Occupancy Period Research Articles

Occurrence of Indoor VOCs in Nursery School - Case Study

Children’s exposure to air pollutants is an important public health challenge. Particular attention should be paid to preschools because younger children are more vulnerable to air pollution than higher grade children and spend more time indoors. The concentrations of volatile organic compounds (VOCs) as well as carbon dioxide (CO2) concentrations in younger and older children’s classrooms during the winter season were studied. An electronic nose based on gas chromatography was used for the analysis of individual VOCs and a photoionization detector with a UV lamp was used for the determination of total volatile organic compounds (TVOC) concentration. Continuous measurements of CO2 concentrations both inside classrooms and outside each building were performed using automatic portable monitors. Improving ventilation, decreasing the occupancy per room and completing cleaning activities following occupancy periods can contribute to alleviating high CO2 and VOCs occurrence levels.

Understanding User Satisfaction Evaluation in Low Occupancy Sustainable Workplaces

This paper presents the findings of a post-occupancy evaluation (POE) applied to a building in the UK. The design of the building was generated through an externally funded research project over two years from 2005 to 2007. The construction of the building was completed in 2010. After a period of occupancy, a POE of the building was carried out in 2015. The POE offered an opportunity to investigate the effect of occupant behaviour on the performance of the building and their level of comfort and satisfaction. We adopted a field survey method to evaluate the comfort and satisfaction of users by asking them a series of questions to analyse how they felt in different parts of the building throughout the course of the year. In our analysis, the users were prompted to provide a subjective measure of the building regarding a range of internal conditions such as air temperature, humidity, air movement, air quality, daylight, artificial light, and noise. The analysis supports the notion that in naturally-ventilated buildings some users may find the building to be hot in summer while cold in winter. The high level of control the users have over the operation of the building contributes to their comfort and satisfaction. The users demonstrated a tendency to be satisfied despite environmental factors and to forgive some aspects of the building which are not performing as they should. The paper offers a perspective on statistical user satisfaction in a low occupancy building and attempts to explain the role of workplace wellbeing on occupant perception of comfort in this case.

Forecasting Occupancy for Demand Driven HVAC Operations Using Time Series Analysis

Building heating, ventilation, and air conditioning (HVAC) systems contribute substantially to the energy consumption of buildings. Today, traditional HVAC systems mostly operate according to the maximum occupancy assumption, which in turn increases energy consumption during periods of low occupancy. Although, recently, implementing demand-driven HVAC operations are accepted as an innovate approach for reducing HVAC-related energy consumption, occupancy forecast is important to realize demand-driven HVAC operations in buildings. This study aims at using time series models in order to forecast the daily number of bank customers in a financial center of a bank, which is located in Izmir, Turkey. Data were collected from the computerized tracking system for a period of 60 weeks and two forecasting methods were used: 1) Decomposition Method, 2) Box-Jenkins Method. To determine the final model identified via the Box-Jenkins Method, goodness-of-fit, residual analysis and Akaike information criterion were taken into consideration. The results show that the SARIMA model with a MAPE of 11% yields a good occupancy forecast for supporting demand-driven HVAC operations.

Persistence of the effects of providing feedback alongside smart metering devices on household electricity demand

Using large-sample high temporal resolution data from a smart metering field trial, we econometrically estimate the effects of providing feedback in addition to smart metering devices. We compare consumption levels and patterns between a pilot group that received feedback in addition to smart metering devices and a control group with only smart metering devices. We investigate, in particular, the persistence of the effects and whether the effects differ between periods of high and low household occupancy, i.e. between morning and evening periods, and between weekdays and weekend days. The findings show that feedback is effective, leading to about 5% electricity consumption reduction that is persistent over an eleven month period. Furthermore, our results show that this reduction affects both low and high occupancy periods, suggesting that feedback is associated with rather permanent changes in habitual behavior and/or investments in energy-efficient technologies.

