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The present paper adopts a sophisticated numerical modeling technique using a plasticity-based simplified micro-model method and the extended finite element method for simulating the nonlinear behaviour of unreinforced masonry (URM) walls with different types of sizes and positions of openings. The validity of this model has been proven by comparing the results subjected to a similar loading obtained by the experimental approach. Thereafter, the validated computational model is used to study the behaviour of the 3D URM wall model with different opening percentages. The effect of the position of the openings is also studied. Further, the load–displacement curves are drawn to provide a clear idea about the load-carrying capacity of the same URM walls. The hysteretic behaviour obtained in each model under cyclic loading gives an idea about the energy dissipation capacity of each of the models studied. The same walls are analyzed by strengthening the walls with two cost-effective materials, wire mesh and polypropylene bands. Since the study on lateral behaviour of masonry walls, particularly regarding the effect of area and the position of the opening, is very rarely available, the present detailed study is believed to be helpful in reducing the seismic vulnerability of actual masonry structures, which always have openings with different sizes and positions. [ABSTRACT FROM AUTHOR]

The effect of the angle of incidence of ground motion on an asymmetric structure is recognized to be significant. However, the previous studies considered only shear wall-type elements for analyses with in-plane stiffness. These models did not capture the bidirectional structural response exhibited by column-type elements, especially in the inelastic range. A detailed investigation has been undertaken to evaluate the effect of angle of incidence on asymmetric structures considering bidirectional interaction arising in the post-yield behaviour of such lateral load-resisting elements. The study shows that bidirectional interaction is a critical design consideration for asymmetric structures. [ABSTRACT FROM AUTHOR]

Carbon-based nanostructured materials are very promising for spintronic applications due to their weak spin-orbit coupling and potentially providing a long spin lifetime. Nanostructured carbons are not magnetic materials, but intrinsic magnetic behavioral nanostructure carbon materials could be fabricated through qualitative alterations. On alterations of carbon nanostructured materials, it changes their critical temperature and magneto-crystalline anisotropy energy that could be useful as favorable magnetic materials for different magnetic/electromagnetic device-based applications. Different processes are used for the alteration of nanostructure carbon materials like chemical doping, introducing defects, changing the density of states, functionalization, intercalation, forming heterostructure and fabricating nanocomposites layered semiconductor materials. Among the carbon-based derived nanostructured materials, the graphene oxide (GO) gets attracted towards the magnet forming in the spin-like structure across the area of the magnet. Due to its magnetic behaviour, it is used for the adsorption of metals and radionuclides and to make nonconductive oxide-metal. In this review article, the basics of magnetic behavioral change of the carbon-based GO/GO-nanocomposites nanostructured materials are described by gathering information from the literature that were/are reported by different researchers/research groups worldwide. [ABSTRACT FROM AUTHOR]

Electronic and structural properties are studied at room temperature, whereas the magnetic performances of MoS2-nanoparticles (MoS2-NPs) are studied from room temperature (300 K) down to 5 K within the range of the magnetic field − 10 T to + 10 T. We find that MoS2-NPs display diamagnetic in the temperature range 300–50 K, whereas at ≈ 45 K the M–H hysteresis curve shows the presence of both diamagnetic and ferromagnetic behaviours. The existence of ferromagnetism is significantly enhanced from 40 K down to 5 K, presumably due to Mo-atom, S-vacancies/O-vacancies, defective structure due to the higher density of dangling bonds, and small MoS2-NPs sizes. Different ferromagnetic parameters viz. saturation magnetization, retentivity, and coercivity of MoS2-NP at ≈ 5 K are 55 m emu/g, 45 m emu/g, and 4500 Oe respectively are obtained from the M–H hysteresis curve. The electronic, microstructures and defects are also studied using XPS/UPS and Raman spectrum that correlated/consistence with the magnetic performances of MoS2-NPs. This low temperature (≤ 40 K) ferromagnetism in MoS2-NPs could be useful for low temperature promising potential technological magnetic applications. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) study show that the SnO2 and SnO2:F are Sn2+ dominated in the formation of SnO2 structure. The SnO2:F thin film is mainly the formation of metallic fluoride. The UPS study confirms the density of states of SnO2:F is higher than SnO2. The work function, valence band maximum and surface potentials of SnO2 (SnO2:F) are estimated from UPS spectra and are 3.9 eV (3.7 eV), 3.7 V (3.5 eV) and 7.6 eV (7.2 eV), respectively. Electrical conductivity and M–H hysteresis loop show SnO2:F have higher conductivity as well as magnetization. [ABSTRACT FROM AUTHOR]

Bedroom ventilation is crucial for providing good indoor air quality, which may contribute to achieving undisturbed sleep. This study presents a detailed characterization of bedroom carbon dioxide (CO2) profiles and ventilation during the heating season in Denmark. The measurements were made in a naturally ventilated (NV) semi-detached house, equipped with trickle vents on the windows and doors (augmented if needed with exhaust fans), and a mechanically ventilated (MV) apartment. The location of sensors in and around the immediate breathing zone of a sleeping person had measurable effect on the absolute level of CO2 only in the NV bedroom and not in the MV bedroom. Using the decay of occupant-generated CO2, the estimated breathing zone air change rate (ACR) was around 0.4 h−1 and 0.6 h−1 for the NV and MV bedrooms respectively. This was adequate for an average breathing zone CO2 level of 1000 ppm for the MV bedroom but not for the NV bedroom. The CO2 emission rate of 7.9–10.9 L/h.person during sleep, obtained from bedroom CO2 measurements, was lower than the estimated values of 12.8–13.9 L/h.person, using currently proposed methods in standards. Thermal comfort parameters during all the experimental sessions in both bedrooms were well within recommended levels. [ABSTRACT FROM AUTHOR]

