Development of an urban health and wellbeing index for work precincts: A comparative study in Sydney,Australia

Work precincts are recognized for their significant role as generators of employment and associated commerce within urban areas. This study describes a method for analyzing the physical characteristics of urban work precincts in promoting the health and wellbeing of their occupants. The following physical parameters are analyzed: public transport accessibility, green and blue spaces, food environments, fitness facilities, supermarkets, and grocery stores. The parameters are assessed using quantitative spatial analysis based on street network data, as well as point of interest data acquired from OpenStreetMap (OSM). The streets and their intersections are stored in the OSM database as links and nodes, respectively. The evaluation of the performance metrics involves measuring the street network distance from each node to the closest node of interest for each parameter. The metrics are then combined, forming an urban health and wellbeing index (UHWI), which can be used to compare the performance of different precincts. The method was tested by investigating four work precincts in Sydney, Australia, all hosting a large office building belonging to the same business institution. Our results identified two of the four precincts with a high UHWI and resulted in the identification of one underperforming precinct.     

Fe3+-substitution effect on the thermal variation of J–E characteristics and DC resistivity of quadruple perovskite CaCu3Ti4O12

The electrical properties of cubic perovskite series, CaCu_3–xTi_4–xFe_2xO₁₂ with x = 0.0, 0.1, 0.3, 0.5, and 0.7, have been studied by employing current density as a function of electric field characteristics registered at different temperatures and thermal variations of direct current electrical resistivity measurements. All of the compositions exhibit strong non-ohmic behavior. The concentration dependence of breakdown field, the temperature at which switching action takes place, and maximum value of current density (J_max) has been explained on account of structural, microstructural, and positron lifetime parameters. The highest ever reported value of J_max = 327 mA/cm² has been observed for pristine composition. The values of the nonlinear coefficient advise the suitability of ceramics for low-voltage varistor applications. The Arrhenius plots show typical semiconducting nature. The activation energy values indicate that electric conduction proceeds through electrons with deformation in the system.     

Wear Performance of Cu-Alloyed Austempered Ductile Iron

An investigation was carried out to examine the influence of structural and mechanical properties on wear behavior of austempered ductile iron (ADI). Ductile iron (DI) samples were austenitized at 900 °C for 60 min and subsequently austempered for 60 min at three temperatures: 270, 330, and 380 °C. Microstructures of the as-cast DI and ADIs were characterized using optical and scanning microscopy, respectively. The structural parameters, volume fraction of austenite, carbon content of austenite, and ferrite particle size were determined using x-ray diffraction technique. Mechanical properties including Vicker’s hardness, 0.2% proof strength, ultimate tensile strength, ductility, and strain hardening coefficient were determined. Wear tests were carried out under dry sliding conditions using pin-on-disk machine with a linear speed of 2.4 m/s. Normal load and sliding distance were 45 N and 1.7 × 10⁴ m, respectively. ADI developed at higher austempering temperature has large amounts of austenite, which contribute toward improvement in the wear resistance through stress-induced martensitic transformation, and strain hardening of austenite. Wear rate was found to depend on 0.2% proof strength, ductility, austenite content, and its carbon content. Study of worn surfaces and nature of wear debris revealed that the fine ausferrite structure in ADIs undergoes oxidational wear, but the coarse ausferrite structure undergoes adhesion, delamination, and mild abrasion too.     

A novel approach to generate a chirp microwave waveform using temporal pulse shaping technique applicable in remote sensing application

Microwave photonics is a prominent field in which photonic technologies are used to empower and extend the functionalities of microwave system which is a very tough exercise to fulfil directly in microwave domain. A photonic technique to generate a high chirp rate arbitrary microwave waveform using dual-drive LiNbO₃ has been put forward and demonstrated experimentally in this paper. Nowadays in order to increase the Range-Doppler resolution of radar, the chirp microwave waveform is widely used. The Mach-Zehnder modulator (MZM) performs the intensity modulation techniques which can operate on the principle of electro-optic effect. In this paper, the authors used a very simple and straightforward method of producing chirped arbitrary millimetre waveform by change in phase at the two arms of dual-drive LiNbO3 MZM. The generated waveform has the 3 dB bandwidth of 12.6 GHz which exists in extremely high-frequency band applicable in high-frequency microwave radio relay, microwave remote sensing, radar range resolution and millimetre wave scanner. The proposed design is simpler, cost-effective and compact than the previously proposed model of chirped waveform generation using MZM and fibre Bragg grating.     

Integrating algae building technology in the built environment: A cost and benefit perspective

Energy consumption rates have been rising globally at an escalating pace since the last three decades. The exploration of new renewable and clean sources of energy globally is thus gaining prime importance. In Australia, coal is still the primary source of energy, which, during the process of energy production, generates greenhouse gases, subsequently resulting in environmental degradation. Within this context, the paper compares the economic and environmental benefits of utilizing two renewable energy production sources: algae building technology (ABT) and solar PV panels. A case study site for retrofitting a specified area on the front façade of a multi-storied building at the University of Technology Sydney, City Campus, Australia was thus chosen for the study. A cost and benefit analysis model using the following performance indicators; return on investment, payback period as well as net present value of the two systems, was thus initiated. Annual revenue generation of both systems which included tangible and intangible benefits of both systems were simultaneously calculated. The investment and operation and maintenance costs of both systems were calculated based on market research as well as quantitative data adapted from our literature review. Our conclusions show that closed tubular photobioreactor systems have more benefit than solar panel system from an environmental impact perspective considering Australia's current struggle with water scarcity, drought, air pollution and carbon emission reduction goals.     

