Lighting Standards Research Articles

Failure assessment of deteriorated steel light poles

Steel poles are extensively used as street light posts and various other applications within the power distribution network. For partially buried pole, the effect of corrosion below and at the ground level significantly controls the overall load capacity. In this study, number of in-service steel pole specimens extracted from field were assessed for the corrosion damage. The level of corrosion was estimated by remaining wall thickness measured using ultrasonic testing and the surface corrosion was estimated using 3D laser scanning to adopt an appropriate existing model for buried steel structures. A relationship between maximum and average corrosion pit depth and loss of embedment depth was then developed. Finally, the corrosion parameters, combined with uncertainty in loading and soil properties were employed to perform time-dependent reliability assessment for steel light poles which can be used to assist the asset maintenance team in planning the replacement or strengthening works for steel pole.

Dark roads aid movement but increase mortality of a generalist herbivore in the American Southwest

AbstractRoad networks pose many well‐documented threats to wildlife, from fragmenting habitats and restricting movement to causing mortality through vehicle collisions. For large, wide‐ranging mammals, home range requirements and seasonal migrations often necessitate road crossings, posing threats to human safety, property, and animal survival. Artificial nightlight, emanating from light posts and urban sky glow, is ubiquitous on and around road networks worldwide; however, its effects on road crossing behavior and the associated mortality risk for wildlife are not well understood. By integrating the latest NASA nightlight products with GPS collar data collected from 67 mule deer (Odocoileus hemionus) over a 7‐year period (2012–2018), we used a resource‐selection framework to assess factors influencing seasonal crossing behavior and road mortality in Salt Lake City, Utah, an expanding metropolitan area in the United States. We found deer preferred to cross the road where surrounding artificial nightlight was lower in both summer and winter seasons, especially during crepuscular and nighttime periods. However, lower nightlight levels also increased the risk of road mortality. Areas with more shrub cover and lower speed limits increased the likelihood of crossing as well as lowered the risk of road mortality. There were five times as many mortality events in winter as in summer, likely because of the combination of deer preference for dark roads mixed with proximity to both higher speed roads and increased human activity. Better understanding how a pervasive and expanding environmental pollutant like artificial nightlight may attract or repel human‐tolerant wildlife species from roadways presents an opportunity to mitigate collision risk while improving population management strategies for this abundant, generalist herbivore and many other economically and ecologically important species.

Mitigation of dust on PV panels that operate light posts using a wind shield, mechanical vibrations and AN antistatic coating

The objective of this research is to minimize dust accumulation on PV panels operating street light posts, in order to maximize the time between successive maintenance and reduce the maintenance costs. A novel technique is proposed to mitigate dust on PV panels that operate light posts, and that is adding a windshield to the panel, which obstructs the dust carried by the wind to reach and settle on the PV panel. 1D and 2D shields were implemented, and their influence on the performance of PV panels were tested outdoors in Cairo, Egypt, and the results were compared to those of a PV panel that is not shielded. Also, the influence of using an antistatic coating and vibrating the panel in addition to the dust shield on the performance of the panel have been examined. The 2D shield obstructs the wind in the North-South and East-West directions, while, the 1D shield obstructed the wind just in the North-South direction only. The results show that the 2D shield assisted in the accumulation of dust on the PV surface compared to the non-shield panel, while the 1D shield had a better performance. Using a mechanical vibrator together with a 1D shield has decreased the accumulation of dust to a very good extent, such that the drop in efficiency exceeded the maintenance limit of 10 %, after 5 weeks of operation, while in case of a 1D shield without mechanical vibrations, the limit was exceeded in 3 weeks. However, applying the antistatic coating together with the 1D shield while vibrating the panel preserved the efficiency of the panel, such that the drop in efficiency did not exceed the maintenance limit during the experiment duration of 6 weeks.