Control of elemental impurities in the drug products evolved from the generic visual testing of heavy metals as their sulfides to specific elements of toxicological concern in the final drug products by instrumental analysis. The International Council for Harmonisation (ICH) Q3D (R1) guideline for elemental impurities describes a risk-based approach to identify, assess, and control the potential elemental impurities in drug products within the established permitted daily exposures (PDE). Challenges to this approach include how to assess the risks associated with contributing sources such as utilities, manufacturing equipment, container-closure systems, and excipients. Defining at what stage of development that such assessment should be performed to identify the risk levels can be equally challenging. In this article, we report an approach to control elemental impurities of toxicological concern, compliant to the Q3D (R1) guideline, and a summary of results obtained on multiple protein therapeutic products. This approach follows the elements of Process Validation, i.e., Design, Qualification, and Continuous Verification. The design includes the selection of excipients and their suppliers that meet the Option 1 requirement of Q3D (R1). It also comprises the selection of manufacturing equipment, container-closure systems, and utilities. The qualification includes the testing of the potential sources of elemental impurities, i.e., excipients, utilities, and leachables/extractables from the manufacturing equipment and container-closure systems. The Continuous Verification comes from the testing of representative batches at the initiation of stability studies of clinical or commercial drug product batches and at the end of shelf-life expiry of the drug product, and when changes are made to the manufacturing equipment, sources of excipients and container closure systems, and any formulation changes. Our experience shows that the risk associated with the impurity levels of the ten elements of toxicological concern in the therapeutic protein drug products, parenterally administered, is well below the control threshold (30% PDE) in the drug product recommended by the ICH Guideline. Although our focus is on the injectable therapeutic proteins, this approach can be applied to the products administered via other routes as well. [ABSTRACT FROM AUTHOR]

Differential settlement of footings of reinforced-concrete buildings is expected to have a considerable effect on design forces in various structural components depending on the characteristics of the soil. The differential settlement combined with the soil–structure interaction (SSI) effect during earthquakes may be a significant factor in deciding the structural response especially for structures that have already undergone differential settlement. This is generally ignored in conventional design practice. A four-storeyed building structure is considered for the study. A typical layered soil profile similar to the profile observed in the Ganges basin, India has been considered for investigation. The SSI effect under dynamic conditions has been considered by adopting Gazetas springs at the support of buildings. Twelve earthquake time histories have been considered for bedrock motion. Convoluted bedrock motions considering the soil profile have been adopted as the input motion for the structure. Effects of various earthquake parameters on the seismic response of buildings, considering the differential settlement and the SSI effect under dynamic conditions, have been investigated and presented in dimensionless terms. The results indicate that the differential settlements along with the SSI consideration may be critical in deciding the structural response. This may even render the structure unsafe during earthquakes. [ABSTRACT FROM AUTHOR]

To comprehend the seismic vulnerability of a particular region, seismic damage assessment of a large number of buildings needs to be conducted. However, a realistic representation of structural damage can only be obtained through post-earthquake field observations and reconnaissance survey reports. Post-earthquake damage survey reports for Nepal (Gorkha) earthquake (2015) and Imphal (India) earthquake (2016) presented in this study are utilized to give an overall idea about the nature of seismic damage prevalent for the widespread civil engineering infrastructural developments in the particular geographical regions. Further, the study applies the existing rapid visual screening (RVS) schemes for predicting seismic vulnerability of the structures to judge the sanctity of the schemes. An extensive state-of-the-art review of the existing RVS schemes reported in the literature is presented. A comparative study exhibiting the efficacy of the existing RVS schemes is conducted on the basis of damage survey reports obtained from the Nepal and Imphal earthquakes. Finally, a modified RVS scheme is proposed here for seismic damage assessment of masonry and low-rise reinforced concrete buildings located in hilly regions of the Indian subcontinent and other developing countries. Excerpts from the study can be useful for researchers and practising engineers to perform seismic damage assessment of buildings using the proposed RVS scheme. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to identify the barriers to including sustainability in management education institutions (MEIs) in India, and subsequently, to analyze the structure of the causal relationships among the barriers. Design/methodology/approach: In this study, the decision-making trial and evaluation laboratory methodology are applied to analyze the structure of the causal relationships among the identified sustainability barriers. Findings: Through an extensive literature review and expert interviews, this paper identified 4 primary barriers and 46 sub-barriers. Encompassing sustainability in Indian MEIs results in changes in behavior involving increased respect for the environment, hence, leading to improved sustainable efficiency. Research limitations/implications: The present study is limited to MEIs in India. Practical implications: The inclusion of sustainability in MEIs equips future managers with the economic, ecological and technical knowledge required to demonstrate sustainable behavior in the workplace. It assists also equips managers with the ability to affect social change at an organizational level. MEIs has been acknowledged as playing a crucial role in societal transformations, including the need for transformation toward sustainability. Originality/value: The present study adds to the current knowledge base regarding the structure of the causal relationships among the identified sustainability barriers. To the author's knowledge, this is the first paper to identify such barriers to including sustainability in an Indian MEI context. [ABSTRACT FROM AUTHOR]

Highlights • Metallic octahedral prismatic 1T- and trigonal prismatic bulk crystal 2H-phase MoS 2. • The work functions are ∼3.5 eV and ∼3.3 eV for 1T- and 2H-phase MoS 2 respectively. • Photoluminescence intensity gradually decrease with synthesized temperature. Abstract Molybdenum di-sulfide thin films of thickness <1500 Å, were prepared by the dip-coating technique at different baking temperatures within the range 400 °C–450 °C using methanolic solution of ammonium molybdate and ammonium thiocyanate and hence studied their different properties using X-ray diffraction (XRD), UV-vis spectroscopy, Photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS) and Current-Voltage (I-V) relationship measurements. XRD result shows that the MoS 2 films are mixed metallic octahedral prismatic 1T- and trigonal prismatic bulk crystal 2H-phases. The I-V relationships show higher electrical conductivity for the films prepared at 400 °C and 450 °C than the films prepared at 425 °C. XPS measurement also shows the formation of mixed phases of MoS 2 thin films as revealed by XRD. We have estimated the valence band maximum (VBM) and work functions from higher and lower energy range of UPS (He-I) spectra of MoS 2 thin films prepared at 425 °C and 450 °C. The VBM are ∼4.4 eV & ∼4.2 eV and their work functions are ∼3.5 eV & ∼3.3 eV respectively that are correlated with conductivity and formation of mixed phases of MoS 2 thin films. [ABSTRACT FROM AUTHOR]

