Santa Barbara Research Articles

Santa barbara city college, Santa Barbara, CA, United states

We have observed that the different methods that people have used to promote recovery from Substance Use Disorders (SUD) all seem to produce a change in the Autonomic Nervous System.

Effect of particle size of nanoscale zero–valent copper on inorganic phosphorus adsorption–desorption in a volcanic ash soil

Zero–valent copper engineered nanoparticles (Cu–ENPs) released through unintentional or intentional actions into the agricultural soils can alter the availability of inorganic phosphorus (IP) to plants. In this study, we used adsorption–desorption experiments to evaluate the effect of particle size of 1% Cu–ENPs (25 nm and 40–60 nm) on IP availability in Santa Barbara (SB) volcanic ash soil. X–Ray Diffraction results showed that Cu–ENPs were formed by a mixture of Cu metallic and Cu oxides (Cu2O or/and CuO) species, while specific surface area values showed that Cu–ENPs/25 nm could form larger aggregate particles compared to Cu–ENPs/40–60 nm. The kinetic IP adsorption of SB soil without and with 1% Cu–ENPs (25 nm and 40–60 nm) followed the mechanism described by the pseudo–second–order (k2 = 0.45–1.13 x 10−3 kg mmol−1 min−1; r2 ≥ 0.999, and RSS ≤ 0.091) and Elovich (α = 14621.10–3136.20 mmol kg−1 min−1; r2 ≥ 0.984, and RSS ≤ 69) models. Thus, the rate–limiting step for IP adsorption in the studied systems was chemisorption on a heterogeneous surface. Adsorption equilibrium isotherms without Cu–ENPs were fitted well to the Freundlich model, while with 1% Cu–ENPs (25 nm and 40–60 nm), isotherms were described best by the Freundlich and/or Langmuir model. The IP relative adsorption capacity (KF) was higher with 1% Cu–ENPs/40–60 nm (KF = 110.41) than for 1% Cu–ENPs/25 nm (KF = 74.40) and for SB soil (KF = 48.17). This study showed that plausible IP retention mechanisms in the presence of 1% Cu–ENPs in SB soil were: i) ligand exchange, ii) electrostatic attraction, and iii) co–precipitate formation. The desorption study demonstrated that 1% Cu–ENPs/40–60 nm increased the affinity of IP in SB soil with a greater effect than 1% Cu–ENPs/25 nm. Thus, both the studied size ranges of Cu–ENPs could favor an accumulation of IP in volcanic ash soils.

Hard template derived N, S dual heteroatom doped ordered mesoporous carbon as an efficient electrocatalyst for oxygen reduction reaction

At present, a low-cost and efficient electrocatalyst is vital to conquering the sluggish oxygen reduction reaction (ORR) in fuel cells. In particular, N and S dual heteroatom doped mesoporous carbon (NSMC) catalysts are believed to be one of the best ORR catalyst options due to the distribution of nitrogen, sulfur sites. In this work, for NSMC synthesis we employed 2D Santa barbara amorphous (SBA-15) silica as support material and L-cysteine as N and S dual precursor. The optimal loading of NSMC-0.4, reveals the high concentration of defect sites (ID/IG = 0.99), pyridinic (21.41 at. %), graphitic-N (50.27 at. %), thiophene-S (77.16 at. %) sites on MC surface resulting in an improved ORR performance. The NSMC-0.4 showed more positive onset potential of 0.78 V vs. RHE, half-wave potential of 0.68 V, current density of 2.8 mA/cm2, peroxide production of 81%, followed by two-electron reduction process and lower Rct of 10 Ω/cm2 in an alkaline electrolyte solution. However, NSMC-0.6 demonstrated the higher amount of peroxide selectivity (150%) due to the presence of a large quantity of pyrrolic-N sites. In addition, our work provide an excellent guide for the synthesis and design of NSMC for efficient peroxide production via an electrochemical synthesis route.

