Enclosure Test Research Articles

A measured energy use, solar production, and building air leakage dataset for a zero energy commercial building

This paper provides an open dataset of measured energy use, solar energy production, and building air leakage data from a 328 m2 (3,531 ft2) all-electric, zero energy commercial building in Virginia, USA. Over two years of energy use data were collected at 1-hour intervals using circuit-level energy monitors. Over six years of solar energy production data were measured at 1-hour resolution by 56 microinverters (presented as daily and monthly data in this dataset). The building air leakage data was measured post-construction per ASTM-E779 Standard Test Method for Determining Air Leakage Rate by Fan Pressurization and the United States Army Corps (USACE) Building Enclosure Testing procedure; both pressurization and depressurization results are provided. The architectural and engineering (AE) documents are provided to aid researchers and practitioners in reliable modeling of building performance. The paper describes the data collection methods, cleaning, and convergence with weather data. This dataset can be employed to predict, benchmark, and calibrate operational outcomes in zero energy commercial buildings.

Optical verification experiments of sub-scale starshades

Starshades are a leading technology to enable the detection and spectroscopic characterization of Earth-like exoplanets. In this paper we report on optical experiments of sub-scale starshades that advance critical starlight suppression technologies in preparation for the next generation of space telescopes. These experiments were conducted at the Princeton starshade testbed, an 80 m long enclosure testing 1/1000th scale starshades at a flight-like Fresnel number. We demonstrate 1e-10 contrast at the starshade's geometric inner working angle across 10% of the visible spectrum, with an average contrast at the inner working angle of 2.0e-10 and contrast floor of 2e-11. In addition to these high contrast demonstrations, we validate diffraction models to better than 35% accuracy through tests of intentionally flawed starshades. Overall, this suite of experiments reveals a deviation from scalar diffraction theory due to light propagating through narrow gaps between the starshade petals. We provide a model that accurately captures this effect at contrast levels below 1e-10. The results of these experiments demonstrate that there are no optical impediments to building a starshade that provides sufficient contrast to detect Earth-like exoplanets. This work also sets an upper limit on the effect of unknowns in the diffraction model used to predict starshade performance and set tolerances on the starshade manufacture.

EVALUATION OF SELECTED DYNAMIC MODELS IN COMPARISON WITH HOT BOX TEST RESULTS FOR MEASUREMENT OF BUILDING ENVELOPE THERMAL PROPERTIES

ABSTRACT This research is mainly focused on the experimental measurement of R-value by several different models. Building energy consumption accounts for about 40% of the total energy use in the U.S, and therefore accurate energy simulation is desired. The R-value is one of the key parameters that can influence the energy simulation results and therefore is of great importance. The Average Model has long been the most widely accepted method to measure the thermal properties of building components. However, its steady-state assumption and dependence on temperature difference limit its use especially for in-situ measurement. In this study, several dynamic models, including the Pentaur Model and R-C Network Models, are studied with test data obtained from a series of hot box tests performed in the Building Enclosure Testing Laboratory. The results show that the 3R2C model has the best performance and a desirable stability of accuracy with respect to different levels of temperature difference, and therefore is recommended for practical measurement. The results also indicate that unlike the Average Model, the accuracy of dynamic models does not necessarily depend on the level of temperature difference.

Electromagnetic Shielding Analysis (EMS) of Hybrid Multilayered Woven Fabric at Different Transmitter Distance

This paper mainly discusses on the effectiveness of multiple plain-woven fabric towards electromagnetic shielding (EMS). The measurement includes the effect of fabric distance from the transmitter antennas in the shielded enclosure test. The conductive fabric consists of copper cover hybrid yarns produced using hollow spindle spinning machine. The electromagnetic shielding test was performed according to IEEE-299 specification at 2000MHz. The range was selected to reflect mobile phones, wireless fidelity, Bluetooth and GPS transmission range frequencies. Four samples of conductive fabrics were used in the work, as 0°/0°, 90°/90°, 0°/90° and 90°/0, respectively. The fabric sample with 0°/90° alignment was found to give the best electromagnetic shielding at -65.79dBM. The initial results also show that the hybrid conductive fabrics have large potential to be utilized for shielding electromagnetic radiation (EMR).