Nowadays, the assessment of blast resistance and mitigation strategies for structures subjected to blast loading are receiving great attention from engineers and researchers because of the increased number of accidental and/or malicious deliberate explosions around the world. As a result, there is a substantial increase in the research publications in terms of journal articles, conference proceedings, design codes and guidelines to familiarise the engineering community with this topic. In addition, advanced computational techniques and available resources have led to the development of different schemes for accurate prediction of blast wave parameters and the structural response. This study presents a comprehensive summary of blast effects on structures, material characteristics under high strain rates, modelling and analysis considerations, response criteria for various structural components and design guidelines. Blast testing, retrofit methodology and probable areas of future research are also critically discussed by collation and analysis of more than 100 research articles. Thus, this paper provides a systematic prologue that will serve as a concise guide to identifying the fundamental issues associated with the design of structures to resist explosion effects. [ABSTRACT FROM AUTHOR]

In this study we collate existing knowledge and suggest a possible methodology for construction on environmentally challenged backfilled mines to restore the sustainability of human settlement. The possibility of reconstruction on a backfill soil with a sustainable solution has been explored. The study highlights the issue of subsidence in backfilled opencast mines through a meticulous understanding of different case studies of construction on mine spoil. The prime focus of the study apart from structural and construction aspects includes the behaviour of heterogeneous mine spoil. Collapse settlement and hydrocompression are discussed to develop an understanding of failure in backfill. The study also incorporates the proposition of possible effective ground improvement treatment for improving soil behaviour through effective utilization of demolished concrete waste material. Further, ground improvement through demolished waste stone column has also been discussed. Finally, a feasible method for constructing a low-rise building on backfilled soil is proposed with available experimental data on bearing capacity. This study along with a comprehensive list of references may prove useful for conducting further research and a thorough understanding of the issues faced by the mining sector in India and other developing countries. [ABSTRACT FROM AUTHOR]

Air conditioning and mechanical ventilation systems may be oversized in commercial buildings in the Tropics. Oversized cooling coils may lead to reduced dehumidifying performance, indoor air quality and thermal comfort and increased energy consumption. In this paper, an adaptable cooling coil design is assessed with a general-purpose coil selection software tool, in which the number of active rows changes as a function of the load. For a 100% oversized coil, it is shown that the adaptable cooling coil is able to provide small but relevant improved humidity control down to 25% of the design load. This was obtained without affecting energy performance in typical variable air volume design and control. For specific applications, where variable air volume systems mainly control space humidity, there are also energy savings. The adaptable cooling coil could be seen as providing additional flexibility in the operation of HVAC systems, particularly in the tropics. [ABSTRACT FROM AUTHOR]

Many people in the Indian subcontinent can only afford non-engineered shelters. Unfortunately, such buildings are easy victims of earthquakes and they need to be assessed and graded to see how susceptible they are to damage during the frequent, moderate tremors of the region. The large number of these buildings warrants a wide screening programme but a dearth of technical personnel requires a simple methodology that can be carried out by non-technical people. This paper discusses the strategies for evolving a rapid visual screening procedure for non-engineered and semi-engineered buildings as a means of seismic vulnerability assessment. It is based on damage surveys of three moderate earthquakes and from shake-table experiments. The proposed methodology can be applied to traditional and semi-engineered buildings using a number of visually identifiable parameters. [ABSTRACT FROM AUTHOR]

Biological fouling (biofouling) on cooling coil surfaces acts as thermal insulation, impeding heat transfer from air to coil surfaces, decreasing airside heat transfer coefficient and degrading coil cooling capacity. It is also a common cause of low ΔT syndrome in chilled water distribution systems. The effects of a commercially available ultraviolet germicidal irradiation system installed in a variable air volume system on the airside heat transfer coefficient, cooling coil capacity, and its potential to mitigate low ΔT syndrome were investigated via a field test. Energy-related measurements including chilled water supply/return temperature, water-/airflow rate and entering/leaving air temperature/relative humidity commenced 4 months before turning on ultraviolet lamps and continued for 10 months after ultraviolet germicidal irradiation intervention. The effects of the ultraviolet germicidal irradiation system were evaluated via a “before ultraviolet” and “after ultraviolet” comparison. After ultraviolet intervention, within the face velocity range of 1.5–3.0 m/s, the airside heat transfer coefficient increased by 11.8%–20.1%, which translated into 8.8%–10.2% increase in the overall enthalpy-based thermal conductance. The coil total cooling capacity and latent cooling capacity increased by 3.3%–3.8% and 4.5%–5.7%, respectively. The chilled water flow rate required to maintain the leaving air temperature set-point decreased by 8.0%–11.9% and the water-side temperature difference increased by 0.4°C–0.6°C. [ABSTRACT FROM AUTHOR]

A comparative study has been made for the non-catalyst based few layer graphene (FLG) and Fe-catalyst based multiwall carbon nanotubes (MWCNTs). Magnetic and electronic properties of FLG and MWCNTs were studied using magnetic M-H hysteresis loops and synchrotron radiation based X-ray absorption fine structure spectroscopy measurements. Structural defects and electronic and bonding properties of FLG/MWCNTs have been studied using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). The work functions of FLG and MWCNTs are 4.01 eV and 3.79 eV, respectively, obtained from UPS (He-I) spectra. UPS (He-II) results suggest that the density of states (DOS) of MWCNTs is higher than FLG and is consistent with Raman spectroscopy result that shows the defect of MWCNTs is higher than FLG. The magnetic coercivity (Hc) of the MWCNTs (~750 Oe) is higher than FLG (~85 Oe) which could be used for various technological magnetic applications. [ABSTRACT FROM AUTHOR]

