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Energetically Consistent Eddy-Diffusivity Mass-Flux Convective Schemes: 1. Theory and Models
No full textInternational audienceThis paper presents a self‐contained derivation, from first principles, of a convective vertical mixing scheme based on the Eddy‐Diffusivity Mass‐Flux (EDMF) approach. This type of closure separates vertical turbulent fluxes into two components: an eddy‐diffusivity (ED) which accounts for local small‐scale mixing in a nearly isotropic environment, and a mass‐flux (MF) transport term, which represents the non‐local transport driven by vertically coherent plumes. Using the multi‐fluid averaging underlying the MF concept, we review consistent energy budgets between resolved and subgrid scales for seawater and dry atmosphere, in anelastic and Boussinesq frameworks. We demonstrate that when using an EDMF scheme, closed energy budgets can be recovered if: (a) bulk production terms of turbulent kinetic energy (TKE) by shear buoyancy include MF contributions; (b) boundary conditions are consistent with EDMF, to avoid spurious energy fluxes at the boundary. Furthermore, we show that lateral mixing, due to either entrainment or detrainment induces a net production of TKE via the shear term, with enhanced production under increased horizontal drag. We also provide constraints on boundary conditions to ensure mathematical consistency. Throughout the theoretical development, we maintain transparency regarding underlying assumptions. In a companion paper (Perrot and Lemarié (2024, https://hal.science/hal‐04666049 ); hereafter Part II) we assess the validity of these hypotheses, and analyze the sensitivity of the scheme to modeling choices against Large Eddy Simulations (LES) and observational data on oceanic convection. Part II also details an energy‐conserving discretization and quantifies energy biases in inconsistent formulations
Wrapping and unwrapping multifractal fields
No full text9 pages, 8 figuresInternational audienceWe develop a powerful yet simple method that generates multifractal fields with fully controlled scaling properties. Adopting the Multifractal Random Walk (MRW) model of Bacry et al. [1], synthetic multifractal fields are obtained from the fractional integration of non-Gaussian fluctuations, built by a non-linear transformation of log-correlated Gaussian fields. The resulting fields are parameterized by their roughness exponent H, intermittency λ and multifractal range ξω. We retrieve all the salient features of the MRW, namely a quadratic scaling exponent spectrum ζq, fat-tail statistics of fluctuations, and spatial correlations of local volatility. Such features can be finely tuned, allowing for the generation of ideal multifractals mimicking real multi-affine fields. The construction procedure is then used the other way around to unwrap experimental data-here the roughness map of a fractured metallic alloy. Our analysis evidences subtle differences with synthetic fields, namely anisotropic filamental clusters reminiscent of dissipation structures found in fluid turbulence
Policy Brief No. 001 of 2025/2026 on Kenya’s Alcohol Taxation Structure: An Overview and Reform Proposals
Get PDFGlobally, alcohol taxation varies significantly, reflecting the diverse socio-economic and public health priorities in different countries. In 2022, about 148 countries in the world were applying excise taxes on alcoholic beverages at the national level, reflecting the relative importance of excise tax on alcohol, for example for revenue generation and as a tool to correct for negative externalities arising from alcohol consumption (WHO, 2022). As pointed out by Cnossen (2007), there is generally a move towards adopting the Pigouvian approach in excise taxation to align the excise tax with the external costs associated with harm from the consumption of the product (though this varies with both the product and country).
Various laws and regulations in Kenya govern taxation of alcohol, including the Excise Duty Act of 2015; the Customs and Excise Act (Cap 472); Alcoholic Drinks Control Act, 2010 (famously known as Mututho Law); Value Added Tax (VAT) Act, 2013; Finance Acts; East African Community Customs Management Act, 2004; and Kenya Revenue Authority (KRA) Regulations
Wajir County Fiscal Strategy Paper 2025
Get PDFThe County Fiscal Strategy Paper (CFSP) 2025, is the third to be prepared under the leadership of HE FCPA Ahmed Abdullahi EGH administration. The paper focuses on key medium term policies and priorities as highlighted in the Governors Manifesto and CIDP 2023/2027. The key priorities include; quality and affordable healthcare, food security, social protection, access to early childhood education, critical infrastructure development as well as building resilience to climate change shocks.
Since 2022, the County Government has initiated key programmes that incude: provision of quality health care across the county; provision of clean and safe water for domestic use; infrastructure expansion and rehabilitation as well as social programs for vulnerable groups. Some of the flagship programmes/projects implemented are upgrading of Wajir referral hospital to level 5 which is ongoing, construction of County Aggregation and Industrial Park, drilling of boreholes and excavation of water pans across the county.
The key challenges facing the county in offering services to the county residents still persist and include: the global supply chain disruptions; elevated prices for basic commodities, poor roads, water and energy infrastructure, public health emergencies, food insecurity and high illiteracy among others. In the medium term, the county is projected to experience suppressed rains hence leading to drought and disease outbreaks. This necessitates the county government to allocated sufficient funds towards responding to these disasters occasioned by climate change hazards
Discussion Paper No. 352 of 2024 on Towards Human Vaccine Production in Kenya: Exploring Key Pathways to Sufficient Production
Get PDFThis study examines human vaccine production in Kenya, focusing on key drivers, policies, and regulatory frameworks, while suggesting pathways for sufficient manufacturing through 2040. Employing future foresight methodology, it analyzes data from systematic literature reviews and expert interviews. Vaccine production is vital for Kenya due to the high morbidity and mortality from vaccine preventable diseases; the experiences from the COVID-19 pandemic; and the accelerated phase-out of vaccine supply support from the Vaccine Alliance (Gavi) before 2030. The study finds that strong government support and robust partnerships are essential for successful human vaccine production based on the experiences of leading countries. The key factors include funding from the exchequer, supported by favourable policies, regulatory frameworks, infrastructure, and R&D capabilities. It emerges that there are many opportunities for Kenya to leverage financial and technical support from global and regional organizations in its efforts to establish a vaccine industry, including the African Union. On the legal and regulatory front, Kenya faces a lack of harmony between domestic and international legal frameworks, and gaps in the adoption of international standards. These factors may hinder efforts in human vaccine production. The study recommends that the government, in collaboration with other stakeholders, enhance support for R&D and infrastructure development through national budgeting and public-private partnerships. Essential infrastructure includes formulation and fill-finish facilities, along with advanced equipment for vaccine production
Circular on Deployments, Secondments, Leave of Absence and Transfers in The Public Service
Get PDFReference is made to the self-explanatory Circular Ref. PSC/ADM/13(60) dated 20th.February 2025 on the above subject (copy attached).
