Optimal Thermal Conditions Research Articles

Effect of temperature on growth, photosynthesis and biochemical composition of Nannochloropsis oceanica, grown outdoors in tubular photobioreactors

Since temperature is an important factor affecting microalgal growth, photosynthetic rate and biomass composition, this study has accordingly focused on its effects on biomass yield and nighttime biomass loss, as well as photochemical changes, using Nannochloropsis oceanica as model species, grown in two outdoor 50-L tubular photobioreactors (PBR). In two independent trials, cultures were subjected to a diurnal light:dark cycle, under a constant temperature of 28 °C and, on the second trial, at 18 °C. Changes in culture performance were assessed by measuring growth, lipid and fatty acid composition of the biomass in both morning and evening. Our results revealed that N. oceanica shows a wide temperature tolerance with relevant nighttime biomass loss, that decreased at lower temperatures, at the expenses of its daily productivity. Fluorescence measurements revealed reversible damage to photosystem II in cells growing in the PBR under optimal thermal conditions, whereas microalgae grown at suboptimal ones exhibited an overall lower photosynthetic activity. Lipids were partially consumed overnight to support cell division and provide maintenance energy. Eicosapentaenoic acid (EPA) catabolism reached a maximum after the dark period, as opposed to their saturated counterparts; whereas lower temperatures led to higher EPA content which reached the maximum in the morning. These findings are relevant for the production of Nannochloropsis at industrial scale.

Hot deformation characteristics and dynamic recrystallization mechanisms of a Co–Ni-based superalloy

The hot deformation behavior of a Co–Ni-based superalloy was systematically investigated using thermal compression tests. Stress–strain curves showed a typical dynamic softening after peak stress, especially at high temperatures and low strain rates. An Arrhenius-type constitutive equation was developed to reveal the relationship between the flow stress, strain rate, and temperature, while a processing map was constructed based on the calculations from the stress-strain curves combined with microstructural observations to determine the optimum thermal deformation conditions. The extent of recrystallization was found to increase with increasing temperature, a decreasing strain rate, or an increasing strain. A complete dynamic recrystallization (DRX) condition was reached at 1050 °C/0.01 s−1/0.7. In addition, pre-existing annealing twins were replaced by discontinuous dynamic recrystallization (DDRX) grains along the twin boundaries and the twin-DRX (TDRX) grains in the twin interior. In the case of an un-twinned matrix, a combined DDRX and continuous DRX (CDRX) process occurred at high strain rates, in contrasted with a single DDRX process taking place at low strain rates.

Headspace solid-phase microextraction of semi-volatile ultraviolet filters based on a superhydrophobic metal-organic framework stable in high-temperature steam

Headspace solid-phase microextraction (HS-SPME) of low volatile analytes from complex aqueous samples can be substantially facilitated by elevating the temperature of the samples. However, many SPME coatings prepared from novel sorptive materials may suffer from low stabilities in hot water steam. Herein, a superhydrophobic metal-organic framework (MOF) derived from decorating the metal-oxo nodes of the amino-functionalized UiO-66(Zr) with phenylsilane was prepared and successfully developed into a novel SPME fiber coating. The highest extraction efficiencies towards the semi-volatile ultraviolet (UV) filters were achieved when the aqueous samples were heated up to 100 °C. It was notable that the lab-made coating exhibited extraordinary stability towards hot water steam, probably because the hydrophobic groups capped on the MOF prevented water molecules from entering and deconstructing its lattice. Even after being treated with water steam under 100 °C for 21 h, the extraction performance of the coating remained unchanged, and the crystal structure of the MOF maintained. Furthermore, a negligible matrix effect was observed even in the samples containing humic acid. Under the optimal extraction and thermal desorption conditions, a method for determining UV filters in aqueous samples was established, which possessed low detection limits (0.6–2.1 ng L−1), wide linear ranges (10–50000 ng L−1), good inter-fiber reproducibility (2.3–6.0%, n = 6), and satisfying intra-fiber repeatability (1.8–5.8%, n = 3). The method was successfully applied in quantifying UV filters in environmental water samples. In addition, the lab-made NH2-UiO-66(Zr)-shp-coated fiber was also suitable for the analysis of polycyclic aromatic hydrocarbons (PAHs). This study provided an effective strategy for preparing MOF coatings that can maintain their crystalline structures and high extraction performances in high-temperature steam.

