Types Of Curtains Research Articles

A Influência de Brises e Cortinas na Eficiência Energética de Edifícios de Escritório

The construction sector is responsible for a significant portion of energy consumption and greenhouse gas emissions. In this sense, it is extremely important that initiatives are developed to reduce the energy consumption of buildings, contributing to the sustainability of these buildings. Among the alternatives for reducing energy consumption is the possibility of inserting shading devices into building windows. In this context, this work aims to analyze the influence of the use of shading devices on windows of an office building model geographically located in Passo Fundo - RS. To this end, 24 computer simulations were carried out using the Energy Plus software in a model of an office building considering its windows without any shading device and, subsequently, with the installation of two different types of sun shades and curtains that act according to the internal temperature of the building. environment and with a pre-defined agenda. Single and double glazing were also tested. The results revealed positive influences of shading devices in the office building, reducing electrical energy consumption by up to 4.64% in relation to the reference case. Therefore, the use of sunshades and curtains can help reduce energy consumption in the building, maintaining the thermal comfort of the environment.

Candida auris in the Healthcare Environment: Prevalence, Anti-Fungal Resistance, and Survival on Porous & Non-Porous Surfaces

Candida auris is an emerging multidrug-resistant pathogenic yeast capable of causing severe illness in the healthcare environment. It spreads easily amongst patient populations, is often resistant to anti-fungal treatments and can survive on surfaces for prolonged periods. In the current study, 85 sites within hospital settings were screened for surface-contaminated Candida species and C. auris. Surface swab samples were transferred to chromogenic agar media designed to isolate and identify Candida species and were incubated at 35°C for 48 hr. Samples were confirmed using molecular techniques designed to specifically target C. auris from other Candida species. Data was compiled to show prevalence of six key Candida species (C. albicans, C. auris, C. glabrata, C. krusei and C. tropicalis). Survivability on surfaces was performed using CDC B11903 C. auris strain. Plastic, metal and fabric surfaces used were purchased from a medical supply store. Once inoculated with 500 CFU/ml in sterile distilled water, the surfaces were kept in a Class II hood with minimal airflow and ambient conditions (21°C, 60% RH) and sampled daily. Results showed 25 of the 85 (29.4%) tested sites were positive for Candida species, with 3 of those sites positive for C. auris. Anti-fungal resistance among the three isolates (tested using concentration gradient test strips) showed notable resistance to fluconazole, but not to amphotericin B nor micafungin. C. auris survivability was dependent upon surface type, with the C. auris test strain surviving for 39 days on three different types of hospital curtains, and ≥10 days on a variety of non-porous plastic or metal surfaces. With demonstrated survivability of C. auris for long periods of time on hospital surfaces, it becomes critical for healthcare facilities to consider C. auris when developing infection prevention programs.

Analysis of the absorptance and emittance in particle curtains by means of a discrete MCRT method

Apparent optical properties, absorptance and emittance, in particle curtains are analyzed by means of a discrete Monte Carlo Ray-Tracing model. The effect of solid volume fraction, particle diameter and curtain thickness on these properties is investigated for two types of particles with different absorptivity and emissivity: sand and CARBO HSP. Absorptance and emittance achieved by curtains made of these particles are greater than the values of absorptivity and emissivity of material. The increase in curtain absorptance/emittance compared to the particle absorptivity/emissivity is higher as the particle property is poorer, such as in sand. Both absorptance and emittance are maximum for opaque curtains, which entails high thicknesses. Assuming opaque curtains, the absorptance and emittance increase as the solid volume fraction decreases. The results obtained with the Monte Carlo Ray-Tracing model are used to estimate particle curtain radiative losses including emission and reflection losses. If material properties absorptivity and emissivity are used instead of the obtained curtain properties absorptance and emittance, sand curtain losses are up to 35 pp and only 9 pp in the case of CARBO HSP. Absorptivity is more important than emissivity, that is, it is preferable having high absorptivity than low emissivity to achieve low radiative losses. Emission losses are less important than reflected losses being very similar in both types of curtains. Sand curtains lose 33% of the incoming power while CARBO curtains lose only 7%. Radiative losses are significantly higher than advection losses in sand curtains. However, in CARBO curtains, advection losses are higher.

New patient privacy curtains to provide passive infection prevention

Cloth privacy curtains represent a potentially overlooked high touch surface. Inconsistent cleaning schedules paired with frequent contact allow curtains to provide a surface for the transmission of healthcare associated pathogens. Privacy curtains integrated with antimicrobial and sporicidal agents are shown to reduce the number of bacteria found on the surface of the curtains. The purpose of this initiative is to utilize antimicrobial and sporicidal privacy curtains to mitigate the transmission of healthcare associated pathogens from curtains to patients. The pre/post-test study design compared the bacterial and sporicidal burden of cloth curtains to the bacterial and sporicidal burden of Endurocide curtains following 20-weeks of use within the inpatient setting of a large military medical hospital. The Endurocide curtains were installed on two inpatient units in the organization. We also compared the overall costs associated with the two different types of curtains. The antimicrobial and sporicidal curtains had a significant reduction in bacterial contamination (32.6 CFUs vs 0.56 CFUs, P < 0.05) after instillation on both units. There were no additional hospital associated infections during the study period. In addition, the direct cost savings of replacing the antimicrobial and sporicidal curtains is estimated to be $20,079.38 annually with a reduction of 66.95 hours in environmental services workload. These curtains represent a cost-effective intervention effective at reducing CFUs with the potential to mitigate the transmission of hospital associated pathogens to patients.

Study on the Evaluation of Sealing Performance of Horizontal Blowing Air Curtain Installed in Doorways

Air curtains are installed to reduce heat loss due to drafts intruding into the indoor through the open doorways, and play the role of separating two climatic zones and different environmental zones. It is also used to protect the workplace from impurities or to reduce the spread of cigarette smoke in restaurants. Recently, aircraft to provide the individual air barrier by the vertical blowing air curtains have installed a physical barrier in the breathing zone between adjacent seats to protect passengers from COVID-19. The main factors affecting the sealing performance (SP) of the air curtain are the difference of temperature and pressure between indoor and outdoor, and are used to make the proper jet flow an air barrier with the high airtightness. Until now, various types of air curtains are manufactured and sold. Air curtains with the improved SP do not only have a discharge port but also a suction port. This study was conducted to evaluate the SP of the horizontal blowing air curtain according to the discharge pressure, and to select the minimized volume flow rate required for creating the proper zone separation. The volume flow rate of outdoor air intruding into the indoor through the doorways is used to evaluate the SP of the air curtain, and is calculated using the SVE4 proposed by Murakami in this study.

Time series of hexabromocyclododecane transfers from flame-retarded curtains to attached dust

While the production and new use of hexabromocyclododecane (HBCD) mostly ceased after being listed as a persistent organic pollutant under the Stockholm Convention in 2013, its emission from treated products in use to indoor environments still deserves attention. To examine the transfer of HBCD diastereomers to dust on the surface of flame-retarded curtains and to better characterize the potential of treated fabrics to be sources of HBCD in dust, we carried out a series of 196-day experiments using two types of curtains and attached dusts. Concurrently, the physicochemical properties (vapor pressure, water solubility, and octanol–water partition coefficient) of the HBCD diastereomers were measured. HBCD diastereomers migrated from curtains to dust with half-saturation times of about 20–50 days. By day 196, mean HBCD concentrations in dust had reached 13–290 μg/g, depending on the types of curtains and dusts. The composition of HBCD, dominated by γ-HBCD in the curtains, was dominated by α-HBCD in the post-experiment dusts, probably because of the higher vapor pressure of α-HBCD compared to γ-HBCD. The initial HBCD contents of the two curtains were comparable, but the concentrations and profiles of HBCD diastereomers in the post-experiment dusts differed markedly, probably because differences between the texture and/or surface finishing of the treated fabrics affected HBCD transfer to the attached dust.

Hexabromocyclododecane Transfer from Flame-Retarded Curtains to Attached Dust

Dust is potentially important as a medium of exposure to low- and semi-volatile organic compounds in the indoor environment. To examine the transfer of hexabromocyclododecane (HBCD) isomers to dust on the surface of flame-retarded curtains, a series of 196-day laboratory experiments were conducted using two types of curtains and attached dusts. Concurrently, the physicochemical properties (vapor pressure, water solubility, and octanol&amp;#8211;water partition coefficient) of the HBCD isomers were measured because knowledge of the isomer-specific values of these properties is still limited. HBCD isomers migrated from curtains to dust on a timescale of about 20&amp;#8211;50 days. The composition of HBCD, dominated by &amp;#947;-HBCD in the curtains, was dominated by &amp;#945;-HBCD in the post-experiment dusts, probably because of the higher vapor pressure of &amp;#945;-HBCD compared to &amp;#947;-HBCD. The initial HBCD contents of the two curtains were comparable, but the concentrations and profiles of HBCD isomers in the post-experiment dusts differed markedly, probably because differences between the texture, surface finishing of the treated fabrics, or both affected HBCD transfer to the attached dust. We hypothesized that HBCD vapor from the curtain was sorbed onto dust surface and then gradually diffused into the interior of the dust particles, and a mechanistic model based on this hypothesis qualitatively reproduced the observed HBCD concentrations in house dust.

CFD comparisons of open-type refrigerated display cabinets with/without air guiding strips

Open-type vertical refrigerated display cabinets are used widely in supermarkets and grocery stores due to its attraction for customers and food merchandisers. These cabinets, however, are less energy efficient than cabinets with glass doors because of the interactions between the air curtain, that is used to provide an artificial barrier between the air in the cabinets, and the air in food premises. To improve the energy efficiency of open fronted refrigerated display cabinets, many types of air curtains have been designed, including single layer air curtains, multi-layer air curtains and shelf tip air curtains amongst others. An approach, considered in recent years to improve the efficiency of air curtains is the use of air guiding strips at the front face of the shelves of open-type vertical refrigerated display cabinets with single layer air curtains. This paper uses Computational Fluid Dynamics modelling to investigate the influence of air guiding strips on the performance of vertical multi-deck refrigerated display cabinets.The results showed that the air guiding strips accelerate the air curtain vertically; leading to a stronger and stiffer air curtain, consequently inhibit the infiltration of the ambient warm air into the cabinet. The average temperature of simulated food in the cabinet decreases by 4.9 °C compared to the cabinet without the strip due to the improved protection of the stiffer air curtain. The cooling capacity required to maintain the food chilled decreases by 34%.

Hot-cool box calorimetric determination of the solar heat gain coefficient and the U-value of internal shading devices

In several developing countries, energy performance rating programs are currently in progress. Complex fenestration systems (CFS) are building components that play a key role in reducing energy consumption. The development and testing of equipment is central for beginning the energy efficiency rating process of complex glazing systems in these countries. This paper validates the use of a low-cost hot-cold box calorimeter for measurement of the solar heat gain coefficient (SGHC) and overall heat transfer coefficient (U-value) of interior shading systems. This work aims to determine the energy performance of three types of often employed shading systems: solar control films, interior horizontal venetian blinds, and indoor drapery curtains. Results show that the energy performance of solar shading devices studied depends on both their morphological and optical properties. The shading systems analyzed present similar U-values, where technological features are represented by the thickness and the thermal conductivity of the material. SHGC is mainly defined by the transmittance and, to a lesser extent, the absorptance of the systems, which differ significantly according to the analyzed shading device. The three types of curtains analyzed demonstrate an SHGC dependent on the fabrics openness factor: jacquard curtains (openness factor 0.05) present a SHGC of 0.7, whereas organza curtains (openness factor 0.45) have a SHGC of 0.82. The SHGC of the venetian blinds analyzed varies on average 36% according to the slat tilt (0°–45°). The solar control films examined modify their solar gain according to their spectral selectivity.

Theoretical and experimental research on the additional thermal resistance of a built-in curtain on a glazed window

To reduce the heat loss at night and prevent room overheating in the summer, almost all outside glazed windows are installed with a built-in curtain. However, given the abnormal structure and complex heat transfer process of the built-in curtain, the existing heat load calculation method is generally employed only to consider the heat transfer coefficient of the glazed window, and the thermal resistance of the built-in curtain is ignored. At present, a perfect theoretical analysis model and accurate data for the curtain thermal resistance are still lacking. Therefore, a reasonable, simplified physical model of the built-in curtain is proposed in this paper, and the flow and heat transfer characteristics of the simplified model are analyzed. In addition, the model gives comparatively full consideration to the influence of the fold on the curtain thermal resistance. A method for the calculation of the additional thermal resistance of the curtain is presented. The additional thermal resistance values and the optimal installation thickness for various types of curtains are obtained by analysis and calculation. The results show that the range of the optimal installation is from 0.05 to 0.08m. The minimal and maximal percentages of the curtains additional thermal resistance to the total thermal resistance of the window are 25.9% and 73.8%, respectively. The ranges of the percentage for single curtain and double curtains are 25–60% and 45–75%, respectively. Finally, the rationality of the simplified model and the accuracy of the calculation results are verified through experiments.

Disposable biocidal cubical curtains: can they prevent the transfer of bacterial pathogens?

Potentially harmful bacteria have been shown to contaminate traditional cloth cubical curtains. Health care-associated bacteria may, therefore, have the potential to be transmitted from curtains to patients via the hands of health care workers, especially if hand hygiene is not adequate. Over the past few years disposable biocidal curtains have become available which can offer antimicrobial capabilities, less frequent changes, as well as cost savings on laundering. Microbial testing was undertaken on two types of disposable polypropylene curtains: one coated with the biostatic agent didecyl dimethyl ammoniumchloride and the other coated with polysiloxane. Samples were inoculated with Gram-negative bacteria ( Escherichia coli and Pseudomonas aeruginosa ), Gram-positive bacteria ( Staphylococcus aureus and Enterococcus faecalis ), as well as a toxin-producing Clostridium difficile (containing spores). Finger imprints and curtain impressions were made on agar after 1 day, 10 days, 1 month and 2 months. Both types of curtains showed similar results. Gram-negative bacteria did not grow after 1 day but S. aureus and E. faecalis could be detected at 10 days with no growth thereafter. However, C. difficile persisted up to 2 months post sample contamination, most likely due to the persistence of spores. This study demonstrated that biocide-treated disposable curtains eliminated or reduced the number of hand-transferred bacteria tested; however, spore-forming C. difficile persisted for long periods of time in the environment. Therefore, newer biocide-treated disposable curtains need to contain sporicidal formulations in order to control contamination by this nosocomial pathogen.

The filament curtain: a structure important to systematics and pollination biology in the Acanthaceae

The filament curtain is a complex structure found in Acanthaceae inside the corolla. It usually divides the corolla into two compartments, enclosing the main nectar bulk behind two adjacent filament bands. Four independent floral characters are involved in the structure of the filament curtain: a fusion of the filaments, decurrent filaments along the corolla wall, a slanting border between the synstapetal and apostapetal corolla regions (i.e. stamen corolla tube and corolla tubes.s. ), and geniculate lower, lateral corolla lobe traces at this border. The distribution of a filament curtain within Acanthaceae suggests an enlarged tribe Ruellieae s.l., including Louteridieae and Trichanthereae, excluding subtribe Barleriinae, and raises a question mark as to the systematic position of the genera Calacanthus, Glossochilus,Lankesteria and Whitfieldia. The evolutionary origin of the filament curtain is probably connected with its functions in pollination biology, which are proposed to be those of restricted nectar access, prevention of nectar evaporation, lever arm function facilitating dorsal pollen deposition, and stabilizing of posticous position of anthers and style. Four types of filament curtains are distinguished: phaulopsoid, corolla fold, reduced and strobilanthoid. Variation in the filament curtain structure appears to be related to different pollination syndromes of the flowers. Mapping of this variation on to an existing phylogeny shows an evolution from a phaulopsoid type diverging into the other three types, possibly a development responding to shifts of pollinators.