Occupancy determination based on time series of CO2 concentration, temperature and relative humidity

Occupancy receives considerable attention from building designers and managers. In spite of great importance, its determination is still challenging. Traditional methods have various limitations. Therefore, alternative approaches are developed. The goal of this study is a method which provides information about the total number of occupants inside intermittently occupied space. It is based on the continuous measurements of selected parameters of indoor air and multiclass classification. It was shown that the number of occupants may be successfully determined using time series of CO2 concentration (MCR=1.6%, ME=0.45 person), temperature (MCR=1.6%, ME=0.48 person) and relative humidity (MCR=3.3%, ME=0.79 person) individually. The data record applied for this purpose should include measurement results from 60min long period. When using sensor array, this time may be shortened without performance loss. Particularly useful is the combination of temperature and humidity sensors. The analysis revealed that the choice of appropriate classifier is very important. Nonparametric, nonlinear, minimum distance classifier (k-NN) was very effective, while parametric classifier, utilizing linear discriminant functions (LDA) was unsuccessful. The presented method may be also used for determining the duration of occupancy periods.

Characterization of a humanized PD-L1 blocking antibody with pH-dependent antigen binding in a humanized syngenic tumor model.

81 Background: Checkpoint inhibition is a promising approach for cancer treatment with durable responses and survival benefits. Currently, immune-checkpoint inhibitors are delivered at maximally tolerated doses, resulting in significant toxicities and cost burden. There is significant need to develop more efficacious and safer immune checkpoint inhibitor. Towards this goal, we have developed a next-generation humanized PD-L1 antibody with pH-dependent antigen binding and evaluated its biological activities in vitro and in vivo. Methods: Hybridoma approach was employed to generate anti-PD-L1 antibodies. A cell-based receptor-ligand blocking assay was employed to identify neutralizing antibodies. Antibodies with pH-dependent antigen binding property were identified and characterized further with those without using PD-L1/PD-1 binding assay, mixed lymphocyte reaction assay, and in vivo tumor growth inhibition assay in syngeneic MC38 tumor model expressing human PD-L1 protein. Results: A panel of neutralizing antibodies blocking PD-L1/PD-L1 binding was isolated. Among them we identified antibodies with or without pH-dependent binding property. While the in vitro activities of these antibodies are similar, their tumor growth inhibition activities differ significantly. The in vivo activity of 23F11, an antibody with ph-dependent binding, is maximized at 1mg/kg in MC38/hPD-L1 model. At 1 mg/kg, 23F11 induced complete tumor regression in 7/12 of the mice treated, more potent than antibodies without pH-dependent binding. Imaging study revealed that significantly higher drug concentration in the tumor for 23F11 and correlated with extended period of target occupancy. Furthermore 23F11 treatment is correlated with sustained up-regulation of plasma mIL-18, a potential pharmacodynamics response marker. Conclusions: We have identified antibodies with pH-dependent PD-L1 binding property. These antibodies can maintain high antibody level in PD-L1 expressing tumor and have potent tumor inhibition activity at low dose. Current work will evaluate whether humanized 23F11 can be at least as efficacious as benchmark antibodies yet with improved safety profile in patients.

An integrated approach on energy consumption and indoor environmental quality performance in six Portuguese secondary schools

A major rehabilitation programme of secondary school buildings has been carried out in the last few years in Portugal. With the introduction of HVAC systems in buildings that were previously naturally ventilated, an increase on energy consumption has been verified. During the first occupancy periods of new and refurbished buildings, energy and indoor climate quality audits are important strategies to improve the buildings’ energy use. In this context, this paper aims at showing the relations between the energy consumption and indoor environment quality (IEQ) parameters, obtained from the energy and IEQ audit in six representative modernised secondary schools – part of a larger R&D project untitled 3Es – geographically and climatically distributed in Portugal mainland.The monitoring period during the mid-season 2013 varied between schools, between two and three weeks. Air exchange rates, more specifically infiltration rates, were quantified aiming at determining the current airtightness condition of the refurbished schools. A subjective IEQ assessment was also performed, focusing on occupants' feedback, providing insight on the potential linkages between energy use and occupants’ comfort.A reflection on the energy consumption indicators and the indoor conditions obtained in the classrooms was proposed, and some suggestions were anticipated.