Numerical investigation of the effect of dust shields on accumulation of dust over PV panels

Dust accumulation on photovoltaic panels represents a major challenge for the operation of solar panels especially in the regions known by their high rate of dust and low frequency of rain. The objective of this study is to minimize dust accumulation on PV panels operating street light posts using dust shields. A novel dust shield having the same width of the panel, and subtending an angle of 120° with the panel, is proposed for dust mitigation. Numerical simulations are carried out to evaluate the influence of the dust shield on dust accumulation over the panel’s surface. It is found that using a dust shield decreases the dust deposition rate by more than 44%. Moreover, extending the panel’s surface at the lower edge with an extension plate together with the dust shield decreases the dust deposition rate better than using a dust shield only. Also, the effect of adding an air gap between the shield and the added extension plate is investigated, and it is found that the air gap induces air drafts over the panel’s surface, which acts as an air barrier that obstructs the approach of dust particles to the panel’s surface. These drafts get stronger as the air gap thickness increases, accordingly, less particles deposit on the panel. Finally, it is found that using a dust shield with a length smaller than the panel’s length in addition to an extension plate together and increasing the thickness of the air gap is an effective and efficient solution for dust mitigation, such that the percentage decrease in the dust deposition rate that might be more than 88%.

ARGUS: a pole climbing surveillance robot

Due to the high prevalence and unpredictability of violent protest action in South Africa, a need has arisen for rapidly deployable surveillance. This paper proposes an Automated Robotic Guardian for Urban Surveillance (ARGUS) platform, a wheeled, pole climbing robot as a potential solution. The platform is designed to attach to and traverse up existing cylindrically shaped infrastructure, such as light posts, enabling easy deployment in urban environments. The robot is intended for various surveillance needs, such as public safety at events, and periods of unrest or protest action. Following a detailed concept design stage, simulated results are presented for the proposed robot. This includes comprehensive CAD modelling, static force and torque calculations of the pole climbing robot, and finite element analysis of the component stresses while positioned on the pole. The robotic platform is currently in production and future work will include experimental validation of the simulated system.

The Context and Core of Relational Violence in Families1*

Few topics generate as much controversy and confusion in society, therapeutic practice, and science as violence in families, often referred to as domestic violence. There is a neverending dispute around the definition and about the statistics. Is relational violence mainly against women or are women as violent as men in intimate relationships? Outcomes from research are contradictory. When we zoom out, we can be aware that violence is everywhere and that we are part of it. At the same time, we can sense that the world is full of love. Both are part of the destructive dynamics of escalating conflicts in families that are more related to powerlessness than to power. In a therapeutic context we focus on the destructive dynamics in which the languages of perpetrator and victim are not helpful. We suggest the formulation of keystones as light posts to help us find a way to help family members to de‐escalate conflict.

Influence of vibration time on dust accumulation on PV panels that operate light posts

Dust accumulation on PV panels is a severe threat that greatly affects the energy yield of photovoltaic panels drastically, especially in the Middle East and North Africa region. A new technique consisting of a dust shield, an antistatic hydrophilic coating and a mechanical vibrator has been developed to mitigate dust on PV panels operating light posts. The role of the dust shield is to obstruct the wind which is the dust carrier. The role of the antistatic coating is to prevent the dust particles from adhering to the panel’s surface. The mechanical vibrator is attached at the backside of the PV panel in order to shake off the deposited dust particles and fall off by gravity. Two experiments have been conducted, in the first experiment the impact of increasing the rotational speed of the mechanical vibrator on the amplitude of vibration was investigated, and it was found that increasing the rotational speed increases the amplitude of vibration, consequently, decreases the dust accumulation rate. On the other hand, the influence of increasing the vibration time on the dust accumulation rate has been investigated in the second experiment. This experiment consists of three PV panels mounted on a light post; the first panel is a reference panel for comparison, while the other two panels consist of a dust shield, an antistatic hydrophilic coating and a mechanical vibrator operating for 2 min and 4 min, respectively. The percentage drop in efficiency after 6 weeks of operation in case of the reference panel and vibrating the PV panel for 2 min and 4 min, are 19.02%, 13.75% and 11.14%, respectively. Therefore, vibrating the PV panel for 2 min and 4 min has decreased the percentage drop in efficiency by 27% and 41%, as compared to the reference panel. Moreover, the maintenance time, in case of the 2 min and 4 min of vibrations, is one and two weeks more than the reference panel, which indicates the effectiveness of the vibration time on the developed dust mitigation technique on PV panels operating light posts.

