Results of Millikan Library Forced Vibration Testing

This report documents an investigation into the dynamic properties of Millikan Library under forced excitation. On July 10, 2002, we performed frequency sweeps from 1 Hz to 9.7 Hz in both the East-West (E-W) and North-South (N-S) directions using a roof level vibration generator. Natural frequencies were identified at 1.14 Hz (E-W fundamental mode), 1.67 Hz (N-S fundamental mode), 2.38 Hz (Torsional fundamental mode), 4.93 Hz (1st E-Wovertone), 6.57 Hz (1st Torsional overtone), 7.22 Hz (1st N-S overtone), and at 7.83 Hz (2nd E-Wovertone). The damping was estimated at 2.28% for the fundamental E-W mode and 2.39% for the N-S fundamental mode. On August 28, 2002, a modal analysis of each natural frequency was performed using the dense instrumentation network located in the building. For both the E-W and N-S fundamental modes, we observe a nearly linear increase in displacement with height, except at the ground floor which appears to act as a hinge. We observed little basement movement for the E-W mode, while in the N-S mode 30% of the roof displacement was due to basement rocking and translation. Both the E-W and N-S fundamental modes are best modeled by the first mode of a theoretical bending beam. The higher modes are more complex and not well represented by a simple structural system

The Observed Wander of the Natural Frequencies in a Structure

The Southern California Seismic Network (scsn) has recently installed seismic stations in two buildings on the Caltech campus (Millikan Library and the Broad Center). Continuous real-time accelerometer data from these structures are now freely available to the community. This dataset provides a new opportunity to observe, and better understand, the variances in the primary dynamic property of a building system, its natural frequencies. Historical data (triggered strong-motion records, ambient and forced vibration tests) from the well-studied Millikan Library show dramatic decreases in natural frequencies, attributed mainly to moderately large local earthquakes. The current forced vibration east–west fundamental frequency is 22% lower than that originally measured in 1968. Analysis of the new continuous data stream allows the examination of other previously unrecognized sources of measurable change in the fundamental frequencies, such as weather (wind, rain, and temperature), as well as nonlinear building vibrations from small local and moderate regional earthquakes. Understanding these nonlinear shifts is one of the long-term goals of real-time building instrumentation and is critical if these systems are to be used as a postearthquake damage assessment tool

An ideal multifragmentation kinematics algorithm for nuclear physics, a binary reaction approach

A binary tree data structure is used to represent a nuclear multifragmentation, we constrict the tree in all but one of the leaf nodes. We use geometric arguments in the velocity space to graphically show how the tree can be solved by assigning velocity vectors in both the lab and CM systems at each of the nodes. An experimental comparison with a ternary reaction is also shown

Status of data analysis and preliminary results of the CHIFAR experiment

In the CHIFAR experiment, carried out at the INFN-LNS laboratory, we studied reactions between beams of Sn-124, Xe-124 and Sn-112, accelerated at 20 AMeV, and targets of Ni-64, Zn-64 and Ni-58 by using the CHIMERA multi-detector coupled to 10 telescopes of the FARCOS array. The main topics of the experiment are the competition between reaction mechanisms and the Intermediate Mass Fragment production phenomenon, aiming to extend towards the low energy regime the studies performed in previous CHIMERA experiments carried out at beam energy of 35 AMeV. Status of data analysis arid preliminary results will be presented

IDENTIFICACIÓN DE LA INTERACCIÓN DE MONOCITOS HUMANOS CON LAS LECTINAS DE Olneya tesota (IF2) Y Phaseolus vulgaris (PHA-L) POR CITOMETRÍA DE FLUJO

En este estudio se purificaron tres isolectinas (IF1, IF2 e IF3) de la lectina de palo fierro (PF2) a partir de las semillas de Olneya tesota, usando cromatografía de afinidad, seguida de intercambio iónico. La isoforma más abundante de PF2 (IF2) y la lectina de frijol PHA-L se utilizaron para identificar el patrón de reconocimiento hacia células mononucleares de sangre periférica humana por citometría de flujo. Todos los tipos sanguíneos (ABO) presentaron un perfil de reconocimiento similar por las lectinas. En particular, las estructuras oligosacáridas de los monocitos circulantes fueron reconocidas por IF2 y PHA-L con mayor intensidad que el resto de las células. Los linfocitos B y T presentaron una menor interacción con IF2 que con PHA-L. Los receptores carbohidrato de IF2 pudieran ser usados como marcadores potenciales de monocitos en patologías asociadas con estas células

Identifying xenobiotic metabolites with in silico prediction tools and LCMS suspect screening analysis