Biological fouling (biofouling) on wetted cooling coil surfaces decreases heat transfer efficiency, increases air-side flow resistance and may eventually lead to more energy consumption by fans and chiller plants. Applying ultraviolet germicidal irradiation (UVGI) systems in air handling units (AHUs) has the potential to clean coils, improve coil performance and save energy. In this study, the effectiveness of a coil irradiation system in improving coil performance and saving energy was investigated through a field test in a hot and humid climate. A commercially available coil irradiation system was installed downstream of a cooling coil in a variable air volume (VAV) AHU. The duration of the field test was 14 months, with four months before UVGI intervention and 10 months after UVGI intervention. The effectiveness of UVGI was evaluated via a “before UV” and “after UV” comparison of coil performance. The coil overall thermal conductance increased by 10% and the pressure drop decreased by 13%, with the improvement being most rapid over the first month after UVGI intervention. Fan energy use fell by 9% over the ten months of UVGI operation. Savings in fan energy were 39% greater than the energy used by the UV lamps. [ABSTRACT FROM AUTHOR]

This study is an attempt to underline the lack of preparedness and the nature of immediate further measures to be taken for facing a moderate earthquake in Indian subcontinents. Surprisingly, moderate to severe damage was noticed in structures located in hundreds of kilometres away from epicentre during last Gorkha earthquake. In this context, the present study makes an effort to validate a proposed modified rapid visual screening schemes for low cost houses frequently available in India. This may be used extensively for quick vulnerability assessment of a locality. Examples of retrofitting measures for typical buildings presented in this study may be useful for upgrading the valuable structures. Thus this study may be helpful for quick vulnerability assessment and adopting retrofitting measures for identified structures for earthquake prone developing countries. [ABSTRACT FROM AUTHOR]

Inelastic seismic behaviour of structures is needed to be predicted as accurately as possible. As during the seismic design, structures are allowed to undergo a stipulated amount of inelastic deformation in the dual design philosophy and its further extension of performance-based design. To obtain reasonably accurate behaviour in post-elastic ranges has manifold issues to be addressed together. The simultaneous effect of bidirectional ground motion is one of the major factors that need to be considered, and many studies also did the same. However, hardly any of them did consider the interaction between the deformations along two principal orthogonal directions on the yield criteria, post-elastic range excursion and the criteria of unloading. The present study makes an attempt to address these issues. Further, a few more studies mentioned that the angle of incidence of such orthogonal components of ground motion might influence the response of the structure. Hence, along with incorporating the effect of bidirectional interaction in the post elastic range, the issue of incidence angle is also studied extensively to reach a conclusive end. The detailed results presented in the study not only help to develop the physical insight but also maybe help in fine-tuning the design provisions. • The behaviour of structures under bidirectional ground motion considering interactive bidirectional deformation is studied. • The present paper explored the influence of the angle of incidence of ground motion on structures. • The current study indicates that the sensitivity of the response on the angle of incidence is marginal. • Exception may occur under near-fault ground motion with systems having different lateral periods in two principal directions of structures. [ABSTRACT FROM AUTHOR]

IAQ 2020: Indoor Environmental Quality Performance Approaches Transitioning from IAQ to IEQ: May 4-6, 2022 | Athens, Greece They describe a passive system composed of a radiative cooling (RC) panel combined with two phase change material (PCM) storage tanks that was integrated with a conventional air conditioning (AC) system. The cooling power produced by the RC panel was used to charge the PCM storage tanks and the overall energy consumption of the AC system was reduced by 22.3% when compared with the conventional AC system. [Extracted from the article]

A previous study using a scaled-down model of single-room masonry structures tested on a shaking table has shown that strength may be considerably increased by tying up the masonry walls by polypropylene (PP) bands, wrapping the walls using steel wire mesh, and providing horizontal L-shaped reinforcing bars at corners. The effectiveness of the same economic approaches and their combinations has been studied for similar scaled-down models with proportionate openings representing doors and windows, as a logical further scope of the previous study testing these models on a shaking table. As the presence of openings influences the crack and damage propagation leading to failure, the present study may give a more realistic picture of the seismic behavior of masonry structures with openings. Experiments have shown that PP bands were more effective than horizontal L-shaped reinforcing bars in arresting cracks and preventing collapse of the models, even those severely damaged. Further, the most important aspect of the study is that the technique is economical and can be implemented without involvement of any technical manpower or sophisticated equipment. The interesting observations regarding the effectiveness of such economical strengthening measures obtained from the study may be helpful for seismic strengthening of real-life masonry structures with door and window openings, leading to broad guidelines in this direction. [ABSTRACT FROM AUTHOR]

Masonry structures have exhibited their extreme vulnerability even in the event of past minor to moderate earthquakes. Junction failure followed by out-of-plane collapse of the wall orthogonal to the direction of strong shaking is the reason of failure of small masonry building structures as shown in a recent literature. In this context, present study makes an attempt to examine the efficacy of a few strengthening techniques of such structures verified through testing a large number of small scale models on shake table. Techniques being cost effective and easy to implement may prove useful in improving seismic performance. Large number of experimental results presented in this study may help in choosing one of the suitable techniques depending on specialties of a particular local condition. [ABSTRACT FROM AUTHOR]

Depleting timber resources has generated interest in bamboo, a traditional sustainable building material of the tropics. However, dearth of strength data has been a major hindrance in its engineered application. The present paper reports experimentally verified compressive and cleavage strengths of an Indian bamboo species that is considered suitable for structural applications. The investigated compressive strength is well comparable with that of equivalent timber. The paper reports lesser strength of split bamboo specimens than round ones, which contradicts the provisions of some codes. The paper also observes that compressive strength of bamboo generally increases along its culm length, gradually from bottom to top. The paper further identifies a factor, which when multiplied by the density of a given specimen, yields corresponding permissible compressive strength. Low values of coefficients of variation and skewness of the experimental data indicate its reliability. This paper may be considered as a step towards engineered application of bamboo. [ABSTRACT FROM AUTHOR]

