Building frames—Effect on fire resistance of floor and ceiling assemblies

In many cases, fire endurance tests of seemingly comparable floor and roof assemblies have yielded different results. The author reports on a current study which, thus far, has involved analyzing thermal moments developed in floor assemblies due to fire exposure, evaluating the distribution of thermal forces to the adjacent building frame, and deriving the resultant reaction of the structure. He discusses techniques for determining the onset of structural collapse mechanisms, using mathematical expressions for the change in modulus of elasticity and yield stress as a function of temperature. Note: This paper was presented by the author at a symposium on methods and application of testing building materials for fire resistance held at the Armstrong Cork Company's Technical Center, Lancaster, Pa., June 24 and 25, 1965.     

Effect of Curing Temperature on Mortar Based on Sustainable Concrete Material＇s and Poly-Carboxylate Superplasticizer

Nowadays, technologies in construction field have offered several kinds of chemical admixtures, which offer different behaviors at the fresh state of the batch and by consequence, it is resulted with different mechanical behaviors at the solid state of the mix. This study focused on the behavior of a new kind of admixture at fresh and solid states. Currently, the concrete material has become a very expensive material because the high price mostly of aggregates, representing the three quarters of the concrete components. By consequence, it costs money and on the other hand, it produces a lot of wastes. The main aspect which guides this study is to make a kind of concrete based mainly on local material and sustainable concrete material （SCM or waste material）, which is one very abundant material in quality and quantity, under the current tendency the results obtained in this study summarize up the importance of the temperature during the development of the mechanical characteristics of mortar, mainly on compressive strength at age of 28 days. This is in the case of the addition of limestone crushed additive by percentage of substitution.     

Effect of pH on N₂O reduction and accumulation during denitrification by methanol utilizing denitrifiers

Acidic pH has previously been found to increase nitrous oxide (N₂O) accumulation during heterotrophic denitrification in biological wastewater treatment. However, the mechanism of this phenomenon still needs to be clarified. By using an enriched methanol utilizing denitrifying culture as an example, this paper presents a comprehensive study on the effect of pH (6.0-9.0) on N₂O reduction kinetics with N₂O as the sole electron acceptor, as well as the effect of pH on N₂O accumulation with N₂O as an intermediate of nitrate reduction. The pH dependency of nitrate and nitrite reduction was also investigated. The maximum biomass-specific N₂O reduction rate is higher than the corresponding maximum nitrate and nitrite reduction rates in the entire pH range studied. However, the maximum biomass-specific N₂O reduction rate is much more sensitive to pH variation outside of the optimal range (pH 7.5 to pH 8.0) than the maximum biomass-specific nitrate and nitrite reduction rates. The half-saturation coefficient of the N₂O reductase increased from 0.10 mg N₂O-N/L to 0.92 mg N₂O-N/L as pH increased from pH 6.0 to 9.0. At pH 6.0, approximately 20% and 40% of the denitrified nitrate accumulated as N₂O in the presence and absence of methanol (as an exogenous carbon source), respectively. However, at pH 6.5, these fractions decreased to 0% and 30%, respectively. No N₂O accumulation occurred at pH 7.0 to 9.0 independent of the availability of methanol. These results suggest that the competition for electrons among different nitrogen oxides reductases likely plays a role in N₂O accumulation at low pH conditions.     

Effect of surcharge loading rate and mobilized load ratio on the performance of vacuum–surcharge preloading with PVDs

The results from three laboratory model tests performed under various vacuum and surcharge loads with PVDs are reported. Different SLRs were adopted to investigate the effect on the consolidation of dredged soil. To measure the lateral displacement, a refitted inclinometer was developed and tested. In the tests, the settlement, lateral displacement, and vane shear strength were measured, and the degree of consolidation (DOC), horizontal coefficient of consolidation (C_h), and bearing capacity were calculated. The results indicate that larger SLR values promote consolidation. The largest vane shear strength, settlement, and C_h values were all obtained under the highest SLR, and the bearing capacity under this SLR was more than double that under the lowest SLR. The DOC was found to increase with the growth of the SLR. However, considering the vacuum pressure was higher in Case-III, the influence of SLR on reinforcement effect may not be so significant.     

Effect of geogrid reinforcement on soil - structure – pipe interaction in terms of bearing capacity,settlement and stress distribution

In this study, the contribution of single and multiple layers of geogrids to bearing capacity and stress behavior was determined by laboratory experiments. The effects of parameters such as the depth of the first geogrid, the vertical spacing between the geogrid layers and the number of geogrid layers on the bearing capacity and settlement behavior of soil and stress distribution on geogrid and pipe by using strain gauges have been investigated. The results of experiments were given in dimensionless form of bearing capacity ratio (BCR), settlement reduction factor (SRF) and stress capacity ratio (SCR). As a result of experiments, the contribution of the geogrid on the soil-structure-pipe interaction has been observed together with the stress distribution on the geogrid contributed to the efficient use of the appropriate geogrid capacity.     