Comparative study of Hot Box Test Method using laboratory evaluation of thermal properties of a given building envelope system type

This research mainly focuses on the experimental setup of the Hot Box Test Method and comparison of different models for measurement of thermal properties of building envelope systems. Hot Box Test Method has long been used to determine the thermal properties of building envelope systems, however, the steady-state assumption for calculation is not always desired, especially when the environmental conditions cannot be controlled. To utilize models considering the dynamic behavior of buildings for in-situ measurement, it is desired to first validate such models and compare the performances with hot box test. Therefore, the performances of several dynamic models, including Anderlind's Regression Model and R-C Network Model, have been studied. Hot box tests were performed in the Building Enclosure Testing Laboratory (BETL) at Penn State University and the results show the 3R2C model turns out to be the most accurate one among the dynamic models explored in this study. With a temperature difference larger than 20 °C, all dynamic models are validated with a percentage difference lower than 7% compared with the steady-state analysis, giving us alternatives for R-value measurement when in-situ measurement condition are applied.

Risk assessment considerations for plant protection products and terrestrial life-stages of amphibians

Some amphibians occur in agricultural landscapes during certain periods of their life cycle and consequently might be exposed to plant protection products (PPPs). While the sensitivity of aquatic life-stages is considered to be covered by the standard assessment for aquatic organisms (especially fish), the situation is less clear for terrestrial amphibian life-stages. In this paper, considerations are presented on how a risk assessment for PPPs and terrestrial life-stages of amphibians could be conducted. It discusses available information concerning the toxicity of PPPs to terrestrial amphibians, and their potential exposure to PPPs in consideration of aspects of amphibian biology. The emphasis is on avoiding additional vertebrate testing as much as possible by using exposure-driven approaches and by making use of existing vertebrate toxicity data, where appropriate. Options for toxicity testing and risk assessment are presented in a flowchart as a tiered approach, progressing from a non-testing approach, to simple worst-case laboratory testing, to extended laboratory testing, to semi-field enclosure tests and ultimately to full-scale field testing and monitoring. Suggestions are made for triggers to progress to higher tiers. Also, mitigation options to reduce the potential for exposure of terrestrial life-stages of amphibians to PPPs, if a risk were identified, are discussed. Finally, remaining uncertainties and research needs are considered by proposing a way forward (road map) for generating additional information to inform terrestrial amphibian risk assessment.

Combining hydrogen peroxide addition with sunlight regulation to control algal blooms.

The concentration, light conditions during treatment, and the number of hydrogen peroxide (H2O2) additions as well as the H2O2 treatment combined with subsequent shading to control algal blooms were studied in the field (Lake Dianchi, China). The cyanobacterial stress and injury due to H2O2 were dose dependent, and the control effectiveness and degradation of H2O2 were better and faster under full light than under shading. However, H2O2 was only able to control a bloom for a short time, so it may have promoted the recovery of algae and allowed the biomass to rebound due to the growth of eukaryotic algae. A second addition of H2O2 at the same dose had no obvious effect on algal control in the short term, suggesting that a higher concentration or a delayed addition should be considered, but these alternative strategies are not recommended so that the integrity of the aquatic ecosystem is maintained and algal growth is not promoted. Moreover, shading (85%) after H2O2 addition significantly reduced the algal biomass during the enclosure test, no restoration was observed for nearly a month, and the proportion of eukaryotic algae declined. It can be inferred that algal blooms can be controlled by applying a high degree of shading after treatment with H2O2.