Selectivity oxidation of benzyl alcohol using mesoporous g-C3N4 catalysts prepared by hard template method

The mesoporous g-C3N4 catalyst was prepared by a hard template method using melamine (C and N source) and Santa barbara amorphous-16 (SBA-16) (silica source). The prepared catalysts were characterized by various techniques such as X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), N2-sorption study, Scanning electron microscope (SEM), and Transmission Electron Microscopy (TEM). The selective oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) was performed using SBA-16, bulk (B) and mesoporous (M) (g-C3N4). The g-C3N4-(M) catalyst exhibited superior catalytic performance of 97% and BzH selectivity of 95% under optimized reaction conditions (100 °C, Tertbutylhydroperoxide (TBHP) 1 ratio, 2.5 h, and 0.1 g of catalysts). The reusability of the g-C3N4-(M) catalyst was examined up to the sixth cycle, and it revealed that the prepared g-C3N4-(M) catalyst is highly stable, which is associated with the physicochemical properties of catalyst.

Extreme winds and fire weather in coastal Santa Barbara County,CA: An observational analysis

AbstractCoastal Santa Barbara (SB) County in Southern California, characterized by a Mediterranean climate and complex topography, is a region prone to downslope windstorms that create critical fire weather conditions and rapidly spread wildfires. The Santa Ynez Mountains, oriented from east to west, rise abruptly from the coast, separating air masses from the ocean and the Santa Ynez Valley. The juxtaposition of these geographic features generates spatiotemporally variable wind regimes. This study analyzes diurnal‐to‐seasonal wind cycles and extremes in this region using hourly data from eight weather stations and four buoys for the period 1998–2019. Data from a vertical wind profiler at the Santa Barbara airport in Goleta, CA was extracted from August 2016 to September 2020. Air temperature, dew point temperature, and the Fosberg fire weather index are examined at land stations. We show that cycles in wind speed vary spatiotemporally; mountain (valley and coastal) stations exhibit a pronounced semiannual (annual) cycle, and wind maxima is observed during the evening (afternoon) at mountain (valley and coastal) stations. Differences in wind speed percentiles were evident among stations, particularly at and above the 75th percentile. Strong winds recorded at buoys were significantly correlated (betweenr = 0.3–0.5) to land stations. However, cross‐correlational analysis did not reveal any temporal lags between mountain stations and buoys. Distributions of temperature and dew point during extreme winds differed between east and west mountain stations. Significant fire weather conditions were most frequent at mountain stations in Refugio and Montecito, with 5% occurrence in the spring and over 3% occurrence in fall. Weaker summertime winds lowered fire weather conditions at Montecito in the summer.

Green sonosynthesis of pyridopyrimidines using heterogeneous Pd‐containing catalysts anchored on a hybrid organic–inorganic surface of SBA‐15

AbstractA novel functionalized Santa barbara amorphous (SBA)‐15 mesoporous silica has been prepared as a catalyst and characterized using X‐ray diffraction spectroscopy, Fourier‐transform infrared spectroscopy, field‐emission scanning electron microscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, temperature programmed desorption, N2 adsorption analysis, and differential thermogravimetric analysis (TGA). The yield of the catalyst has been investigated by synthesizing a wide range of polyfunctionalized pyridopyrimidines. This method provides several advantages including excellent yields in short times, the reusability of the catalyst, low catalyst loading, and mild reaction conditions.

Climatology of Sundowner winds in coastal Santa Barbara, California, based on 30 yr high resolution WRF downscaling

Sundowner winds are a type of downslope windstorms observed on the southern slopes of the Santa Ynez Mountains (SYM) in Santa Barbara, southern California. The name “Sundowner” is due to the onset of strong winds near sunset. Sundowner winds can reach gale force and are extremely dangerous during wildfires. This study presents a climatology of Sundowners based on a 30 yr high spatiotemporal resolution dataset obtained with the Weather Research and Forecasting model. Combined empirical orthogonal function (EOF) analysis of hourly zonal and meridional winds (10 m) with 1 km grid spacing is performed to characterize the diurnal variability of surface winds. The first two eigenmodes (EOF-1, EOF-2) (58% of total variance) characterize the variability of surface winds in the western and eastern parts of the SYM, respectively. The hourly percentiles of the frequency distribution of the first two time coefficients (PC1, PC2) are used to identify three types of Sundowner regimes. The western (eastern) regime occurs when surface winds project strongly on EOF-1 (EOF-2) but not on EOF-2 (EOF-1). The western regime is characterized by a strong coastal jet around Point Conception with northwesterly winds extending into the Santa Barbara Channel. In contrast, a weak coastal jet not extending into the Santa Barbara Channel is observed in the eastern regime. In the Santa Barbara (SBA) regime, hourly surface winds project strongly on both EOF-1 and EOF-2. The western regime occurs more frequently than the eastern and SBA regimes and peaks during March-May. The eastern regime has maximum in January-February, whereas the SBA regime has a seasonal cycle similar to the western regime. Horizontal and vertical structures of winds and potential temperature show that the lee slope jet and mountain wave activity on the SYM exhibit strong spatial variations in the three regimes.

