Evaluation of Mechanical and Control Systems Serving the Art Museums at Colonial Williamsburg

This NEH planning grant would be used to evaluate mechanical and control systems serving the DeWitt Wallace Decorative Arts Museum and the Abby Aldrich Rockefeller Folk Art Museum, with the goals of a) developing a plan to replace and upgrade systems and thereby improve reliability, performance and efficiency, and b) creating and sustaining a safer environment for the Colonial Williamsburg collections. Targeted areas include evaluation of: 1) the condition and performance of mechanical equipment, especially the 1984 air handlers and heating plant; 2) the condition and performance of the chiller plant, including assessment of plate heat exchanger fouling of modular chillers used with open tower condensing loop; 3) optimum control strategies and BAS programming to maintain museum environmental conditions with minimal energy use; 4) existing BAS operations and maintenance support; 5) lighting upgrade options to reduce energy usage and light exposure to the collections

Transient behavior of photorefractive gratings in a polymer

The transient behavior of photorefractive gratings in the polymer composite poly(N-vinyl carbazole) (PVK), 2,4,7-trinitro-9-fluorenone (TNF), and N,N-diethyl-para-nitroaniline (EPNA) doped with various amounts of 4-(diethylamino)benzaldehyde diphenylhydrazone (DEH) is presented. The influence on the hole drift mobility due to the change in the trap density induced by DEH, was directly measured. (C) 1995 American Institute of Physics

The adoption of AI in Zimbabwe’s newsrooms: A case of Zimpapers and Alpha Media Holdings

Artificial Intelligence (AI) has changed the face of journalism in many ways. Newsrooms across the world are deploying AI in various aspects of news gathering distribution and creation. Many newsrooms are also at different stages when it comes to AI adoption. The general objective of this study was to examine the adoption of AI in two media houses in Zimbabwe: Zimpapers and Alpha Media Holdings (AMH), from newsroom operations and insights from journalists and editors to understand their perception and views on the future of journalism in the wake of AI technologies as well as documenting the status thereof. This study examined the adoption of AI technologies within Zimbabwe’s newsrooms, with a specific focus on Zimpapers and Alpha Media Holdings (AMH). The study was guided by the Diffusion of Innovation and Mediamorphosis theories as well as Technology Acceptance Model (TAM) as the conceptual framework. A mixed methods approach was adopted while quantitative and qualitative data was collected using survey questionnaire, key informant interviews and observation as data collection tools. Systematic sampling was used for quantitative data, and purposive sampling was used for qualitative data. The researcher distributed a survey questionnaire to reporters, news editors, editors, sub-editors, IT department (developers, data scientists), and photographer/ video editors. Key informant interviews targeted 12 media executives from both organisations, selecting 6 per each organisation. Observation was done by spending one week at each media house, observing newsroom operations from news gathering until publishing, understanding phases where AI was being deployed and issues relating to accelerated or delay in its adoption. The research findings revealed that AI adoption in Zimbabwe’s newsrooms is still in its nascent stages and much of its utilization was of more of individual effort than organization’s strategy. While there is growing recognition of AI’s potential to revolutionize journalism, several challenges hinder its widespread adoption. Key findings on challenges include the absence of formal policies and guidelines for AI usage within newsrooms, limited training opportunities for journalists and editors, and a general lack of awareness and understanding of AI’s capabilities and limitations. These factors contribute to a cautious and hesitant approach to AI adoption, with many news organizations taking a wait-and-see attitude. The findings also indicated the presence of cultural resistance and knowledge silos within newsrooms. The results indicate the need for more investment in AI technologies as well as knowledge. There is also evidence that newsrooms have not invested in technology for a while and there is lack of expertise in bridging the gap between journalism and technology. The research recommends an accelerated approach in designing guidelines and AI policies for newsrooms. It also recommends that newsrooms invest in training

An evaluation of wetland no net loss and mitigation under section 404 of the Clean Water Act on the Santa Rosa Plain, Sonoma County, California.