The filament curtain: a structure important to systematics and pollination biology in the Acanthaceae

The filament curtain is a complex structure found in Acanthaceae inside the corolla. It usually divides the corolla into two compartments, enclosing the main nectar bulk behind two adjacent filament bands. Four independent floral characters are involved in the structure of the filament curtain: a fusion of the filaments, decurrent filaments along the corolla wall, a slanting border between the synstapetal and apostapetal corolla regions (i.e. stamen corolla tube and corolla tubes.s. ), and geniculate lower, lateral corolla lobe traces at this border. The distribution of a filament curtain within Acanthaceae suggests an enlarged tribe Ruellieae s.l., including Louteridieae and Trichanthereae, excluding subtribe Barleriinae, and raises a question mark as to the systematic position of the genera Calacanthus, Glossochilus,Lankesteria and Whitfieldia. The evolutionary origin of the filament curtain is probably connected with its functions in pollination biology, which are proposed to be those of restricted nectar access, prevention of nectar evaporation, lever arm function facilitating dorsal pollen deposition, and stabilizing of posticous position of anthers and style. Four types of filament curtains are distinguished: phaulopsoid, corolla fold, reduced and strobilanthoid. Variation in the filament curtain structure appears to be related to different pollination syndromes of the flowers. Mapping of this variation on to an existing phylogeny shows an evolution from a phaulopsoid type diverging into the other three types, possibly a development responding to shifts of pollinators.

Mitigation of problem clouds

Abstract This paper describes the use of fluid curtains for the mitigation of problem clouds. Mechanical and physico-chemical actions of spray barriers are examined. Practical engineering codes are developed with the support of experimental findings gathered on dedicated facilities. It is shown that forced dispersion is more appropriate for the dilution of flammable gases, while the efficient dispersion of a toxic dense pollutant requires the use of inhibiting liquid curtains. The design rules of these two types of spray curtains exhibit important differences. Mechanical curtains require coarse upward sprays in combination with a small upstream fence. Physico-chemical absorbing barriers rely on fine sprays; therefore, additional studies of wind effect are needed. The concept of the dual diluting/inhibiting curtain is suggested for future investigation.

カーテンによる木材加工場の騒音音場処理の一実験

Previously, we reported that the sound radiated in an ordinary woodworking shop sometimes creates a non-uniform field of sound pressure. For example, the sound radiated from a woodworking machine such as a single surface planer has low frequency noise components, and produce an interference pattern in the test region. The interference between the direct sound wave from the source and the reflected sound wave from the boundary wall causes errors in evaluating the sound power of a machine considered. To eliminate this, a new measuring space having a volume of 27m3 and a surface area of 54m2 was constructed with two types of cloth curtains. This space is thought to be small for the measurement of radiated sound pressure, but can be constructed easily and cheaply. Although several wall conditions of boundary curtains were tried using an isotropic sound source fed with random noise, it was not possible to get an effective result about the distribution of sound pressure levels in this new space. For the router machine noise, however, the distribution of sound pressure level inside of this space was rather uniform than in the original space. Besides, no interference pattern was noticed in this new space tested.

Thermal characteristics of glazing and shading materials

The paper presents the detailed description of Solar Calorimeter designed and fabricated at this Institute for measurement of thermal characteristics of glazing and shading materials. This has been used to evaluate the transmission and shade characteristics of different types of glasses, curtains, venetian blinds and external shading. The apparatus has also been found useful for the study of transmission properties of glazing material at different angles of incidence with given percentage of external shading. The solar heat transfer factor ( K D -values) for different types of internal and external shading has been computed from the measured values of solar transmission properties of glass and shading materials, thermal conductance for a given percentage of external shading. Close agreement has been observed between the computed and measured values.

Concrete-pile cutoff wall at the foundation of the rockfill dam of the erevansk hydroelectric plant

1. When there is need for a vertical impervious curtain and it is not possible to construct a grout curtain, the most rational solution is a concrete-pile cutoff. 2. The construction of a concrete-pile cutoff eliminates completely the necessity of carrying out the extremely difficult operations related to support of the trenches, dewatering, formwork, and compaction of the concrete, which are inherent to the construction of other types of vertical curtains. 3. Due to the fact that the volume of drilling for the wells is comparatively small, the soil at the foundation undergoes almost no deterioration. 4. The successful experience in the construction of the concrete-pile cutoff of the dam for the Erevansk hydroelectric project indicates that this installation conforms fully to the corresponding requirements. This type of curtain should be more widely utilized in hydraulic engineering practice. In some cases it may prove more rational to utilize it rather than a blanket.