Studies on Group 10 Pincer Carbene Metal Complexes

Selective oxidation chemistry is a topic of intense interest worldwide, in particular when using molecular oxygen (O2) directly as the oxidizing species. The primary reason for using O2 rather than other oxidants is to take advantage of the inexpensive nature of oxygen; however, the radical ground state of O2 leads to non-selective reactions with organic substrates. As such, basic knowledge and understanding involving the fundamental reactions of O2 with organometallic species will be required in order to overcome this lack of selectivity. The work presented in this dissertation has two main research goals to help address this issue. First, we have synthesized and characterized a number of various pincer-carbene containing Ni and Pd hydrides. We have postulated that these species might function as homogeneous catalysts to deliver O atoms to various organic or inorganic substrates. Second, we are interested in demonstrating the reactions of these carbene complexes with O2. As both the precursors and O2 reaction products of carbene-pincer complexes have been studied only briefly previously, we anticipated that our studies would add to the fundamental understanding of these complexes. Specifically, syntheses and characterization of novel pincer carbene Pd-H complexes was achieved. The pincer carbene Pd-H complex proved reactive with O2; however, the isolation of a discrete Pd-OOH species was unsuccessful. Investigation of the oxygen transfer ability of these complexes was done through in situ reaction of Pd-H species, O2 and organic substrates. However, there was no evidence indicating oxygen transfer to the organic substrates. New pincer carbene Pd and Ni complexes were prepared and characterized through alternative routes to M-H or M-OOH. Although none of these routes led to isolation of M-OOH species, MeCCC-Pd-OTf reacted with H2O2/H2O to form MeCCC-Pd-OH. Further investigation on this reaction suggested that the desired Pd-OOH species may initially be formed which slowly decomposed to the Pd-OH species. Attempts to prepare carbene pincer Ni-H complexes and their precursors via a variety of routes resulted in several novel reaction products. We have prepared and structurally-characterized the first example of a unique dinuclear Ni compound containing MeCNC ligands in both bridging and chelating modes. As well, we have obtained a new 3-dimensional Ag-carbene coordination polymer obtained through a novel reverse transmetallation. This result is only the second case in which carbene transfer from Ni2+ to Ag+ is observed

Factors influencing customers' satisfaction in tourist hotels in Tanzania

The major objective of this study was to investigate factors influencing customer satisfaction in tourist hotels. More specifically, the study intended to investigate whether there is significant relationship between the level of perceived service quality and customer satisfaction in tourist hotels, to assess the extent to which perceived price influence customer satisfaction in tourist hotels and to evaluate whether the hotel location has significant influence on customer satisfaction in tourist hotels. The survey covered some hotels allocated near the beach and those located at the city centers. The major findings from this study is that, among other factors, perceived quality, and perceived prices are influential factors in determining customers' satisfaction in the hotel industry. The study findings indicated that there was a positive and significant relationship between perceived quality, perceived price and customers' satisfaction in tourist hotels. However, the relationship between hotel location and customers' satisfaction was found to be week in this study. Lastly, it was found that most of tourist hotels are opened and constructed not only in urban areas but also concentrating in strategic areas like beaches and other tourist centers which may be far from the city centers. The study recommended that setting reasonable prices and providing high quality of services may meet customers' satisfaction, hence attracting more customers from all over the world

Feed-forward: Strengthening assessment of pre-primary and primary science and mathematics education in Tanzania

Classroom assessment is a critical part of teaching and learning and is a potentially useful tool for enhancing learning outcomes. It provides information on where learners are with their learning goals and what they need to do to improve their understanding and meet the intended learning outcomes. In response to the agent\u27s need for proper interpretation of classroom assessment, researchers and policymakers have developed guidelines, principles, and models to help teachers understand and implement effective assessment conceptions. Despite these initiatives, research continues to show that teachers struggle to interpret assessment policies and implement practices aligned with contemporary formative assessment notions. This paper presents a narrative review of 52 pieces of literature related to pre-primary and primary science and mathematics education assessment between 2008 and 2023. To respond to the proposed research questions using Tanzania as a case study, and focusing on science and mathematics in pre-primary and primary education, we performed this narrative review of the literature on formative assessment and its potential to improve classroom teaching. Findings indicate that principles and models alone are insufficient to create the necessary changes in classroom assessment and thus call for the need for integrated and focused professional learning initiatives that enable teachers to collaboratively explore new assessment practices. Findings indicate further that such professional learning models require ongoing support by knowledgeable practitioners. In addition, effective support strategies require time and effort to develop learning cultures that recognize the value of assessment for learning and translate it into action

Leadership, Teaching and Learning in Times of Crisis in Southern Tanzania

The outbreak of the COVID-19 pandemic has had a significant impact on education provision worldwide. School leaders, teachers and parents found themselves in uncharted circumstances, which hugely impacted their roles in promoting children’s learning. The purpose of this study was to investigate the roles played by leaders, teachers, and parents during the COVID-19 crisis. This paper discusses teaching and learning in this time of crisis. The study sampled 10 head teachers, 60 schoolteachers and 57 parents representing 10 primary schools in five districts in the Lindi region of Tanzania. A postmodernism lens was applied to respond to questions about the strengths and weaknesses of support structures, such as parents, teachers, and local and central government, in the era of COVID-19. Data indicate that teachers, parents, and even the government, had to try various approaches to shift between different roles involved in addressing learning demands in the era of COVID-19 in Tanzania. Generally, the study identifies complex tensions between the support structures, that had been brought on by the pandemic. It is through understanding the complex tensions and balancing various roles that we can begin to understand the teaching and learning landscape in times of crisis

Design of Soft Viterbi Algorithm Decoder Enhanced With Non-Transmittable Codewords for Storage Media