The Sesquicentennial, So What? An Assessment a Quarter Century Afterward

The Sesquicentennial, So What? An Assessment a Quarter Century Afterward

Influence of seasonal effect on dust accumulation on Photovoltaic panels that operate light posts

Dust accumulation on Photovoltaic (PV) panels is a severe threat that decreases the energy production of PV panels and therefore, lowers their efficiency especially in the Middle East and North Africa (MENA) region. Cleaning of the PV panels has always been a challenge for most of the countries in this region due to scarcity of water resources and high dust accumulation rates throughout the year. A new dust mitigation technique has been developed in this research, which consists of a wind shield, antistatic hydrophilic coating and a mechanical vibrator. The objective of this research is to study the seasonal effects on the performance of this new dust mitigation technique for PV panels that operate street light posts. Two experiments were conducted for six weeks in 2021; the first one was in winter while the other one was in summer. In both experiments, two PV panels were examined. The first PV panel is used as a reference panel for comparison and the second panel is provided with a wind shield and a mechanical vibrator, in addition to being coated with an antistatic hydrophilic coating. The function of the wind shield is to obstruct the wind coming from the South direction. The antistatic coating prevents the dust particles from adhering to the panel’s surface. The role of the mechanical vibrator is to shake off the deposited dust particles on the panel’s surface. The experimental results show that applying the antistatic coating together with the wind shield with vibrating the panel in case of the winter experiment preserved the efficiency of the panel, such that the drop in efficiency did not exceed the maintenance limit of 10% during the experiment. While in the summer experiment, the maintenance limit has been exceeded in the fifth week. This is mainly due to the effect of wind direction and rainfalls, which were present in the winter, unlike the summer experiment where winds and rainfalls are rarely found. This clearly shows that the combination of the wind shield and the mechanical vibrator together with the coating is a promising dust mitigation technique for PV panels operating light posts especially in winter.

Measuring Streetscape Features with High-Density Aerial Light Detection and Ranging

This study investigates the feasibility of extracting streetscape features from high-density United States Geological Survey (USGS) quality level 1 (QL1) light detection and ranging (LiDAR) and quantifying the features into three-dimensional (3D) volumetric pixel (voxel) zones. As the USGS embarks on a national LiDAR database with the goal of collecting LiDAR across the continuous U.S.A., the USGS primarily requires QL2 or QL1 as a collection standard. The authors’ previous study thoroughly investigated the limits of extracting streetscape features with QL2 data, which was primarily limited to buildings and street trees. Recent studies published by other researchers that utilize advanced digital mapping techniques for streetscape measuring acknowledge that most features outside of buildings and street trees are too small to detect. QL1 data, however, is four times denser than QL2 data. This study divides streetscapes into Thiessen proximal polygons, sets voxel parameters, classifies QL1 LiDAR point cloud data, and computes quantitative statistics where classified point cloud data intersects voxels within the streetscape polygons. It demonstrates how most other common streetscape features are detectable in a standard urban QL1 dataset. In addition to street trees and buildings, one can also legitimately extract and statistically quantify walls, fences, landscape vegetation, light posts, traffic lights, power poles, power lines, street signs, and miscellaneous street furniture. Furthermore, as these features are processed into their appropriate voxel height zones, this study introduces a new methodology for obtaining comprehensive tabular descriptive statistics describing how streetscape features are truly represented in 3D.

Mixture Design Study of Fiber‐Reinforced Self‐Compacting Concrete for Prefabricated Street Light Post Structures

In recent years, there has been an increasing demand to produce strong precast street light posts that are aesthetically pleasing. This study presents experimental results of a considerable number of mixture designs for fabricating precast street light posts where fiber‐reinforced self‐compacting concrete (FRSCC) was employed. The performance of many FRSCC mixtures was evaluated in terms of their structural properties and aesthetic characteristics. A trial‐and‐error procedure was performed for a series of FRSCC mixtures where silica fume, fly ash, and fibers were used. Slump flow and air content tests were conducted to determine the fresh FRSCC properties, and specimens were cast to evaluate their aesthetic. Three‐day and seven‐day compression tests were performed to examine the FRSCC hardened properties. The amount of cement in all batches was kept constant, whereas the distributions of fine and coarse aggregates, water, and other admixtures were adjusted. The largest slump flow of 73.7 cm (29 in) was recorded, and the maximum three‐day compressive strength was 43 MPa (6209 psi). Further refinement of the mixtures, which displayed the best strength and aesthetic attributes, was performed. Test results of the selected FRSCC mixtures indicated an excellent slump flow, air content, and compression values while achieving advantageous aesthetic qualities. Seven‐day compressive strength of 39 MPa (5686 psi) with the air content of 4.8 percent and the slump flow of 66 cm (26 in) was recorded. The study results and the developed FRSCC mixes can be used for mass production of precast concrete street light posts in precast plants.