On 18 September 2011, all the Indian states and countries surrounding Sikkim witnessed a devastating moderate earthquake of magnitude 6.9 ( Mw ). Originating in Sikkim–Nepal border with an intensity of VI+ in MSK scale, this earthquake caused collapse of both unreinforced masonry buildings, heritage structures and framed structures followed by landslides and mud slides at various places of Sikkim. Significant damages have been observed in relatively new framed structures mainly in Government buildings, thick masonry structures, while, the older wooden frame ( ekra ) non-engineered structures performed well during the earthquake. Further, it is noteworthy that government buildings suffered more than private ones and damages were observed more in newer framed structures than older ones. Analysis of the damages identify lateral spreading of slope, pounding of buildings, out-of-plane rotation, generation of structural cracks, plastic hinge formation at column capitals and damage of infill wall material as predominant damage features. A few remedial measures are also attempted to be mentioned with future need of research and application. It has been felt to create awareness regarding these issues and is the need of the hour. [ABSTRACT FROM AUTHOR]

The IAQ 2016 conference convened in Alexandria, Virginia, USA from September 12–14, 2016 was the 18th in the series inaugurated in Atlanta, Georgia in 1986 and was co-organized with the Air Infiltration and Ventilation Center (AIVC) as its 37th conference. The Indoor Air Quality Association (IAQA) and the Indoor Environmental Quality Global Alliance (IEQ-GA) were co-sponsors. [ABSTRACT FROM PUBLISHER]

This paper presents an initial effort to investigate seismic response of soil-pile raft-structure system considering soil-structure interaction effect. In general, structure and piled raft under seismic load are designed considering fixed base condition. However, soil flexibility may result significant changes in the response of soil-pile raft-structure system. The study considers one storey system consisting of a mass in the form of a rigid floor slab supported by four columns. The piles are modelled by beam-column element supported by laterally distributed springs and dampers. This simple model used in present study is adequately tuned to exhibit reasonably accurate dynamic characteristics while compared to the existing well accepted methodologies. The study shows that soil-structure interaction leads to considerable lengthening of period though the lateral shear in columns are not significantly changed. However, the shear in piles is significantly increased due to SSI effect as inertia of the considerable foundation mass contributes to this increase in shear of pile. Thus, neglecting SSI may lead to unsafe seismic design of piles. A parametric study encompassing feasible variations of parameters is made under spectrum consistent ground motion. Effect of uncertainty in the soil subgrade modulus on the pile and column response variability is also studied. [ABSTRACT FROM PUBLISHER]

In healthcare centers, healthcare workers would not know if patients are infected or not until the infected person is diagnosed and moved to an isolation room; therefore, the effectiveness of ventilation systems in removing the exhaled infectious air in the consultation room becomes important. To prevent the transmission of exhaled air, two types of personalized exhaust devices were explored: top-personalized exhaust and shoulder-personalized exhaust. Three different arrangements with 30 cases between 2 manikins were studied experimentally using tracer gas. The intake fraction was compared with and without the personalized exhaust at the end of three different exposure durations: 10, 20, and 30 min. The results show that after applying either top-personalized exhaust or shoulder-personalized exhaust, the intake fraction is significantly decreased. With the higher flow rate of 20 L/s of personalized exhaust, the intake fractions at 30 min are found to be even lower than the intake fractions at 10 min without personalized exhaust. This implies that despite a longer exposure time, if the exposure amount is reduced, the infection risk is observed to be lower. [ABSTRACT FROM PUBLISHER]

Performance based design of structure requires a reasonably accurate prediction of displacement or ductility demand. Generally, displacement demand of structure is estimated assuming fixity at base and considering base motion in one direction. In reality, ground motions occur in two orthogonal directions simultaneously resulting in bidirectional interaction in inelastic range, and soil–structure interaction (SSI) may change structural response too. Present study is an attempt to develop insight on the influence of bi-directional interaction and soil–pile raft–structure interaction for predicting the inelastic response of soil–pile raft–structure system in a more reasonably accurate manner. A recently developed hysteresis model capable to simulate biaxial interaction between deformations in two principal directions of any structural member under two orthogonal components of ground motion has been used. This study primarily shows that a considerable change may occur in inelastic demand of structures due to the combined effect of such phenomena. [ABSTRACT FROM AUTHOR]

The present paper compares the performance of some alternative methods of finite-element modelling and analytical formulation in the prediction of in-plane and out-of-plane stiffness and natural periods of masonry wall. It also aims to elaborate on the suitability of such techniques for masonry buildings through a number of case studies. While comparing these results with those predicted by relevant formula proposed by seismic codes of various countries, it has been observed that code formulas overestimate the periods considerably. The gap between the results from code formula and those from the analytical formulation is reduced if soil-structure interaction is incorporated in the analytical formulation, implying its suitability for predicting lateral period. Finally, the presented seismic safety assessment of masonry buildings for different combinations of number of storeys and bays may lead to valuable design insight. The study as a whole gave a good insight into effective finite-element modelling and seismic safety assessment of masonry buildings. [ABSTRACT FROM AUTHOR]

• Magnetic behavior of MoS 2 -SC, MoS 2 -NP and 2D bi-layer-MoS 2 thin films. • M−H hysteresis loops measured at 300 K. • Room temperature ferromagnetism in 2D bi-layer-MoS 2. • MoS 2 -SC/MoS 2 -NP shows diamagnetism/paramagnetic. Comparisons of magnetic behavior of pristine single crystal-MoS 2 (MoS 2 -SC), nanoparticle-MoS 2 (MoS 2 -NP) and two-dimensional (2D) bi-layer-MoS 2 thin film were investigated by the M−H hysteresis loops measured at 300 K, using the superconducting quantum interface device-type magnetometer. Results clearly shows that the room temperature ferromagnetism in 2D bi-layer-MoS 2 with saturation of magnetization ∼ 10 × 10-4 emu/g, whereas pristine MoS 2 -SC / MoS 2 -NP shows diamagnetism/paramagnetic behaviour. The X-ray photoelectron and Raman spectroscopy results confirms the observed ferro-magnetization in 2D bi-layer-MoS 2 is related to the presence of edge spins on the edges of layers, S-vacancies (defects at the grain boundaries region) and higher density of states. This 2D bi-layer-MoS 2 may find applications in nanodevices and spintronics by controlling the edge structures. [ABSTRACT FROM AUTHOR]