Synthesis, characterization, and applications of novel Co(II)‐pyridoxalphosphate‐Schiffbase/SBA‐15 as a nanocatalyst for the green synthesis of benzothiazole heterocycles

AbstractMesoporous heterogeneous santa barbara amorphous (SBA)‐15‐supported cobalt complex, as a novel nanocatalyst containing N–O chelating Schiff‐base ligand was successfully synthesized by the reaction of SBA‐15 and Cobalt(II)‐Schiff‐base complex. The Co(II)‐Schiff base complex also was prepared for the first time, by the reaction of pyridoxal 5′‐phosphate or PLP (biological active form of vitamin B6), 3‐(aminopropyl)‐triethoxysilane in methanol that complexation with CoCl2. The subsequent grafting of entitled complex to SBA‐15 afforded Co(II)‐PLP‐Schiff base/SBA‐15 mesoporous catalyst. Characterization of the product was carried out with powder X‐ray diffraction, Brunauer–Emmett–Teller nitrogen adsorption–desorption, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, atomic absorption spectroscopy, and inductively coupled plasma, Fourier‐transform infrared spectroscopy. The results revealed the retention of the textural properties and hexagonally uniform structures of SBA‐15 during the grafting procedure. This nanocatalyst was applied successfully for one‐pot synthesis of various benzothiazole heterocycles under green conditions. This catalyst is an active, reusable, and stable nanomaterial with no leaching of metal ions to the reaction medium. It was used for the synthesis of desired benzothiazole heterocycles by the cyclo‐condensation of aryl‐aldehydes with 2‐aminothiophenol with good to excellent yields and under green conditions.

The Sundowner Winds Experiment (SWEX) Pilot Study: Understanding Downslope Windstorms in the Santa Ynez Mountains, Santa Barbara, California

AbstractSundowner winds are downslope gusty winds often observed on the southern slopes of the Santa Ynez Mountains (SYM) in coastal Santa Barbara (SB), California. They typically peak near sunset and exhibit characteristics of downslope windstorms through the evening. They are SB’s most critical fire weather in all seasons and represent a major hazard for aviation. The Sundowner Winds Experiment Pilot Study was designed to evaluate vertical profiles of winds, temperature, humidity, and stability leeward of the SYM during a Sundowner event. This was accomplished by launching 3-hourly radiosondes during a significant Sundowner event on 28–29 April 2018. This study showed that winds in the lee of the SYM exhibit complex spatial and temporal patterns. Vertical profiles showed a transition from humid onshore winds from morning to midafternoon to very pronounced offshore winds during the evening after sunset. These winds accompanied mountain waves and a northerly nocturnal lee jet with variable temporal behavior. Around sunset, the jet was characterized by strong wind speeds enhanced by mountain-wave breaking. Winds weakened considerably at 2300 PDT 29 April but enhanced dramatically at 0200 PDT 29 April at much lower elevations. These transitions were accompanied by changes in stability profiles and in the Richardson number. A simulation with the Weather Research and Forecasting (WRF) Model at 1-km grid spacing was examined to evaluate the skill of the model in capturing the observed winds and stability profiles and to assess mesoscale processes associated with this event. These results advanced understanding on Sundowner’s spatiotemporal characteristics and driving mechanisms.