Gateway sink placement for sensor node grid distribution in lora smart city networks

<span>Low Power Wide Area Network (LPWAN) is a type of wireless communication network designed to allow long range communications at a low bit rate among things (connected objects), such as sensors operated on a battery. It is a new technology that operates in unauthorized spectrum which designed for wireless data communication [1]. It is used in Internet of Thing (IoT) applications and M2M communications. It provides multi-year battery lifetime and is intended for sensors and applications that need to transmit only a few information over long distances a few times per hour from different environments. In order to have an insight of such long range technology, this paper evaluates the performance of LoRa radio links under shadowing effect and realistic smart city utilities node grid distribution. Such environment is synonymous to residential, industrial and modern urban centers. The focus is to include the effect of shadowing on the radio links while attempting to study the optimum sink node numbers and their locations for maximum sensor node connectivity. Results indicate that the usual unrealistic random node distribution does not reflect actual real-life scenario where many of the these sensing nodes follow the utilities infrastructure around the city (e.g., street light posts, water and gas delivery pipes,…etc). The system is evaluated in terms of connectivity and packet loss ratio.</span>

A method of vehicle positioning using a non-satellite navigation system

Abstract The paper discusses shortcomings of the existing vehicle positioning methods and proposes an option of a non-satellite navigation system based on positioning of vehicles equipped with radars reading data from RFID tags located on road signs, traffic lights, light posts and other structures where such tags may be installed. RFID tag coordinates are predetermined, e.g. by their single assignment using any well-known global positioning system or by assignment of coordinates related only to a unique position of tags with respect to intersections and road forks and turnoffs, including those not officially shown on maps.

The Italian foreign policy: challenges and continuities

Italian foreign politics is facing tough challenges in the near future. For more than 60 years, the Italian foreign policy compass was set on two poles, the European Union and the United States. Sometimes alternatively, much more often conjointly, these two polar stars oriented each and every Italian government’s choice since the end of Second World War. All this has been changing over the last few years. In this context, the article intends to introduce the special issue on Italian foreign policy drawing a stylized map of theoretical approaches that knits together the dispersed theoretical and empirical studies of Italian foreign policy, using a couple of theoretical perspectives as light posts in orienting the articles in this special issue. This introduction is organized in four sections. First, it discusses the approaches that explicitly combine together domestic and international factors in explaining foreign policy. Next, it maps studies on the Italian foreign policy within these frameworks. Then the main characteristics of Italian foreign policy, using these theoretical perspectives, are discussed. The article concludes summarizing how the contributions in this special issue fits into these theoretical frameworks and help shed light on present Italian foreign policy.

Optimization of a vertical axis wind turbine for application in an urban/suburban area

