Open Squares Research Articles

Radio Propagation Measurements and Statistical Channel Models for Outdoor Urban Microcells in Open Squares and Streets at 142, 73, and 28 GHz

Radio Propagation Measurements and Statistical Channel Models for Outdoor Urban Microcells in Open Squares and Streets at 142, 73, and 28 GHz

Microclimate and its influencing factors in residential public spaces during heat waves: An empirical study in Hong Kong

Creating thermally comfortable living environment under the new normal of heat waves requires pertinent knowledge as references. In subtropical residential areas, various types of public spaces exist, whose microclimate differences during heat waves, as well as their relationship with surrounding building and greenery characteristics, have not been systematically investigated. We therefore evaluated microclimate performances in three typical types of residential public spaces, i.e., open squares, vegetated spaces, and semi-outdoor spaces, and their relationship with surrounding built environment during summertime heat waves. Field measurement of microclimate parameters was conducted in two selected public housing estates in Hong Kong, followed by calculation of thermal comfort indices. Their relationship with building and greenery factors was analyzed. Results show inconsistent patterns in different microclimate variables among three types of spaces across different times of the day, while thermal comfort conditions in the three types of spaces are significantly different. In vegetated spaces and open squares, three-dimensional factors play dominant roles in determining microclimate and thermal comfort condition, with sky view factor (SVF) contributing the most. We detected key SVF threshold for effective thermal comfort enhancement around 0.4, based on which we discussed building and greenery optimization in similar urban context from a point-based SVF perspective and its potential application in practice. In semi-outdoor spaces, two-dimensional land-cover composition contributes greater than three-dimensional factors. This study provides empirical evidence on thermal performance of residential public spaces, which can assist practitioners in achieving adaptation to heat waves in high-density urban contexts in subtropical regions.

PACAP-PAC1 receptor inhibition is effective in opioid induced hyperalgesia and medication overuse headache models

Opioids prescribed for pain and migraine can produce opioid-induced hyperalgesia (OIH) or medication overuse headache (MOH). We previously demonstrated that pituitary adenylate cyclase activating polypeptide (PACAP) is upregulated in OIH and chronic migraine models. Here we determined if PACAP acts as a bridge between opioids and pain chronification. We tested PACAP-PAC1 receptor inhibition in novel models of opioid-exacerbated trigeminovascular pain. The PAC1 antagonist, M65, reversed chronic allodynia in a model which combines morphine with the migraine trigger, nitroglycerin. Chronic opioids also exacerbated cortical spreading depression, a correlate of migraine aura; and M65 inhibited this augmentation. In situ hybridization showed MOR and PACAP co-expression in trigeminal ganglia, and near complete overlap between MOR and PAC1 in the trigeminal nucleus caudalis and periaqueductal gray. PACAPergic mechanisms appear to facilitate the transition to chronic headache following opioid use, and strategies targeting this system may be particularly beneficial for OIH and MOH.

Площадь как визуальный паттерн городской среды

This article is devoted to the analysis of the square as one of the key visual elements (patterns) of the urban environment. To understand how a city works, it is necessary to find out what urban practices are associated with the square, what its role is in shaping the overall appearance of the city, and in what ways it relates to other visual patterns. The study of the city square in its aesthetic, semiotic, social, and cultural aspects is a necessary part of the discourse, which is focused on the theoretical understanding and practical formation of the overall image of the city. The article deals with questions about the human scale of the square, its cultural functions, artistic integrity, and forms of its participation in the scenography of urban space. A comparison of the closed and open squares is made by referring to some well-known examples. It is shown that a normal urban pattern is a square that combines the properties of ‘openness’ and ‘closedness’ and at the same time includes elements of geometry, architecture, sculpture, and local history in its ensemble. It is concluded that a stable visual pattern of the urban environment can only be such a square that combines several functions, is in obvious combination with patterns of other types, has a human scale, and is a noticeable architectural ensemble. The square can act as a visual dominant of the entire urban structure, determine the general perception of the city, its appearance and silhouette. At the same time, the city also influences the square, programming its form, style, and function. The degradation of squares, which leads to the degradation of the urban environment as a whole, is explained by their dehumanization, functional reduction (the transformation of squares into transport hubs) and, most importantly, the fragmentation of their visual perception. The city square is degrading precisely because the townspeople cease to understand and perceive it as a certain and very complex form of organization of the urban texture, on which both the compositional unity of the city and the continuity of its cultural identity rest.