Stabilizing Anode-Free Lithium Batteries Via External Thermal Gradients

Temperature is known to have a profound impact on battery electrochemistry and performance due to the strong temperature-dependence of kinetics and diffusion. However, the role of temperature on battery behavior has mostly been considered in the case of an isothermal cell. Though active thermal management systems for batteries strive to maintain isothermal control, localized thermal gradients can still develop within individual cells, which can significantly influence local electrochemistry. For this reason, it is important to understand the consequences and also the potential benefits of non-uniform temperature distribution across batteries.Thermal gradients have been applied to lithium symmetric cells to significantly improve performance and stability. The direction of an interelectrode thermal gradient governs lithium plating morphology and dictates whether unstable, one-dimensional Li electroplating or stable, homogeneous electroplating occurs (1). With a warm positive electrode (40°C) and a cold negative electrode (0°C) (negative thermal gradient) we observe unstable cell behavior, extensive side reactions between Li and the electrolyte, and internal shorting. Reversing these temperatures so that the negative electrode is warmer than the positive electrode (a “positive” thermal gradient) decreases overpotentials, minimizes deleterious side reactions between Li and the electrolyte, and encourages long cycle life. Additionally, a positive thermal gradient stabilizes high-rate plating and stripping (1), showing promise for enabling fast-charging in lithium metal batteries.This presentation will discuss the impact of thermal gradients on stabilizing lithium plating and stripping and its application for improving long-term cycle life in anode-free lithium metal batteries. First, we will use symmetric Li metal coin cells to investigate the roles of thermal gradient magnitude and electrode temperatures on lithium plating stability. After identifying optimal thermal conditions for highly reversible Li plating and stripping, we will apply this thermal gradient to an anode-free full cell with LiFePO4 cathode to confirm its benefit on long-term cycling in a practical cell. Operando techniques, such as optical microscopy and internal thermal sensing, as well as post mortem materials characterization, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy, will be used to describe and characterize cell behavior in the presence of an applied thermal gradient.

Hot Deformation Behavior and Microstructure Evolution of Cu-Ni-Co-Si Alloys.

The Cu-1.7Ni-1.4Co-0.65Si (wt%) alloy is hot compressed by a Gleeble-1500D machine under a temperature range of 760 to 970 °C and a strain rate range of 0.01 to 10 s−1. The flow stress increases with the extension of strain rate and decreases with the rising of deformation temperature. The dynamic recrystallization behavior happens during the hot compression deformation process. The hot deformation activation energy of the alloy can be calculated as 468.5 kJ/mol, and the high temperature deformation constitutive equation is confirmed. The hot processing map of the alloy is established on the basis of hot deformation behavior and hot working characteristics. With the optimal thermal deformation conditions of 940 to 970 °C and 0.01 to 10 s−1, the fine equiaxed grain and no holes are found in the matrix, which can provide significant guidance for hot deformation processing technology of Cu–Ni–Co–Si alloy.

Optimal thermal treatment conditions for durability improvement of highly sulfonated poly(ether ether ketone) membrane for polymer electrolyte fuel cell applications

In this study, a series of sulfonated poly(ether ether ketone) (SPEEK) membranes are prepared and thermally treated in different conditions, i.e., temperature (120–180 °C), time (6–42 h), and residual solvent (RS) values (15–45%). Proton conductivity, water uptake, swelling ratio, hydrogen permeability, mechanical properties, and chemical stability of samples are systematically investigated. Also, membranes' characteristics are studied using FTIR, TGA, and AFM. Two stages of “annealing dominated” and “cross-linking dominated” were observed during thermal treatment. Annealing dominated samples exhibited higher flexibility and overall stability with annealing-induced homogenous microstructure while cross-linking dominated samples showed poor mechanical properties and proton conductivity. Results indicate that the treatment of SPEEK membranes with higher RS value facilitates cross-linking at much lower temperatures with a more controlled rate to inhibit excessive cross-linking. Furthermore, response surface methodology suggested that prolonged thermal treatment at low temperatures (<130 °C) with RS of around 30% results in sufficient proton conductivity and improved overall stability.