The goal of this study is to investigate the effect of various design parameters on the performance of a Vertical Axis Wind Turbine (VAWT) subjected to realistic unsteady wind conditions. Thirteen turbine design configurations are examined to determine if an optimal VAWT has applications in an urban/suburban environment. The four design parameters of interest include the height-to-diameter aspect ratio (0.83≤H/D≤1.34), blade airfoil shape (NACA 0012, 0015, 0018), turbine solidity (12≤S≤25%), and turbine moment of inertia. The height and diameter of the turbine varied between 1.89 and 2.54 m, depending on the aspect ratio. The turbine moment of inertia was calculated using a computer-aided design drawing of the turbine, along with the realistic material properties of blades, shafts, and supports. The energy generated by each VAWT design configuration is simulated using a full year of actual wind speed data collected in 2009 at 9 different locations around Oklahoma City spanning an area of approximately 500 km2. The wind data were acquired from the top of traffic light posts at a height of about 9 m above the ground. In all cases, an active control strategy is used that allows the turbine to continuously adjust its rotational speed in response to the fluctuating wind. The results suggest that, for the case of operation in unsteady winds, the optimal power coefficient (Cp) versus tip speed ratio curve is not necessarily the one exhibiting the highest peak Cp value but rather the broadest shape. Of the thirteen configurations examined, the optimal wind turbine design capable of harvesting the most energy from the gusty winds was found to have an aspect ratio of H/D=1.2, a solidity of S=12%, and a blade shape using the NACA 0015 airfoil. This design also displayed the lowest moment of inertia. However, when the effects of mass were removed, this design still performed the best. The site-to-site variation in terms of energy captured relative to the available energy in the gusty winds was only about 5% on average and increased slightly with turbine moment of inertia. Four of the suburban sites studied were deemed to be economically viable locations for a small-scale VAWT. The results further indicate that, at one of these sites, the levelized cost of energy associated with the top performing turbine designs examined in the study was about 10% less than the national electricity price, meaning that wind energy provides a cheaper alternative to fossil fuel at this location. It is surmised that VAWTs could economically harvest wind energy in the urban center as well if the turbines were located higher than 9 m, such as on the rooftops of commercial/residential buildings.

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light.

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour. Different spectra may therefore be applied to reduce negative impacts. We used a unique set-up of eight field sites to study the response of bats to three different experimental light spectra in an otherwise dark and undisturbed natural habitat. We measured activity of three bat species groups around transects with light posts emitting white, green and red light with an intensity commonly used to illuminate countryside roads. The results reveal a strong and spectrum-dependent response for the slow-flying Myotis and Plecotus and more agile Pipistrellus species, but not for Nyctalus and Eptesicus species. Plecotus and Myotis species avoided white and green light, but were equally abundant in red light and darkness. The agile, opportunistically feeding Pipistrellus species were significantly more abundant around white and green light, most likely because of accumulation of insects, but equally abundant in red illuminated transects compared to dark control. Forest-dwelling Myotis and Plecotus species and more synanthropic Pipistrellus species are thus least disturbed by red light. Hence, in order to limit the negative impact of light at night on bats, white and green light should be avoided in or close to natural habitat, but red lights may be used if illumination is needed.

Hell can’t get enough

Visual essay composed of portraits of friends of the author, who were imprisoned and registered by the DOPS (Department of Political and Social Order) during the invasion of PUC–SP (Pontifical Catholic University of Sao Paulo) on September 22, 1977. The photographs are superimposed with a religious poster attached to light posts, deteriorated over time.

Light-transmitting fiber optic posts: An in vitro evaluation

Statement of problemThe clinical challenge of adhering cement to intracanal dentin is transmitting light to the most apical parts of root canals to allow more efficient polymerization of the cement. PurposeThe purpose of this in vitro study was to compare the cement-polymerizing ability, microstructure, and radiopacity of a new fiber optic post (iLumi fiber optic Post) with a clinically successful fiber post (DT Light Post). Material and methodsPolymerizing ability was compared using a modified depth-of-polymerization protocol. A split aluminum mold with a 12-mm cylindrical hole (diameter=4.7 mm) was filled with light-polymerized resin cement (Variolink Esthetic LC). Each fiber post (n=12) was positioned and light-polymerized on the coronal end for 60 seconds with a light-emitting diode polymerization light. Unpolymerized resin was dissolved with an organic solvent, and the weight and length of the polymerized resin cement were measured. Scanning electron microscopy was used to examine vertical and horizontal cross-sections. The radiopacity values of both the posts and 5 additional reference posts were evaluated using an aluminum step wedge. ResultsThe weight and length of the polymerized resin cement were significantly greater (P<.05) with the fiber optic post, which scanning electron microscopy showed to have a higher density of parallel fibers. The iLumi post demonstrated greater radiopacity among the tested fiber posts and a titanium alloy post. ConclusionsThe iLumi fiber optic posts have a unique structural fiber composition and excellent radiopacity and light-transmitting ability that produce more complete polymerization of the resin cement than the DT Light posts.

