Addressing community energy challenges with utility-scale renewables : a case study of Hopefield Wind Farm

Thesis (MPhil)--Stellenbosch University, 2019.ENGLISH SUMMARY : This thesis documents how a utility-scale renewable energy project has addressed community energy challenges through the development of a wind farm as part of South Africa’s Renewable Energy Independent Power Producer Procurement Programme (REIPPPP). The implementation of the REIPPPP in South Africa has been designed for the procurement to secure additional renewable energy capacity and makes allowance for local beneficiation to the country. The procurement framework mandates successful independent power producers (IPPs) to spend a percentage of annual income in local communities found within a 50-kilometre radius of a renewable energy project site. It prescribes that this percentage of annual income be used on socio-economic development (SED) and enterprise development (ED) in surrounding communities that are commonly implemented through the practice of community development. Despite well-intended community beneficiation stemming from the programme, early reports have highlighted several challenges that IPPs experience in integrating social and economic development as part of their core business operations. Challenges range from a lack of guidance from the government regarding the practice of social and economic development to poor engagement with communities over upliftment projects accrued to them. These challenges hamper the potentially transformative social and economic development considerations of the REIPPPP. This masters research study showcases how the SED and ED funds, stemming from the Hopefield Wind Farm (owned by Umoya Energy) and arising as a result of its participation within the REIPPPP, have addressed community energy challenges experienced in the beneficiary town of Hopefield. Presented as a narrative analysis, the case study showcases the particular leadership style Umoya Energy undertook in its community engagement process. This resulted in positive outcomes for the community in the form of a strategic project that responds to the energy challenges faced in the beneficiary community, while at the same time addressing other common challenges faced, such as unemployment.AFRIKAANSE OPSOMMING : Hierdie tesis bestudeer in watter mate ’n hernubare-energieprojek op nutskaal die energie-uitdagings van ’n gemeenskap die hoof bied. Die projek is ’n windkragaanleg wat as deel van Suid-Afrika se program vir die verkryging van hernubare energie van onafhanklike kragprodusente, oftewel die “REIPPPP”, ontwikkel is. Die doel van die REIPPPP is om bykomende hernubare-energievermoë vir Suid-Afrika te skep en terselfdertyd die moontlikheid van plaaslike benefisiëring te ondersoek. Die verkrygingsraamwerk vereis dat suksesvolle onafhanklike kragprodusente (“IPPs”) ’n persentasie van hulle jaarlikse inkomste in plaaslike gemeenskappe binne ’n omtrek van 50 km vanaf die perseel van die hernubare-energieprojek bestee. Volgens projekvoorskrifte moet hierdie geld aangewend word vir sosio-ekonomiese en sakeontwikkeling in die omliggende gemeenskappe, welke inisiatiewe oor die algemeen deur die praktyk van gemeenskapsontwikkeling geïmplementeer word. Ondanks hierdie goed bedoelde programelement van gemeenskapsbenefisiëring, dui aanvanklike terugvoering op verskeie uitdagings vir IPP’s om maatskaplike en ekonomiese ontwikkeling by hulle kernsakebedrywighede te integreer. Uitdagings wissel van gebrekkige leiding van die regering om maatskaplike en ekonomiese ontwikkeling teweeg te bring, tot swak skakeling met gemeenskappe oor die opheffingsprojekte wat vir hulle op die been gebring word. Hierdie uitdagings verhinder die potensieel lewensveranderende maatskaplike en ekonomiese ontwikkeling wat die REIPPPP beoog. Hierdie magisternavorsingstudie toon hoe die sosio-ekonomiese en sakeontwikkelingsfinansiering uit die Hopefield-windkragaanleg (wat deur Umoya Energy besit word) die energie-uitdagings van die begunstigdedorp Hopefield die hoof bied as deel van dié kragprodusent se deelname aan die REIPPPP. Die gevallestudie, wat as ’n narratiewe ontleding aangebied word, bring ’n bepaalde leierskapstyl aan die lig wat Umoya Energy in hulle gemeenskapskakelingsproses gebruik. Dít het tot dusver positiewe uitkomste vir die gemeenskap tot gevolg gehad in die vorm van ’n strategiese projek wat nie net op die betrokke gemeenskap se energie-uitdagings reageer nie, maar terselfdertyd ook ander algemene uitdagings soos werkloosheid die hoof bied

