Roles of sulfuric acid in elemental mercury removal by activated carbon and sulfur-impregnated activated carbon

This work addresses the discrepancy in the literature regarding the effects of sulfuric acid (H(2)SO(4)) on elemental Hg uptake by activated carbon (AC). H(2)SO(4) in AC substantially increased Hg uptake by absorption particularly in the presence of oxygen. Hg uptake increased with acid amount and temperature exceeding 500 mg-Hg/g-AC after 3 days at 200 °C with AC treated with 20% H(2)SO(4). In the absence of other strong oxidizers, oxygen was able to oxidize Hg. Upon oxidation, Hg was more readily soluble in the acid, greatly enhancing its uptake by acid-treated AC. Without O(2), S(VI) in H(2)SO(4) was able to oxidize Hg, thus making it soluble in H(2)SO(4). Consequently, the presence of a bulk H(2)SO(4) phase within AC pores resulted in an orders of magnitude increase in Hg uptake capacity. However, the bulk H(2)SO(4) phase lowered the AC pore volume and could block the access to the active surface sites and potentially hinder Hg uptake kinetics. AC treated with SO(2) at 700 °C exhibited a much faster rate of Hg uptake attributed to sulfur functional groups enhancing adsorption kinetics. SO(2)-treated carbon maintained its fast uptake kinetics even after impregnation by 20% H(2)SO(4).     

Copper oxide nanoparticle mediated DNA damage in terrestrial plant models

Engineered nanoparticles, due to their unique electrical, mechanical, and catalytic properties, are presently found in many commercial products and will be intentionally or inadvertently released at increasing concentrations into the natural environment. Metal- and metal oxide-based nanomaterials have been shown to act as mediators of DNA damage in mammalian cells, organisms, and even in bacteria, but the molecular mechanisms through which this occurs are poorly understood. For the first time, we report that copper oxide nanoparticles induce DNA damage in agricultural and grassland plants. Significant accumulation of oxidatively modified, mutagenic DNA lesions (7,8-dihydro-8-oxoguanine; 2,6-diamino-4-hydroxy-5-formamidopyrimidine; 4,6-diamino-5-formamidopyrimidine) and strong plant growth inhibition were observed for radish (Raphanus sativus), perennial ryegrass (Lolium perenne), and annual ryegrass (Lolium rigidum) under controlled laboratory conditions. Lesion accumulation levels mediated by copper ions and macroscale copper particles were measured in tandem to clarify the mechanisms of DNA damage. To our knowledge, this is the first evidence of multiple DNA lesion formation and accumulation in plants. These findings provide impetus for future investigations on nanoparticle-mediated DNA damage and repair mechanisms in plants.     

Remote sensing of ammonia and sulfur dioxide from on-road light duty vehicles

This study reports the largest data set of on-road, fuel-based mass emissions of ammonia and sulfur dioxide from vehicles of known make, model year, and fuel type. Ammonia is the first pollutant observed for which the emissions decrease with increasing fleet age from 10 to 20 years. The fixed nitrogen emission ratio is 15.0% by mass and 24.7% by mole, larger than current models predict. Diesel fueled vehicles emit more SO2 than gasoline, and unexpectedly, gasoline SO2 emissions decrease continuously with newer model year vehicles.     

Serum levels of polybrominated diphenyl ethers (PBDEs) in foam recyclers and carpet installers working in the United States

Increased exposure to the flame retardants known as polybrominated diphenyl ethers (PBDEs) may be expected to occur during the recycling of polyurethane foam containing these chemicals. To date, no studies in the United States have investigated occupational exposure to these flame retardants during recycling processes. The objective of the present study was to determine if individuals working in foam recycling facilities, and/or carpet installers who may install carpet padding manufactured from recycled foam, possess significantly higher PBDE serum levels relative to that of the general U.S. population. As a control group, serum was collected from four spouses and one clerical worker. In addition, levels in workers were also compared to the recently published national health and nutrition examination survey (NHANES) data set on PBDEs in the general U.S. population. Serum samples were collected in duplicate and analyzed by two different laboratories as quality control. Total PBDE levels were found to be significantly higher (p < 0.05) in the individuals recycling foam and installing carpet (n = 15) relative to the control group (n = 5). Median sigmaPBDE levels in the foam recyclers, carpet layers, and control group were 160, 178, and 19 ng/g lipid, respectively. In contrast, concentrations of a polybrominated biphenyl (BB-153) and a polychlorinated biphenyl (CB-153) were equivalent among all groups tested. The PBDE congeners BDE-47, 99, 100, and 153 contributed 90% of the sigmaPBDE concentration in serum and no differences in congener patterns were apparent among the different groups. Relative to concentrations measured in the NHANES, foam recyclers and carpet layers have body burdens that are an order of magnitude higher. These data suggest individuals recycling foam-containing products, and/ or using products manufactured from recycled foam (i.e., carpet padding), have higher body burdens of PBDEs, and thus may be at higher risk from adverse health effects associated with brominated flame retardant exposure.     