Intercalation of copper salt to montmorillonite K‐10 and its application as a reusable catalyst for Chan–Lam cross‐coupling reaction

A simple and efficient catalytic system has been developed by adsorption of copper salt in the interlayers of montmorillonite K‐10. The catalytic system impressively exercises the green chemistry perspective leading to effortless recovery and recyclability for the cross‐coupling of arylboronic acids and N‐nucleophiles. The effect of catalytic activity was studied for electronically diverse arylboronic acids and imidazoles relying on various optimizations under optimum thermal condition. The catalytic system was characterized and the morphology was determined.

Magneto-optical properties of spin-coated bismuth-substituted yttrium iron garnet films on silicon substrates at 1550-nm wavelength

Bismuth-substituted yttrium iron garnet (Bi:YIG) films were prepared by using spin coating processes with metal-organic-decomposition-method-based solutions on crystalline silicon (Si) substrates, and their magneto-optic properties at the 1550-nm wavelength region were investigated by performing various thermal treatments. The maximum Verdet constant of the Bi1Y2Fe5O12 film on the Si substrate with a middle buffer layer of Bi2Y1 Fe5 O12 was measured to be 1 072 038°/T/m at 1550-nm wavelength in the unsaturated linear magnetization region by accounting for the negative Verdet constant of the silicon substrate. The optimum thermal treatment condition was observed at the maximum annealing temperature of 700 °C and the annealing speed of 3 °C/min. These spin coating enabled processes may be included to the conventional complementary metal-oxide semiconductor fabrication processes to demonstrate integrated optical waveguide-type isolators on silicon-on-insulator wafers.

A seasonal approach to alliesthesia. Is there a conflict with thermal adaptation?

Literature on thermal comfort presents two concepts beyond a static view of perception: adaptation and alliesthesia. Both concepts are typically analyzed separately and consequences for optimal conditions when following one or the other concept are not compared. Predictions concerning preferred conditions in different seasons derived from these concepts are antithetic – while adaptation suggests warmer conditions in summer being closer to neutrality – often equated with comfort – alliesthesia suggests cooler conditions in summer leading to a higher level of pleasantness – also set synonymous with comfort. The objectives of this study were to compare both concepts and the resulting views on optimal thermal conditions experimentally. The experimental study consisted of a between-subject design with two groups of participants experiencing the same three thermal conditions (classified as cool, neutral, warm) each for 50 min in a balanced order in a field laboratory with windows to the outdoors in winter (N = 32) or in summer (N = 31). Participants evaluated their thermal perception on three dimensions: thermal sensation, thermal comfort, and thermal pleasantness at the end of each session. Indoor environmental parameters and subjects’ skin temperature were recorded. Statistical analyses with participants’ ratings as the dependent, and standard effective temperature, season and sex as independent variables showed that optimal thermal conditions varied significantly between seasons, sex, the dimension of thermal perception, and the applied statistical method. Based on the results, a new type of alliesthesia is proposed to explain such effects: seasonal alliesthesia. Adaptation and alliesthesia focus on different dimensions of thermal perception and lead to distinctive results concerning optimal thermal conditions. Future work in the area of thermal comfort needs to discuss, which dimension is appropriately considered in which context and the consequences drawn for design and operation of buildings.