Models for Metal Hydride Particle Shape, Packing, and Heat Transfer

A multiphysics modeling approach for heat conduction in metal hydride powders is presented, including particle shape distribution, size distribution, granular packing structure, and effective thermal conductivity. A statistical geometric model is presented that replicates features of particle size and shape distributions observed experimentally that result from cyclic hydride decreptitation. The quasi-static dense packing of a sample set of these particles is simulated via energy-based structural optimization methods. These particles jam (i.e., solidify) at a density (solid volume fraction) of 0.665+/-0.015 - higher than prior experimental estimates. Effective thermal conductivity of the jammed system is simulated and found to follow the behavior predicted by granular effective medium theory. Finally, a theory is presented that links the properties of bi-porous cohesive powders to the present systems based on recent experimental observations of jammed packings of fine powder. This theory produces quantitative experimental agreement with metal hydride powders of various compositions.Comment: 12 pages, 12 figures, 2 table

Family-based pediatric weight management interventions in US primary care settings targeting children ages 6-12 years old: A systematic review guided by the RE-AIM framework.

Obesity is a pandemic that disproportionately affects children from vulnerable populations in the USA. Current treatment approaches in primary care settings in the USA have been reported to be insufficient at managing pediatric obesity, primarily due to implementation challenges for healthcare systems and barriers for families. While the literature has examined the efficacy of pediatric obesity interventions focused on internal validity, it lacks sufficient reporting and analysis of external validity necessary for successful translation to primary care settings. We conducted a systematic review of the primary-care-setting literature from January 2007 to March 2020 on family-based pediatric weight management interventions in both English and/or Spanish for children ages 6-12 years in the USA using the Reach, Efficacy/Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. A literature search, using PRISMA guidelines, was conducted in January 2022 using the following electronic databases: Medline Ovid, Embase, and Cochrane Library. 22 270 records were screened, and 376 articles were reviewed in full. 184 studies were included. The most commonly reported dimensions of the RE-AIM framework were Reach (65%), Efficacy/Effectiveness (64%), and Adoption (64%), while Implementation (47%) and Maintenance (42%) were less often reported. The prevalence of reporting RE-AIM construct indicators ranged greatly, from 1% to 100%. This systematic review underscores the need for more focus on external validity to guide the development, implementation, and dissemination of future pediatric obesity interventions based in primary care settings. It also suggests conducting additional research on sustainable financing for pediatric obesity interventions

Is bioelectrical impedance accurate for use in large epidemiological studies?

Percentage of body fat is strongly associated with the risk of several chronic diseases but its accurate measurement is difficult. Bioelectrical impedance analysis (BIA) is a relatively simple, quick and non-invasive technique, to measure body composition. It measures body fat accurately in controlled clinical conditions but its performance in the field is inconsistent. In large epidemiologic studies simpler surrogate techniques such as body mass index (BMI), waist circumference, and waist-hip ratio are frequently used instead of BIA to measure body fatness. We reviewed the rationale, theory, and technique of recently developed systems such as foot (or hand)-to-foot BIA measurement, and the elements that could influence its results in large epidemiologic studies. BIA results are influenced by factors such as the environment, ethnicity, phase of menstrual cycle, and underlying medical conditions. We concluded that BIA measurements validated for specific ethnic groups, populations and conditions can accurately measure body fat in those populations, but not others and suggest that for large epdiemiological studies with diverse populations BIA may not be the appropriate choice for body composition measurement unless specific calibration equations are developed for different groups participating in the study

The relationship between buildings and health: A systematic review

© 2018 The Author(s). Published by Oxford University Press on behalf of Faculty of 268 Public Health. All rights reserved. Background The built environment exerts one of the strongest directly measurable effects on physical and mental health, yet the evidence base underpinning the design of healthy urban planning is not fully developed. Method This study provides a systematic review of quantitative studies assessing the impact of buildings on health. In total, 7127 studies were identified from a structured search of eight databases combined with manual searching for grey literature. Only quantitative studies conducted between January 2000 and November 2016 were eligible for inclusion. Studies were assessed using the quality assessment tool for quantitative studies. Results In total, 39 studies were included in this review. Findings showed consistently that housing refurbishment and modifications, provision of adequate heating, improvements to ventilation and water supply were associated with improved respiratory outcomes, quality of life and mental health. Prioritization of housing for vulnerable groups led to improved wellbeing. However, the quality of the underpinning evidence and lack of methodological rigour in most of the studies makes it difficult to draw causal links. Conclusion This review identified evidence to demonstrate the strong association between certain features of housing and wellbeing such as adequate heating and ventilation. Our findings highlight the need for strengthening of the evidence base in order for meaningful conclusions to be drawn

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

Peer reviewe

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe