Utilisation of green urban space for food sufficiency and the realisation of the sustainable development goals-UK stakeholders perspective

The exponential growth of food demand due to the increasing global population has the potential to seriously threaten the quality and quantity of food supplies due to climate change.This study explores the utilisation of green urban spaces for achieving food self-sufficiency by investigating the extent to which sustainable urban farms could be used to reduce the consumption of imported produce in the UK.It also examines urban farming stakeholders'perspective on how food self-sufficiency can help realise the SDGs especially SDG 2(Zero hunger)and SDG 13(Climate action).The study adopts a mixed method approach through a survey with 115 respondents and semi-structured interviews conducted with 12 respondents from 4 different urban farming stakeholder groups.The findings of this study presented a strong correlation between stakeholders who had concerns about where their food came from and the carbon footprint of imported produce.The research shows that,urban farms will no doubt play a vital role in the future of food security in our cities/communities and that the SDGs could be realised through sustainable urban farms implemented within the relevant planning regulations/policies.

The Architectural Expression of Space and Form Created by the Light in the Works of Alvaro Siza

The light is an important element which helps people perceive objects. Therefore, it is important for architects to make the light and space be in harmony with each other. In this study, we analyzed the works of Alvaro Siza with a view to understand the conceptual value of the light expressed in his works and his principles in controlling it. According to the results of the study, the Siza’s architecture is not a mere theoretical one trapped inside formality, but is a sensual and experiential one based on the locality. He was willing to use void spaces to invite the light in free-flowing plans, in order to invigorate and extend architectural spatiality to create deeper visual effect. In addition, the refined light in his works helped visitors experience the continuous forms and spaces by their own movements, while using the changes of the light to stimulate the interest of visitors and highlight the sequence of spaces.

Influence of Erosion Induced by NaCl on the Mechanical Performances of Alkali-Activated Mineral Admixtures

In this paper,the influence of NaCl freeze-thaw(F-T)cycles and dry-wet(D-W)alternations on theflexural,com-pressive and bonding strengths of alkali-activatedfly ash(FA)and a blast furnace slag powder(BFS)is investi-gated.The considered NaCl concentration is 3%.The effect of polypropylenefibers on the mechanical strengths is also examined.Scanning electron microscopy(SEM),thermogravimetry(TG)and X-ray diffraction(XRD)are selected to discern the mechanisms underpinning the NaCl-induced erosion.The obtained results indicate that the best results in terms of material resistance are obtained with admixtures containing 60%BFS and 40%FA in terms of mass ratio and 3%polypropylenefibers in terms of volume ratio.The maximum rates of decrease of theflexural,compressive and bonding strengths after 300 NaCl F-T cycles are 21.5%,20.3%and 22.6%,respec-tively.The corresponding rates of decrease due to NaCl D-W alternations are 28.1%,26.1%and 31.5%,respec-tively.The TG curves show that the alkali-activating activity of BFS is higher than that of FA.Moreover,in thefirst case,the microstructure of the hydration products is more compact.The results also show that NaCl F-T cycles lead to increasing cracks in the alkali-activated BFS.

Malware Attacks Detection in IoT Using Recurrent Neural Network(RNN)

IoT(Internet of Things)devices are being used more and more in a variety of businesses and for a variety of tasks,such as environmental data collection in both civilian and military situations.They are a desirable attack target for malware intended to infect specific IoT devices due to their growing use in a variety of applications and their increasing computational and processing power.In this study,we investigate the possibility of detecting IoT malware using recurrent neural networks(RNNs).RNNis used in the proposed method to investigate the execution operation codes of ARM-based Internet of Things apps(OpCodes).To train our algorithms,we employ a dataset of IoT applications that includes 281 malicious and 270 benign pieces of software.The trained model is then put to the test using 100 brand-new IoT malware samples across three separate LSTM settings.Model exposure was not previously conducted on these samples.Detecting newly crafted malware samples with 2-layer neurons had the highest accuracy(98.18%)in the 10-fold cross validation experiment.A comparison of the LSTMtechnique to other machine learning classifiers shows that it yields the best results.