Revealing the Impact of Urban Form on COVID-19 Based on Machine Learning: Taking Macau as an Example

The COVID-19 pandemic has led to a re-examination of the urban space, and the field of planning and architecture is no exception. In this study, a conditional generative adversarial network (CGAN) is used to construct a method for deriving the distribution of urban texture through the distribution hotspots of the COVID-19 epidemic. At the same time, the relationship between urban form and the COVID-19 epidemic is established, so that the machine can automatically deduce and calculate the appearance of urban forms that are prone to epidemics and may have high risks, which has application value and potential in the field of planning and design. In this study, taking Macau as an example, this method was used to conduct model training, image generation, and comparison of the derivation results of different assumed epidemic distribution degrees. The implications of this study for urban planning are as follows: (1) there is a correlation between different urban forms and the distribution of epidemics, and CGAN can be used to predict urban forms with high epidemic risk; (2) large-scale buildings and high-density buildings can promote the distribution of the COVID-19 epidemic; (3) green public open spaces and squares have an inhibitory effect on the distribution of the COVID-19 epidemic; and (4) reducing the volume and density of buildings and increasing the area of green public open spaces and squares can help reduce the distribution of the COVID-19 epidemic.

Hitler’s Northern Utopia: Building the New Order in Occupied Norway

Hitler’s Northern Utopia: Building the New Order in Occupied Norway

The more walkable, the more livable? -- can urban attractiveness improve urban vitality?

As one of the walkability attributes, attractiveness seems to play an essential role in improving urban vitality and is highly correlated with urban redevelopment. This paper aims to examine whether and to what extent the improvement of the level of attractiveness can encourage urban vitality. Four squares from the “Open Squares” project in Milan are selected as cases. This project transformed several neighborhood squares into attractive nodes by a series of similar low-cost interventions to encourage urban vitality. The methodology is subdivided into four steps. First of all, the spatial features of the squares were measured before and after the transformation. Then, several relevant walkability attributes of the surroundings, where the squares locate, were measured incorporating GIS (Geographic information system) and semantic segmentation of street view data. Thirdly, urban vitality levels before and after the transformation were evaluated based on the analysis of posts, photos, and textual contents of the squares posted on social media (e.g., Twitter, Facebook, and Instagram). Finally, with comprehensive comparisons between the results of walkability assessment and social media data in different periods, the potentiality of attractiveness in improving urban vitality was evaluated.

ЕКСПОЗИЦІЙНІ МАЙДАНЧИКИ ДЛЯ ТВОРІВ ВІЗУАЛЬНОГО МИСТЕЦТВА В ІВАНО-ФРАНКІВСЬКУ У ХХ – НА ПОЧАТКУ ХХІ СТОЛІТТІ: ЗДОБУТКИ, ВТРАТИ, ПЕРСПЕКТИВИ

The exhibition spaces of Ivano-Frankivsk, where works of visual art are exhibited, are considered in the work. The activity of the most significant sites in the artistic life of the city is covered, including gallery and museum halls, premises of educational institutions, libraries, shops, public catering facilities, open city squares and spaces. The purpose of the scientific research is to reveal the potential of exhibition locations for the exhibition of visual art works in Ivano-Frankivsk and to trace the specifics of their functioning in chronological terms. The dynamic process of both gains in the exposition activity of the city and losses of exhibition premises, which at one time became important for the cultural life of the city, where world-class creative events took place, is considered. The problem of lack of exhibition premises in Ivano-Frankivsk museums is studied. The work traces the searches for new exhibition areas in connection with the changing role and functions of art, as well as, in particular, in connection with the shift of emphasis and focus in the perception and retransmission of contemporary art works. It was found that the purpose of the appearance of new exhibition spaces in the city at the beginning of the XXI century was to form a more pronounced impact of artifacts on the viewer, depriving a certain outrage,the desire to make this space more open to communication and discussion. The following methods are used in the article: empirical that help to identify individual facts, observation of individual exhibitions and art locations, etc.; analytical with the help of which important processes in the exposition activity of the city are traced; systematization and generalizations that help to make reasoned conclusions about the state, problems and prospects of the exhibition industry of the regional center.

