Engineering Science & Technology

Design of a Tiny House Generator with Location Parameterisation Function

2025-08-11T14:20:50+08:00

In light of growing housing shortages and rising rental prices, alternative housing forms such as Tiny Houses are becoming increasingly popular. This housing form is characterised by compact floor plans, with sizes typically under 45 m² (480 sqft) per person. As the trend originated in the USA, much of the literature and design proposals refer to the prevalent climate conditions found there. This research aims to bridge this gap by developing a script that generates a proposal for a Tiny House for any given location, using construction strategies adapted to the local climate. First, an analysis was conducted to determine which building components of a Tiny House are particularly susceptible to climatic influences and how specific weather conditions affect these components. Based on four case studies and relevant literature, parametric construction principles were developed. These principles were incorporated into a script that used weather and climate data to generate a 3D model of the Tiny House. The script was implemented within the Grasshopper environment of the 3D modelling software Rhino 3D. To provide a user-friendly interface, it was integrated into a web application. This allows users to select locations and various input parameters, to visualize the generated model, as well as to access detailed information about the construction decisions and how they are influenced by the local climate. To exemplify the output generated by the tool, three models for different locations were selected and slightly modified to show how these buildings might be built and look in reality. The thesis was successful in developing a fully parametric building generator, which can further be expanded to include features such as complete indoor climate simulations. The script and implementation are fully documented. However, given the general complexity of architecture and construction, the question arises as to whether a future approach based on artificial intelligence might be more effective than the algorithmic approach taken here.

An Accurate Measurement Technique for the Biological Oxygen Uptake Rate

2025-10-30T10:37:40+08:00

For any wastewater treatment aeration tank, the paper proposes an accurate technique to deal with the Oxygen Uptake Rate (OUR) measurements. Since it measures the rate at which oxygen is used (in mg O²/L/hour), it is a useful tool to evaluate process performance, aeration equipment, and the biodegradability of the waste. Unfortunately, the literature abounds with examples of inconsistent measurement results. The manuscript observes that if a sample of mixed liquor is withdrawn from an aeration tank operating at low Dissolved Oxygen (DO) (dissolved oxygen), the OUR measured in the sample after shaking (or other means of perturbation) will be higher than the true OUR which is limited by oxygen supply. The composition of a sample of activated sludge being analyzed is continually changing, making it necessary to obtain measurements as quickly as possible at the site of the aeration basin. To alleviate the many problems in measurement, the proposed method using water dilution with saturated DO may give a more accurate measurement than the current standard method as described by the American Public Health Association (APHA). The discrepancy in the new method between the measured and the calculated SOTR_pw is in the assumed mole fraction of the exit gas of 0.19 which is reasonable but still based on guesswork. However, the discrepancies in the conventional method are that, the measured value of R is incorrect because of the inherent shortfall in the APHA (Biological Oxygen Demand (BOD) bottle shaking) technique, and it is more realistically given by the modified Eq. (2-3), which is originally stated as for a batch process provided by the American Society of Civil Engineers (ASCE) Guidelines, ASCE/Environmental and Water Resources Institute (EWRI) 18-18 recently published; and secondly, the incorrect driving force at the steady state, making the OTR at test conditions erroneously high. With a more accurate measurement of the OUR, it may be justified to modify the fundamental equation for oxygen transfer in a respiring system, as applied to the example given by the Guidelines. The specific content of the revised formula is proposed to be for a batch process.

Optimal Allocation of Clean Energy in Terms of Probabilistic Multi-Objective Optimization Method

2025-09-15T17:55:25+08:00

In this paper, the Probabilistic Multi-Objective Optimization method (PMOO) is applied to perform the optimal allocation of clean energy with multiple objectives. A solar photo-thermal system, wind energy, and a comprehensive energy storage system for photo-thermal power generation are involved. In PMOO, a new concept of "preferable probability" is put forward to address the preference degree of an attribute of a candidate and the corresponding evaluation method and attributes of the alternative scheme are divided into two types, i.e., beneficial type and unbeneficial (cost) type of attributes, and the corresponding evaluation algorithms of their partial preferable probability are formulated quantitatively. The total preferable probability of each alternative scheme is the product of all possible partial preferable probability, which is employed as the unique indicator to conduct the ranking of the optimization. In the application of optimum allocation problem of clean energy, the solar energy assurance rate and efficiency index of the heating system are the optimal criteria to be maximized, while the heat collecting area of solar collector, the heating capacity of heat pump and the volume of water tank for heat storage are used as input parameters. Especially, the range analysis of the total preferable probability of each alternative scheme is conducted using orthogonal experimental design. The result indicates the optimum configuration for this allocation of clean energy design. Alternatively, in the application of wind-photo-thermal power generation and storage comprehensive energy system problem, both carbon emissions and total operating costs are the optimization criteria to be minimized for the three scenarios, yielding an optimal configuration.

From Neat Epoxy to Nanocomposites: Innovations in Bonding Systems for FRP-based Concrete Retrofitting: A Mini Review

2025-10-31T16:52:23+08:00

Structural retrofitting with Fiber-Reinforced Polymer (FRP) systems has become a vital approach for enhancing the strength, ductility, and durability of deteriorating concrete structures. The efficiency of these systems largely depends on the adhesive layer, where conventional Neat Epoxy (NE) adhesives often suffer from brittleness and limited crack resistance. Recent advancements in Nanomaterial-Modified Epoxy Adhesives (NMEAs) have led to notable improvements in their mechanical, thermal, and interfacial properties. Incorporating carbon-based nanomaterials such as Carbon Nanotubes (CNTs), Carbon Nanofibers (CNFs), and graphene has been shown to enhance fracture toughness, tensile strength, and load transfer. For example, introducing 0.1 wt.% single-walled CNTs resulted in a 13% increase in fracture toughness and a 3.5% improvement in compression-after-impact strength, while 0.5 wt.% multi-walled CNTs achieved up to 7% higher elastic modulus and 10% greater tensile strength compared to NE. Similarly, silicon-based nanomaterials, including silica nanoparticles and nanoclays, enhance stiffness, minimize porosity, and improve adhesion efficiency in both Externally Bonded Reinforcement (EBR) and Near-Surface Mounted (NSM) FRP systems. Spectroscopic and microstructural analyses reveal that nanoparticles influence cross-linking and crystallinity within the epoxy matrix, leading to more stable and durable adhesive bonds. Beyond mechanical enhancement, eco-friendly nanomaterials, such as rice husk ash-derived silica and biomass-based graphene, contribute to sustainability by lowering embodied carbon and extending the structural lifespan. This mini-review synthesizes recent developments, identifies critical research gaps, and outlines future directions toward resilient, high-performance, and sustainable FRP-retrofitting systems.