Evaluation of user’s thermal perception and satisfaction towards indoor environmental quality

Chapter 3 compared the building characteristics of renovated offices such as facade types and the HVAC system and energy consumption with different units. These physical building characteristics do not only contribute to energy performance but also to the indoor environment. For user satisfaction studies, a comfortable indoor environment is one of the primary conditions of the working environment. Therefore, it is important to identify the impact of indoor climate on user satisfaction in different office buildings (technical attributes of renovated office buildings). The purpose of this chapter is to identify the impact of indoor climate on user satisfaction, comparing how much they are satisfied with the indoor climate to temperature and relative humidity and how much the users can adapt the certain temperature. Section 4.2 presents the data collection for 2 weeks in three seasons: summer, winter, and the intermediate season. Monitored indoor climate such as temperature, and relative humidity is compared in section 4.3. Section 4.4 compares the occupants’ thermal sensation, preference and satisfaction with physical measurements are compared in section 4.3. Lastly, the predicted optimal thermal conditions, and limitations are discussed in section 4.5.

Особенности размножения живородящей ящерицы Zootoca vivipara (Lichtenstein, 1823) (Sauria, Lacertidae) различных высотных поясов Кузнецкого Алатау

In order to identify the specific features of mountain populations of the wide-range species of reptiles Zootoca vivipara, we analyzed various aspects of reproduction. This is the key process that ensures the existence of the species in extreme mountain conditions. From spring to autumn 2012-2016, we studied of Z. vivipara populations in the subalpine and mountain forest belts on the western slope in the central part of the Kuznetsk Alatau ridge (54-55° N, 87-88° E, southeast of Western Siberia). We studied the phenology of the active period of Z. vivipara (dates of the first and last encounters, copulation, birth of yearlings and duration of the active period). The age of animals was determined by the method of skeletochronology. As a result, life expectancy, growth rates of different sexes, gender and age structure during the activity season were estimated. The state of the reproductive system of males (n=61) and females (n=114) during the activity season was studied (See Table 1). The scientific and technical council of the Nature Reserve “Kuznetsk Alatau” approved the research program (Protocol No. 2 as of April 6, 2012). The procedures for trapping and collecting animals comply with international and national requirements for the humane treatment of animals. We detected that the duration of the active period in the studied populations varied from 85 to 152 days. It depended on the height of the territory above sea level and weather conditions in the observed year. The phenological phases of the reproductive period and the sexual cycles of males and females differed depending on the environmental conditions of a particular altitudinal zone: in the mountains, the season of Z. vivipara activity was reduced, which led to a decrease in the growth rate and an increase in the age of puberty of males (2-3 years) and females (3-4 years). As a result, the linear sizes and life expectancy of Z. vivipara individuals were greater in mountain populations than in plain populations. We found that the reproductive core of the low and mid-mountain populations were three-year-old females, and the high-mountain populations were four to five-year-old females. The reproductive core of the high-mountain and mid-mountain populations were two-year-old males, and the low-mountain ones were two- or three-year-old males. The maximum age of breeding males and females in the highlands reaches 8 years (See Fig. 1). The reproductive cycles of males and females of the populations of Z. vivipara of the Kuznetsk Alatau and other populations of the species are similar, but slightly differ in temporal characteristics. It depends on environmental conditions. The cold mountain climate of the Kuznetsk Alatau leads to the fact that spring spermiogenesis, spermation, and mating in the reproductive cycle of males occur a short time before the onset of the warmest period. It is necessary so that the gestation of the offspring by females occurs in optimal thermal conditions. There were no differences in the seasonal dynamics of the relative volume of the testes: the highest values of this parameter were in the beginning and at the end of the active period, as well as during reproduction (See Fig. 2). The sizes of the testes correlated with the length of the males’ body (p<0.01). The relationship of the females’ length and weight with the brood size was revealed (n=80; p<0.01) (See Fig. 3). In the reproductive cycle of females, vitellogenesis occurs in a short time, and the period of embryonic development can be different in time as it largely depends on the temperature conditions of the environment. In some years, the embryo development may be delayed until wintering begins. In the females, vitellogenesis took place after wintering; ovulation and fertilization were in May – early June, and pregnancy and childbirth took place in the third decade of July-August (See Fig. 4). In the midmountain population of Z. vivipara, the body length of newborns is longer compared to the high-mountain population (U=235; Z=4.6; p<0.001) (See Table 3). For mountain populations, a wider range of values was shown; a higher fecundity of females was in low and middle mountains, then in high mountains. In all altitudinal zones, the average long-term population fecundity of females, equal to 7.3 (from 7.1 to 7.6; p<0.001), was 1.2 times higher than in the plain populations in the southeast of Western Siberia and throughout the range (See Table 4). The range of intra-population variability of fertility in the mountains (3-11) was lower than on the plain (2-12). The relationship of the length and weight of females with the brood size was revealed (n = 80; p<0.01). The paper contains 4 Figures, 4 Tables and 30 References.

