and even propose solutions for MCS/PMS. The thesis ended up by proposing a conceptual model for MCS/PMS that aims to reconcile conflicting goals and logics. The model integrates strategic management control tools (BSC and ERP) to support strategy implementation and formulation as well as to reconcile the different interests of the various stakeholders.

We present the synthesis and characterisation of novel single organic molecules known as phenoxylene borazines and borazatruxenes. Using temperature-dependant and concentration-dependant 1H NMR, we probe the supramolecular aggregation of these molecules in solution. Finally, we synthesise 2D hybrid material comprised of electron delocalised benzene rings and electron localised borazine rings. Using a combination of solid-state 11B and 13C NMR techniques, Raman spectroscopy and XPS, we confirm the presence of benzene and borazine regions in these novel materials.

The use of mobile devices and social media has been increasing dramatically and becoming critical for B2C businesses. Such businesses need to consider implementing e-commerce services in the mobile environment with social integration to satisfy their customers’ needs. Concepts like mobile commerce and social commerce are already being used extensively by many businesses. However, there are no clear guidelines in the literature on how to use mobile and social characteristics together for B2C e-commerce. Fusing these two concepts is what we call mobile social commerce (ms-commerce). In this thesis, we performed a thorough literature review to identify the characteristics of ms-commerce. The findings enabled us to first devise a proper definition for ms-commerce as the concept of performing online commercial activities in a mobile environment with the help of contributions from customers. Second, elements of the building blocks of ms-commerce, namely business models, m-commerce and s-commerce were identified based on commonly accepted fundamentals of the related concepts. Each building block has a critical role in increasing the value and efficiency of the product/service being delivered online by B2C businesses. We propose a mobile social commerce design framework along with a modular design model consisting of a generic class diagram that can be used for designing and developing ms-commerce applications that fit the specific needs of businesses. Businesses can choose the right elements to integrate in their ms-commerce application with the purpose of increasing the efficiency and integrating the social participation of customers. Three different scenarios were devised, and three mobile app prototypes were developed to support them, using the design model of our proposed framework. Finally, in light of our experience in developing ms-commerce applications, we discussed and contrasted the three different mobile development strategies, namely native, hybrid and web-based.

Digital communication systems which use Orthogonal Frequency Division Multiplexing (OFDM) are now widely used and have many advantages. The main disadvantage is the requirement for highly linear analogue electronics including the high power amplifier (HPA). This requirement cannot be met in all circumstances because of the occurrence of symbols with high peak to average power ratio (PAPR). Such symbols may be non-linearly distorted by limiting. Approaches to solve this problem have been either to reduce the PAPR at the transmitter or to try to mitigate the effect of the non-linearity at the receiver. Soft-limiting, i.e. applying limiting in software prior to the HPA is a simple way to reduce the PAPR. It produces non-linear distortion which will cause an increase in the bit-error-rate (BER) at the receiver. This thesis surveys existing alternatives ways of reducing the effect of non-linearity and proposes some new ones. Two iterative receiver techniques, based on statistical analysis of the nature of the non-linearity, have been implemented and investigated. These are the ‘Bussgang Noise Cancellation’ (BNC) technique and the ‘Decision Aided Reconstruction’ (DAR) techniques. As these techniques are valid for any memory-less nonlinearity, an alternative form of limiting, named as Inverted-Wraparound (IWRAP) has been included in the BNC investigation. A new method is proposed which is capable of correcting the received time-domain samples that are clipped, once they have been identified. This is named the ‘Equation-Method’ and it works by identifying constellation symbols that are likely to be correct at the receiver. If there are a sufficient number of these and they are correctly identified, the FFT may be partitioned to produce a set of equations that may be solved for the clipped time-domain samples. The thesis proposes four enhancements to this new method which improve its effectiveness. It is shown that the best form of this method outperforms conventional techniques especially for severe clipping levels. The performance of these four enhancements is evaluated over channels with additive white Gaussian noise (AWGN) in addition to clipping distortion. A technique based on a ‘margin factor’ is designed to make these methods work more effectively in the presence of AWGN noise. A new combining algorithm referred as ‘HARQ for Clipping’ is presented where soft bit decisions are combined from multiple transmissions. ‘HARQ for Clipping’ has been combined with the best version of the Equation-Method, and the performance of this approach is evaluated in terms of the BER with different levels of AWGN. It has been compared to other approaches from the literature and was found to out-perform the BNC iterative receiver by 3dB at signal to noise ratios around 10dB. Without HARQ, the best version of the Equation-Method performs better than the BNC receiver, at signal-to-nose ratios above about 17dB.

With the growth of modern communication techniques, demand for image data compression is increasing rapidly. The main goal of image compression techniques is to save a image using as much less bits as possible so that it occupies less space and it transmission is easy. Thus save lots of time while transmitting the image and also storage space. Image compression techniques are divided mainly into two domains: spatial domain and transform domain. Spatial domain techniques have the advantages of hardware complexity whereas transform domain techniques have the advantage of better compression ratio. This thesis is based on combining the two domain techniques to achieve better results. The two techniques used are BTC and DCT. Various test images are used to find the results and compare it with other compression techniques. Also compression efficiency, PSNR, MSE are found for all and compared.”

碩士
亞洲大學
資訊工程學系
103
With advances in computer networks and applications, the Internet has become indispensable to delivering confidential data. Information security is a prime concern as people’s use of the Internet increases. Various research studies have been done to better protect data in transit and ensure information security. Cryptographic methods and steganography are the most commonly used strategies to secure communications on the Internet. To compliment cryptographic methods, which do not hide secret data in transmitted packets, steganography is used to embed secret data so that unintended recipients are unaware of the secret data been transmitted in a steganographic image. Therefore, the quality of the stego image must be high for the embedded secret message. In general, information hiding (also called data hiding or data embedding) technique includes digital watermarking and steganography. These information hiding methods are currently used by many researchers for various applications. Embedding capacity is one of the key issues in data hiding research. In theory, a higher embedding capacity in the original medium usually means poorer visual quality. Block Truncation Coding (BTC) is one of the popular compression techniques used in image data hiding because of its low computation cost and ease of implementation. For a color image, there are three pairs of high mean and low mean values with three bitmaps. A common bitmap can be used to reduce the size of the BTC compression code. Chang et al. presented a data hiding method to conceal secret data in the color image BTC compression code by rearranging the encoding sequences of the high mean and low mean values. The proposed method attempts to embed more secret data into the color BTC compression code. In this thesis, a novel method is proposed to encrypt data based on the number of the element ‘1’. If the number is even, the data for the secret bit is ‘0’; otherwise, the secret bit is ‘1’. Furthermore, the Less Significant Bit (LSB) of all high mean and low mean pairs can also be used to embed the secret data. Experimental results show that with the proposed method, each block conceals at least 10 secret bits while good visual quality is maintained.

碩士
國立中興大學
企業管理學系所
107
In recent years, the demand for online shopping platforms has increased rapidly under the change of consumer behavior. After realizing the potential development of this market, numerous brand vendors expand merchandising channels by launching their products to online shopping platforms. The online shopping platform consists of more than a single model - B2B2C model and B2C model. Therefore, how do brand vendors select the appropriate model when it comes to online merchandising given various external factors is worth studying. This study uses the game theory to establish a dynamic game and further analyzes the optimal strategy a brand vendor could apply under all kinds of circumstances by considering the substitution effect among different merchandising channels under the two online shopping platform models, the proportion of transaction fees charged by platforms, and the number of consumers on each platform. The results indicate that the demand of B2B2C model grows along with the substitution effect increase, which prompts brand vendors to modify B2C model to B2B2C model and finally, running both models simultaneously. Moreover, it is also shown that the profit of online shopping platforms does not necessarily go up as the transaction fee rises.