The effect of temperature on the emission of formaldehyde and volatile organic compounds (VOCs) from laminate flooring — case study

The effect of temperatures of 23, 29, 50°C on formaldehyde and volatile organic compounds (VOCs) emission from laminate flooring Type A (with particleboard as substrate) and Type B (with high density fibre (HDF)) was examined. At 23 and 29°C the measurements did not show any emissions of formaldehyde and very low emissions of VOCs. At a temperature of 50°C, Type A showed a high initial emission of formaldehyde and VOCs, which decreased with time. The emission from Type B was much lower. In conclusion, some laminate flooring may affect the chemical contamination of indoor air with the use of floor heating.     

Effect of Physical Environment on the Behaviors of Residents with Dementia： A Comparison between a Small-Group Unit and a Traditional Care Unit

This is a comparative study examining the influence of a small-scale dementia unit and a traditional dementia unit on behaviors of the residents. The small-scale unit and the traditional unit were selected through two phases in Vancouver, Canada. Seven residents from each facility completed the study. Physical environmental assessments were performed using two tools： PEAP （professional environmental assessment protocol） and TESS-NH （therapeutic environment screening survey for nursing homes）. For the assessment of residents＇ behaviors, three assessment tools were used： MOSES （multidimensional observation scale for elderly subjects）, MDS （minimum data set） and DCM （dementia care mapping）. The study found that the residents living in a small-scale environment were more engaged in activities and more likely to respond in understanding their fellow residents. Residents living in a traditional long-term care exhibited fewer signs of social interaction. The findings suggest that a small-scale homelike environment could positively influence people with dementia to be more engaged in social exchanges and activities, and consequently help in reducing their withdrawn behavior.     

Removal of organic compounds by adsorption on pyrolusite (β-MnO2)

This paper deals with the determination of the adsorption capacities of various organic compounds in water suspension on MnO₂ pyrolusite which can be present in the natural environment and in potabilisation treatment. The adsorption was linearised according to Langmuir and Freundlich models. Humic acids were adsorbed on MnO₂ under the working conditions used in this study. Tannic acid was also removed by MnO₂ but at a lesser level and the model appeared to be more complex, thus suggesting tannic acid precipitation at the surface of MnO₂. More generally, it was observed after studying the adsorption capacity of various molecules, that negatively charged molecules were poorly adsorbed on MnO₂ probably because of electrostatic interactions whereas cationic molecules were easily adsorbed. Hydrophobic interactions seemed to be a second factor making adsorption on MnO₂ much easier. Electrokinetic potential measurement of suspended particles of MnO₂ was in good correlation with these hypotheses.     

(Re-)creating Urban Destination Image: Opinions of Foreign Visitors to South Africa on Safety and Security?

The intention of tourists to visit urban destinations is influenced by their perceptions or their knowledge of that destination. Risk perceptions, although situation specific, have an impact on travel behaviour. Mega events are once-off occasions in which a negative perception of destination, in this case related to crime, can be turned into a positive image. Can the 2010 Fédération Internationale de Football Association World Cup (WC) help South Africa undo the current perceptions and opinions, especially among foreign visitors, that our cities are dangerous places to visit? Can South Africa manage the 2010 WC in such a way that the destination image can be changed to a more positive one? It is within the context of speculating about the potential impacts the event may have in 2010 on reshaping internationally (and nationally) the safety and security image that visitors have of South African cities as crime ridden that this paper aims mainly to investigate international visitors’ perceptions and opinions on safety and security. Nine hundred and seven international visitors were interviewed when exiting the country at the OR Tambo and Cape Town International airports. The findings revealed that more than a third of the respondents indicated that they were worried about their safety before travelling to South Africa, that the central business districts of Cape Town and Johannesburg are the most feared places they visited and 6% of the respondents were victims of crime. Perceptions, however, changed for the better after their visit to the country, and it is against this background that the 2010 WC can potentially show the world that the country is a safe destination to visit and in the process re-create the destination’s image as a safe tourist experience.     

