Observations of upper-extremity skin temperature and corresponding overall-body thermal sensations and comfort

This paper explores how upper extremity skin temperatures correlate with overall-body thermal sensation. Skin temperature measurements of the finger, hand, and forearm might be useful in monitoring and predicting people's thermal state. Subjective perceptions of overall thermal sensation and comfort were collected by repeated surveys, for subjects in a range of test chamber temperatures. A positive temperature gradient (finger warmer than the forearm) of as much as 2 K was seen when subjects felt warm and hot, while a negative temperature gradient (finger colder than the forearm) as much as 8.5 K was seen for cool and cold subjects. A useful warm/cold boundary of 30 °C was found in finger temperature, for both steady state and transient conditions. When finger temperature was above 30 °C, or finger-forearm skin temperature gradient above 0 K, there was no cool discomfort. When finger temperature was below 30 °C, or the finger-forearm skin temperature gradient less than 0 K, cool discomfort was a possibility. Finger temperature and finger-forearm temperature gradient are very similar in their correlation to overall sensation. We also examine how overall sensation is affected by actively manipulating the hand's temperature.     

Compartment fire near-field entrainment measurements

A widely accepted consensus on entrainment models for large fires in compartments does not yet exist. To obtain further information on such entrainment rates, 20 full-scale, near-field experiments were conducted. Near-field entrainment occurs when hot layer interface heights are beneath the burner mean flame height so that cold layer entrainment occurs only near the burner surface. A durable compartment, similar to the standard fire test compartment, was designed and used in conjunction with a 0·61 m × 1·22 m porous surface propane burner to produce compartment fires with heat release rates from 330 to 980 kW. Entrainment rates of 0·74–0·98 kg/s were calculated from temperature measurements made within the compartment and in the doorway. The entrainment rates determined here were correlated with values from the literature. This correlation led to two curve fits which modify Zukoski's far-field offset model and can be used to estimate near-field entrainment rates. An offset for the near-field model of Thomas was also developed. The fire plume model of Baum and McCaffrey was found to compare favorably with the entrainment rates determined here.     

Optimum use of solar energy techniques in a semi-underground house: First-year measurement and computer analysis

In order to obtain fundamental information on techniques for the optimum use of solar energy in a semi-underground house, a twin-type test house was constructed on the campus of Tohoku University in September 1984. The test house has two rooms, with a south-facing window above the ground surface and a corridor situated between the two rooms. Insulation 10 cm deep and 1.35 m wide was installed horizontally 30 cm below the ground surface, surrounding one room of the house. The other room is not insulated. During the first year, all windows were insulated with weather shutters to avoid disturbing the heat gain due to solar radiation. As a result, the yearly room temperature swing varied °C less than the temperature swing of outdoor air. The air temperature in the insulated room was 1.2°C higher in the winter and 0.5°C lower in the summer than in the room without insulation. The influence of various thermal insulation formations in the earth around the house on room temperature fluctuation and heating and cooling loads was calculated using the two-dimensional finite element method. Calculations were performed hourly for a year under standard climate conditions in Sendai, Japan.     

Aerobic treatment of piggery waste

The operating characteristics of laboratory waste treatment systems were studied during the aerobic degradation of pig excrement at different loading rates and temperatures. The treatment systems were of two types: one was operated with floc formation and gravity separation of liquid and suspended solid effluents; and a second was operated without floc formation or separation of the effluent into liquid and solid fractions.

With an operating temperature of 15°C the parameters most affected by loading rate were (1) the concentrations of suspended solids and chemical oxygen demand in the liquid effluent; (2) the pH value of the mixed liquor; (3) nitrification; (4) the BOD of the supernatant from the mixed liquor; and (5) output of suspended solids as a percentage of input.