Investigating Hybridization between the Two Sibling Bat Species Myotis myotis and M. blythii from Guano in a Natural Mixed Maternity Colony

Because they can form seasonal mixed-species groups during mating and maternal care, bats are exciting models for studying interspecific hybridization. Myotis myotis and M. blythii are genetically close and morphologically almost identical, but they differ in some aspects of their ecology and life-history traits. When they occur in sympatry, they often form large mixed maternity colonies, in which their relative abundance can vary across time due to a shift in the timing of parturition. For the first time, we used non-invasive genetic methods to assess the hybridization rate and colony composition in a maternity colony of M. myotis and M. blythii located in the French Alps. Bat guano was collected on five sampling dates spread across the roost occupancy period and was analysed for individual genotype. We investigated whether the presence of hybrids followed the pattern of one of the parental species or if it was intermediate. We identified 140 M. myotis, 12 M. blythii and 13 hybrids among 250 samples. Parental species appeared as genetically well-differentiated clusters, with an asymmetrical introgression towards M. blythii. By studying colony parameters (effective size, sex ratio and proportion of the three bat types) across the sampling dates, we found that the abundances of hybrid and M. blythii individuals were positively correlated. Our study provides a promising non-invasive method to study hybridization in bats and raises questions about the taxonomic status of the two Myotis species. We discuss the contribution of this study to the knowledge of hybrid ecology, and we make recommendations for possible future research to better understand the ecology and behaviour of hybrid individuals.

A Day in the Life of a Parking Space: Testing a Parking Hour Utilization Metric

The peak period utilization metric is the basis for most parking studies. This long-held practice frames the problem as being a limited number of peak occupancy periods. This practice became established when few parking management tools were available and the cost of parking was ignored. Although the effectiveness of parking management varies across context, many more tools are now available. For most land uses, basing supply decisions on peak period utilization leads to grossly oversupplying parking on a parking hour basis. “Parking hour utilization” is the percentage of total hours that a parking space is occupied per year. This paper demonstrates the parking hour utilization metric by using three suburban land uses in Southern California. The methodology employs field counts, air photo interpretation, and Urban Land Institute data to compare peak period and parking hour utilization. The results show low parking hour utilization in these freestanding suburban land uses that ranges from 20.3% for an office complex to 30.1% for a shopping mall and 60.1% for a multifamily residential development. The paper argues that this metric should be employed in parking studies so that parking supply decisions can be made with better information on the efficiency with which parking resources are used. Adopting this metric will lead to strategies, such as shared parking and peak period management, that better use parking resources.

A longitudinal building fabric and energy performance analysis of two homes built to different energy principles

This paper reports on the building performance monitoring and annual energy demand of two homes built side-by-side over an occupancy period of three years. The study compares the results from on-site monitoring against the assumed parameters and calculations from compliance modelling at design stage. It focuses on the differences and impact of occupancy behaviour, weather conditions, quality of construction and operation which contribute to an increase in energy consumption creating a gap in performance between design and actual. The results from the study show disparities in the fabric performance reflecting on the overall consumption of energy. This longitudinal analysis highlights how building performance needs to be evaluated over longer periods in order to fully understand how homes and their occupants operate and consume energy. The impact of the real performance of homes in Scotland over longer periods needs to become standardised, and a mechanism for feedback into regulatory mechanisms and construction practices applied, if carbon emission targets are to be met.

Daytime space cooling with phase change material ceiling panels discharged using rooftop photovoltaic/thermal panels and night-time ventilation

The possibility of using photovoltaic/thermal panels for producing cold water through the process of night-time radiative cooling was experimentally examined. The cold water was used to discharge phase change material in ceiling panels in a climatic chamber. Both night-time radiative cooling and night-time ventilation were used as the discharging method in five experiments, simulating summer conditions. The operative temperature remained within the range of Category III of standard DS/EN 15251 for 50% to 99% of the occupancy period. The percentage of electrical energy usage covered from the photovoltaic/thermal varied from 56% to 122%. The phase change material ceiling panels were thus, capable of providing an acceptable thermal environment and the photovoltaic/thermal panels were able to provide most of the required electricity and cold water needed for cooling.

Indoor and outdoor particulate matter in primary school classrooms with fan-assisted natural ventilation in Singapore.