Optimisation of outdoor shading devices with thermal comfort criteria: The case of the Venetian Port of Chania

While the optimisation of building shading devices is a frequently researched topic, few studies focus on optimising the form and location of devices that shade outdoor spaces. Consequently, there is no agreed consensus on the workflow that should govern the design of outdoor shading installations with respect to microclimate and human thermal comfort. The present study addresses this research gap by developing a flexible workflow that informs the architectural design process with parametric thermal comfort simulations. The proposed workflow acknowledges that although an environmentally optimal design may exist, the designer is often forced to select a sub-optimal solution that can satisfy non-comparable design objectives including practical on-site constraints and political pressure from stakeholders with often conflicting interests. Considering that outdoor shading devices are often found at the fringe of public and private spaces, the influence of the aforementioned non-environmental objectives on the design process becomes significant. For these reasons, the proposed workflow utilises state- of-the-art techniques such as ComfortCover in order to map the ‘usefulness’ of shade over a specified area and to explore alternative forms of shading devices. Thus, shading optimisation becomes a matter of weighting alternatives and choosing appropriate solutions from the examined parametric space, rather than a fully automated process. This ‘designer-first’ approach evolved through extensive pilot-testing at the Old Venetian Port of Chania, Greece as part of a series of urban regeneration interventions coordinated by the Municipal Port Fund of Chania. This design process resulted in a typology of shading devices that offer optimal annual thermal comfort conditions while satisfying the rest of the design objectives as well.

Evaluation of user’s thermal perception and satisfaction towards indoor environmental quality

Chapter 3 compared the building characteristics of renovated offices such as façade types and the HVAC system and energy consumption with different units. These physical building characteristics do not only contribute to energy performance but also to the indoor environment. For user satisfaction studies, a comfortable indoor environment is one of the primary conditions of the working environment. Therefore, it is important to identify the impact of indoor climate on user satisfaction in different office buildings (technical attributes of renovated office buildings). The purpose of this chapter is to identify the impact of indoor climate on user satisfaction, comparing how much they are satisfied with the indoor climate to temperature and relative humidity and how much the users can adapt the certain temperature. Section 4.2 presents the data collection for 2 weeks in three seasons: summer, winter, and the intermediate season. Monitored indoor climate such as temperature, and relative humidity is compared in section 4.3. Section 4.4 compares the occupants’ thermal sensation, preference and satisfaction with physical measurements are compared in section 4.3. Lastly, the predicted optimal thermal conditions, and limitations are discussed in section 4.5.

The Mechanism of General Providence in the Astronomical-Astrological Section of Levi ben Abraham's &lt;em&gt;Livyat ḥen&lt;/em&gt;

The third book of Levi ben Abraham ben Ḥayyim's voluminous treatise, Livyat ḥen, is a compendium of astronomical and astrological knowledge. In its twelfth chapter, Levi describes a cosmological mechanism that ensures optimal thermal conditions for human life, thereby securing the persistence of the inhabited world. Levi identifies this mechanism with God's general providence, or at least one aspect of it. This article examines the mechanism in detail, and sheds light on Levi's views on the providential role of the celestial bodies. The article also shows that the mechanism was known to Gersonides, and compares it with Gersonides' naturalistic account of providence. In addition, the article identifies some of the scientific sources Levi drew on in compiling the astronomical-astrological section of Livyat ḥen, and provides insight into its overall profile.