The concentrations of suspended solids and chemical oxygen demand in the liquid effluents were little affected by loading rates in the range 0·05-0·15 g SS g MLSS⁻¹ d⁻¹ (0·02-0·06 g BOD g MLSS⁻¹ d⁻¹) but increased with increasing loading rate in the range 0·15-0·30 (0·06-0·12 BOD). At loading rates below about 0·17 g SS g MLSS⁻¹ d⁻¹ (0·07 g BOD g MLSS⁻¹ d⁻¹) the mixed liquors were acidic, with pH values down to 5·2, whereas at loading rates above about 0·80 (0·32 BOD) they were alkaline, with pH values up to 8·9. At intermediate loading rates the mixed liquor pH value was more variable though in general the higher the loading rate the higher also the pH value of the mixed liquor. Acidic conditions in the mixed liquors were attributed to the occurrence of nitrification, while in the absence of nitrification the mixed liquors remained alkaline. The concentration of BOD₅ in the supernatant from the mixed liquors increased with increasing loading rate from about 35 mg 1⁻¹ at a loading rate of 0·17 g SS g MLSS⁻¹ d⁻¹ (0·07 g BOD g MLSS⁻¹ d⁻¹) to about 250 mg 1⁻¹ at a loading rate of 1·30 (0·52 BOD). The output of suspended solids from the treatment systems represented about 70 per cent of input suspended solids at loading rates of about 0·15 g SS g MLSS⁻¹ d⁻¹ (0·06 g BOD g MLSS⁻¹ d⁻¹) and increased to about 100 per cent at loading rates of 0·80 (0·32 BOD). Output of chemical oxygen demand was about 60 per cent of input at the lower loading rates and 80–90 per cent at the higher ones.

Operation of treatment units at temperatures of 5 and 10°C instead of 15°C had little effect on the efficiency of degradation at loading rates in the range 0·085-0·20 g SS g MLSS⁻¹ d⁻¹ (0·034-0·08 g BOD g MLSS⁻¹ d⁻¹), but nitrification was prevented at 5°C. At loading rates of 0·77 (0·31 BOD) and 1·46 (0·58 BOD) operation at 25°C appeared to increase the amount of degradation as compared with that achieved at 15°C.

The practical implications of the results and possible future approaches to the aerobic treatment of farm wastes are discussed.     

People''s clothing behaviour according to external weather and indoor environment

In prehistoric times man wore furs of animals to protect himself from the cold. Successively over the centuries clothing has become also a tool to distinguish ourselves in society. Clothing has in addition an important impact on people's perception of the indoor environment.

Clothing behaviour has been analysed by investigating the external and indoor parameters that motivate people's choice of clothing. Based on two existing databases, two types of buildings have been investigated: air-conditioned and naturally ventilated (NV) buildings. The impact of outdoor temperature on people's clothing selection has been considered. The outdoor temperature at 6 a.m. seems to affect people's choice of clothes the most. Gender does not significantly affect the selection of clothing insulation.

Latitude has also been investigated and a good correlation has been found between clothing insulation and external temperature in the ranges 20°–40° and −20° to −40° for NV buildings.

Indoor air temperature does not seem to influence the clothing choice early in the morning but it does seem to influence the change of clothing during the day, if this is authorized, in workplaces in NV buildings. Such action can be termed “clothing adjustment” during the day.

Some computer simulations on a test reference year have been carried out for a typical air-conditioned office to analyse a person's comfort when wearing different clothes. It is possible to see that in air-conditioned buildings a variation of 0.1 clo is sufficient to change totally the comfort evaluation. It is evident that further studies are needed in this field.     

低温作业对人体的危害及防寒工作服的性能评价

防寒工作服是冬季保护石油行业室外作业人员的重要措施。文章阐述了低温环境对石油行业室外作业人员身体健康的影响,列举了防寒工作服生产和检测的重要性能参数和测定方法,概括了国内外对于防寒工作服生产和检测的相关标准,展望了防寒工作服研发应用空间和发展方向,对防寒工作服的研究和配备有一定的参考价值。     

Aerobic Biological Treatment of a Pharmaceutical Wastewater: : Effect of Temperature on COD Removal and Bacterial Community Development

The effect of temperature was studied on the efficiency of soluble COD removal and bacterial community development during the aerobic biological treatment of a pharmaceutical wastewater. Using wastewater and bacterial inoculum obtained from the full-scale facility treating this wastewater, batch laboratory cultures were operated at 5°C intervals from 30°C to 70°C. Following four culture transfers to allow for bacterial acclimation, residual soluble COD levels were measured and bacterial community fingerprints were obtained by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments. Soluble COD removal efficiency declined as temperature increased from 30°C (62%) to 60°C (38%). Biological treatment of this wastewater failed to occur at temperatures higher than 60°C. Gradual shifts in bacterial community structure were detected as temperature increased, including a concomitant reduction in the number of different bacterial populations. The impact of temperature on a two-stage biological treatment process was also compared. Better soluble COD removal was achieved when both reactors were operated at 30°C compared to a system where the two stages were consecutively operated at 55°C and 30°C. These results indicate that operation of aerobic biological wastewater treatment reactors at elevated temperatures can have adverse effects on process performance.     