Globalization and the Evolution and Characteristics of Spatial Distribution of Transnational Organizations in Guangzhou(1949–2012)

Transnational organizations refer to governmental and non-governmental organizations engaged in transnational behaviors,which are important carriers of political globalization.Given the wave of world city studies sweeping the academia worldwide,transnational organizations have attracted increasing attentions.Through a review of existing research,an analysis of historical archive and interviews,and the application of space syntax,this paper examines the development process and characteristics of spatial distribution of transnational organizations in Guangzhou since the founding of P.R.China.It divides the development process of transnational organizations in Guangzhou into three stages: budding period,starting period,and developing period.In this process,the number of organizations and related types increased sharply,and the business was much extended.Along with the eastward shift of the city center,the distribution center of transnational organizations consequently moved to the east,indicating their location characteristics of geographical centrality and proximity to major globalized spaces.The spatial distribution of transnational organizations shows: proximity to city center or high-level transportation center; demands for security,communication,and notability of geographical position; locations of different types of organizations owning different levels of integration value; organizations of specific functions prefer urban districts with related functions.     

Comment on “Comparative study of the deformation modulus of rock mass” by Panthee et al. (2018) in the Bulletin of Engineering Geology and the Environment

Bulletin of Engineering Geology and the Environment -     

The “effect procargo” on technical and scale efficiency at airports: The case of Spanish airports (2009–2011)

This paper studies the “effect procargo” (or effect of the proportion of cargo traffic relative to total traffic) on technical and scale efficiency at airports. To this end, using Data Envelopment Analysis (DEA) methodology, a comparative technical efficiency analysis is developed for 35 Spanish airports over the 2009 to 2011 period. In a second stage, using Tobit regression, we analysed the effects of airport size, low-cost carrier (LCC) presence, and cargo traffic on efficiency. The results suggest that cargo traffic has a positive impact on the technical and scale efficiency of Spanish airport operations. Airports with a higher share of cargo traffic are expected to have higher overall technical efficiency, pure technical efficiency, and scale efficiency, in comparison to airports with a lower share.     

Effects of ferric iron on the anaerobic treatment and microbial biodiversity in a coupled microbial electrolysis cell (MEC) – Anaerobic reactor

Adding Fe(III) into a MEC – anaerobic reactor enhanced the degradation of organic matters. To clarify the respective effects of combining Fe(III) dosage and a MEC and Fe(III) dosage only on strengthening anaerobic digestion, three anaerobic reactors were operated in parallel: a MEC – anaerobic reactor with dosing Fe(OH)₃ (R1), an anaerobic reactor with dosing Fe(OH)₃ (R2) and a common anaerobic reactor (R3). With increasing influent COD from 1500 to 4000 mg/L, the COD removal in R1 was maintained at 88.3% under a voltage of 0.8 V, which was higher than that in reactor R2 and R3. When the power was cut off, the COD removal in R1 decreased by 5.9%. The addition of Fe(OH)₃ enhanced both anaerobic digestion and anodic oxidation, resulting in the effective mineralization of volatile fatty acids (VFAs). The reduced Fe(II) combined with electric field resulted more extracellular polymeric substances (EPS) production. Quantitative real – time PCR showed a higher abundance of bacteria in the anodic biofilm and R1. Pyrosequencing and denaturing gradient gel electrophoresis (DGGE) analysis revealed that the dominant bacteria and archaea communities were richer and more abundant in the anode biofilm and R1.     

Laboratory study on the adsorption of Mn²⁺ on suspended and deposited amorphous Al(OH)₃ in drinking water distribution systems

Manganese (II) is commonly present in drinking water. This paper mainly focuses on the adsorption of manganese on suspended and deposited amorphous Al(OH)₃ solids. The effects of water flow rate and water quality parameters, including solution pH and the concentrations of Mn²⁺, humic acid, and co-existing cations on adsorption were investigated. It was found that chemical adsorption mainly took place in drinking water with pHs above 7.5; suspended Al(OH)₃ showed strong adsorption capacity for Mn²⁺. When the total Mn²⁺ input was 3 mg/L, 1.0 g solid could accumulate approximately 24.0 mg of Mn²⁺ at 15 °C. In drinking water with pHs below 7.5, because of H⁺ inhibition, active reaction sites on amorphous Al(OH)₃ surface were much less. The adsorption of Mn²⁺ on Al(OH)₃ changed gradually from chemical coordination to physical adsorption. In drinking water with high concentrations of Ca²⁺, Mg²⁺, Fe³⁺, and HA, the removal of Mn²⁺ was enhanced due to the effects of co-precipitation and adsorption. In solution with 1.0 mg/L HA, the residual concentration of Mn²⁺ was below 0.005 mg/L, much lower than the limit value required by the Chinese Standard for Drinking Water Quality. Unlike suspended Al(OH)₃, deposited Al(OH)₃ had a much lower adsorption capacity of 0.85 mg/g, and the variation in flow rate and major water quality parameters had little effect on it. Improved managements of water age, pipe flushing and mechanical cleaning were suggested to control residual Mn²⁺.