INVESTIGATION OF VARIABLE MODES OF CENTRALIZED HEAT SUPPLY SYSTEMS OPERATION WITH QUALITATIVE AND QUANTITATIVE REGULATION

The combined method of generating electric and heat energy at CHP plants has been and remains the most effective way of fuel saving both in housing and communal services and in industry. In Russia, historically, a qualitative method of regulation has been adopted, which consists in changing the temperature of the fluid depending on the change in the temperature of the outside air at a constant flow rate of the fluid. An analysis of the heat supply schemes of a number of Russian cities revealed that central quality regulation at heat sources has practically ceased everywhere. In modern methods of calculating the qualitative and quantitative regulation, the main load is heating, and the load of hot water is taken into account only by increasing the flow rate of network water and the variable modes of joint operation of heating and hot water systems are not calculated. Thus, at present, there are no methods for calculating the qualitative and quantitative regulation, allowing to fully taking into account the effect of the load of hot water on the operation of heating systems. Therefore, in modern conditions, the previously developed methods and technological methods of controlling the combined heat load are characterized by a decrease in efficiency, and, accordingly, the problem of their optimization arises. For different temperatures of outdoor air, the calculation of variable operating modes of the heat supply system was carried out, which showed that the existing schedules of qualitative and quantitative regulation cannot provide a comfortable temperature condition of the premises. Under the conditions of a connected supply of heat, simply adding up the flows of network water for heating and hot water supply fails to achieve optimal thermal conditions for the premises. Therefore, further improvement of the technology of the central qualitative and quantitative regulation of the heat load taking into account hot water supply is required.

Climate Preferences for Tourism: Perceptions Regarding Ideal and Unfavourable Conditions for Hiking in Spain

Physical activity is an increasingly frequent part of our leisure time. Within this context, hiking is a popular form of tourism which has a positive impact on the quality of life. In spite of the importance of climate conditions for this recreational activity, relatively little research has been done on hiking from the perspective of climate and tourism. With this in mind in this paper we make the first detailed extensive assessment of climate preferences for the practice of hiking tourism in Spain. To this end a review of the theoretical/methodological body of literature on tourism climatology was conducted together with a survey aimed at evaluating the stated climate preferences of hiking tourists. The results are offered within the framework of international research on climate preferences for a range of tourism activities. The comparative analysis of these results with regard to those obtained in previous research highlights various similarities but also certain factors specific to hiking in Spain. Overall, the climate preferences of hiking tourists are similar to those of other segments of the tourism market in terms of the aesthetic and physical aspects of the climate, although they also have certain specific preferences as regards thermal aspects, especially regarding the optimal daily thermal conditions for hiking. The results obtained are useful for assessing the suitability of the climate for the practice of hiking tourism in Spain and for promoting proper management and planning of this leisure activity in tourist destinations, including the development of climate calendars detailing the most suitable times of the year for hiking at these destinations. These issues will be addressed in future research studies.

Utilization of excess corn kernels for hydrogen gas biofuel production

Corn kernels are good candidates for production of various value-added products such as gas biofuel, hydrogen due to the carbohydrate-rich composition. In this study, widely grown corn, field corn kernels were dissolved in subcritical water at different temperatures to determine optimal thermal hydrolysis condition. Organic-rich hydrolysate obtained from hydrolysis process was gasified by aqueous-phase reforming (APR) for hydrogen gas production.Since hydrolysis at 200 °C resulted in significantly more total organic carbon release than other temperatures and the lowest amount of insolubilized solid residue. Different concentrations of this hydrolysate (diluted with water at different ratios) were evaluated for high yielding hydrogen gas production. Gasification performance of corn kernels was also compared with lignocellulosic biomass using corn stover as a representative biomass material.The hydrolysate with 2486 mg/L TOC concentration showed the best performance for hydrogen gas production (130 mL H2/g corn) and left less amount of ungasified solid residue. Corn kernels produced 2.3 times more hydrogen gas compared to corn stover biomass. Thus, corn kernels are promising feed materials for APR process, and excess production of corn can be utilized for hydrogen gas production in higher yield and richer composition.

Thermal tolerance of Cyclops kolensis lilljeborg, 1901 (Copepoda: Cyclopoida) and its relationships with pessimal to optimal performance.