A Thrombospondin-1 Release Assay (TRA) Coupled to PF4-Treated Cryopreserved Platelets for the Detection of Pathogenic HIT and VITT Antibodies

Background: Platelet-activating anti-PF4 antibodies that cause thrombocytopenia and thrombosis are implicated in Heparin-induced thrombocytopenia (HIT) and, more recently, in a newly recognized entity, vaccine-induced immune thrombotic thrombocytopenia (VITT). Current frontline PF4-Polyanion ELISAs utilize simple techniques but are highly non-specific. Functional gold-standard assays such as the serotonin-release assay (SRA) and PF4-dependent P-selectin expression assay (PEA) have limited availability due to technical complexity and the requirement for freshly-drawn normal donor platelets which results in significant delays in diagnosis. Thus, there is an unmet need for near-patient, functional assays for HIT/VITT diagnosis.Aim: To develop a highly sensitive and specific functional assay to detect platelet-activating antibodies associated with HIT and VITT using long-term stored platelets. The assay should be technically simple, avoiding current functional HIT testing endpoints such as aggregometry, radioactivity measurement or flow cytometry.Methods: Platelets were subjected to controlled-rate freezing in a trehalose-based buffer. Cryopreserved platelets were then thawed after variable storage periods, incubated with platelet factor 4 (PF4), and sera from HIT or VITT suspected patients. Thrombospondin-1 (TSP1), a protein highly expressed in platelet α-granules, was quantified from activated platelet supernatants in an ELISA-based assay as a measure of platelet activation.Results: In initial studies, p-selectin expression was induced by platelet-activating HIT antibodies using cryopreserved platelets and the TSP1-release assay (TRA) detected HIT antibody-mediated PF4-dependent cryopreserved platelet activation across 20 different platelet lots (data not shown). A representative study using platelets stored for 11 months is shown in Figure 1A. A cohort of thirty-six HIT-suspected patient sera, half with PF4-dependent platelet-activating antibodies (PEA+) and without (PEA-), were used to evaluate the diagnostic accuracy of the TRA (Figure 1B). All 18 PEA+ samples activated platelets strongly with a mean TSP1 concentration of 147 µg/mL measured in the supernatant compared to a mean of 43 µg/mL obtained with non-activating samples. TSP1 release in a subgroup of 7 PEA+/SRA+/ELISA+ and 4 PEA-/SRA-/ELISA+ samples that were matched for ELISA Optical Density was examined (Figure 1C). Results demonstrated that even strong ELISA+ samples that were non-activating (PEA-/SRA-) did not induce platelet activation in the TRA, confirming high specificity of the assay. The TRA was tested for its ability to detect platelet-activating antibodies in four patients who developed VITT after the Janssen vaccine (Ad26.COV2.S). All samples induced high levels of TSP1 release from cryopreserved platelets (Figure 1D).Conclusions: Our results demonstrate that cryopreserved platelets stored for several months are viable and capable of degranulation upon activation. Further, we demonstrate that measurement of TSP-1 released from cryopreserved, PF4-treated platelets is highly accurate for detecting platelet-activating HIT and VITT anti-PF4 antibodies. Specificity and sensitivity were both 100% even with samples that were strongly false-positive in the HIT ELISA. Coupling cryopreserved platelet activation to a simple ELISA endpoint, as demonstrated here, precludes the need for fresh platelets and complex testing techniques. Thus, the TRA has the potential to transform the diagnostic testing paradigm in HIT and VITT by making near-patient in-hospital functional testing available for rapid and accurate diagnosis.Figure Legend:Figure 1. TSP-1 quantification of (A) 3 HIT patient samples (closed circles) relative to 3 normal control samples (open circles) after 11-months of frozen platelet storage. (B) Thirty-six HIT-suspected patient samples: 18 PEA+ samples (closed circles), and 18 PEA- samples (open squares). Data are compared using two-tailed, unpaired Student's t test. **** P<0.0001. (C) Eleven high optical density matched HIT ELISA patient sera: 7 PEA+/SRA+ samples (closed circles) and 4 PEA-/SRA- samples (open squares). (D) TSP-1 quantification of VITT patient sera. NC-normal control. [Display omitted] DisclosuresPruthi: Instrumentation Laboratory: Honoraria; HEMA Biologics: Honoraria; Bayer Healthcare AG: Honoraria; Genentech: Honoraria; CSL Behring: Honoraria; Merck: Honoraria. Padmanabhan: Veralox Therapeutics: Membership on an entity's Board of Directors or advisory committees.

