Humidity-dependent surface tension measurements of individual inorganic and organic submicrometre liquid particles.

Surface tension, an important property of liquids, is easily measured for bulk samples. However, for droplets smaller than one micron in size, there are currently no reported measurements. In this study, atomic force microscopy (AFM) and force spectroscopy have been utilized to measure surface tension of individual submicron sized droplets at ambient pressure and controlled relative humidity (RH). Since the surface tension of atmospheric aerosols is a key factor in understanding aerosol climate effects, three atmospherically relevant systems (NaCl, malonic and glutaric acids) were studied. Single particle AFM measurements were successfully implemented in measuring the surface tension of deliquesced particles on the order of 200 to 500 nm in diameter. Deliquesced particles continuously uptake water at high RH, which changes the concentration and surface tension of the droplets. Therefore, surface tension as a function of RH was measured. AFM based surface tension measurements are close to predicted values based on bulk measurements and activities of these three chemical systems. Non-ideal behaviour in concentrated organic acid droplets is thought to be important and the reason for differences observed between bulk solution predictions and AFM data. Consequently, these measurements are crucial in order to improve atmospheric climate models as direct measurements hitherto have been previously inaccessible due to instrument limitations

Psychiatric Effects of Solitary Confinement

The author, Dr. Grassian, is a Board Certified Psychiatrist who was on the faculty of the Harvard Medical School for over twenty-five years. He has had extensive experience in evaluating the psychiatric effects of solitary confinement, and in the course of his professional involvement, has been involved as an expert regarding the psychiatric impact of federal and state segregation and disciplinary units in many settings. The following statement is largely a redacted, non-institution and non-inmate specific, version of a declaration which was submitted in September 1993 in Madrid v. Gomez

Dream a Little Dream of Us ... United for Success!

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Atmospheric chemistry of bioaerosols: heterogeneous and multiphase reactions with atmospheric oxidants and other trace gases.

Advances in analytical techniques and instrumentation have now established methods for detecting, quantifying, and identifying the chemical and microbial constituents of particulate matter in the atmosphere. For example, recent cryo-TEM studies of sea spray have identified whole bacteria and viruses ejected from ocean seawater into air. A focal point of this perspective is directed towards the reactivity of aerosol particles of biological origin with oxidants (OH, NO3, and O3) present in the atmosphere. Complementary information on the reactivity of aerosol particles is obtained from field investigations and laboratory studies. Laboratory studies of different types of biologically-derived particles offer important information related to their impacts on the local and global environment. These studies can also unravel a range of different chemistries and reactivity afforded by the complexity and diversity of the chemical make-up of these particles. Laboratory experiments as the ones reviewed herein can elucidate the chemistry of biological aerosols

Teaching in a Tea House

Librarians have made laudable efforts in developing information literacy instruction (ILI) programs, and in working with K-12 and public libraries, leveraging efforts to prepare students for college and university-level work, supporting lifelong learning. However, up to now few may have asked key questions across libraries of all types regarding a broader, more sequential approach to lifelong information literacy. What came before and what comes after your ILI efforts at your institution and beyond? Does your ILI build on what came before and offer additional foundation for what may come after? Who contributes to ILI, in which arenas, and how? How can we all best contribute to helping develop a populace with questioning, critical thinking, and researching knowledge and skills clearly understood and integrated into school, work, and personal/leisure activities and endeavors throughout a lifetime? LILi, a group of librarians from a spectrum of California libraries (university, college, community college, school, government, public and special libraries), is investigating IL definitions, standards and instruction in California. LILi began by mounting an online survey and promoting it to over 13,000 California libraries of all types. A quick review of initial responses revealed surprises, including this: librarians are teaching in a tea house! Other interesting findings are bound to surface as LILi analyzes this ILI snapshot and begins to… Explore what different types of libraries are teaching their users regarding IL; Identify gaps and overlaps among their efforts; Suggest at which age and educational level gaps and overlaps occur; Consider whether overlaps reinforce earlier instruction or not, and if so, what should be taught repeatedly and at which levels; Consider who should be responsible for teaching various IL competencies, and at which levels; Suggest what should be emphasized at various points throughout a lifelong ILI sequence

Sea Spray Aerosol: Where Marine Biology Meets Atmospheric Chemistry.

Atmospheric aerosols have long been known to alter climate by scattering incoming solar radiation and acting as seeds for cloud formation. These processes have vast implications for controlling the chemistry of our environment and the Earth's climate. Sea spray aerosol (SSA) is emitted over nearly three-quarters of our planet, yet precisely how SSA impacts Earth's radiation budget remains highly uncertain. Over the past several decades, studies have shown that SSA particles are far more complex than just sea salt. Ocean biological and physical processes produce individual SSA particles containing a diverse array of biological species including proteins, enzymes, bacteria, and viruses and a diverse array of organic compounds including fatty acids and sugars. Thus, a new frontier of research is emerging at the nexus of chemistry, biology, and atmospheric science. In this Outlook article, we discuss how current and future aerosol chemistry research demands a tight coupling between experimental (observational and laboratory studies) and computational (simulation-based) methods. This integration of approaches will enable the systematic interrogation of the complexity within individual SSA particles at a level that will enable prediction of the physicochemical properties of real-world SSA, ultimately illuminating the detailed mechanisms of how the constituents within individual SSA impact climate

Interactions of Water with Mineral Dust Aerosol: Water Adsorption, Hygroscopicity, Cloud Condensation, and Ice Nucleation

Mineral dust aerosol is one of the major types of aerosol present in the troposphere. The molecular level interactions of water vapor with mineral dust are of global significance. Hygroscopicity, light scattering and absorption, heterogneous reactivity and the ability to form clouds are all related to water–dust interactions. In this review article, experimental techniques to probe water interactions with dust and theoretical frameworks to understand these interactions are discussed. A comprehensive overview of laboratory studies of water adsorption, hygroscopicity, cloud condensation, and ice nucleation of fresh and atmspherically aged mineral dust particles is provided. Finally, we relate laboratory studies and theoretical simulations that provide fundemental insights into these processes on the molecular level with field measurements that illustrate the atmospheric significance of these processes. Overall, the details of water interactions with mineral dust are covered from multiple perspectives in this review article.United States. National Aeronautics and Space Administration (Grant NNX13AO15G)Massachusetts Institute of Technology. Victor P. Starr Career Development Chai