We conducted multiday continuous monitoring of indoor and outdoor particulate matter (PM) in classrooms with fan-assisted natural ventilation (NV) at five primary schools in Singapore. We monitored size-resolved number concentration of PM with diameter 0.3-10μm at all schools and alveolar deposited surface area concentrations of PM with diameter 0.01-1.0μm (SA0.01-1.0) at two schools. Results show that, during the monitoring period, schools closer to expressways and in the downtown area had 2-3 times higher outdoor PM0.3-1.0 number concentrations than schools located in suburban areas. Average indoor SA0.01-1.0 was 115-118μm(2)cm(-3) during periods of occupancy and 72-87μm(2)cm(-3) during unoccupied periods. There were close indoor and outdoor correlations for fine PM during both occupied and unoccupied periods (Pearson's r = 0.84-1.0) while the correlations for coarse PM were weak during the occupied periods (r = 0.13-0.74). Across all the schools, the size-resolved indoor/outdoor PM ratios (I/O ratios) were 0.81 to 1.58 and 0.61 to 0.95 during occupied and unoccupied periods, respectively, and average infiltration factors were 0.64 to 0.94. Average PM net emission rates, calculated during periods of occupancy in the classrooms, were lower than or in the lower range of emission rates reported in the literature. This study also reveals that indoor fine and submicron PM predominantly come from outdoor sources, while indoor sources associated with occupancy may be important for coarse PM even when the classrooms have high air exchange rates.

Landscapes at the Periphery of Glacierization – Retrospect and Prospect

This paper reviews the evolution of palaeoglaciological reconstructions in regions at the periphery of glacierization, where an improved understanding of the role of glacial thermal regime has helped refine the delimitation of ice sheet maxima. Also significant has been the recognition in numerical models that some areas, especially ice sheet marginal zones, are subject to short periods of ice occupancy and hence that glacial landsystem signatures can be extremely subtle. This is compounded wherever cold-based conditions dominate during early stages of ice sheet recession, giving rise to a landform imprint typical of peripheral regions and hence often misinterpreted as unglaciated or glaciated only by older glaciations. Subtle landform imprints include meltwater channels, thin glacigenic veneers or scattered erratics and modified tors. More substantial glacigenic landform-sediment assemblages (‘drift belts’) do not always represent ice sheet maxima but instead may record significant changes in thermal regime, possibly linked to periods of ice-marginal stabilization. Some upland areas that lie beyond the traditionally demarcated limits of glaciation (e.g. Dartmoor in SW England) may contain subtle evidence of satellite ice cap development which has been overlooked due to the strong periglacial landform signature.

Opportunities for Implementation of MPC in Commercial Buildings

Commercial and Institutional (C&I) buildings are responsible for approximately 20% of total energy consumption in North America, of which heating, ventilation and air conditioning (HVAC) accounts for around 50% in Canada and 30% in USA. As such, C&I buildings represent a substantial energy use reduction opportunity using new technologies. However, given that a building is principally to insure comfortable indoor conditions, it is critical that these requirements are not compromised. Model Predictive Control (MPC) is a growing field of research for operating buildings that takes advantage of changing internal and external conditions of a building to save energy, operating cost, and greenhouse gas (GHG) emissions, while maintaining and potentially enhancing occupant comfort. The aims of this paper are twofold: a) to identify building characteristics that are beneficial to the performance of MPC strategies and provide explanation for their selection; and b) to provide detailed review of prototypical C&I building categories to identify those that are the most suitable for the application of MPC. C&I buildings that exhibit thermal mass, high solar gains, discrete occupancy periods, and the opportunity to vary temperature setpoints represent best candidates for MPC application. Offices and education buildings are best candidates based on their use profile, construction, and ubiquity.