Cyclops kolensis Lilljeborg, 1901 belongs to the Arctic complex of Palaeoarctic species, yet in the past 20 years, its occurrence has extended to the summer months in waterbodies with high water temperatures. This species is considered one of the most active migrants from the northern waterbodies in the Volga reservoir cascade to the Volga delta. Here, we explored the ranges of the preferred and avoidance temperatures of C. kolensis from two geographically isolated populations. Thermal tolerance was measured in a thermogradient installation and compared to the temperatures at which members of these populations occurred in their source waterbodies. Temperature preference was determined using the "chronic" method. Individuals of C. kolensis possessed a bimodal final temperature preferendum of 2-6 °C and 13-21 °C, which corresponds to the optimal thermal conditions of the species in a pond. These ranges were the same for individuals of both populations irrespective of the geographical location and water temperature of their source waterbodies. The temperature range of normal performance was 2-4 to 21-25 °C, and the pessimal temperature ranges were from 1 - 2 to 3-4 °C and from 22-25 °C to 26-30°С. These temperature ranges coincide with field observations over a recent 20-year period of temperature conditions under which the species develops in nature. Our results allow us to characterize C. kolensis as an ecologically plastic species, which, despite its strong association with the cold-water Complex species, is adapting to a wider temperature range as global warming occurs.

Eight-month experimental study of energy impact of integrated control of sun shading and lighting system based on HDR vision sensor

One fifth of the electricity consumption of Swiss buildings is due to electric lighting. Integrated control of sun shading and artificial lighting can mitigate this demand while maintaining user comfort. However, the drawback of existing building control approaches is that they do not consider one of the main aspects of human-centric lighting: visual comfort. An ‘on-the-fly’ measurement of a visual comfort index, Daylight Glare Probability (DGP), by a novel High Dynamic Range (HDR) vision sensor was introduced into the building control system optimizing the sun shadings position and electric lighting status. As the first approach, this novel solution was tested during a short-term experiment for 15 afternoons at the LESO solar experimental building. The long-term effect of such novel system was evaluated during an eight-month data monitoring campaign. This experiment was carried out in the same building in order to study the ability of a novel control approach to maintain optimal visual and thermal comfort conditions while reducing the energy performance gap of a room as well as its electric lighting demand. The experimental results showed that the advanced controller mitigated the performance gap during the heating season by 72% with regard to a simulated scenario where a standard occupant manually controls the sun shadings and electric lightings; and by 19% with respect to an experimented scenario with best-practice integrated automated shading and lighting system. This system reduced backup heating demand leading to lower CO2 gas emissions. At the same time, visual comfort constraints regarding DGP and workplane horizontal illuminance were respected for 88.1% of work hours.

Three new species of ambrosia beetles established in Great Britain illustrate unresolved risks from imported wood

Bark and ambrosia beetles (Scolytinae) are frequently introduced to new areas through international trade of wood and wood products. When novel host trees are encountered, they can be naive and susceptible to attack, enabling previously harmless scolytine species to become damaging, or the symbiotic fungi of ambrosia beetles to become pathogenic. Invasive Scolytinae are often only recognised after they have become harmful, so the early detection of such species is important for forest protection and management. The first nationwide survey of Scolytinae in Great Britain was conducted between 2013 and 2017, to determine the presence and distribution of previously undetected alien species. Study sites included pine, spruce and oak forests and forests near ports where wood and forest products are imported. Insect traps baited with ‘broad-spectrum’ lures were employed to maximise the diversity of scolytine species collected. Three recently established alien species were detected, Xylosandrus germanus, Gnathotrichus materiarius and Cyclorhipidion bodoanum; the latter two species are new records for Britain. All three species appear to be largely restricted to south-east England at present, and strikingly, all are ambrosia beetles. Current EU plant health regulations for wood importation and movement are limited in their effectiveness against ambrosia beetles, since bark removal does not typically destroy them. In the relatively cool summer climate of Britain, southern England appears to provide the most optimal thermal conditions for the establishment of invasive wood and bark-boring beetle species.