Recent Transition in Transportation Environment in Jakarta Metropolitan Area Over Years

The Jakarta metropolitan area of Indonesia with more than 24 million populations is the capital region of one of the emerging countries.Along with economic development,the number of motorized trips,especially,use of motorcycles has been rapidly increasing.Two surveys that were conducted in 2002 and 2010,Household Travel Survey(HTS)and Commuter Travel Survey(CTS),revealed significant alteration in,for example,transportation pattern,income,mode share,mode choice,and so on in Jakarta metropolitan area.Number of population as well as number of registered vehicle is increasing.Existence of BRT also indicated changes in mode choice before and after the introduction of the BRT system in 2004.The characteristics of these preferences were also identified.

Geometric and material nonlinear analysis of tensegrity structures

A numerical method is presented for the large deflection in elastic analysis of tensegrity structures including both geometric and material nonlinearities.The geometric nonlinearity is considered based on both total Lagrangian and updated Lagrangian formulations,while the material nonlinearity is treated through elastoplastic stress-strain relationship.The nonlinear equilibrium equations are solved using an incremental-iterative scheme in conjunction with the modified Newton-Raphson method.A computer program is developed to predict the mechanical responses of tensegrity systems under tensile,compressive and flexural loadings.Numerical results obtained are compared with those reported in the literature to demonstrate the accuracy and efficiency of the proposed program.The flexural behavior of the double layer quadruplex tensegrity grid is sufficiently good for lightweight large-span structural applications.On the other hand,its bending strength capacity is not sensitive to the self-stress level.

Analyses on performances of heat and multilayer reflection insulators

This research was conducted to study the performances of the heat and multilayer reflection insulators used for buildings in South Korea to realize eco-friendly,low-energy-consumption,green construction,and to contribute to energy consumption reduction in buildings and to the nation's greenhouse gas emission reduction policy(targeting 30% reduction compared to BAU(business as usual) by 2020).The heat insulation performance test is about the temperatures on surfaces of test piece.The high air temperature and the low air temperature were measured to determine the overall heat transfer coefficient and thermal conductivity.The conclusions are drawn that the heat transmission coefficients for each type of existing reflection insulator are:A-1(0.045 W/(m·K)),A-2(0.031 W/(m·K)),A-3(0.042 W/(m·K)),A-4(0.078 W/(m·K)),and the average heat conductivity is 0.049 W/(m·K);The heat conductivity for each type of Styrofoam insulator are 0.030 W/(m·K) for B-1,0.032 W/(m·K) for B-2,0.037 W/(m·K) for B-3,0.037 W/(m·K) for B-4,and the average heat conductivity is 0.035 W/(m·K) regardless of the thickness of the insulator;The heat conductivity values of the multilayer reflection insulators are converted based on the thickness and type C-1(0.020 W/(m·K)),C-2(0.018 W/(m·K)),C-3(0.016 W/(m·K)),and C-4(0.012 W/(m·K));The multilayer reflection insulator keeps the indoor-side surface temperature high(during winter) or low(in summer),enhances the comfort of the building occupants,and conducts heating and moisture resistance to prevent dew condensation on the glass-outer-wall surface.

Seismic vulnerability evaluation of axially loaded steel built-up laced members I:experimental results

An experimental program was initiated to investigate the seismic performance of built-up laced steel brace members. Quasi-static testing of twelve typical steel built-up laced member （BLM） specimens was conducted. These were designed to span a range of parameters typically encountered for such members based on findings from a survey of commonly used shapes and details that have been historically used. The specimens were subdivided into groups of three different cross-sectional shapes, namely built-up I-shape section, and built-up box shapes buckling about the x or the y axis. Within each group, global and local buckling slenderness ratios had either kl/r values of 60 or 120, and b/t ratios of 8 or 16. The specific inelastic cyclic behavior germane to each specimen, and general observations on overall member hysteretic behavior as a function of the considered parameters, are reported. A companion paper （Lee and Bruneau 2008） investigates this observed response against predictions from analytical models, and behavior in the perspective of system performance.