Indoor air quality in urban nursery schools in Gliwice, Poland: Analysis of the case study

Children's exposure to air pollutants is an important public health challenge. Particular attention should be paid to preschools because younger children are more vulnerable to air pollution than higher grade children and spend more time indoors. The purpose of this study was to compare the indoor air quality (IAQ) at nursery schools located in Gliwice, Poland.We investigated the concentrations of volatile organic compounds (VOCs), particulate matter (PM) and bacterial and fungal bioaerosols, as well as carbon dioxide (CO2) concentrations in younger and older children's classrooms during the winter season at two urban nursery schools, located within traffic and residential areas. The concentration of the investigated pollutants in indoor environments was higher than those in outdoor air. The results clearly indicate the problem of elevated concentrations of PM2.5 and PM10 inside the classrooms. High levels of CO2 exceeding 1000 ppm in relation to outdoor air also confirmed the low indoor air quality of classrooms. This is concerning in terms of the exposure effects on the health of children. The relation between IAQ in older and younger children's classrooms was also statistically significant in the case of PM and CO2.Improving ventilation, decreasing the occupancy per room and completing cleaning activities following occupancy periods can contribute to alleviating high CO2 and particle levels.

Evaluation of inhalation exposure contributed by backfill mill tailings in underground uranium mine

Radon and its short-lived decay products are the most important contributors of inhalation exposure to ionizing radiation in uranium mines. This paper describes the assessment of inhalation exposure potential of backfill mill tailings in Jaduguda uranium mine. The inhalation exposure of the miners to radon daughters in nine stopes was estimated based on the measurement of radon exhalation rate from backfill tailings, airflow rate, occupancy period and equilibrium factor in the stopes. The maximum inhalation exposure in the stopes was worked out to be 0.19 WLM year−1, which is about 5 % of the prescribed limit of 4 WLM year−1 for the miners recommended by the International commission on radiological protection. Thus, it may be concluded that the inhalation exposure of miners to radon daughters contributed by backfill mill tailings is not significant in a well-ventilated uranium mine extracting low-grade uranium ore.

Pulmonary vascular smooth muscle cells remodeling and dysfunction in cystic fibrosis

Background Pulmonary hypertension (PH) is a major feature of advanced cystic fibrosis (CF) and may lead to right ventricular dysfunction and cor pulmonale. Although PH is usually moderate in CF, its severity varies greatly across patients and its presence may negatively affect the prognosis. Extensive pulmonary vessel remodeling with muscularisation of the small arterioles are major pathological features of PH in CF. Although these structural changes are considered the major cause of the increase in pulmonary vascular resistance, their pathogenesis remains uncertain. The aim of this study was to determine whether the CFTR channel is present and affects functions of human pulmonary arteries smooth muscle cells (SMCs). Methods Lung and pulmonary arteries from CF and control patients were obtained from Hospital Foch, surgical department. Primary vascular smooth muscle cells (VSMCs) were isolated from the pulmonary artery (PA) of patients. Cytosolic Ca 2+ was measured using Fura-2 and dual-wavelength microfluorimetry. Protein expression was analyzed by immunofluorescence, immunoblot and RT-PCR analysis. Results Histological analysis revealed increased muscularisation of small pulmonary arteries from CF patients comparing to control patients (75 vs. 45%, n = 10, P 2+ ATPase 2a (SERCA2a). CFTR was detected in both control and CF PA-SMCs but exhibited differential intracellular localization. Particularly, in control PA-SMCs CFTR was localized within plasma membrane (PM) whereas in CF PA-SMCs CFTR was localized within the sarcoplasmic reticulum (SR), in line with previous observations in human airway epithelial cells (Front Pharmacol 2011;2:67). Accordingly, major alterations of calcium handling were detected in primary CF PA-SMCs. Particularly, total SR calcium content was increased in CF VSMCs, whereas PM Ca 2+ influx (store operated Ca 2+ entry [SOCE]) was decreased. Furthermore, primary CF PA-SMCs were poorly sensitive to Thrombin (inductor of proliferation) but highly sensitive to serotonin (inductor of contraction). In opposite to the brief increase in cytosolic Ca 2+ observed in control cells, in CF PA-SMCs serotonin-induced a sustained long-lasting oscillatory Ca 2+ transient, suggesting establishment of “membrane oscillator” during whole period of occupancy of serotonin receptor. Conclusions Relocalization of ΔCFTR to RS in PA-SMCs results in major alterations of Ca 2+ handling favoring hypercontractility of PA-SMCs in CF patients.