The -delta (-) effect imposes higher ductility demand during earthquakes, which may not be adequately catered for in the prescribed values of response reduction factors ( ). The present work investigates the - effect on inelastic seismic response of slender bridge piers through a case study. Displacement ductility demands and overturning moments of a typical pier are computed both with and without the - effect using non-linear dynamic analysis and pushover methods. Response history analysis is carried out for four hysteresis behaviours: elasto-plastic, strength degrading, stiffness degrading, and combined strength and stiffness degrading behaviour. The study shows that the - effect at the plastic stage is a progressive phenomenon and depends on strength rather than on stiffness. The conventional practice to restrict sway based on first-order analysis to prescribed values for containing the - effect is ineffective. By using a case study, the research provides a methodology for arriving at acceptable values to prevent occurrence of any instability due to the - effect arising from undue low lateral strength. [ABSTRACT FROM AUTHOR]

This article investigates the performance of three different types of personalized exhaust devices. A top-personalized exhaust, which is a round device just above the human head; a shoulder-personalized exhaust, which consists of two local exhaust devices installed at the chair just above shoulder level; and a chair-personalized exhaust, which is at the upper part of a chair just behind the human head, were simulated, evaluated, and compared numerically using the computational fluid dynamics method. Two seated occupants representing healthy and infected manikins equipped with two types of personalized ventilation devices in a simulated consulting room in a healthcare center were modeled. Two indices—personalized exposure effectiveness and inhaled fraction—were introduced to evaluate the improvement of general inhaled air quality after adding different types of personalized exhaust devices and to compare the performance of different kinds of personalized exhaust devices with respect to the healthy manikin's exposure to exhaled contaminated air. The computational fluid dynamics models were validated with a set of experiments conducted in an environmental chamber. The results indicate that all the three personalized exhaust devices might be able to reduce the transmission of exhaled air between occupants. The lowest inhaled fraction was achieved by the combination of a vertical desk grill and a top-personalized exhaust. However, only the shoulder-personalized exhaust device has the potential to improve the amount of personalized ventilation air in the inhaled air. [ABSTRACT FROM AUTHOR]

Background: Caregiving has been identified as a basic component of human nature and a primary element of close relationship. This study aims to assess the extent and pattern of burden felt by the caregivers of patients with schizophrenia in comparison with bipolar disorder. Materials and Methods: Fifty-two patients with schizophrenia and fifty-one patients with bipolar disorder attending the outpatient department were assessed in the study. The burden among the caregivers was assessed using Burden Assessment Schedule. Results: The caregivers of schizophrenia group had significantly higher total burden score as compared to caregivers of bipolar disorder. Caregivers of schizophrenia experienced significantly higher burden in area of external support, caregivers routine, and other relations. Conclusion: The extent of burden among families of schizophrenic patients is more than those of bipolar disorder. The families of patients with bipolar disorder do also experience considerable burden. The pattern of burden among families of schizophrenia and bipolar disorder is almost identical in most of the domains except for external support, caregivers routine, and other relations [ABSTRACT FROM AUTHOR]

Abstract: Existing practice to estimate inelastic seismic demands does not consider the impact of inelastic bidirectional interaction of load resisting members arising due to bidirectional horizontal ground motions. This paper utilizes a simple yet reasonably accurate bidirectional hysteresis model to study the storey drifts of single as well as multistorey idealized systems under both bidirectional and unidirectional seismic excitations using 20 far fault ground motions. The ratio of the storey drifts under bidirectional and unidirectional excitations is investigated for a feasible range of system parameters. Biaxial interaction is found to cause magnification in drift demand. [Copyright &y& Elsevier]

Performance based seismic design requires precise assessments of inelastic seismic demand. Often, the studies to assess such demands are made without due cognizance to the impact of axial load caused by gravity. In this paper, the effect of gravity-induced axial force on load resisting members on such demand quantities is examined. To encompass the behavior of steel as well concrete structures with various types of degrading features, four different hysteresis models are used in the study. The results show that the effect of axial force on inelastic seismic demand become more significant for systems with short periods having degrading hysteresis behavior. Neglecting the effect of axial force may lead to an underestimation of yield capacity resulting in an overestimation of demand implying a safer design. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the potential for energy and water sustainability in hot and humid climates by utilizing the condensate captured from large dedicated air handling units (AHUs) for pre-cooling outdoor air in another AHU and subsequently offsetting cooling tower water needs. In such climates, latent load is large enough throughout the year to produce a substantial amount of condensate, which is typically drained away from all the AHUs. In this study, condensate is collected from several AHUs and directed through another coil that pre-cools the warm and humid outdoor air which is supplying another AHU, called the condensate assisted pre-cooling (CAP) AHU. During the same time, the cooling towers require considerable amounts of make-up water to replace water losses occurring on a regular basis. The condensate, including that from the main cooling coil of the CAP AHU, is first supplied to the pre-cooling coil of the CAP AHU and is then routed through the cooling tower, which significantly reduces potable water usage and improves cooling tower water chemistry. It is found that condensate production is large enough to make pre-cooling cost-beneficial with energy savings of approximately 10% and the ability to offset cooling tower water demand in excess of 50%. [Copyright &y& Elsevier]

Masonry structures are most popular form of habitats in developing countries providing shelter to a majority of population in the world. Such structures demand to have a separate reasonably accurate formula for their lateral period which is the most basic and vital input for the estimation of seismic loading. This paper is an initial step in composing this formula. To understand the behavior of such structures which primarily offer resistance through in-plane and out-of-plane actions of two sets of mutually orthogonal masonry walls connected at vertical joints, the in-plane and out-of-plane behavior of masonry walls is attempted to be investigated thoroughly. Resorting to a finite element modeling with its validity proved against parallel analytical formulation and experimental data, the periods in various modes of vibration are predicted by such modeling for various combinations of masonry walls' dimensions. It is visualized that the higher modes dominate in-plane dynamic behavior, while the lower modes their out-of-plane counterparts. So, the higher modes may regulate the seismic behavior in a masonry structure containing both walls with in-plane and out-of-plane orientations, as the lion's share of seismic resistance is offered by walls acting in plane. The periods of these modes are compared with the ones obtained from various available code formulae. The study presented in this paper shows that the predictions of such general purpose formulae are higher than the one predicted through the computational model. This may lead to an underestimation in calculation of seismic forces from design spectrum provided in various codes. Thus, this study points out the need for a thorough investigation which may lead to the development of separate period formula for masonry structures with adequate physical background. However, the results presented in the study may be directly applicable for free standing masonry walls. [ABSTRACT FROM AUTHOR]