Physical scaling of water mist fire extinguishment in industrial machinery enclosures

Froude-based scaling relationships had previously been theoretically extended to, and experimentally validated in the laboratory for, water mist suppression of fires in open environment and in enclosures, which were shown applicable to gas, liquid and solid combustible fires. Before applying these relationships to real-world settings, their applicability needs to be further evaluated for the intended protection. This paper presents such an evaluation on scaling water mist fire extinguishment in an industrial machinery enclosure. In this evaluation exercise, a full-scale water mist protection set-up tested for a 260-m3 machinery enclosure was selected as the benchmark. A ½-scale machinery enclosure test replica was then constructed, together with a ½-scale nozzle whose orifices were geometrically similar to those of the full-scale nozzle. Spray measurements indicated that the ½-scale spray closely met the scaling requirements, in terms of discharge K-factor, water mist flux, droplet velocity and droplet size distribution. Two spray fires and one pool fire, which were scaled with the respective full-scale fires, were used to challenge the water mist protection in the ½-scale enclosure. At least five replicated tests were conducted for each of the four tested fire scenarios. Overall, the instantaneous local gas temperature and oxygen concentration measured inside the ½-scale enclosure for each fire scenario agreed reasonably well with those measured at the corresponding locations inside the full-scale enclosure, meeting Froude modeling's requirement that scalar quantities be preserved in different scales. The fire extinguishment times obtained from the ½-scale tests for each fire scenario were also statistically consistent with that observed in the corresponding full-scale test. Based on the obtained results, it is concluded that, for machinery enclosures and other similar occupancies, the previously laboratory-validated scaling relationships for water mist fire suppression can be used to determine the fire extinguishing performance of a full-scale water mist protection in a ½-scale test facility.

Seed trait-mediated selection by rodents affects mutualistic interactions and seedling recruitment of co-occurring tree species

As mutualists, seed dispersers may significantly affect mutualistic interactions and seedling recruitment of sympatric plants that share similar seed dispersers, but studies are rare. Here, we compared seed dispersal fitness in two co-occurring plant species (Armeniaca sibirica and Amygdalus davidiana) that inhabit warm temperate deciduous forest in northern China. We tested the hypothesis that seed trait-mediated selection by rodents may influence mutualistic interactions with rodents and then seedling establishment of co-occurring plant species. A.davidiana seeds are larger and harder (thick endocarps) than A.sibirica seeds, but they have similar levels of nutrients (crude fat, crude protein), caloric value and tannin. More A.sibirica seedlings are found in the field. Semi-natural enclosure tests indicated that the two seed species were both harvested by the same six rodent species, but that A.sibirica had mutualistic interactions (scatter hoarding) with four rodent species (Apodemus peninsulae, A. agrarius, Sciurotamias davidianus, Tamias sibiricus), and A.davidiana with only one (S. davidianus). Tagged seed dispersal experiments in the field indicated that more A.sibirica seeds were scatter-hoarded by rodents, and more A.sibirica seeds survived to the next spring and became seedlings. A.sibirica seeds derive more benefit from seed dispersal by rodents than A.davidiana seeds, particularly in years with limited seed dispersers, which well explained the higher seedling recruitment of A.sibirica compared with that of A.davidiana under natural conditions. Our results suggest that seed dispersers may play a significant role in seedling recruitment and indirect competition between co-occurring plant species.

Do stocked hatchery‐reared juveniles ecologically suppress wild juveniles in Salvelinus leucomaenis?

The dominancy of semi-wild and hatchery-reared white-spotted charr Salvelinus leucomaenis juveniles was evaluated using pair-wise enclosure tests and field stocking tests. The semi-wild S. leucomaenis originated in a hatchery, being stocked into the test stream as eyed-eggs. In the pair-wise enclosure test, the semi-wild S. leucomaenis dominated the hatchery S. leucomaenis that were of a similar standard length (L(S) ). The semi-wild S. leucomaenis were subordinate to hatchery S. leucomaenis that were > 11% larger in LS . In the field stocking test, the abundance and growth of semi-wild S. leucomaenis was decreased in the presence of larger hatchery S. leucomaenis (14% larger LS ). Taken together, these results suggest that larger hatchery S. leucomaenis ecologically suppress the smaller semi-wild S. leucomaenis. Salvelinus leucomaenis juveniles that are stocked with the intention of supplementing natural populations should be < 10% larger than their wild counterparts at the time of stocking to minimize their competitive advantage. The semi-wild and hatchery S. leucomaenis used in both tests were genetically similar individuals, suggesting that the differences are due to the early rearing environment of either a natural stream or hatchery. The hatchery S. leucomaenis have lower levels of aggression as a result of selection in the hatchery rearing environment. Rearing in a natural stream from the eyed-egg stage is likely to increase their lowered aggression.