Design and optimization of HPLWR high pressure Turbine gamma ray shield

This work proposes the optimum gamma ray shield thickness around the HPLWR high pressure turbine for different occupancy periods in the turbine building. Monte Carlo method was employed in the design process and only radioactive nitrogen-16 was considered as the source of radiation. Five grades of concrete (ordinary, magnetite, heavy magnetite, steel magnetite and barite) were used as shielding materials. The isotope source term in the high pressure turbine was estimated by modeling the HPLWR three pass core in MCNP and tracking the inventory using a simple algorithm. The high pressure turbine was thereafter modeled in MCNP with a concrete shield arrayed in layers around it. The surface flux tally and ICRP74 dose conversion coefficients were employed to estimate the dose profile across the shield. For some shielding materials, exponential functions were fitted on the calculated data to extrapolate dose values beyond the model thickness. The optimum shield thickness was determined by comparing the calculated dose profiles with dose limit proposals in the IAEA standard (NS-G-1.13) on radiation protection considerations during nuclear power plant design. It was observed that with a 120cm thick heavy concrete shield, the turbine building would be safe for most occupancy periods. However for ordinary concrete the shield would require some extension to guarantee safety. For very long occupancy (more than 10 person hours per week), magnetite shield may also require slight extension. It can therefore be concluded that the shield thickness recommended for BWR turbines (which operate on a direct cycle like HPLWR) could be sufficient for HPLWR if high density concretes are used.

Air quality metrics and wireless technology to maximize the energy efficiency of HVAC in a working auditorium

HVAC is the single largest consumer of energy in commercial and residential buildings. Reducing its energy consumption without compromising occupants' comfort would have environmental and financial benefits. A wireless testbed consisting of a retrofitted wireless Condensation Particle Counter (CPC), 25 wireless temperature sensors, 2 HVAC-embedded temperature and CO2 sensors, and a webcam was deployed in a working auditorium, to monitor the air quality, temperature, and occupancy of the room. The main objectives were to identify particle sources using the retrofitted CPC, map the temperature variability of the room and select an optimal sensor location for HVAC control using clustering algorithms, and examine possible energy savings by operating the HVAC only during periods of occupancy using calendar-based scheduling and air quality indicators as proxies of occupancy. All air quality metrics increased with higher occupancy rates, although HVAC-modes changes were also identified as a source for particle numbers. Operating the HVAC using calendar-based scheduling resulted in energy savings of between 8 and 79%, increasing if occupancy events were scheduled close together. Finally, CO2 was the strongest predictor of occupancy counts with an R2 of 0.62 (p < 0.001) during simple regression analysis. Incorporating particle numbers and temperature improved estimates of occupancy only slightly (R2 = 0.67), however incorporating a particle metric may enable the general air quality to be monitored, and identify when filters should be replaced.

TREND ON THE LACK OF PRIVATE OPEN SPACE IN SEVERAL CONTIGUOUS HOUSING IN SIDOARJO

Limited proportion between built area and open space of house-lots in housing district seems to become trend in some housing. Within period of occupancy, house-owners are continuously requiring more rooms. A common solution is to transform available open space in the lot into building. Several contiguous housing in Sidoarjo Regency, comprises of low-to-medium and medium-to high housing types was studied to learn on the trend. The study concluded that definition of low-to-medium and medium-to-high class housing was a correct term here. In average, respondents had duration of occupancy of 15 to 20 years and most were undertaken housing extension. From 83 respondents out of 170 suspected houses of having insufficient open space was significantly proved that the extension leaved open space toward 0%. This means that lack of private open space is a factual trend here. When lack of open space is a trend, we may easily suspect that green open space is in similar term. Interesting phenomenon was found that apart from good level of early and prior awareness on the necessity of open space, average respondents had significantly lower early knowledge on the importance of open space especially in term of providing rainwater absorption bed. Their knowledge increased gradually currently. However, their current knowledge was still lower than their awareness. This finding is expected to be useful in planning further stage of community outreach to give informal lecture among community due to actual procedure in fixing open space inexistence, especially to further generation.