Fiber-Reinforced Polymer Bridge Design in the Netherlands： Architectural Challenges toward Innovative, Sustainable, and Durable Bridges

本文综述了纤维增强复合材料(FRP)在荷兰桥梁的建筑性与结构性设计方面的应用,讨论了这种相对较新的材料给建筑师和工程师带来的挑战和机遇。本文涵盖了纤维增强复合材料的最新结构处理方案,以及对于纤维增强复合材料在建筑方面应用的讨论,这些应用来源于笔者与其他科研人员在建筑上的实践。

Assessment of green roof performance for sustainable buildings under winter weather conditions

A green roof is a specialized roof system that supports vegetation growth on rooftops.This technology is rapidly gaining popularity as a sustainable design option for buildings.In order to contribute to an understanding of green roof in regions with cold winters and snow,an on-site experimental investigation was present with a focus on the assessment of green roof performance during the winter.This field experiment took place on a six small buildings during the winter of 2010-2011.The work monitored three buildings with green roofs,two buildings with reference roofs and one building with a bare soil coverage for the roof.These six buildings were identically constructed and instrumented with sensor networks to provide heat flux data through the roofs.The 15 min averaged data were statistically analyzed for a week under the two separate periods,first without a snow cover and second with a snow cover.The results show that the roof type is a significant factor in affecting the thermal performance of these buildings.Most importantly,green roofs reduce heat flow through the roof and thus reduce the heating energy demand during the winter.However,the energy savings for buildings with the green roofs are reduced under snow conditions because the snow diminishes thermal resistance of the roof and increases the heat transfer process through the roofs.

Tests on Alkali-Activated Slag Foamed Concrete with Various Water-Binder Ratios and Substitution Levels of Fly Ash

To provide basic data for the reasonable mixing design of the alkali-activated (AA) foamed concrete as a thermal insulation material for a floor heating system, 9 concrete mixes with a targeted dry density less than 400 kg/m3 were tested. Ground granulated blast-furnace slag (GGBS) as a source material was activated by the following two types of alkali activators: 10% Ca(OH)2 and 4% Mg(NO3)2, and 2.5% Ca(OH)2 and 6.5% Na2SiO3. The main test parameters were water-to-binder (W/B) ratio and the substitution level (RFA) of fly ash (FA) for GGBS. Test results revealed that the dry density of AA GGBS foamed concrete was independent of the W/B ratio an RFA, whereas the compressive strength increased with the decrease in W/B ratio and with the increase in RFA up to 15%, beyond which it decreased. With the increase in the W/B ratio, the amount of macro capillaries and artificial air pores increased, which resulted in the decrease of compressive strength. The magnitude of the environmental loads of the AA GGBS foamed concrete is independent of the W/B ratio and RFA. The largest reduction percentage was found in the photochemical oxidation potential, being more than 99%. The reduction percentage was 87% - 93% for the global warming potential, 81% - 84% for abiotic depletion, 79% - 84% for acidification potential, 77% - 85% for eutrophication potential, and 73% - 83% for human toxicity potential. Ultimately, this study proved that the developed AA GGBS foamed concrete has a considerable promise as a sustainable construction material for nonstructural element.