Tensile and fatigue behaviour of glassfibre/epoxy laminates

The behaviour of unidirectional 45 °, angle-ply ± 45 ° and multidirectional [±45 °,0 °]_s fibreglass/epoxy laminates at room temperature under tensile and fatigue loadings has been investigated. Results for angle-ply ± 45 ° laminates show that the rate/frequency effect is significant in both tensile and fatigue loadings. In the case of tensile loading tests, the rate effect was observed in the stress-strain response. Fatigue data indicate a considerable accumulated cyclic creep which depends on the loading condition, i.e. applied load and frequency. The effect of frequency on the fatigue life is explained in terms of cyclic creep and its detrimental influence on the fatigue resistance. In contrast, laminates made of 45 ° unidirectional and multidirectional [± 45 °,0 °]^s show very little frequency effects.     

Storage of refrigerated liquefied gases in rock caverns: characteristics of rock under very low temperatures

The results of laboratory experiments on changes in the mechanical properties of various types of rock at low temperature (to -160°C), and the results of thermal shock tests, and freezing and thawing tests (from 15°C to -45°C, up to 300 temperature-change cycles) are described. Thermal conductivities and the expansion (shrinkage) rate of various rocks at temperatures from +15°C to -160°C are measured and the temperature-dependent thermal characteristics are examined. Engineering problems for cryogenic storage —e.g., the critical freezing temperature of seepage water flow into the caverns, durability of rock bolt and grout materials under low temperature—are examined in some fundamental experiments.     

Degradation of chlorophenols in soil, sediment and water at low temperature

Chlorophenol degradation was studied under aerobic conditions in soil, sediment and water. Ortho-chlorophenol, p-chlorophenol and 2,4-dichlorophenol were degraded by soil and sediment microorganisms at 0°C and 4°C. Metachlorophenol and pentachlorophenol were also degraded, but to a lesser extent. Stream-water microorganisms were only able to degrade 2,4-dichlorophenol at 20°C. None of the other chlorophenols examined were degraded by stream-water microorganisms at 0 or 20°C. The addition of some chlorophenols stimulated aerobic, and to a lesser extent, anaerobic microbial growth in sediment incubated at 0°C. A decrease in the concentration of some chlorophenols was noted in both sterile and non-sterile stream water at 0 and 20°C; which could not be explained by microbial contamination, photodecomposition or volatilization.     

Evidence of thermally induced borehole elongation: a case study at Soultz, France

When they occur, borehole breakouts are considered strong markers of principal stress directions at depth. An innovative processing method for automatically identifying breakouts from ultrasonic borehole wall images has been developed. It has been applied to data sets from two deep, sub-vertical wells (GPK1 and GPK2) at the Soultz geothermal site in eastern France. In well GPK1, below 3 km depth, compression breakouts, with a 95°±7° azimuth, increasingly occur with depth. They result from time dependent compression failure at sub-critical stress levels and are indicators of the minimum horizontal principal stress orientation. However, in the uppermost logged section of well GPK2 (1.6–2.9 km depth), continuous borehole elongations share roughly the same azimuth with so called drilling-induced fractures (164°±18° and 175°±17° azimuth, respectively). Both features concomitantly vanish with depth, together with the amplitude of the thermal perturbation induced by drilling. It is proposed that these latter borehole elongations result from a pervasive, cooling-induced, tensile micro-cracking process prior to macroscopic failure localization. They are termed thermal elongations and are indicators of the maximum horizontal principal stress orientation. Had a simple logging caliper tool been used for this work, these thermal elongations might have been confused with classical compression breakouts. A simple criterion for differentiating compression breakouts from thermal elongation is proposed.     

Preservation du contenu en o-phosphate d''echantillons d''eau du fleuve saint-laurent

On a étudié l'efficacité d'un certain nombre de produits comme préservatifs du contenu en o-phosphate d'échaotillons d'eau du fleuve St-Laurent à des températures d'entreposage de −10°, 4° et 20°C. Parmi les produits testés soit le thymol (0.01%), le fluorure de potassium (0.01%), ;lácide sulfurique (0.0 N), le chlorure de tributylétain (0.001%) et le chloroforme (5 ml/l), seuls les deux derniers se sont revélés potentiellement intéressants. Une série d'expériences a confirmé que le contenu en o-phosphate pouvait ètre préseré de façon süre pendant au moins deux sernaines par un entreposage à 4°C en présence de chloroforme (5 ml/l).

Abstract

The effectiveness of some materials in preserving the o-phosphate content of water samples from the St-Lawrence River at storage temperatures of −10°, 4° and 20°C was studied.