Experimental Study on the Burning Behavior of Pool Fires in Rooms with Different Wall Linings

An experimental test series, comprising 10 experiments with varying pool sizes, lining materials and amounts of liquid burning, was conducted under free burn and room burn conditions. The thermal feedback from the enclosure (ISO 9705 Room Corner Test facility) enhanced the burning rate of the pools and resulted in a thermal runaway in some of the runs. The onset of the thermal runaway, which can be associated with flashover, varied with all the input parameters. The lining with the lowest thermal inertia lead to the fastest increase in the heat release rate (HRR) in the enclosure and caused flashover in the shortest time. Given the profound difference between the enclosure tests and the free burn tests and also between enclosure tests with different linings, it is recommended to show great caution if free burn tests are to be used in design fire scenarios.

Evaluation of attractants for non-invasive studies of Iberian carnivore communities

Context The estimation of population parameters for mammalian carnivore species is a challenging task because of their low densities and large home ranges, which make detection probabilities very low. Several factors, such as the species abundance, habitat structure or the use of an attractant affect carnivore detection probabilities; however, attractants are the most easily manipulated. Some previous research suggests that the use of effective attractants can significantly increase detection probabilities. Aims To assess the effectiveness of several attractants for Iberian carnivores, and to evaluate their usefulness for non-invasive survey methods. Methods The responses of seven carnivore species to six potential attractants were evaluated through cafeteria-like experiments with captive specimens. A selectivity index was applied to assess the relative attractiveness of each tested substance. The enclosure tests were followed by field trials with camera-trapping, using the most promising attractants for field evaluation of their efficiency. Key results Enclosure trials revealed that lynx urine was the most effective and generalist attractant because it successfully attracted six of the seven species tested. Rubbing behaviour was also induced in the greatest number of species by lynx urine. Field tests using a combination of lynx urine and valerian extract solution induced investigative behaviours in over 50% of all detection events in all species, with the exception of the Eurasian badger. Conclusions No single attractant is effective for all species. Nevertheless, a combination of lynx urine and valerian solution should efficiently attract the majority of species present in Iberian carnivore communities. Furthermore, some species exhibit a rubbing behaviour when they come in contact with the attractants. Regardless of the generalist efficiency of the lynx urine, other tested substances revealed promising results for single-species monitoring. Implications Our results provide a baseline for selecting attractants in survey and monitoring programs that focus on carnivore species. The rubbing behaviours exhibited by several of the species tested suggest the use of these attractants could improve the efficiency of field studies that rely on rub-pads for the collection of biological samples.

Biotechnological remediation of an acidic pit lake: Modelling the basic processes in a mesocosm experiment

Due to lignite mining and pyrite oxidation, there are about 100 acidic pit lakes in Germany. Several research projects are dealing with the examination of the chemical and ecological state of such pit lakes to assess the possibilities of a natural or an artificial restoration. A biotechnological remediation, which accelerates the microbial sulphate and iron reduction at the water–sediment interface (successfully tested by column-experiments), started with the addition of lime and straw in one of these lakes (enclosure tests). Parameters such as pH, redox state and TRIS (total reduced inorganic sulphur) indicate significant changes in the treated lake sediments. The development and stability of reaction products over time, and the interaction between the acidic lake water and the anoxic sediment layer have been investigated for 3 years. The progress of the remediation can be calculated from the amount of accumulated sulphur species in the sediment and the diffusive exchange between sediments and water of the lake. Hydrogeochemical processes and limnophysical characteristics of the lake are combined to understand the geochemical behaviour in greater detail and predict further development. A simple model based on the code AQUASIM allows to realise important uncertainties as far as the remediation strategy is concerned. The low sulphate reduction rates in the upper sediment, a slow diffusive exchange at the water–sediment interface, the inflow of groundwater and mineral reactions inhibit the success of remediation in the lake area of the enclosure under investigation.