This study examined the inelastic seismic behavior of low-rise systems with varying story eccentricities (i.e., general class of eccentric systems). Seismic demands of such systems were found to be potentially high relative to those obtained from single-story or regularly asymmetric models, particularly for flexible-side elements of torsionally stiff systems and stiff-side elements of torsionally flexible systems. This appears to be a consequence of the complex participation of higher torsion-dominated modes in multistory systems with general class of asymmetry, unlike the predominant participation of single torsional mode in its regularly asymmetric counterpart. The study also indicates that the degrading features of RC structural elements may cause a significant increase in inelastic demands. Summarizing elastic range response, coefficients α and δ are proposed to predict seismic demand through equivalent static analysis. Further, a design envelope was outlined to predict inelastic seismic demand. This may prove useful in the selection of the appropriate response reduction factor in practical design. Observations highlighting the dynamics of multistory systems with generalized asymmetry establish the conceptual framework for envisioning the seismic response. [ABSTRACT FROM AUTHOR]

Inverted pendulum-like structures such as elevated tanks are not only subjected to overturning moments from lateral seismic forces, but also from P-Δ effect which originates due to gradual shifting of line of actions of gravity loads due to largely increasing inelastic displacements, causing progressive increase in the tendency of overturning in the inelastic range. The response reduction factors are prescribed in the code to limit the inelastic displacement demands of the structures depending on their ductility capacities. In this context, the present study investigates the influence of P-Δ effect on elevated tanks. The study attempts to propose a simple enough mathematical model to assess the comparative difference in lateral displacement and overturning moment due to consideration of progressive P-Δ effect with and without computed through nonlinear response history analysis. Two typical hysteresis behaviors, namely, elastoplastic and strength and stiffness degrading ones, are chosen to represent the seismic behavior of typical steel frame and reinforced concrete frame structures. The study may provide useful input towards developing refined guidelines for performance-based seismic design of elevated tanks. [ABSTRACT FROM AUTHOR]

Abstract: This study is to evaluate energy saving potential of ceiling mounted personalized ventilation (PV) system in conjunction with background mixing ventilation compared with mixing ventilation system alone and with mixing ventilation system when occupants are provided with individually controlled desk fans for generating additional air movement at each desk. Control strategy applied includes different number of personalized ventilation air terminal devices used and different PV airflow rates supplied. Energy calculation is based on design conditions in Singapore, representing a hot and humid climate. The results reveal that increasing room temperature can save cooling energy when the combination of PV with ceiling mounted personalized ventilation nozzles and background mixing ventilation is used. In this case the energy for transport of air increases but the total energy decreases, i.e. energy can be saved due to elevated room temperature. Comparing with mixing ventilation plus desk fans, ceiling mounted personalized ventilation cannot only realize better cooling effect but also decrease the total energy consumption. [ABSTRACT FROM AUTHOR]

Abstract: A critical review of past earthquakes reveals damage/failure of important lifeline facilities like elevated water tanks in recurrence, leading to serious hazards even after the event. In the context of such hazards indicating deficiencies in the existing seismic design strategy of such structures, dynamic characteristics of elevated tanks supported by cylindrical shaft (shaft staging) are comprehensively studied in the first part of present investigation. The same is made through analytical formulations developed and validated by rigorous finite element analysis and small-scale experimentation. Subsequent examination on seismic response of representative tanks indicates that the columns of the frame-supported tanks (tanks with frame staging) and the wall of the shaft-staging of such reinforced concrete () tanks are susceptible to tension, particularly at tank empty condition. Such possibility seems to be further aggravated if the effect of soil–structure interaction (SSI) is ignored in design. Identifying the deficiencies in current design, simple design procedure of such elevated tanks utilizing the formulations developed is proposed. Torsional vulnerability of shaft-supported elevated water tanks is also identified to be marginal as opposed to the same for frame supported ones. [Copyright &y& Elsevier]

To obtain the stress distribution within a shallow foundation, a distributed spring approach is proposed to represent soil behavior. Relevant analytical formulations for grid and raft foundations are derived on the basis of the lumped stiffness coefficients developed by Gazetas and recommended in modern codes such as FEMA 356 [2000]. The efficacy of the proposed formulations to represent the overall dynamic behavior and seismic response of the building frames with grid and raft foundations is checked against the established Gazetas scheme. A limited parametric study is also made to observe the effect of soil damping. This helps to arrive at a suitable damping ratio for combined structure-foundation-soil system. Subsequently, the variations in stress distributions incorporating the effect of soil-structure interaction at various locations of two types of foundations are also presented for some representative cases. Results show a substantial increase in the bending moment and shear force in the foundation itself due to such interaction effect. Such increase is observed to be strongly dependent on the framing action of the structure. This emphasises the necessity of considering this effect for safe seismic design. To this end, Distributed approach proposed in the present article may be conveniently employed with the help of any standard building analysis software besides using the outcomes of the parametric studies presented herein. [ABSTRACT FROM AUTHOR]

Abstract: Structures may experience degradation in strength in the event of strong seismic shaking. A rational estimation of the reserve strength of the structures is often desired in the process of retrofitting or strengthening the same. To achieve this end, the present paper confirms the suitability of an existing hysteresis model in reproducing experimental load–displacement characteristics for reinforced concrete (R/C) structural members. Attempt has also been made for rational and realistic estimation of the degradation parameter required for the model in absence of any case-specific calibrated value. Subsequently, post-earthquake behaviour of the low-rise symmetric structures is assessed with and without accounting for the effect of soil–structure interaction. Such response for low-rise multistorey systems with regular asymmetry has also been investigated in the sample form. To develop insight into the behaviour of asymmetric (uni-directional and bi-directional) systems, detailed investigation has been made on idealized single-storey asymmetric systems under simulated and real ground motions with different phase difference or time lag variation. This suggests a serious implication of occurrence of peaks of the ground motions on the seismic performance of bi-directionally eccentric structures and indicates a relatively higher torsional vulnerability of bi-directionally eccentric system compared to equivalent uni-directional counterpart. The results along with the endeavour toward measuring the ductility capacity for R/C structural members based on the systematic observation and interpretation of the available experimental results, made in the paper, may prove useful in evaluating the seismic safety of low-rise R/C structures. [Copyright &y& Elsevier]