Viterbi Algorithm Decoder Enhanced with Non-transmittable Codewords is one of the best decoding algorithm which effectively improves forward error correction performance. HoweverViterbi decoder enhanced with NTCs is not yet designed to work in storage media devices. Currently Reed Solomon (RS) Algorithm is almost the dominant algorithm used in correcting error in storage media. Conversely, recent studies show that there still exist low reliability of data in storage media while the demand for storage media increases drastically. This study proposes a design of the Soft Viterbi Algorithm decoder enhanced with Non-transmittable Codewords (SVAD-NTCs) to be used in storage media for error correction. Matlab simulation was used in this design in order to investigate behavior and effectiveness of SVAD-NTCs in correcting errors in data retrieving from storage media.Sample data of one million bits are randomly generated, Additive White Gaussian Noise (AWGN) was used as data distortion model and Binary Phase- Shift Keying (BPSK) was applied for simulation modulation. Results show that,behaviors of SVAD-NTC performance increase as you increase the NTCs, but beyond 6NTCs there is no significant change and SVAD-NTCs design drastically reduce the total residual error from 216,878 of Reed Solomon to 23,900

Exploring Effective ICT Integration Strategies in Education: A Case of Two Public Primary Schools in Mombasa, Kenya

Purpose: The contemporary education landscape is undergoing a significant transformation, largely driven by the integration of Information and Communication Technologies (ICT). This paper explores the experiences of educators as they incorporate ICT into teaching and learning. Methodology: The study was conducted in Mombasa City, Kenya, and utilized qualitative research methods, including in-depth interviews, focus group discussions, and classroom observations, in a case study design involving two urban primary schools. The research meticulously documented the experiences of 16 participants. Findings: The findings of the study highlight several advantages of using ICT in teaching and learning, including easy access to information, interactive and personalized learning opportunities, as well as collaboration. However, the data also revealed significant challenges faced by educators, such as unstable electricity, inadequate ICT gadgets, internet fluctuation, and a lack of skills to integrate ICT into teaching. Unique Contribution to Theory, Policy, and Practice: Educators consistently stressed the importance of continuous support and professional development to enhance their ICT integration skills. Furthermore, the research emphasized several promising recommendations, including the installation of alternative sources of electricity, sourcing for additional ICT devices, supervising learners while using ICT gadgets, and conducting professional development initiatives tailored to the creation of a collaborative community of practice (COP), which have the potential to effectively address these challenges. To fully leverage the potential of ICT for enriching the learning experience, equipping students with essential digital skills, and preparing them for a digital-centric world, educational institutions, and policymakers must prioritize investments in technological infrastructure and foster a culture of innovation and collaboration among educators

Assessment of non transmittable codewords enhancement to Viterbi Algorithm Decoding

A research was submitted to (IJCSIS) International Journal of Computer Science and Information Security, Vol. 12, No. 9, September 2014Researchers have shown that practical mobile communication channels introduce errors that are concentrated in a certain locality rather than random errors. These are burst errors caused by deep fading of the wireless channel or a lightning strike. The existing Viterbi Algorithm (VA) capable of correcting random errors is inefficient in correcting burst errors and therefore resulting in unacceptable amount of residual errors. This paper presents an assessment of Non- Transmittable Codewords (NTCs) enhancement technique to VA in decoding the received signals subjected to burst errors that may occur in poor channels. A hard decision, 1/2 rate and constraint length K is equal to 3 Viterbi Algorithm decoding technique, Binary Phase- Shift Keying (BPSK) and Additional White Gaussian Noise (AWGN) are components used in MATLAB software based simulation when assessing the proposed technique. Applying 6NTCs to VA decoder enables the decoder to reduce 83.7 percent of its residual errors. However, the technique reduces the encoder’s data transmission rate from 1/2 to 1/

Bandwidth Aware FEC Algorithms for Wireless Communication Systems

Forward Error Correction (FEC) codes used by receivers to correct transmission errors without retransmission add a considerable amount of redundant bits to data bits. The addition of redundant bits lowers the overall network throughput, thus increasing the demand for more required bandwidth. In this paper we investigate and discuss various techniques used in FEC and show their effects to data communication in terms of bandwidth utilization. Additionally we propose improvement of (2, 1, 2) Convolutional encoder to (3, 2, 3) encoder. The proposed improvements increase the code rate from 1/2 to 2/3 hence reducing error control information and increasing bit rate. The received codeword can be decoded by Soft-Output Viterbi Algorithm. Keywords: FEC, Bandwidth, Convolutional Codes, Code Rate, Soft Output Viterbi Algorith

Investment in Teacher-Education Versus Teacher-Educational Research for Effective Teacher-Professional Learning

Purpose: This systematic research paper provides a comprehensive review of studies and literature on three terms i.e., teacher education, teacher professional learning and teacher education research more specifically in the context of the Tanzania education system. One of the most important aspects identified in teacher education in recent years is teacher educational research despite being yet overlooked. Teacher educational research creates a better juncture through which a gap between teacher education and teacher professional learning is bridged and the two present well with one another. Methodology: The analysis used 45 articles related to the three aspects, published in ten years between 2012 and 2022. The findings indicate that through teacher education, teacher professional learning is up-to-date and kept on track by equipping and updating teachers with contemporary knowledge and teaching practices. Findings: In Tanzania, teacher professional learning is mostly done in form of workshops and seminars that few teachers from various educational institutions are allowed to attend. In addition, the integration of teacher education research content in teacher education is considered one of the approaches to facilitate teachers’ (both pre-service and in-service) capacity to draw on a wide knowledge base through teacher professional learning. Unique Contribution to Theory, Policy And Practice: Generally, the main focus of teacher education research should be to understand how teachers develop and acquire knowledge, and investigate the diversity of experiences in learning to teach, thus contributing to teacher professional learning program design