Strategic network design for multi-zone truckload shipments

In recent years, the truckload trucking industry has faced a serious problem in retaining drivers. The primary reason for this problem is the very-long driver tour lengths that keep drivers on the road for extended time periods. In this paper, we present a mathematical model for a multi-zone dispatching method that addresses this issue. In addition to reducing driver tour lengths to desirable levels, the model captures important aspects of other practical problems via unique constraints that address the perspectives of both the truckload company and the customers. Using this model, we first provide insights into various aspects of the problem as well as the nature of the interaction among the problem components that pertain to these perspectives. We later develop a construction heuristic and a tabu search framework, which considers driver tour length constraints (a major determinant of driver turnover rate) to solve the model. We provide computational results illustrating the excellent performance of the proposed solution procedure.     

A model for idiopathic intracranial hypertension and associated pathological ICP wave-forms.

Idiopathic intracranial hypertension (IIH) is a syndrome of unknown cause characterized by elevated intracranial pressure (ICP). While imaging often reveals a stenosis of the transverse sinuses, the role of this feature in IIH has been in dispute. Many patients with chronic daily headache have been found to actually be suffering from a milder form of IIH without papilledema (IIHWOP). These patients often demonstrate hypertensive B-waves and plateau-like waves upon continuous ICP monitoring. Recently, we presented modeling studies which suggest that the sinus stenosis and hypertension of IIH are physiological manifestations of a stable state of elevated pressures that exists when the transverse sinus is sufficiently collapsible. Many of the features of IIH were explained by this model but the prevalence of pathological ICP wave-forms observed in IIHWOP remained unresolved. The model presented here is a modified version of a previous model with a semi-collapsible sinus represented by a refined downstream Starling-like resistor based on experimental data. The qualitative behavior of this model is presented in terms of the collapsibility of the transverse sinus. For a sufficiently rigid sinus, there is a unique stable state of normal pressures. As the degree of collapsibility increases, there is a Hopf bifurcation, the normal state becomes unstable, low-frequency, high-amplitude ICP waves prevail, and small perturbations can lead to hypertensive ICP spikes. As the collapsibility increases further, so does the duration of the waves, until they are replaced by two stable states: one of normal pressures and one of elevated pressures. In this parameter domain, temporary perturbations can now cause permanent transitions between states. The model presented here retains the capability of our previous model to elucidate many features of IIH and additionally provides insight into the prevalence of the low-frequency, high-amplitude waves observed in IIHWOP.     

Berry polyphenols inhibit pancreatic lipase activity in vitro

Polyphenol-rich extracts from a range of berries were tested for their ability to inhibit pancreatic lipase activity in vitro. Blackcurrant and rowan extracts had no effect, blueberry caused slight inhibition, whilst lingonberry, Arctic bramble, cloudberry, strawberry and raspberry were considerably more effective. Inhibition by the cloudberry extract showed a saturation effect with an apparent EC₅₀ of around 5 μg phenols/ml.     

From smart to empathic cities

This paper acknowledges the contemporary neoliberal mode of operation of Smart Cities.The pitfalls of Smart Cities concerning its propensity towards techno-centric and efficiency-focused governance are identified,with diminutive emphasis on social equity and human-centric urban growth.Thus,the paper elaborates upon an alternative mode of person-environment-interaction based approach towards placemaking:Empathic Cities.This approach implies embracing a shift from efficiency to sufficiency and wellbeing embedded regenerative perspective for conceiving the built environment.First,the variable dimensions of urban growth and governance,which gave rise to the smart city,are contextualized.The embedded neoliberal operational agenda of smart cities are established.On this basis,the un-derpinnings of an empathic city are established by acknowledging the shift from techno-centric to human-centric and from product-based to context-based smart city and wellbeing perspectives.Strategies toward urban development are proposed,such as embracing a regen-erative perspective wherein the city and its constituents need to be understood as interdepen-dent systemic elements while embracing a human-centric and ethical approach.Additionally,a transition from efficiency to sufficiency-oriented practices and a shift towards inclusive modes of participatory governance are proposed as fundamental principles for an empathic future of the built environment.     

Outdoor thermal comfort: Analyzing the impact of urban configurations on the thermal performance of street canyons in the humid subtropical climate of Sydney

The quality of outdoor space is becoming increasingly important with the growing rate of urbanization. Visual, acoustic, and thermal balance degradation are all negative impacts associated with outdoor comfort in dense urban fabrics. Urban morphology thus needs assessment and optimization to ensure favorable outdoor thermal comfort (OTC). This study aims to evaluate the thermal performance of streets in residential zones of Liverpool, NSW, Australia, and tries to improve their comfort index (Physiological Equivalent Temperature) to reveal optimum urban configurations. This evaluation is done by investigating the following urban design factors affecting OTC using computational simulation techniques: street orientation, aspect ratio, building typology, and surface coverage. Our findings reveal that street canyon orientation is the most influential factor (46.42%), followed by aspect ratio (30.59%). Among the influential meteorological parameters (air temperature, wind speed, humidity and solar radiation), wind velocity had the most significant impact on the thermal comfort of the outdoor spaces in this coastal region, which typically experiences intense airflow. The results of our analysis can be utilized by multiple stakeholders, allowing them to understand and extract the most vital design factors which contextually influence the thermal comfort of outdoor spaces. Outdoor thermal comfort has a direct effect on the health and wellbeing of occupants of outdoor spaces.