In the above referenced Circular, the Public Service Commission (PSC) notes that there have been irregular deployments, secondments, leave of absence and transfers being done in various Ministries, Departments and Agencies. These irregularities have led to the public service being deemed as inefficient and ineffective and, in some cases, the affected public officers have ended up being disadvantaged
Machakos County Programme Based Budget 2025/2026
Get PDFBudget preparation is a highly regulated process by law. The prime legal framework guiding budget preparation is the Constitution of Kenya, 2010. Article 220 (2) states that national legislation shall prescribe: The structure of the development plans and budgets of counties. When the plans and budgets of the counties shall be tabled in the County assemblies; and; The form and manner of consultation between the National Government and County Governments in the process of preparing plans and budgets. Section 129 (2) of the PFM Act, 2012 stipulates that following approval of the budget estimates and supporting draft legislation by the County Executive Committee, the Executive Committee member for Finance shall: Submit to the County Assembly the budget estimates, supporting documents, and any other Bills required to implement the budget, except the Finance Bill, by the 30th April in that year; Ensure that the estimates submitted in subsection (a) are per the resolutions adopted by County Assembly on the County Fiscal Strategy Paper (CFSP)
Nyamira Couny Fiscal Strategy Paper 2025
Get PDFThe document outlines various flagship and ongoing projects by the County Government of Nyamira, focusing on economic planning, resource mobilization, and infrastructure development.Nyamira County Government Projects OverviewThe Nyamira County Government is implementing various flagship and township projects aimed at improving infrastructure, health services, and environmental sustainability.Flagship Projects in Nyamira County
The flagship projects focus on significant infrastructure and health improvements.Maintenance of roads leading to ward offices with a budget of Kshs 15,000,000, currently at 0% completion.Digitization of primary health facilities with a budget of Kshs 6,000,000, also at 0% completion. Spring protection countywide with a budget of Kshs 14,000,000, procurement ongoing. Borehole water distribution project with a budget of Kshs 1,000,000, procurement ongoing. Township Projects in Nyamira CountymThe township projects aim to enhance local services and facilities. Establishment of an indigenous tree nursery in Nyamira South with a budget of Kshs 3,000,000, procurement process ongoing. Multiple spring water projects, each with a budget of Kshs 217,500, currently in the procurement process. Construction and completion of a 300-bed capacity isolation block at NCRH with a budget of Kshs 95,500,000, currently at 48% completion. Renovation and installation of a new cooling system at NCRH mortuary, budgeted at Kshs 9,040,205, nearing completion at 98%. Ongoing Projects and Their Status The ongoing projects reflect the county's commitment to improving public services. Renovation and installation of a cooling system at Nyamira County Referral Hospital, budgeted at Kshs 9,040,205, currently at 98% completion. Construction of a twin staff house at Nyaigesa Health Facility, budgeted at Kshs 4,786,404, currently at 65% completion. Various ECDE centers and classrooms are under construction, with completion percentages ranging from 50% to 95%.Economic Planning and Resource Mobilization The county is focusing on enhancing its economic planning and ICT capabilities
Narok County Annual Development Plan 2025/2026
Get PDFThe Public Finance Management Act (PFMA), 2012 Section 126 sub-section 1 requires county Governments to prepare an Annual Development Plan (ADP) in accordance with Article 220 (2) of the constitution. As a statutory document, ADP guides the implementation of projects and programmes in each department in the financial year as stipulated in the County Integrated Development Plan CIDP 2023-2027. This plan is also aligned to with the national development framework as envisioned in Medium Term Plan IV as outlined in Vision 2030 and the Bottom Up Economic Transformation Agenda (BETA). The ADP provides the description of the County in terms of the location, size, physiographic and natural conditions, demographic profiles as well as the administrative units. It also gives the ecological conditions and climatic conditions of Narok County.
The 2025/26 Narok County ADP lays the foundation and sets the tone for priority projects and programmes for the Third year of the CIDP 2023-2027.
The County Government of Narok will roll out developmental projects that will create an environment for its residents to enjoy a high quality of life and increase productivity
Kenya Economic Report 2025 on Creating Decent jobs for Posterity
Get PDFThe Kenya Economic Report 2025 provides a detailed and technical analysis, and policy prescriptions for enhancing decent job creation for prosperity across Kenya’s strategic economic sectors. The report begins by providing an overview of the macroeconomic performance and economic projections based on the medium-term forecasts. These are followed by thematic discussions, which include enhancing decent jobs in agriculture through digital extension services, enhancing the competitiveness of the manufacturing sector for decent job creation, revitalizing job creation in the domestic trade sector, promoting youth employability through investment in technical and vocational education and training, harnessing the potential of decent jobs in the e-mobility sector, and enhancing creation of decent jobs at the county level