A New Assay for Platelet-Activating HIT Antibodies, the PEA, Is Specific, Reproducible and Relatively Independent of the Choice of Platelet Donor

A New Assay for Platelet-Activating HIT Antibodies, the PEA, Is Specific, Reproducible and Relatively Independent of the Choice of Platelet Donor

Model of Third-Party Risk Index for Unmanned Aerial Vehicle Delivery in Urban Environment

In order to assess the airspace risk of unmanned aerial vehicles (UAVs) operating at low altitudes, the third-party risks of UAV urban operations were defined: the risks caused by drones to people on the ground who are not involved in operations and do not profit from operations, and the sources and objects of the risk were clarified. Taking into account the drone crash, noise, on-board camera, and ground environment factors, a UAV urban logistics risk index evaluation model was constructed. First, the UAV image regression model was used to construct a three-dimensional grid, and then a comprehensive third-party risk index model of UAV urban logistics was built based on the casualty and noise risks. Finally, the Southern District of Civil Aviation University of China was selected as an example scene, and surface data were obtained through a field investigation and instrument measurements. Then, the risk of drone operations in the airspace 30–60 m above this area was evaluated. The results showed that the third-party risk was lower when the UAV flying altitude above a building was greater. However, in other areas such as lakes, woods, roads, open spaces, a lower flight altitude had a lower risk. A comparison of the whole airspace showed that the third-party risk was the lowest when the drone operated at an altitude of 30 m. The results also showed that the third-party risk above the lake and greenery was the lowest when on the same plane, followed by the lower risk above the buildings and open squares, with the highest third-party risk above the canteen passage.

Shading analysis of urban squares using open-source software and free satellite imagery

The purpose of the study is to develop a method for analyzing, from satellite imagery and GIS tools, the impact of shading from surrounding buildings on open public squares in a subtropical location in Brazil, in order to assist and provide subsidies for urban planning. The method integrates open data, spatial data, and GIS simulation tools for the analysis of shading profiles on winter and summer solstices, and spring equinox. Different types of spaces were analyzed for the current configuration of adjacent buildings, starting with a historic square, Japan Square, in Curitiba. The analysis for 25 urban public squares with the current height configuration showed that four of them had more than 50% of their surface area shaded more than 3 h in winter solstice. The detailed analysis of a possible future scenario for one of the squares evaluated showed that the study of the impact of future constructions on open-air public spaces is important and necessary, especially when vertical growth is allowed in cities such as Curitiba, characterized by a cold winter, when solar access is largely recommended. The method proved to be applicable and reliable, and can be useful for the initial stages of urban planning, as well as for readjustments of existing spaces. Furthermore, it is a tool to analyze the impact of new constructions of surrounding buildings or even for studies of boundary height parameters of buildings around these sites.