Properties of extruded expandable breadfruit products

It is vital to process breadfruit in order to develop new value-added products with improved sensory and physicochemical characteristics. In this research, dried breadfruit was extruded with a twin screw extruder and effects of barrel temperature, moisture content, feeding rate and screw speed on product physicochemical properties and process energy consumption were studied. Quadratic models were obtained to predict the product quality under various processing conditions. The best range of crispness of the extrudate was from 2.0 to 3.5N/s, hardness from 60 to 75 N and bulk density from 0.3 to 0.38 g/cm³. Corresponding operating conditions of feeding rate, temperature, screw speed and moisture content to obtain best results of crispness, hardness and bulk density were 16 kg/h, 130 °C, 160 rpm, 22 g/100 g; 22 kg/h, 150 °C, 160rpm, 22 g/kg; 19 kg/h, 140 °C, 115 rpm, 19 g/100 g; and 25 kg/h, 140 °C, 145 rpm, 19 g/100 g, respectively. The linear term of screw speed significantly effected all indexes (p < 0.001), especially water absorption and solubility indexes, sectional expansion ratio, bulk density, color and specific mechanical energy. The interaction term of feed rate and temperature, and square term of screw speed had no significant influences (p ≥ 0.1). The findings were useful for developing and optimizing extruded or value-added co products of breadfruit.     

Foreword.

Recognizes the individuals who aided in publishing this monograph as a special issue of the journal. The support of the American Cancer Society is also acknowledged. Information is given on how to obtain additional copies of this issue. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Silk purses into sow's ears: The decline of psychological testing and a suggestion for its redemption.

Views psychological testing as declining from its recent ascendency as the predominant mode for decision-making. It is averred that the fall is caused by psychodynamically-oriented clinicians who perceive behavior as resulting from underlying needs, drives, and transsituational traits, and by test developers who have become overly concerned with psychometric esthetics while neglecting validity. Standardized tests and projective instruments lack decisional utility in the acquisition of knowledge relevant to the identification of talent or to the construction of instructional or therapeutic strategies. As an alternative, it is suggested that assessment be performed within a framework labeled "psychosituational assessment" that emphasizes the direct and continuous measurement and observation of behavior in natural settings. Specific techniques useful toward that end are described and discussed. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social unrest: Powerlessness and/or self-direction?

Presents a theoretical model for understanding social unrest which is based on the experience of control. It is proposed that social unrest indicates powerlessness and consequently an inability to make self-directed choices to alter one's environment. The model postulates 4 interacting components or sources of behavioral determinants: (a) control from internal organismic states (e.g., impulses), (b) control over these internal states, (c) control over the environment, and (d) control from the environment. It is argued that social unrest must be dealt with in terms of the resources of the social sciences and not in political or managerial priorities. The question of whether social unrest is the outgrowth of the effects of social systems on individuals (overemphasis of control from the environment) or enlightenment regarding the individual's self-directing potential (increased control over the environment) is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The potential for bicultural communication in a dyadic situation.

Studied cross-cultural communication with Canadian university students who identified themselves as French-speaking or English-speaking. Ss were divided into 36 French-English pairs (18 of which were tested in a French setting and 18 in an English setting) and 36 same-ethnic pairs. The pairs performed an experimental task under 1 of 3 instructional sets in which Ss were forced to communicate, communication was optional, or no communication set was provided. Each condition was followed by an unstructured period where Ss were free to communicate. Following the communication task, Ss completed a questionnaire which assessed their attitudes about communicating with their partner. Results were analyzed in terms of patterns of communication, content of communication, and languages used for communication. Findings suggest that effective cross-cultural communication is possible and that, at least in a dyadic situation, members of 2 ethnic groups are motivated to communicate. (French summary) (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of interaction anticipation upon the extremity of trait ratings.

Examined the effect of interaction anticipation upon the perception of a future partner by 80 undergraduates. Experimental Ss were led to anticipate interaction with a stimulus person for either 3 or 30 min. Control Ss anticipated either no interaction or interaction with a different person. A process of "commitment reluctance" was discovered; experimental Ss made less extreme ratings across warm-cold dimensions of stimulus persons who had been described as either "warm" or "cold." These ratings were not, however, related to the length of the expected interaction. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)