Modeling convective drying of ventilated wall chambers in building enclosures

In North America, residential enclosure walls are often built with provision for natural convection and, therefore, provide potential for ventilation drying within the wall. At present, our knowledge of the drying process in the wall systems is limited. The drying process is driven by very low airflow rates with complex flow patterns through the narrow and irregular wall cavities, resulting mostly in unstable ventilation driven by natural convection. Different venting strategies coupled with the stochastic nature of driving forces for ventilation contribute to the complexity of the drying process. Both the physical and the mathematical modeling of wall cavity convective drying are challenging. However, it is difficult to accurately predict the convective drying rates in wall cavities at any time during the year. Nevertheless, the convective drying process is probably one of the key mechanisms for mold suppression in residential walls in the US, and therefore, needs to be fully understood and quantified. An equation is developed to estimate the convective moisture transport in screened and ventilated wall systems. The intent was to develop a simple equation for practical design applications. The equation represents a solution of the two-dimensional moisture transport equation, solved for steady state conditions assuming laminar flow with a uniform velocity field in the wall cavity. The results derived from the simple equation were compared to measured data obtained in the Building Enclosure Test Laboratory (BeTL) at the Pennsylvania State University (PSU). The comparison showed that the simple equation can accurately predict the convective drying rates. The results are highly sensitive to the environmental conditions in the immediate vicinity of the wet wall surfaces. This equation could be used in engineering practice to provide an estimate of convective drying rates in the ventilated chamber of rain-screened and ventilated wall systems. Future validation with on-site experiments is necessary.

형상 추론과 기하학적 검색 기반의 다단계 경로 계획

전통적인 경로 계획기는 로봇의 최적 경로를 찾기 위해 광대한 기하학적 검색을 수행한다. 완전성이 있는 경로계획기는 만약 해가 존재하면 반드시 찾아야 한다. 때문에 많은 검색 시간을 소요하여 해를 찾든지, 아니면 해가 없는 경우에는 없다고 증명을 하여야 함으로 역시 많은 시간을 소요한다. 그러나 인간의 경우는 대부분의 경우에 충돌 회피 경로가 있는지 없는지 빨리 파악할 수 있는 능력을 가지고 있으며, 극단적으로 어려운 문제들을 제외하고는 무둔 경우의 수를 나열하지 않고도 쉽게 해를 찾는다. 본 연구의 목표는 이러한 인간의 사고 능력을 알고리즘화하여, 이동로봇의 운동 경로를 보다 빠르게 찾거나, 아니면 컴퓨터의 계산자원을 낭비하지 않고 일찍이 포기하게 한다. 다각형 환경과 다각형 로봇에 대한 경로계획에, 정량적인 형상 추론과 광대한 기하학적 검색을 결합한 새로운 경로 계획 방법을 제시한다. 제시되어진 알고리즘은 울타리 검증을 통해 해가 없는지를 먼저 검색하고, 만약에 해가 있으면, 정량적인 추론을 통해서 해를 찾고, 그래서 해가 존재하지만 해를 찾을 수 없으면, 완전 검색 알고리즘으로 해를 찾게 된다. 본 연구의 기여는 여러 개의 능률적인 기하학적 검사를 통해, 많은 계산량의 완전 알고리즘을 가능하면 사용하지 않고 해를 찾거나 해가 없음 증명하여, 운동 계획기의 평균 계산량을 최소화한다. A novel approach for path planning of a polygonal robot is presented. Traditional path planners perform extensive geometric searching to find the optimal path or to prove that there is no solution. The computation required to prove that there is no solution is equivalent to exhaustive search of the motion space, which is typically very expensive. Humans seems to use a set of several different path planning strategies to analyse the situation of the obstacles in the environment, and quickly recognize whether the path-planning problem is easy to solve, hard to solve or has no solution. This human path-planning strategies have motivated the development of the presented algorithm that combines qualitative shape reasoning and exhaustive geometric searching to speed up the path planning process. It has three planning stages consisting of identification of no-solution cases based on an enclosure test, a qualitative reasoning stage, and finally a complete search algorithm in case the previous two stages cannot determine of the existence of a solution path.