A highly sensitive electrochemical sensor for the determination of methanol based on PdNPs@SBA-15-PrEn modified electrode

In this study, a novel electrochemical sensor for the determination of methanol based on palladium nanoparticles supported on Santa barbara amorphous-15- PrNHEtNH2 (PdNPs@SBA-15-PrEn) as nanocatalysis platform is presented. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electrochemical methods are employed to characterize the PdNPs@SBA-15-PrEn nanocomposite. The Nafion-Pd@SBA-15-PrEn modified glassy carbon electrode (Nafion-PdNPs@SBA-15-PrEn/GCE) displayed the high electrochemical activity and excellent catalytic characteristic for electro-oxidation of methanol in an alkaline solution. The electro-oxidation performance of the proposed sensor was investigated using cyclic voltammetry (CV) and amperometry. The sensor exhibits a good sensitivity of 0.0905 Amol−1 Lcm−2, linear range of 20–1000 μM and the corresponding detection limit of 12 μM (3σ). The results demonstrate that the Nafion-PdNPs@SBA-15-PrEn/GCE has potential as an efficient and integrated sensor for methanol detection.

Adsorption of methylene blue from an aqueous dyeing solution by use of santa barbara amorphous-15 nanostructure: Kinetic and isotherm studies

Santa Barbara Amorphous-15(SBA-15) nanoparticles were utilized as the inexpensive and effective adsorbents to remove methylene blue dye from the aqueous solution.SBA-15 was created by Zhao et al method. Infrared spectroscopy, X-ray diffraction and scanning electron microscopy (SEM) were used for the evaluated physical properties of SBA-15. The results of diffraction X-ray indicated that was the crystalline structure for it. Also IR spectroscopy indicated was a silica the whole structure of the groups and SEM image verify the structure of relatively identical particles size of SBA-15. Factors affecting adsorption including the amounts of adsorbent, pH and contact time were investigated by a SBA-15 nanomaterial design. The extent of dye removal enhanced with increasing initial dye concentration and pH from 4 to 10. The higher percentage adsorption were obtained under optimum conditions of variables (sorbent dose of 200 mg/liter, initial MB concentration 10 mg/liter, initial pH of 10 and temperature of 25oC). Maximum adsorption happened after the 2 hour and the kinetic processes of the dyes adsorption were described by applying the pseudo-first-order and the pseudo-second-order and the relatively High correlation with the kinetic Ellovich models. It was found that the pseudo-second-order models kinetic equation described the data of dye adsorption with a good correlation (R2>0.999) which indicated chemisorption mechanism. Freundlich and Langmuir adsorption models were investigated in conditions of variables (adsorbent dose 0.01 gr/liter, MB concentration 10, 20, 30 mg/liter, pH of 4, 7, 10, contact time 90 min and temperature of 27oC). The adsorption data were represented by Langmuir isotherm model. These values are higher than the adsorption capacities of some other adsorbents that have recently been published in the literature.

WRF simulation of downslope wind events in coastal Santa Barbara County

The National Weather Service (NWS) considers frequent gusty downslope winds, accompanied by rapid warming and decreased relative humidity, among the most significant weather events affecting southern California coastal areas in the vicinity of Santa Barbara (SB). These extreme conditions, commonly known as “sundowners”, have affected the evolution of all major wildfires that impacted SB in recent years. Sundowners greatly increase fire, aviation and maritime navigation hazards and are thus a priority for regional forecasting. Currently, the NWS employs the Weather Research Forecasting (WRF) model at 2km resolution to complement forecasts at regional-to-local scales. However, no systematic study has been performed to evaluate the skill of WRF in simulating sundowners.This research presents a case study of an 11-day period in spring 2004 during which sundowner events were observed on multiple nights. We perform sensitivity experiments for WRF using available observations for validation and demonstrate that WRF is skillful in representing the general mesoscale structure of these events, though important shortcomings exist. Furthermore, we discuss the generation and evolution of sundowners during the case study using the best performing configuration, and compare these results to hindcasts for two major SB fires. Unique, but similar, profiles of wind and stability are observed over SB between case studies despite considerable differences in large-scale circulation, indicating that common conditions may exist across all events. These findings aid in understanding the evolution of sundowner events and are potentially valuable for event prediction.