ПРОГРАММА «БЕЗОПАСНЫЙ ГОРОД» КАК ВАЖНОЕ НАПРАВЛЕНИЕ ГОСУДАРСТВЕННОЙ ПОЛИТИКИ В СФЕРЕ БОРЬБЫ С ПРЕСТУПНОСТЬЮ

The article analyzes the crime rate in the Russian Federation, including the Yaroslavl region. The author carried out a sociological study, within the framework of which a selective analysis of the implementation of the Safe city program in cities in the Russian Federation was carried out. In addition, a survey of students was carried out in 2018–2019 and a series of in-depth interviews with positional experts were conducted. A series of in-depth interviews with students were carried out: the faculty of law of Yaroslavl state university, the faculty of social and political sciences from Yaroslavl state university, pedagogical specialties from Yaroslavl state pedagogical university. It is concluded that the fight against crime will be more effective in comparison with the existing practice if the following conditions are met: purposeful increase in the degree of protection of citizens and infrastructure of cities and rural areas; full-scale implementation of information and communication technologies to control closed (markets, museums, etc.) and open (squares, parks, etc.) territories; development of basic information systems and resources, formation of technical and organizational foundations for further digital transformation of cities and rural areas; active participation of citizens in the life of society and in decision-making on the digitalization of urban space. The author's selective analysis of the implementation of the Safe city program in cities in the Russian Federation showed that the program is designed to reduce the number of offenses and especially dangerous crimes. In addition, this program provides for the solution of issues related to the migration aspect, with the need to reduce the risks caused by man-made and natural disasters and is aimed at identifying the potential danger of objects left in public places. As part of the study, a content analysis of the blogosphere was also carried out, a secondary analysis of publications of research results carried out by scientists from the Federal research center of the Russian academy of sciences (Moscow), was carried out. Based on the results of the study, measures are proposed to reduce crime in cities.

(Invited) High-Speed GaN-Based Micro-Scale Light-Emitting Diodes for Visible-Light Communication

The increasing demand for wireless data communication and popularity of solid-state lighting has prompted research into visible-light communication (VLC) systems using GaN-based light-emitting diodes (LEDs). VLC is a promising candidate for next-generation (5G and beyond) light-fidelity (Li-Fi) network systems. To support multi-Gb/s data rates, VLC systems will require efficient LEDs with large modulation bandwidths. Conventional lighting-class LEDs cannot achieve high-speed operation due to their large chip size, large active region volume, and phosphor-converted output. Conversely, micro-scale LEDs (micro-LEDs) offer a viable path to high-speed operation due to their lower parasitic capacitance and ability for operation at high current densities where the carrier lifetime is significantly reduced. Furthermore, conventional c-plane LEDs suffer from polarization-related electric fields, which reduce the overlap between the electron and hole wave functions and lower the carrier recombination rate. Since modulation bandwidth is proportional to the carrier recombination rate (inversely proportional to the carrier lifetime), the overlap between the wave functions should be maximized for high-speed operation. Nonpolar and semipolar orientations have significantly reduced polarization effects and wave function overlaps approaching unity. These orientations can enable high-efficiency LEDs with simultaneously large modulation bandwidths, especially at relatively low current densities. In this work, we introduce VLC and discuss progress on the growth, fabrication, and characterization of high-speed micro-LEDs. Polar (0001), nonpolar (1010), and semipolar (2021) InGaN/GaN micro-LEDs on free-standing GaN substrates are investigated for their small-signal modulation characteristics as a function of current density, temperature, device area, and active region design. We demonstrate that the modulation bandwidths are well correlated with the wave function overlap in the active region by examining the orientation-dependence of the bandwidth. Record modulation bandwidths for GaN-based LEDs above 1 GHz are achieved for the nonpolar and semipolar orientations. We also show the modulation characteristics of an electrically injected nanowire-based LED, which achieves a modulation bandwidth of 1.2 GHz. Finally, we present a small-signal modeling method for determining the RC characteristics, differential carrier lifetime, carrier escape lifetime, and injection efficiency of the LEDs under electrical injection and discuss the results in the context of efficiency droop. Figure 1: Bandwidth vs. current density for the nonpolar LEDs (open black triangles), semipolar LED (open blue circles), and polar c-plane LED (open green squares) compared to other reported polar c-plane LEDs on sapphire or with a flip-chip design and compared to semipolar (1122) LEDs. The bandwidth characteristics for a nanowire-based LED are also included. Also shown are the crystal orientations used in the orientation-dependent bandwidth study. Figure 1