The Musi River, in Hyderabad, the capital city of Andhra Pradesh state in India, is relatively dry for most of the year except for the four monsoon months when 700–800 mm of rain falls. Throughout the year, sewage, industrial, and hospital waste is released into the river. In the present work the Musi River from Amberpet Bridge to Nallacheruvu (8 km stretch) was assessed and monitored for heavy metal contamination attributable to sewage and industrial effluents. Twelve locations were assessed for Zn, Cr, Cu, Ni, Co, As, Hg, Cd, and Pb in soils, waters, forage grass, milk, and vegetables. A sequential extraction scheme revealed that high levels of Zn, Cr, and Cu were associated with labile fractions, making them more mobile and phytoavailable. Human risk was assessed in people exposed to pollution by analyzing metals concentrations in venous blood and urine. Results showed high amounts of Pb, Zn, Cr, and Ni compared to permissible limits, attributable to the consumption of contaminated food. Metals concentrations were monitored systematically to assess risks and support management decisions to help curtail the possible entry of metals into human food chains. An assessment was also made of a possible analysis of a remediation technology for lead-contaminated soils and water. [ABSTRACT FROM AUTHOR]

Extreme seismic vulnerability of bidirectionally eccentric structural systems such as street corner buildings has been demonstrated repeatedly during past severe earthquakes. Inelastic range response of such structural systems may vary considerably depending upon the sense of eccentricities regulated by relative quadrant wise position of center of stiffness with respect to center of mass particularly for reinforced concrete (RC) structures with strength and stiffness degrading behavior. Recognizing the same, an effort has been made in the present paper to analyze the inelastic range response of bidirectionally asymmetric structures designed as per the existing codal standards. Such response helps to perceive the adequacy of the code provisions to minimize the progressively damaging effects expected to arise in RC bidirectionally eccentric structural systems due to strength and stiffness degradation under severe seismic excitation. The effect of change in stiffness eccentricity due to cracking of reinforced concrete members is also attempted to be studied in the limited form. Inelastic seismic response of code-designed bidirectionally eccentric structural systems with only strength deteriorating and only stiffness degrading structural elements are also investigated to examine the potential of such comparatively simpler hysteresis models. Effort has also been made toward assessing the response of similar elastoplastic structural systems. The study clearly indicates the limitation of the design code provisions to take adequate care of seismic torsional vulnerability of bidirectionally eccentric structures made up of strength and stiffness degrading RC structural elements. However, the performance of the same seems satisfactory for elastoplastic structural systems. [ABSTRACT FROM AUTHOR]

Abstract: In the conventional design, buildings are generally considered to be fixed at their bases. In reality, flexibility of the supporting soil medium allows some movement of the foundation. This decreases the overall stiffness of the building frames resulting in a subsequent increase in the natural periods of the system and the overall response is altered. The present study considers low-rise building frames resting on shallow foundations, viz. isolated and grid foundation. Influence of soil–structure interaction on elastic and inelastic range responses of such building frames due to seismic excitations has been examined in details. Representative acceleration–time histories such as artificially generated earthquake history compatible with design spectrum, ground motion recorded during real earthquake and idealized near-fault ground motion, have been used to analyze the response. Variation in response due to different influential parameters regulating the effect of soil-flexibility is presented and interpreted physically. The study shows that the effect of soil–structure interaction may considerably increase such response at least for low-rise stiff structural system. [Copyright &y& Elsevier]

The overall lateral stiffness of any building decreases due to the compressibility of soil. This leads to a subsequent increase in the natural periods of the structural system. The seismic lateral response may change due to natural periods while seismic torsional response arising out of mass or stiffness eccentricity depends on the ratio of uncoupled torsional-to-lateral natural period of the building. Hence, the effect of soil–structure interaction on lateral natural period, seismic base shear and fundamental torsional-to-lateral period ratio of building frames resting on raft foundation needs a detailed investigation. Present study is a limited effort to accomplish these objectives. Influence of the variation of a number of parameters such as (a) different soil conditions, (b) number of stories, (c) number of bays, (d) the ratio of flexural stiffness of columns to that of beams and (e) ground excitation frequency is considered in the present study. Buildings are modelled by two parallel approaches, viz., (1) frame with brick in-fill having fixed supports and (2) frame with brick in-fill having supports accounting for soil-flexibility. The soil-flexibilities for various types of soil and foundation based on their properties, e.g., shear modulus, the Poisson ratio of the soil, and shape and size of the rafts are computed following the well-accepted literature. The lateral natural period, torsional-to-lateral natural period ratio and seismic base shear of a variety of building frames at fixed base condition are compared to the same considering soil-flexibility due to variation in different influencing factors. The trends observed are attempted to be interpreted physically. The curves and tables presenting the change in lateral natural period and torsional-to-lateral period ratio due to effect of soil-flexibility of various building frames seem to be useful for calculating base shear of low-rise buildings through a simple methodology. Such simple methodology may be useful in the design offices for its simplicity and accuracy. [Copyright &y& Elsevier]

The interaction among structures, their foundations and the soil medium below the foundations alter the actual behaviour of the structure considerably than what is obtained from the consideration of the structure alone. Thus, a reasonably accurate model for the soil–foundation–structure interaction system with computational validity, efficiency and accuracy is needed in improved design of important structures. The present study makes an attempt to gather the possible alternative models available in the literature for this purpose. Emphasis has been given on the physical modeling of the soil media, since it appears that the modeling of the structure is rather straightforward. The strengths and limitations of the models described in a single paper may be of help to the civil engineers to choose a suitable one for their study and design. [Copyright &y& Elsevier]