Aplicación de índices bióticos de calidad de agua en cuatro arroyos de la cuenca del río Gualeguaychú (Entre Ríos, Argentina)

La acelerada pérdida de calidad de agua en ríos y arroyos, está asociada con pérdida de biodiversidad, por tanto la determinación de parámetros de calidad de agua en estos sistemas acuáticos es fundamental y urgente. El objetivo del trabajo fue estudiar la calidad de agua de cuatro arroyos de la cuenca del río Gualeguaychú, utilizando bioindicadores. El área de estudio se encuentra en la Pampa Mesopotámica, donde se desarrollan actividades agrícolas y ganaderas, y está sujeta a una profunda transformación de sus ecosistemas desde hace dos décadas. Entre 2013-2015, se estudiaron los arroyos García (GA), Los Perros (LP), Santa Bárbara (SB) y La Cañada (LC). Se realizaron muestreos periódicos determinando variables fisicoquímicas, de ribera, macroinvertebrados bentónicos y de audal. Se aplicaron los índices Biótico de Familias (IBF), Biological Monitoring Working Party (BMWP), el Índice Biótico Pampeano (IBPamp) y el Índice de Calidad de Ribera (ICR). Se recolectaron e identificaron 10007 organismos de 67 taxones. Los índices BMWP e IBF determinaron que existe contaminación de severa a intermedia, el IBPamp determinó escasa contaminación. Según el ICR, los arroyos LP, GA y SB, poseen alteraciones en la ribera; LC, no posee alteraciones. Los índices bióticos de calidad de agua y ribera resultaron una herramienta muy valiosa para determinar el estado ecológico de los cuerpos de agua de la zona, sin embargo, debido a la particularidades de la Pampa Mesopotámica, es necesario realizar ajustes que permitan una mejor interpretación de la diversidad regional y de sus variaciones en el espacio y en el tiempo.

Effect of silica/titania ratio on enhanced photooxidation of industrial hazardous materials by microwave treated mesoporous SBA-15/TiO2 nanocomposites

In this study microwave assisted technique has been adopted for the synthesis of different weight ratios of TiO2 dispersed on Santa barbara amorphous-15 (SBA-15) support. Morphological study revealed TiO2 particles (4–10 nm) uniformly distributed on SBA-15 while increases in SBA-15 content results in higher specific surface area (524–237 m2/g). The diffraction intensity of 101 plane of anatase polymorph was seen increasing with increase in TiO2 ratio. All the photocatalysts were having a mesoporous nature and follow the Langmuir IV isotherm, SBA-15 posses the highest pore volume (0.93 cm3 g−1) which consistently decreased with TiO2 content and was lowest (0.50 cm3 g−1) in case of 5 wt% of TiO2 followed by P25 (0.45 cm3 g−1) while pore diameter increased after TiO2 incorporation due to pore strain. The photocatalytic activity of the nanocomposites were analysed for the photodegradation of alizarin dye and pentachlorophenol under UV light irradiation. The reaction kinetics suggested the highest efficiency (98 % for alizarin and 94 % for PCP) of 5 wt% TiO2 compared to other photocatalysts, these nanocomposites were reused for several cycles, which is most important for heterogeneous photocatalytic degradation reaction. This study demonstrates the synthesis of silica embedded TiO2 nanocomposites by microwave assisted technique and their catalytic influence on degradation of organic dyes and pollutants. Higher loading of titania (SBA-15/TiO2, 1:5) results better catalytic performance than commercial nano TiO2 (P25).

Food & Health of a Full Earth

DAVID TILMAN, a Fellow of the American Academy since 1995, is Regents Professor and McKnight Presidential Chair in the College of Biological Sciences and Director of the Cedar Creek Ecosystem Science Reserve at the University of Minnesota. He is also a Professor at the Bren School of Environmental Science and Management at the University of California, Santa Bar bara. He is the author of Functional Consequences of Biodiversity: Empirical Prog ress and Theoretical Extensions (with Ann P. Kinzig and Stephen Pacala, 2002), Plant Strategies and the Dynamics and Structure of Plant Com munities (1988), Resource Compe tition and Com mu nity Structure (1982), and more than two hundred scienti1⁄2c papers. The world is about to be full. Within two or three generations, our global population–currently seven billion people–will level off between ten billion and eleven billion. Although humanity steadily increased in size as it spread from Africa across the habitable lands of Earth, it was not until the 1920s that this growth turned explosive. In 1850, the global population was 1.1 billion people, on a trajectory to double every one hundred 1⁄2fty years. This low growth rate held until World War I, after which the emergence of modern medicine and sanitation led to increasingly rapid annual growth rates. When this rate hit its peak in 1970, the global population was on course to double every thirty-1⁄2ve years. Now, our population growth rate–though still positive–is steadily slowing as we approach our maximum Earth density. What will life be like on a full Earth? Can we provide eleven billion people with a secure supply of nutritious foods? Is it even possible for so many people to live on Earth without destroying its remaining natural ecosystems? Agriculture already accounts for more than 25 percent of global greenhouse gas emissions and occupies 55 percent of Earth’s iceand desert-free land area. Can we feed up to eleven billion people and still maintain a livable climate? Will the ethics, customs, rights, and laws established when the world had one billion or fewer people adequately guide a world that is ten times more populous? Or will new ethical principles be needed to live sustainably in this new context?