On optimal piercing of a square

We treat the following problem: given an n×n square ABCD, determine the minimum number of points that need to be chosen inside the square ABCD such that there does not exist a unit square inside the square ABCD containing none of the chosen points in its interior. In other words, we are interested to know how to most efficiently “destroy” a square-shaped object of side length n, where “destroying” is achieved by piercing as few as possible small holes, and the square is considered “destroyed” if no unpierced square piece of unit side length can be salvaged. This problem actually belongs to the family of problems centered about the so-called piercing number: indeed, if Un denotes the collection of all open unit squares that can be fitted inside a given n×n square, the value that we are looking for is the piercing number of the collection Un, denoted by π(Un). We show that π(Un)=n2 when n⩽7, and give an upper bound for π(Un) that is asymptotically equal to 23n2, which we believe is asymptotically tight. We then generalize our reasoning in order to obtain a similar upper bound when ABCD is a rectangle, as well as an upper bound for π(Ux) when x is not necessarily an integer. Finally, we show that our results have an application to the problem of packing a given number of unit squares in the smallest possible square; it turns out that our results present a general “framework” based on which we are able to reprove many results on the mentioned problem (originally obtained independently of each other) and also obtain a new result on packing 61 unit squares.

The polygonal model: A simple representation of biomolecules as a tool for teaching metabolism.

Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student. In this report, we describe the "polygonal model" as a new means of graphically representing biomolecules. This model is based on the use of geometric figures such as open triangles, squares, and circles to represent hydroxyl, carbonyl, and carboxyl groups, respectively. The usefulness of the polygonal model was assessed by undergraduate students in a classroom activity that consisted of "transforming" molecules from Fischer models to polygonal models and vice and versa. The survey was applied to 135 undergraduate Biology and Nursing students. Students found the model easy to use and we noted that it allowed identification of students' misconceptions in basic concepts of organic chemistry, such as in stereochemistry and organic groups that could then be corrected. The students considered the polygonal model easier and faster for representing molecules than Fischer representations, without loss of information. These findings indicate that the polygonal model can facilitate the teaching of metabolism when the structures of biomolecules are discussed. Overall, the polygonal model promoted contact with chemical structures, e.g. through drawing activities, and encouraged student-student dialog, thereby facilitating biochemical learning. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):66-75, 2018.

Human-biometeorological significance of shading in urban public spaces—Summertime measurements in Pécs, Hungary

Shading is shown to be one of the most effective strategies to mitigate urban heat stress, especially on a small scale. This paper presents an empirical study investigating the effectiveness of different means of shading—by sun sails and trees—to improve the local thermal environment during the summer. Three different urban settings were investigated through detailed human-biometeorological measurements in the Hungarian city of Pécs. Our study employed the accurate six-directional radiation measurement technique, and calculated Physiological Equivalent Temperature (PET) from the obtained data to assess outdoor thermal conditions. Our results indicate that in open urban squares trees can mitigate heat stress more effectively than low-hanging sun sails, installed right above the head of pedestrians. In the period of 9:00–16:00, the average PET reduction by trees and low sun sails was 9.0°C and 5.8°C, respectively. Sun sails, installed at higher elevation to shade an entire street canyon, and mature trees with dense canopy had more pronounced heat stress reduction ability, and were able to reduce the local PET by over 10°C. Our study demonstrates the importance of detailed small-scale field measurements, the outcomes of which can be incorporated into climate-responsive urban design strategies with ease.

Kyawthuite, Bi3+Sb5+O4, a new gem mineral from Mogok, Burma (Myanmar)