Tests were done with thymol (0.01%), potassium fluoride (0.01%), sulfuric acid (0.1 N), tributylin chloride (0.001%) and chloroform (5 ml/l), the last two products showing some activity. From further testing it can be concluded that the o-phosphate content is stable for at least two weeks of storage at 4°C with chloroform added as preservative.     

《混凝土结构工程施工规范》GB50666—2011编制简介——冬期、高温和雨期施工

《混凝土结构工程施工规范》GB50666—2011第10章分一般规定、冬期施工、高温施工、雨期施工,共4节41条。与《混凝土结构工程施工及验收规范》GB50204—92比较,增加了高温施工和雨期施工内容,将原版中冬期钢筋施工调到钢筋工程章节。冬期施工介绍了气温界限的确定、混凝土热工计算的重要性、水泥选用、外加剂选用、原材料预热、混凝土养护等内容;高温施工介绍了进入高温的条件、高温施工专项方案、施工措施等;雨期施工介绍了施工过程质量控制、安全控制等内容。     

Toxicity of chlorine to juvenile spot, Leiostomus Xanthurus

The sensitivity of juvenile spot, Leiostomus xanthurus, to total residual chlorine (TRC) in flowing sea-water was investigated. Incipient LC₅₀ bioassays, histopathology, avoidance tests and the combined effect of thermal stress and TRC were used to assess sensitivity.

Estimated incipient LC₅₀ values were 0.12 mg 1⁻¹ TRC at 10°C and 0.06 mg 1⁻¹ TRC at 15°C. Histological examination of spot used in the incipient LC₅₀ bioassay at 15°C and sacrificed while alive indicated pseudobranch and gill damage occurred in individuals exposed to a measured TRC concentration of 1.57 mg 1⁻¹. Spot exposed to lower concentrations of TRC, 0.02 0.06 mg 1⁻¹ at 15°C and sacrificed alive showed no consistent tissue damage.

Spot demonstrated temperature dependent avoidance responses to TRC. At 10°C, a concentration of 0.18 mg 1⁻¹ was required for significant (X²; P < 0.05) avoidance; at 15 and 20°C, spot showed significant avoidance of TRC concentrations as low as 0.05 mg 1⁻¹.

Simultaneous exposure of spot to thermal stress (5, 10 or 13°C above the acclimation temperature of 15°C) at measured TRC concentrations of 0.05 0.07 and 0.34–0.52 mg 1⁻¹ demonstrated a significant, (Z²) with Yates correction, P < 0.05) increase in sensitivity to TRC with increased temperature and exposure times for some of the groups tested.     

Comparative study of confirmation media for detecting group D streptococci

Four media were compared for confirming the presence of group D streptococci in azide dextrose broth enrichment cultures inoculated with water samples and incubated at 37°C. Ethylviolet azide broth incubated at 37°C (EVA 37) did not support growth of all group D streptococci tested and gave positive reactions with some non group D strains. Moreover, the typical “purple button” was frequently absent with group D strains. Azide dextrose broth incubated at 44°C (ADB 44) was also inhibitory to some group D streptococci and in addition was sensitive to overgrowth by catalasepositive bacteria. Bile esculin azide agar incubated at 44°C (BEA 44) supported growth of group D streptococci almost exclusively, but also was most inhibitory of all media tested against these bacteria. KF-streptococcus agar incubated at 37°C (KF 37) on the contrary, gave positive reactions with most group D streptococci but also with non group D strains. Based on these results, for critical work a combination of BEA 44 and KF 37 is suggested.     

Sequential inactivation of Cryptosporidium parvum using ozone and chlorine.

Inactivation of bovine-derived C. parvum oocysts was studied at bench-scale in oxidant demand free 0.05 M phosphate buffer using free chlorine alone or ozone followed by free chlorine at temperatures of 1°C, 10°C and 22°C at pH 6. Animal infectivity using neonatal CD-1 mice was used for evaluation of oocyst viability after treatment. Kinetic models based on the linear Chick–Watson model were developed for free chlorine inactivation and ozone/free chlorine sequential inactivation for 0.4 or 1.6 log-units of ozone primary kill. At 22°C, ozone pre-treatment increased the efficacy of free chlorine for about 4–6 times depending on the level of ozone primary kills. Gross kills of the ozone/free chlorine sequential inactivation were a function of ozone primary kills and increased linearly with the free chlorine C_avgt (arithmetic average of the initial and final residual×contact time) product. Temperature was critical for both single and sequential inactivation, and the efficacy of free chlorine after 1.6 log-units of ozone primary inactivation decreased by a factor of 1.8 for every 10°C temperature decrease. Given an ozone primary kill of 1.6 log-units, the free chlorine C_avgt products required for a gross kill of 3.0 log-units were 1000, 2000 and 3300 mg min/L for 22°C, 10°C and 1°C, respectively.     