Understanding the metabolic fate of a xenobiotic substance can help inform its potential health risks and allow for the identification of signature metabolites associated with exposure. The need to characterize metabolites of poorly studied or novel substances has shifted exposure studies towards non-targeted analysis (NTA), which often aims to profile many compounds within a sample using high-resolution liquid-chromatography mass-spectrometry (LCMS). Here we evaluate the suitability of suspect screening analysis (SSA) liquid-chromatography mass-spectrometry to inform xenobiotic chemical metabolism. Given a lack of knowledge of true metabolites for most chemicals, predictive tools were used to generate potential metabolites as suspect screening lists to guide the identification of selected xenobiotic substances and their associated metabolites. Thirty-three substances were selected to represent a diverse array of pharmaceutical, agrochemical, and industrial chemicals from Environmental Protection Agency’s ToxCast chemical library. The compounds were incubated in a metabolically-active in vitro assay using primary hepatocytes and the resulting supernatant and lysate fractions were analyzed with high-resolution LCMS. Metabolites were simulated for each compound structure using software and then combined to serve as the suspect screening list. The exact masses of the predicted metabolites were then used to select LCMS features for fragmentation via tandem mass spectrometry (MS/MS). Of the starting chemicals, 12 were measured in at least one sample in either positive or negative ion mode and a subset of these were used to develop the analysis workflow. We implemented a screening level workflow for background subtraction and the incorporation of time-varying kinetics into the identification of likely metabolites. We used haloperidol as a case study to perform an in-depth analysis, which resulted in identifying five known metabolites and five molecular features that represent potential novel metabolites, two of which were assigned discrete structures based on in silico predictions. This workflow was applied to five additional test chemicals, and 15 molecular features were selected as either reported metabolites, predicted metabolites, or potential metabolites without a structural assignment. This study demonstrates that in some–but not all–cases, suspect screening analysis methods provide a means to rapidly identify and characterize metabolites of xenobiotic chemicals

Optimisation of biomass, exopolysaccharide and intracellular polysaccharide production from the mycelium of an identified Ganoderma lucidum strain QRS 5120 using response surface methodology

Wild-cultivated medicinal mushroom Ganoderma lucidum was morphologically identified and sequenced using phylogenetic software. In submerged-liquid fermentation (SLF), biomass, exopolysaccharide (EPS) and intracellular polysaccharide (IPS) production of the identified G. lucidum was optimised based on initial pH, starting glucose concentration and agitation rate parameters using response surface methodology (RSM). Molecularly, the G. lucidum strain QRS 5120 generated 637 base pairs, which was commensurate with related Ganoderma species. In RSM, by applying central composite design (CCD), a polynomial model was fitted to the experimental data and was found to be significant in all parameters investigated. The strongest effect (p lt 0.0001) was observed for initial pH for biomass, EPS and IPS production, while agitation showed a significant value (p lt 0.005) for biomass. By applying the optimized conditions, the model was validated and generated 5.12 g/L of biomass (initial pH 4.01, 32.09 g/L of glucose and 102 rpm), 2.49 g/L EPS (initial pH 4, 24.25 g/L of glucose and 110 rpm) and 1.52 g/L of IPS (and initial pH 4, 40.43 g/L of glucose, 103 rpm) in 500 mL shake flask fermentation. The optimized parameters can be upscaled for efficient biomass, EPS and IPS production using G. lucidum

Volume reduction of water samples to increase sensitivity for radioassay of lead contamination

The World Health Organisation (WHO) presents an upper limit for lead in drinking water of 10 parts per billion ppb. Typically, to reach this level of sensitivity, expensive metrology is required. To increase the sensitivity range of low-cost devices, this paper explores the prospects of using a volume reduction technique of a boiled water sample doped with Lead-210 (210 Pb), as a means to increase the solute’s concentration. 210Pb is a radioactive lead isotope and its concentration in a water sample can be measured with e.g. High Purity Germanium (HPGe) detectors at the Boulby Underground Germanium Suite. Concentrations close to the WHO limit have not been examined. This paper presents a measurement of the volume reduction technique retaining 99±(9)% of 210Pb starting from a concentration of 1.9×10−6 ppb before reduction and resulting in 2.63×10−4 ppb after reduction. This work also applies the volume reduction technique to London tap water and reports the radioassay results from gamma counting in HPGe detectors. Among other radio-isotopes, 40K, 210Pb, 131I and 177Lu were identified at measured concentrations of 2.83×103 ppb, 2.55×10−7 ppb, 5.06×10−10 ppb and 5.84×10−10 ppb in the London tap water sample. This technique retained 90±50% of 40K. Stable lead was inferred from the same water sample at a measured concentration of 0.012 ppb, prior to reduction

Characterization of germanium detectors for the first underground laboratory in Mexico

This article reports the characterization of two High Purity Germanium detectors performed by extracting and comparing their efficiencies using experimental data and Monte Carlo simulations. The efficiencies were calculated for pointlike γ-ray sources as well as for extended calibration sources. Characteristics of the detectors such as energy linearity, energy resolution and full energy peak efficiencies are reported from measurements performed on surface laboratories. The detectors will be deployed in a γ-ray assay facility that will be located in the first underground laboratory in Mexico, Laboratorio Subterr'aneo de Mineral del Chico (LABChico), in the Comarca Minera UNESCO Global Geopark [1]