A78 Establishing the foundation for Age- and Disability-friendly Road Safety Policies in Sri Lanka

Abstract Background With increased motorization and hazards embedded in the built environment, elderly and people living with physical, sensory and mobility impairments encounter a variety of barriers in transportation, mobility and social participation. The Moneragala district in the Uva province of Sri Lanka provides an opportunistic study base in which to evaluate the context and inherent risks involved through linkage to an existing initiative developing an age- and disability-friendly community. The objective of the study was to identify risks relating to road traffic injury among older people and those living with disability and guide advocacy, community development, and policy change to address these risks in the Uva province in Sri Lanka. Methods This was a mixed methods participatory research study conducted in three randomly selected divisional secretariats in Moneragala district. The sources of data were collected included a household travel survey of the vulnerable road users of interest (i.e., older people aged 60 years and older, and people living with disabilities aged five year and older), focus groups, key informant interviews and photographic documentation of barriers and facilitators for road safety. Records of road traffic “accidents” (as defined in Police databases) for the past ten years were examined. Areas in the community deemed vulnerable were mapped and photographed. Results Barriers for travel identified by the vulnerable road users in this study included problems with public transport (inconvenient stops, high foot boards, delays), poor accessibility to roads and important institutions (e.g., hospitals, banks), economical and medical reasons and poor recognition or indifferent attitude of service providers and the public. Common hazards expected to influence injury risks included the state of the pavements or sidewalks (e.g., absent or poorly maintained, too narrow, obstructed by sign posts, light posts or parked vehicles), high speeds of vehicles, the state of the main roads (inadequate signage for crossings, bus stops; lack of tactile paving or other features assisting the visually impaired) and poorly constructed or absent culverts on all types of roads. Suggestions to reduce road traffic injury risks from both the participants and the stakeholders included the introduction of disable-friendly cost effective modes of transportation, improved road engineering designs and transportation infrastructure, public awareness programs for targeted groups (e.g., drivers of public buses and three wheelers, school children and teachers, policy makers and other stakeholders) and the implementation and monitoring of effective legislation. Conclusions This research highlights both the imperative and substantial potential for identifying and addressing priority needs among the most vulnerable populations as transportation and urban design plans are rolled-out in less-resourced settings.

INFLUÊNCIA DAS FLORESTAS URBANAS NA VARIAÇÃO TERMO-HIGROMÉTRICA DA ÁREA INTRAURBANA DE CURITIBA – PR

http://dx.doi.org/10.5902/1980509816579De modo a entender a influência das florestas urbanas na variação termo-higrométrica da área intraurbana da cidade de Curitiba, este trabalho teve como objetivo analisar a variação temporal e espacial da temperatura e da umidade relativa do ar em cada estação do ano e relacioná-la com a presença das florestas urbanas. Para a coleta dos dados meteorológicos foram estabelecidos 44 pontos de monitoramento em quatro transectos na malha urbana da cidade. Nestes pontos foram instalados miniabrigos meteorológicos com sensores modelo Hobo®, fixados nas hastes de sinaleiros e placas de sinalização. O monitoramento da temperatura e umidade relativa do ar foi realizado em períodos correspondentes às quatro estações do ano, com 22 dias de coleta e registro contínuo de dados em intervalos de 15 minutos. Nos quatro transectos analisados na área intraurbana de Curitiba foram encontradas diferenças termo-higrométricas significativas entre os pontos de monitoramento em todos os períodos analisados. Mesmo nas estações do ano de mais baixas temperaturas, o outono e o inverno, foram encontradas diferenças térmicas, relacionadas ao calor antropogênico. Pela análise do perfil longitudinal das temperaturas, observou-se curva semelhante ao perfil clássico das ilhas de calor urbano, com as maiores temperaturas nos locais com maior intensidade de ocupação e atividades antrópicas, como na área central e região centro-sul. As menores temperaturas foram encontradas em bairros residenciais e periféricos, como nas porções norte e noroeste do município e limite sul, além de se evidenciar o efeito do resfriamento das florestas urbanas presentes na área intraurbana, como os Parques Municipais Barigui e São Lourenço. As regiões com maior quantidade de áreas permeáveis, concentração de remanescentes florestais ou espaços verdes públicos apresentaram menores temperaturas e aumento da umidade relativa do ar.