Correction to “Tough Coating Proteins: Subtle Sequence Variation Modulates Cohesion”

Addition/Correction pubs.acs.org/Biomac Correction to “Tough Coating Proteins: Subtle Sequence Variation Modulates Cohesion” Saurabh Das, Dusty R. Miller, Yair Kaufman, Nadine R. Martinez Rodriguez, Alessia Pallaoro, Matthew J. Harrington, Maryte Gylys, Jacob N. Israelachvili,* and J. Herbert Waite* Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on September 10, 2015 | http://pubs.acs.org Publication Date (Web): June 17, 2015 | doi: 10.1021/acs.biomac.5b00759 Biomacromolecules, 2015, 16 (3), 1002−1008. DOI:10.1021/bm501893y F igure 3 caption corrected. Corrections highlighted in bold. Figure 3. pH dependence of Fe 3+ -mediated cohesion between two symmetric mfp-1 (Mc) films. Representative force vs distance plot showing the interaction between two symmetric mfp-1 (Mc) films deposited at 50 μg/mL in 0.1 M sodium acetate buffer, pH 5.5, 0.25 M KNO 3 , and 1 mM bis− tris with C Fe 3+ = 0 (gray) and 10 μM (blue) at pH 5.5. The cohesion between the mfp-1 (Mc) films was preserved after increasing the pH to 7.5 (magenta). (b) Representative force vs distance plot showing the interaction between two symmetric mfp-1 (Me) films deposited at 20 μg/mL in 0.1 M sodium acetate buffer, pH 5.5, 0.25 M KNO 3 , and 1 mM bis−tris with C Fe 3+ = 0 (gray) and 10 μM (blue) at pH 5.5. The surfaces showed a weak bridging cohesion (W c < 0.2 mJ/m 2 ) after increasing the pH to 7.5 (magenta). It should be noted that C Fe 3+ is the concentration of ferric cation in the bulk solution between the surfaces. Flushing with buffer at pH 7.5 removes iron from the bulk solution, however, to the extent that the preadsorbed protein films already had some bound Fe 3+ , the Dopa−Fe 3+ complexes will be present in them. Published: June 17, 2015 © 2015 American Chemical Society DOI: 10.1021/acs.biomac.5b00759 Biomacromolecules 2015, 16, 2254−2254

Adsorption properties of argon on Ti doped SBA-15.

Thermodynamic properties of argon on Ti doped Santa barbara amorphous No. 15 (SBA-15) were investigated in the temperature range of 77-89 K to understand the interaction of gas molecules with porous materials. When the total amount of adsorbed molecules is plotted as a function of the equilibrium vapor pressure of the adsorbed Ar, the results exhibit two distinct isotherm steps. The first step appears at the beginning of the isotherm while the second step locates at 0.7 of the normalized pressure. The existence of the second isotherm step which spanned in the normalized pressure from 0.7 to 0.9 is confirmed when the isotherm data were plotted in terms of the 2-dimensional compressibility values. The total amount of adsorbed molecules forming the second isotherm step is 2.5 times greater than the one for the first step. These adsorption behaviors are typical patterns noted from porous materials and far different from the ones observed from non-pore materials. Our observations demonstrate that most of adsorbed molecules reside in the pores and the height of the second isotherm step is strongly associated with filling pores with gas molecules.