Seismic vulnerability evaluation of axially loaded steel built-up laced members II:evaluations

The test results described in Part 1 of this paper （Lee and Bruneau, 2008） on twelve steel built-up laced members （BLMs） subjected to quasi-static loading are analyzed to provide better knowledge on their seismic behavior. Strength capacity of the BLM specimens is correlated with the strength predicted by the AISC LRFD Specifications. Assessments of hysteretic properties such as ductility capacity, energy dissipation capacity, and strength degradation after buckling of the specimen are performed. The compressive strength of BLMs is found to be relatively well predicted by the AISC LRFD Specifications. BLMs with smaller kl/r were ductile but failed to reach the target ductility of 3.0 before starting to fracture, while those with larger kl/r could meet the ductility demand in most cases. The normalized energy dissipation ratio, EC/ET and the normalized compressive strength degradation, Cr″/Cr of BLMs typically decrease as normalized displacements δ/δb,exp increase, and the ratios for specimens with larger kl/r dropped more rapidly than for specimens with smaller kl/r; similar trends were observed for the monolithic braces. The BLMs with a smaller slenderness ratio, kl/r, and width-to-thickness ratio, b/t, experienced a larger number of inelastic cycles than those with larger ratios.

Cellular automaton modeling of pedestrian movement behavior on an escalator

As a convenient passenger transit facility between floors with different heights, escalators have been extensively used in shopping malls, metro stations, airport terminals, etc. Compared with other vertical transit facilities including stairs and elevators, escalators usually have large transit capacity. It is expected to reduce pedestrian traveling time and thus improve the quality of pedestrian’s experiences especially in jamming conditions. However, it is noticed that pedestrians may present different movement patterns, e.g., queuing on each step of the escalator, walking on the left-side and meanwhile standing on the right-side of the escalator. These different patterns affect the actual escalator traffic volume and finally the passenger spatiotemporal distribution in different built environments. Thus, in the present study, a microscopic cellular automaton(CA) simulation model considering pedestrian movement behavior on escalators is built. Simulations are performed considering different pedestrian movement speeds, queuing modes, and segregation on escalators with different escalator speeds.The actual escalator capacities under different pedestrian movement patterns are investigated. It is found that walking on escalators will not always benefit escalator transit volume improvement, especially in jamming conditions.

Interfacial properties of g-C_(3)N_(4)/TiO_(2) heterostructures studied by DFT calculations

Constructing the hetrostructure is a feasible strategy to enhance the performances of photocatalysts. However, there are still some fundamental details and mechanisms for the specific design of photocatalysts with heterostructure,which need further confirming and explain.In this work,g-C_(3)N_(4)-based heterostructures are constructed with TiO_(2) in different ways,and their intrinsic factors to improve the photocatalytic activity are systematically studied by density functional theory(DFT).When g-C_(3)N_(4) combines horizontally with TiO_(2) to form a heterostructure,the interaction between them is dominated by van der Waals interaction.Although the recombination of photo-generated electron-hole pair cannot be inhibited significantly,this van der Waals interaction can regulate the electronic structures of the two components,which is conducive to the participation of photo-generated electrons and holes in the photocatalytic reaction.When the g-C_(3)N_(4) combines vertically with TiO_(2) to form a heterostructure,their interface states show obvious covalent features,which is very beneficial for the photo-generated electrons’ and holes’ transport along the opposite directions on both sides of the interface.Furthermore,the built-in electric field of g-C_(3)N_(4)/TiO_(2) heterostructure is directed from TiO_(2) layer to g-C_(3)N_(4) layer under equilibrium,so the photo-generated electron-hole pairs can be spatially separated from each other.These calculated results show that no matter how g-C_(3)N_(4) and TiO_(2) are combined together,the g-C_(3)N_(4)/TiO_(2) heterostructure can enhance the photocatalytic performance through corresponding ways.

Effect of fluidity on the manufacturing of open cell magnesium alloy foams

The effect of fluidity on open cell AZ31 metal foam samples fabricated using a solid state space holder method was investigated.Granule was fabricated by plaster powder and perlite powder.Granules were sieved which compacted layer by layer in casting mold.Preforms which made by granules were then heated to 200℃,300℃,400℃,500℃ under a rough(mechanical)vacuum before pressure infiltration with AZ31 Mg alloy.Samples were infiltrated using vacuum pressure values range of 8-14 KPa.The conditions of pressure and temperature were performed in order to get different fluidity on manufacturer of open cell AZ31 metal foam specimen quantity.It is found that the fluidity plays significant role to determine the open cell AZ31 alloy foam.The fluidity is affected by preheat temperature and infiltration vacuum pressure.The macrostructure,the distribution of the pores,microstructure,infiltration length,and porosity were investigated.