The Santa Rosa Plain (Plain), Sonoma County, California, has lost 85% of its vernal pools, affecting the survival of four threatened and endangered species. The ability of Section 404 of the Clean Water Act to achieve the goal of no net loss is a particular importance in areas, such as the Plain, where wetland resources have become severely impacted. The objective of the study was to determine if a no net loss of wetland area occurred on the Plain, to evaluate the implementation of the Santa Rosa Plain programmatic permit, and to examine trends associated with compensatory medication. Fifty-two Section 404 permits affecting seasonal wetlands on the Santa Rosa Plain between July 17th, 1998 and December 31st, 2004 were examined. The no net loss based on required mitigation was determined and adjusted for loss due to mitigation failure and loss resulting from enhancement. The medication acreage That could be verified was determined in the acreage appended to the programmatic permit was totaled. The frequency of the type of mitigation (on-site, off-site, bank) selected was evaluated by type of proponent (public or private). The location of impacts and mitigation sites were evaluated to assess the effects of geographic displacement. Required mitigation resulted in a net gain of 3.512 acres; however, the combined effects of failure in enhancement resulted in a net loss of 0.504 acre. Only 53% of the mitigation was verified. In most cases the programmatic permit was properly applied and maximum acreage limits had not been exceeded. Mitigation banking was the most frequently used type of mitigation; however, banks were found to result in greater geographic displacement. A majority of the impacts were due to private developers occurred within urban boundaries, while a majority of the mitigation sites were located outside of urban areas. Mitigation banks were found to play an important role in mitigation on the Plain

Assessment of the effectiveness of treatment methods on Eucalyptus grandis yielding pencil props

Abstract: Supporting of underground hanging-walls is an important task that ensures a safe working environment and a continuous opening in underground mining operations. Underground stope support systems such as yielding pencil props, packs, tendons and backfill are used to stabilise hanging-walls in excavations to reduce or eliminate falls of ground and rock-bursts. The brushingoff of the pod end of an installed E. grandis pencil prop is the initial yielding part of the support unit under load. This failure mechanism allows inelastic hanging-wall to converge or vertically dilate while the support unit maintains contact with the rock unit without losing its support integrity (i.e. it does not buckle). Higher Moisture Content (MC) in yielding pencil props allows the props to fail according to the expected mechanism. Tonnes of timber products are wasted annually due to severe cracking / checking during the storage phase. Physical deterioration in a form of cracks of more than 10 mm wide and longer than 1/3 of the longitudinal dimension of the yielding pencil prop are criteria used by timber units’ suppliers to reject yielding pencil props...M.Ing. (Engineering Management

Challenges of e-learning adoption in South African public schools: Learners’ perspectives

Educational technology (EdTech) plays a vital role in teaching and learning with e-learning ensuring equal access to education and continuity even when contact classes are impossible. The South African departments of education are making efforts to realize the use of technology in schools. The COVID-19 pandemic has an adverse impact on the education sector and accelerated the adoption of technology by many institutions with some shifting to distant learning to ensure academic continuity. There are various educational technologies. The aim of the study is to explore public high school learners’ perspectives on e-learning and the challenges in its adoption. Secondary data is used to draw conclusion. An interpretivism paradigm with an exploratory sequential mixed-method approach is used. The findings show that e-learning implementation needs careful consideration and planning. The results of this study indicate that lack of access to devices, the high cost of internet access, a perceived lack of interest among teachers and perceived ineffectiveness are the key challenges to e-learning adoption in South African public schools within poor communities. Addressing key challenges will ensure a successful implementation of e-learning

Strategi Peningkatan Kinerja Karyawan Untuk Mencapai Tujuan Usaha Pada PD. Mustika Prima Telur Dawuan

Tujuan Praktikan memilih untuk melakukan kegiatan kerja praktik di PD. Mustika Prima Telur Dawuan karena ingin mempelajari bagaimana strategi yang digunakan untuk meningkatkan kinerja pegawai di PD. Mustika Prima Telur Dawuan. Selain itu juga Praktikan ingin mempelajari bagaimana atasan mengelola karyawannya sehingga menghasilkan kinerja yang baik. Metode yang digunakan dalam praktik lapangan ini yaitu menggunakan metode analisis deskriptif kualitatif, yang bertujuan untuk menjelaskan objek penelitian dan permasalahan penelitian sedetail mungkin dengan menggunakan fakta lapangan. Dapat disimpulkan Strategi yang digunakan PD. Mustika Prima Telur Dawuan diterapkan strategi yang lebih terkait lingkungan internal dan eksternal, analisis alternatif strategi, tujuan, serta implementasi

Exploring senior phase teachers’ use of Kahoot! Gamification as a formative assessment tool to scaffold mathematical understanding