99/02705 Some simple considerations on the turbulent mixing process in relation to flame-scaling

Froude-based scaling relationships had previously been theoretically extended to, and experimentally validated in the laboratory for, water mist suppression of fires in open environment and in enclosures, which were shown applicable to gas, liquid and solid combustible fires. Before applying these relationships to real-world settings, their applicability needs to be further evaluated for the intended protection. This paper presents such an evaluation on scaling water mist fire extinguishment in an industrial machinery enclosure. In this evaluation exercise, a full-scale water mist protection set-up tested for a 260-m3 machinery enclosure was selected as the benchmark. A ½-scale machinery enclosure test replica was then constructed, together with a ½-scale nozzle whose orifices were geometrically similar to those of the full-scale nozzle. Spray measurements indicated that the ½-scale spray closely met the scaling requirements, in terms of discharge K-factor, water mist flux, droplet velocity and droplet size distribution. Two spray fires and one pool fire, which were scaled with the respective full-scale fires, were used to challenge the water mist protection in the ½-scale enclosure. At least five replicated tests were conducted for each of the four tested fire scenarios. Overall, the instantaneous local gas temperature and oxygen concentration measured inside the ½-scale enclosure for each fire scenario agreed reasonably well with those measured at the corresponding locations inside the full-scale enclosure, meeting Froude modeling's requirement that scalar quantities be preserved in different scales. The fire extinguishment times obtained from the ½-scale tests for each fire scenario were also statistically consistent with that observed in the corresponding full-scale test. Based on the obtained results, it is concluded that, for machinery enclosures and other similar occupancies, the previously laboratory-validated scaling relationships for water mist fire suppression can be used to determine the fire extinguishing performance of a full-scale water mist protection in a ½-scale test facility.

Influence of rearing conditions and breed on social behaviour and activity of cattle in novel environments

The effects of breed and rearing condition on the activities and heart and respiratory rates of cattle were studied. The animals were Salers (S; n=27) or Friesians (F; n=28). They had been reared artificially (N; n=29) or mothered (M; n=26). The animals were isolated twice in an enclosure at 3.5 and 4.5 years of age. Data from the first test have been subjected to a principal component analysis. The first axis reflected the “activity”. Mothered animals were more active than non-mothered ones. The second axis expressed “disturbance” (more mooings and eliminations). Salers were more disturbed than Friesians. During the second test, heart and respiratory rates were obtained by telemetry. Salers had a lower heart rate than Friesians. Non-mothered subjects had a higher respiratory rate than mothered ones. Social behaviour was observed at pasture. Mothered Salers dominated non-mothered ones, but rearing conditions had no influence on agonistic behaviour of Friesians. Whatever the rearing conditions, Salers dominated Friesians and they took part in many more non-agonistic interactions. Relationships among these parameters were significantly different between groups. Heart rate was related to the activity level (score on the first axis of the principal component analysis) during the second test for Salers but not for Friesians. Activity level during the first test was negatively related to agonistic behaviour for non-mothered animals but not for mothered ones. This activity level was positively related to non-agonistic interactions for Friesians but not for Salers. A novel enclosure test alone does not seem appropriate for understanding the “reactivity” or “social motivation” of adult cattle.