AbstractKyawthuite, Bi3+Sb5+O4, is a new gem mineral found as a waterworn crystal in alluvium at Chaung-gyi-ah-le-ywa in the Chaung-gyi valley, near Mogok, Burma (Myanmar). Its description is based upon a single sample, which was faceted into a 1.61-carat gem.The composition suggests that the mineral formed in a pegmatite. Kyawthuite is monoclinic, space group I2/c, with unit cell dimensions a = 5.4624(4), b = 4.88519(17), c = 11.8520(8) Å, β = 101.195(7)°, V = 310.25(3) Å3and Z = 4. The colour is reddish orange and the streak is white. It is transparent with adamantine lustre. The Mohs hardness is 5½. Kyawthuite is brittle with a conchoidal fracture and three cleavages: {001} perfect, {110} and {110} good. The measured density is 8.256(5) g cm–3and the calculated density is 8.127 g cm–3. The mineral is optically biaxial with 2V = 90(2)°. The predicted indices of refraction are α = 2.194, β = 2.268, γ = 2.350. Pleochroism is imperceptible and the optical orientation is X = b; Y≈ c; Z ≈ a. Electron microprobe analyses, provided the empirical formula (Bi0.823+Sb0.183+)∑1.00(Sb0.995+Ta0.015+)∑1.00O4. The Raman spectrumis similar to that of synthetic Bi3+Sb5+O4. The infrared spectrum shows a trace amount of OH/H2O. The eight strongest powder X-ray diffraction lines are [dobs in Å(I)(hkl)]: 3.266(100)(112), 2.900(66)(112), 2.678(24)(200), 2.437(22)(020,114), 1.8663(21)(024), 1.8026(43)(116,220,204), 1.6264(23)(224,116) and 1.5288(28)(312,132). In the crystal structure of kyawthuite (R1 = 0.0269 for 593 reflections with Fo &gt; 4σF), Sb5+O6 octahedrashare corners to form chequerboard-like sheets parallel to {001}. Atoms of Bi3+, located above and below the open squares in the sheets, form bonds to the O atoms in the sheets, thereby linking adjacent sheets into a framework. The Bi3+ atom is in lopsided 8 coordination,typical of a cation with stereoactive lone electron pairs. Kyawthuite is isostructural with synthetic β-Sb2O4 and clinocervantite (natural β-Sb2O4).

Microclimatic differences and their influence on transpirational cooling of Tilia cordata in two contrasting street canyons in Munich, Germany

Urban trees can help to mitigate the urban heat island through evapotranspiration. However, growing conditions in cities are heterogeneous and micrometeorological conditions in street canyons can have a large impact on a tree’s transpiration. Here we investigated a common urban street tree species Tilia cordata of different ages and sizes, planted in two contrasting street canyons in a densely built neighbourhood within the centre of Munich, Germany: Bordeaux Platz, an open green square (OGS), and Pariser Platz, a circular paved square (CPS) with similar aspect ratio≈0.5. The experiment was carried out during the exceptionally hot and dry summer of 2015. The open green square showed significantly higher wind speed and vapour pressure deficit but lower soil temperature, less negative soil moisture potential and also a smaller wind tunneling effect compared to the circular paved square. All these variables showed strong relationship with the sapflux density (Js) of trees grown at these two sites. They explain almost 78% of the variation in Js. On average Js values of the trees at Bordeaux Platz peaked to 0.30–0.35mlcm−2min−1 during the day compared to the peak values of 0.20–0.23mlcm−2min−1 for trees at Pariser Platz. Consequently, trees grown at the open green square showed higher peak cooling of 2.3kWtree−1 or 82wm−2 than at the circular paved square (1.9kWtree−1). Interestingly, nocturnal cooling was higher for trees at the circular paved square with 18% of daytime transpiration compared to 2% for trees at the open green square. The study gave new insights into the cooling benefits of urban trees planted in open green squares compared to closed and paved squares and its temporal variation.

A simulation model for visitors’ thermal comfort at urban public squares using non-probabilistic binary-linear classifier through soft-computing methodologies

Sustaining outdoor life in cities is decreasing because of the recent rapid urbanisation without considering climate-responsive urban design concepts. Such inadvertent climatic modifications at the indoor level have imposed considerable demand on the urban energy resources. It is important to provide comfortable ambient climate at open urban squares. Researchers need to predict the comfortable conditions at such outdoor squares. The main objective of this study is predict the visitors' outdoor comfort indices by using a developed computational model termed as SVM-WAVELET (Support Vector Machines combined with Discrete Wavelet Transform algorithm). For data collection, the field study was conducted in downtown Isfahan, Iran (51°41′ E, 32°37′ N) with hot and arid summers. Based on different environmental elements, four separate locations were monitored across two public squares. Meteorological data were measured simultaneously by surveying the visitors' thermal sensations. According to the subjects' thermal feeling and their characteristics, their level of comfort was estimated. Further, the adapted computational model was used to estimate the visitors’ thermal sensations in terms of thermal comfort indices. The SVM-WAVELET results indicate that R2 value for input parameters, including Thermal Sensation, PMW (The predicted mean vote), PET (physiologically equivalent temperature), SET (standard effective temperature) and Tmrt were estimated at 0.482, 0.943, 0.988, 0.969 and 0.840, respectively.