Evaluating Cross-Channel Exchange in the Santa Barbara Region: Experimental Data on Acorn Processing and Transport

mash of southern California were one of the most complex hunter-gatherer groups in North America (Arnold 2001; Gamble 2008). A key component of Chumash complexity concerns the intensive exchange that occurred across the Santa Barbara Channel (Figure 1). Over the course of several centuries starting around 900 C.E., Chumash bead specialists on Santa Cruz Island produced millions of shell beads that were exported to the mainland coast and traded throughout southern California and the Great Basin (Bennyhoff and Hughes 1987; Eerkens et al. 2005). In exchange for such beads, it has often been suggested that the Island Chumash received terrestrial plant foods, which were rare on the islands but abundant on the mainland coast (Arnold 1992, 2001; Gamble 2008; Kennett 2005). Of the many plant foods that might have been traded to the islands, acorns are among the most frequently mentioned in ethnohistoric literature (King 1976; Timbrook 2007) and represent one of the most easily storable and transportable food items available to the Chumash. As such, acorns can serve as a good proxy for the evaluation of food transport from the mainland to the islands. Numerous recent scholarly works have mentioned acorns as representing an important mainland contribution to Chumash exchange systems (Arnold 2001, 2012; Gamble 2008; Kennett 2005). Despite the prominence of acorns in the literature, archaeological evidence for their exchange across the Santa Barbara Channel is extremely thin. This problem is most apparent when we look at evidence from macrobotanical studies conducted on Santa Cruz Island (Martin 2010; Martin and Popper 2001), which have found only a handful of acorns after decades of archaeological work. Additionally, bedrock mortars are extremely rare on the islands (Hudson and Blackburn 1983:102), a pattern that we would not expect to see if islanders were importing large amounts of acorns and grinding them into meal. EVALUATING CROSS-CHANNEL EXCHANGE IN THE SANTA BARBARA REGION: EXPERIMENTAL DATA ON ACORN PROCESSING AND TRANSPORT

Adsorption Behaviors of Nitrogen on Ti Doped SBA-15

Thermodynamic properties of nitrogen on Ti doped santa barbara amorphous No. 15 samples having large pore sizes in an order of a few micrometers were studied by analyzing the adsorption isotherm data obtained near the triple point (63.15 K). A series of adsorption data as a function of the normalized pressure revealed that nitrogen forms two distinctive isotherm steps. The first step represents the adsorption behavior on surface while the second step is believed to be responsible for the interaction of gas molecules in a capillary, so called a 'capillary condensation.' The existence of a hysteresis measured between adsorption and desorption isotherms at 77.3 K evidenced that gas molecules fill the pores in the sample. Plots of 2-dimensional compressibility values that were calculated in terms of change of adsorbed molecules with respect to the change of measured pressure exhibit a prominent peak near the second isotherm step supporting that the pores are filled with adsorbed molecules. A careful examination of the second isotherm step revealed that the amount of adsorbed molecules increased at temperatures below the triple point while it decreased above the triple point, and such a phenomenon is responsible for the geometrical confinement of gas molecules in porous materials.

The ancestry and magmatic evolution of Archaean TTG rocks of the Quadrilátero Ferrífero province, southeast Brazil

Combined LA-ICP-MS and SHRIMP U–Pb ages from Quadrilátero Ferrífero (QF) province reveals for the first time three main periods of TTG magmatism in the southern part of the São Francisco Craton (Brazil). These periods – described here as the Santa Barbara (SB), Rio das Velhas I (RVI) and Rio das Velhas II (RVII) events – embody a significant part of a protracted tectonomagmatic history of the Craton, spanning from 3220 to 2770Ma. The initial stages of TTG magmatism (the SB event) led to formation of a core of Palaeoarchaean TTG crust via magmatic additions of juvenile felsic rocks into mafic–ultramafic rocks, at ca. 3212–3210Ma. The following event (RVI event) saw the growth of this Palaeoarchaean core into a more composite, polydefomed continental segment through magmatic additions of juvenile TTG rocks and tectonic accretion of mafic–ultramafic greenstone belt terrains. Our U–Pb data and regional constraints suggest that much of the TTG crust exposed in the QF region today was produced during the RVI event, between 2930 and 2900Ma. The final stages of TTG crust production (RV II event) were marked by convergence-related magmatism, affecting an extensive Palaeo- to Mesoarchaean continental block (The RVI block). The timing and duration of the latest TTG event coincides with the felsic volcanism and deposition of turbiditic wackes of the main greenstone belt sequence.