A three-year study in Vernon B.C. considered the effects of two levels of wastewater irrigation on tree growth, nutrient uptake rates by the foliage and wood, nutrient leaching, and chemical properties of soils in a short rotation intensive culture (SRIC) hybrid poplar plantation where fourteen different clones were planted in separate subplots in a 5-ha area. Wastewater irrigation levels were determined on the basis of the calculated values of the local monthly potential evapotranspiration (ETp). In the first year, all plots received almost equal amounts of wastewater. In the second and third years, treatment 1 and the freshwater (control) plots were irrigated at the rate of ETp + 30%ETp. Treatment 2 received approximately twice this amount. The effect of wastewater irrigation on increased height, basal diameter, total leaf area, leaf biomass and woody biomass was measured as early as the end of the first growing season. During the third year, woody biomass production of the plantation was 11, 20, and 24 Mg/ha for control, treatment 1 and treatment 2, respectively. Concentration of N,P, and K in the foliage of wastewater irrigated trees increased significantly in the third year. Nutrients in the soil solution were monitored in samples from suction lysimeters. In the first growing season, concentrations of N, P, K, in soil solution were significantly higher than in the following two years. This was attributed to cultivation of the land at the time of establishment of the plantation. At the end of the third year, concentrations of N and P in the foliage of wastewater-irrigated plots were higher than in the freshwater plot. Other nutrients remained unchanged in different irrigation treatments. Soil N, P, Na and Mn decreased while K, Ca, Mg, Zn, Cu and Fe remained unchanged from 1988 through 1990. Efficiency of the soil-plant system in removing nutrients added through wastewater was: N, 97% and 95%; P, 97% and 94%; K, 40% and 0%; Na, 12% and 0%; Mn, 79% and 66%; Zn, 93% and 80%; Cu, 100% and 100%; and Fe, 100% and 92%; for treatments 1 and 2, respectively. Because of the high concentrations of Ca and Mg in the soils, removal efficiencies of these elements were not measurable. Nutrient uptake rates by the woody biomass were N, 71% and 42%; P, 29% and 20%; K, 50% and 33%; Ca, 21% and 14%; Mg, 8% and 5%; Na, 0.6% and 0.5%; Mn, 46% and 36%; Zn, 78% and 70%; Cu, 18% and 4%; and Fe, 30% and 22% for treatments 1 and 2, respectively. Based on these data, it was concluded that the optimal wastewater irrigation level for the plantation in the first three years would be treatment 1 (1.3 x ETp), where nutrient uptake levels by woody biomass and nutrient removal efficiencies were higher than for treatment 2 (2.6 x ETp), therefore the groundwater contamination level would be lower.

博士
國立臺灣科技大學
化學工程系
99
This research was divided into three parts to study the effect of solvent basicity, kinetics and structure studies, and application of N,N’-bismaleimide-4,4’- diphenylmethane (BMI) polymerization reacted with barbituric acid (BTA). In the first part, the polymerizations of BMI initiated by BTA carried out in a variety of solvents at 130 ℃ were studied. The nitrogen-containing cyclic solvents such as N-methyl-2-pyrrolidinone (NMP) acted as a catalyst to promote the formation of the three-dimensional crosslinked network structure. By contrast, the polymerization in a cyclic solvent that did not contain nitrogen such as γ-butyrolactone resulted in nil gel content. The higher the solvent basicity, the larger the amount of insoluble polymer species formed. The molar ratio of BTA to BMI also played an important role in the polymerizations. The resultant polymers, presumably having a hyper-branched structure, exhibited much narrower molecular weight distributions than those prepared by conventional free radical polymerizations. The BMI polymerizations using BTA as the initiator could not be adequately described by conventional free radical polymerization mechanisms. A polymerization mechanism that took into account the generation of a ketone radical pair between BTA and BMI and the subsequent initiation, propagation and termination reactions was proposed. In the second part, both the isothermal and non-isothermal polymerizations of BMI with BTA were investigated by the differential scanning calorimeter. The experimental results showed that the polymerizations of BMI with BTA were governed by the competitive Michael addition reaction and free radical polymerization mechanisms. Furthermore, the contribution of free radical polymerization becomes more important when the mole fraction of BTA decreases. 1H-NMR and 13C-NMR measurements further support the coexistence of the Michael addition reaction and free radical polymerization mechanisms. A preliminary kinetic model that took into account the competitive Michael addition reaction and free radical polymerization mechanisms was developed. Finally, synthesis and characterization of the vinyltriethoxysilane-modified silica nanoparticles were investigated. It was shown that the vinyltriethoxysilane molecules had been successfully grafted onto the silica nanoparticles. The native and silane-modified silica dispersions in NMP with the total solids contents in the range 1-6 wt% exhibited dramatically different flow behaviors. The polymerization of BMI initiated by BTA in the presence of the native or vinyltriethoxysilane-modified silica nanoparticles were then carried out inγ–butyrolactone (total solids content = 20%). The higher the level of silica, the better the thermal stability of the BMI/silane/silica composite particles. The silane-modified silica particles significantly improved their dispersion capability within the continuous BMI oligomer matrix. Furthermore, the degree of dispersion of the vinyltriethoxysilane-modified silica particles in the BMI oligomer matrix decreased with the weight percentage of silica based on total solids being increased from 20 to 40 wt%. In addition, preparation and characterization of novel polymeric composite materials comprising diglycidyl ether of a bisphenol A (DGEBA), 4,4’-diamino diphenylsulfone (DDS), BMI and BTA were investigated, too. Incorporation of a small level (5%-20% based on total weight) of BMI/BTA into the thermosetting system of DGEBA/DDS resulted in polymeric composite materials exhibiting a homogeneous morphology, enhanced heat resistance and dimensional stability, and rather balanced mechanical properties. These results were attributed to the competitive curing reaction mechanisms including the ring-opening, Michael addition and free radical polymer reactions simultaneously occurring during the formation of the three-dimensional intercrosslinked network structure.