In South Africa, digital technology, particularly gamification, continues to become an important teaching and learning tool. Its importance lies in scaffolding mathematical understanding, improving the quality of assessment, and developing twenty-first-century technological skills for effective mathematics assessment. To explore this importance, senior phase mathematics teachers are encouraged to adopt gamification technology such as Kahoot! in assessment. The study adopted a case study research design with a interpretivist research paradigm, as this method allows detailed exploration and understanding of a specific context through a close connection with the participants. Data was collected using semi-structured questionnaires, focus group interviews, non-participant observations, and reflective journals. The research involved ten purposively selected senior-phase mathematics teachers from two schools in the Sarah Baartman District, Eastern Cape Province, South Africa. The study drew upon Vygoysky's Sociocultural Theory for its theoretical framework, while the Technological, Pedagogical, and Content Knowledge was used for analysis. The data analysis pursued an inductive approach. Adopting a thematic analysis included coding participant responses, organizing codes into concepts and categories, and developing a theoretical framework from the resultant categories. A four-phase process was involved: coding, conceptualizing, categorizing, and theorizing, was employed. This process and using NVivo software for data organization and management helped identify patterns, themes, and significant concerns surrounding the study's core subject. The findings from the study were as follows: Firstly, it was revealed that most teachers have a positive perception and attitude towards using Kahoot! for formative assessment, believing that it enhances teaching and learning quality. However, they showed scepticism due to insufficient Information and Communication Technologies knowledge and training. Second, teachers' pedagogical and technological experiences were predominantly enjoyable. Kahoot! was accepted as beneficial for promoting collaboration, interaction, and immediate feedback. Third, the study identified enabling and constraining factors in using Kahoot! for formative assessment. The enabling factors include Kahoot!, which was convenient and accessible, promoted immediate feedback and fostered collaboration and interaction. The constraining factors include Information and Communication Technologies and network interference, which posed limitations. The research concluded that Kahoot! as a platform for formative assessment indeed scaffold mathematical understanding. The study recommends increasing teachers' access to educational technology, incorporating continuous professional development programs, providing subject-specific training, and encouraging teachers to adapt to emerging technologies. The study also provided recommendations for future research to explore learner perceptions, employ a mixed methods approach to help quantify learner performance and investigate the pedagogical and technological experiences of senior phase mathematics teachers regarding formative assessment.Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 202

Effect of nutrient concentration and growing seasons on growth, yield and quality of leafy lettuce (Lactuca sativa L.) in a hydroponic system

Lettuce is becoming an increasingly important vegetable, both as a fresh market product and a ready-to use vegetable, especially in urban areas of South Africa. Nutrient solution concentration is one of the most practical and effective ways of controlling and improving the yield and nutritional quality of crops for human consumption. However, optimal fertilizer concentration for leafy vegetables also depends on the prevailing environmental conditions. This study was carried out to determine the effects of different nutrient solution concentrations and growing seasons on growth, yield and quality of leafy lettuce. The trial was conducted in a black and white shade net structure and the nutrient concentration treatments were 1.0, 2.0, 3.0, and 4.0 mS.cm-1. Measurements taken included: leaf number, leaf area, fresh leaf mass, dry leaf mass, dry root mass, as well as chlorophyll content. The sensory evaluation procedure was only done on plant samples grown during summer and winter seasons. The results showed that growth was less affected by nutrient concentration than by growing season. Regardless of the nutrient concentration, plants grown in summer reached maturity quicker as compared to plants grown in winter. Generally, leaf number, leaf area, leaf area index, fresh leaf mass, dry leaf mass and dry root mass did not significantly increase with increasing nutrient concentrations and therefore, yield was not influenced by nutrient concentrations. Quality was influenced by nutrient concentrations during the summer-autumn seasons where increasing nutrient concentration induced increased chlorophyll content of the leaves. During the winter-spring seasons this phenomenon was not significant. The study demonstrated that growth, yield and quality of lettuce were not significantly influenced by nutrient solution concentrations of 1.0, 2.0, 3.0 and 4.0 mS.cm-1. The sensory evaluation also showed no significant differences on the colour (quality) and flavor of the lettuce samples grown during summer and winter seasons and unfortunately it was not done during autumn and spring seasons. Irrespective of the nutrient solution concentration, growth was influenced by growing season because plants grown during summer reached maturity quicker as compared to plants grown during the other seasons.Dissertation (MInstAgrar)--University of Pretoria, 2012.Plant Production and Soil Scienceunrestricte