Variation of fracture toughness of asphalt concrete under low temperatures

This study presents the results of experimental evaluation on fracture toughness of asphalt concrete at various low temperatures (from −5°C to −30°C in 5°C steps). An asphalt cement, penetration grade of 85/100 and two aggregates, a granite and a limestone, were used to prepare asphalt concrete beam specimens which were conditioned using two different procedures and tested under three-point bending setup. The first procedure dealt with evaluation of fracture toughness of the asphalt concrete at a control temperature, −5°C, following conditioning at the specified temperatures. The second procedure dealt with evaluation of fracture toughness at the temperatures at which the samples were conditioned. The results showed that fracture toughness (K_IC) for both aggregate mixtures in both procedures changed in a manner that it increased by lowering temperature from −5°C to −15°C, and then decreased thereunder. An improved mechanical adhesion due to the strengthened grip of asphalt matrix resulted from differential thermal contraction (DTC) is responsible for increased resistance to the applied loads. The reduction of fracture toughness below −15°C is explained as the effect of internal damage due to DTC that is a consequence of the large difference in coefficients of thermal contraction between aggregate and asphalt cement. Granite aggregate mixture showed a slightly better resistance to fracture throughout the temperatures. Relatively good linear relations between average values of σ_f and K_IC were found from the regression analysis. Increasing flexural strength resulted in an increased fracture toughness for all mixtures. K_IC of granite mix showed more critical to the change of σ_f.     

Sulfolane biodegradation potential in aquifer sediments at sour natural gas plant sites

Sulfolane is used in the treatment of sour natural gas. It is a highly water soluble compound that has been introduced into soils and groundwaters at a number of sour gas processing plant sites. Aquifer sediments from contaminated locations at three sites in western Canada were assessed for microbial activity and their ability to degrade sulfolane under aerobic and five anaerobic (nitrate-, Mn(IV)-, Fe(III)-, sulfate- and CO₂-reducing) conditions. The microcosms were supplemented with 200 mg/L sulfolane and adequate supplies of N, P, and the appropriate terminal electron acceptor. Microcosms containing contaminated aquifer sediments from each of the three sites were able to degrade sulfolane aerobically at 8°C and 28°C, and the biodegradation followed zero-order kinetics. The lag times before the onset of sulfolane biodegradation were shorter when sulfolane-contaminated sediments were used as inocula than when uncontaminated soils were used. No anaerobic sulfolane biodegradation was observed at 28°C, nor was sulfolane biodegradation observed at 8°C under Fe(III)-, sulfate- and CO₂-reducing conditions. At 8°C, anaerobic degradation of sulfolane coupled to Mn(IV) reduction was observed in microcosms from two sites, and degradation coupled to nitrate reduction was seen in a microcosm from one of the contaminated sites.     

The effect of low temperature on BOD in antarctic seawater

Untreated sewage has been released from McMurdo Station, Antarctica, into McMurdo Sound for several years. In this study organic carbon degradation was compared in seawater from McMurdo Sound at −1.8°C and 20°C using the BOD test. The ultimate BOD was 3 times larger at 20°C than at −1.8°C following 25 days of incubation. On the basis of on these findings, sewage from McMurdo Station, Antarctica, should receive at least secondary treatment before release to lessen the impact of anthropogenic organic carbon on the polar marine environment of McMurdo Sound.     

Pentachlorophenol adsorption and desorption characteristics of granular activated carbon-I. Isotherms

The adsorption/desorption of pentachlorophenol (PCP) with Calgon F300 granular activated carbon (GAC) was studied and modelled. A modified Radke-Prausnitz (1972) isotherm model, incorporating a temperature- and pH-dependent proportionality constant, was found to best describe the observed PCP adsorption and desorption. The modified isotherm is valid in the ranges 4 ≤ pH ≤ 11 and 10 ≤ T ≤ 60°C. The activation energy of PCP adsorption was calculated to be 5.2 kJ/mol. At 30°C, PCP adsorbed strongly, and the rate of subsequent desorption was very low. However, the amount of PCP desorbed could be increased significantly by increasing the temperature to 60°C.