The Hierarchical Order of Spaces in Arab Traditional Towns: The Case of Najd, Saudi Arabia

The built environment faces many challenges in accommodating multi-cultural diversity and migrating from the suburbs, which led to different places being isolated or neglected. Sub-identities established by a specific group of people become isolated and away from the shared identity that the built environment established for itself. We examine this issue in the Najdi built environment by examining how Najdi locals generated a holistic hierarchical order of specs. This paper argues that the spatial order encouraged locals to develop a shared and agreed mechanism while in parallel, it gave individuals the ability to modify their places without affecting that shared holistic spatial order.

Comparison of Risk Assessment for a Nuclear Power Plant Construction Project Based on Analytic Hierarchy Process and Fuzzy Analytic Hierarchy Process

Recently, plant construction throughout the world, including nuclear power plant construction, has grown significantly. The scale of Korea’s nuclear power plant construction in particular, has increased gradually since it won a contract for a nuclear power plant construction project in the United Arab Emirates in 2009. However, time and monetary resources have been lost in some nuclear power plant construction sites due to lack of risk management ability. The need to prevent losses at nuclear power plant construction sites has become more urgent because it demands professional skills and large-scale resources. Therefore, in this study, the Analytic Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP) were applied in order to make comparisons between decision-making methods, to assess the potential risks at nuclear power plant construction sites. To suggest the appropriate choice between two decision-making methods, a survey was carried out. From the results, the importance and the priority of 24 risk factors, classified by process, cost, safety, and quality, were analyzed. The FAHP was identified as a suitable method for risk assessment of nuclear power plant construction, compared with risk assessment using the AHP. These risk factors will be able to serve as baseline data for risk management in nuclear power plant construction projects.

Analysis of coupled thermo-hydro-mechanical behavior of unsaturated soils based on theory of mixtures I

This paper analyzes a coupled thermo-hydro-mechanical behavior of unsaturated soils based on the theory of mixtures. Unsaturated soil is considered as a mixture composed of soil skeleton, liquid water, vapor, dry air, and dissolved air. In addition to the mass and momentum conservation equations of each component and the energy conservation equation of the mixture, the system is closed using other 37 constitutive （or restriction） equations. As the change in water chemical potential is identical to the change in vapor chemical potential, a thermodynamic restriction relationship for the phase transition between pore water and pore vapor is formulated, in which the impact of the change in gas pressure on the phase transition is taken into account. Six final govern- ing equations are given in incremental form in terms of six primary variables, i.e., three displacement components of soil skeleton, water pressure, gas pressure, and temperature. The processes involved in the coupled model include thermal expansions of soil skeleton and soil particle, Soret effect, phase transition between water and vapor, air dissolution in pore water, and deformation of soil skeleton.

Bacteria Adherence Properties of Nitrided Layer on Ti6Al4V by the Plasma Nitriding Technique

The nitrided layer on Ti6A14V substrate was prepared by the plasma nitriding technique. The sample was characterized by X-ray diffraction （XRD）, glow discharge optical emission spectroscopy （GDOES）, X-ray photoelectron spectroscopy （XPS）, and rough-meter. X- ray diffraction analysis reveals that TiN, Ti2N and Ti phase exist in the nitrided layer subsurface. GDOES analysis shows the thickness of the nitrided layer is about 3 ~tm. XPS analysis shows that there is higher N, lower A1 and lower V in the nitrided layer surface than in the Ti6A14V surface. Rough-meter analysis results show the roughness of the nitrided layer is greater than that of Ti6A14V alloy base. The bacteria adherence property of the nitrided layer on Ti6A14V substrate on the Streptococcus mutans was investigated and compared with that of Ti6A14V alloy by fluorescence microscope. It shows that the nitrided layer inhibits the bacteria adherence.