This work project consisted of developing a Marketing Plan for SEMEAR, a program of a social organization with the mission to help the full integration of people with Intellectual and Developmental Disabilities (IDD) in society. The group focused on the role of SEMEAR na Mercearia business unit to help improve SEMEAR’s overall performance and, for that purpose, conducted a strategic diagnosis and analyzed the market and consumers of artisan al products. Each member of the group suggested one strategic initiative, each one with three tactics, presented as recommendations to SEMEAR, focusing on fighting seasonality and increasing the financial stability all yearlong (a key step towards financial self-sustainability) and on increasing brand awareness with the ultimate goal of promoting the inclusion of disabled people in our society.

This work project consisted of developing a Marketing Plan for SEMEAR, a program of a social organization with the mission to help the full integration of people with Intellectual and Development al Disabilities (IDD) in society. The group focused on the role of SEMEAR na Mercearia business unit to help improve SEMEAR’s over all performance and, for that purpose, conducted a strategic diagnosis and analyzed the market and consumers of artisan al products. Three strategic initiatives were suggested, each one with three tactics, presented as recommendations to SEMEAR, focusing on fighting seasonality and increasing the financial stability all year long (a key step towards financial self-sustainability) and on increasing brand awareness with the ultimate goal of promoting the inclusion of disabled people in our society.

碩士
國立中興大學
全球事務研究跨洲碩士學位學程
105
Taiwanese SMEs’ growth has been stabilizing along with Taiwanese economics and they are faced with fierce competition in the domestic market. Different from past researches that study theoretically on SME internationalization, this thesis aims to conduct a comprehensive analysis and provide SMEs a practical guidance to their transformation and internationalization by combining Balanced Scorecard (BSC) and Hybrid-Expert Based ISM and DEMATEL Models. The case applied in this thesis is a Taiwanese SME publisher, Future Career Professional Publisher (FCPP), who is undergoing its transformation and internationalization process due to the many problems faced. The questionnaire designed in this thesis is sent to the senior managers and the company owner for their professional opinions on the company’s internationalization, while in the end six questionnaires are retrieved for further analyses. Results from this research indicate that SMEs’ internationalization is an unstable system and has to be continuously reevaluated. Finance is not always the most important factor, while, in the practical case, elements in different BSC aspects form more complicated relationships than it should be theoretically. Managers’ global mindset is taking the lead in SMEs internationalization, while employee human capital is regarded to be of little impact. Organizational adaptability, innovation, customer expecting value and customer core benefit are influential but unstable elements that will lead the case company into a breakthrough or complete failure. Complete educational service and oversea sales growth are the main indicators to the company’s effectiveness of the company’s internationalization strategies implemented. There are three contributions of this thesis to SME internationalization: (1) in the academic perspective, BSC is no longer a result-oriented measurement tool but rather a forward-looking one that offers directions for strategic plans; (2) in the managerial perspective, the strategy map constructed helps Taiwanese SMEs to transform and make its way to internationalization; while (3) the Hybrid-Expert Based ISM and DEMATEL Models applied serves as a tool for SMEs to examine the status of their internationalization and enhance their performance.