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Two-level systems (TLS) coupled to waveguides are a fundamental paradigm for light-matter interactions and quantum networks. We introduce and experimentally demonstrate a method to tune the interaction between a TLS, implemented as a flux qubit, and a transmission line waveguide from a decoupled state to a coupling strength that is a significant fraction of the TLS transition frequency, near the ultra-strong coupling regime. The coupling, controlled via magnetic flux, is described by a normalized coupling strength $\alpha$ that is measured to range between $6.2\times10^{-5}$ and $2.19\times10^{-2}$, with larger attainable maximum values predicted by a circuit model of the device. This system enables future investigations in the dynamics of the spin-boson model, microwave photonics, and relativistic quantum information., Comment: Main: 6 pages, 5 figures. Supplementary Information: 7 pages, 4 figures

We consider the random hypergraph on a finite vertex set by choosing each set of vertices as an hyperedge independently at random. We express the probability distributions of the (lower-)associated simplicial complex and the (lower-)associated independence hypergraph of the random hypergraph in terms of the probability distributions of certain random simplicial complex and certain random independence hypergraph of Erd\"os-R\'enyi type. We construct a graded structure of the map algebra explicitly and give algorithms to generate random hypergraphs and random simplicial complexes., Comment: 20 pages

Inner-shell K$\alpha$ x-ray lasers have been created by pumping gaseous, solid, and liquid targets with the intense x-ray output of free-electron-lasers (FELs). For gaseous targets lasing relies on the creation of K-shell core-holes on a time-scale short compared with filling via Auger decay. In the case of solid and liquid density systems, collisional effects will also be important, affecting not only populations, but also line-widths, both of which impact the degree of overall gain, and its duration. However, to date such collisional effects have not been extensively studied. We present here initial simulations using the CCFLY code of inner-shell lasing in solid density Mg, where we self-consistently treat the effects of the incoming FEL radiation and the atomic kinetics of the Mg system, including radiative, Auger, and collisional effects. We find that the combination of collisional population of the lower states of the lasing transitions and broadening of the lines precludes lasing on all but the K$\alpha$ of the initially cold system. Even assuming instantaneous turning on of the FEL pump, we find the duration of the gain in the solid system to be sub-femtosecond., Comment: This paper has been submitted to Philosophical Transactions A

Natural products (NPs) are a valuable source for anti-inflammatory drug discovery. However, they are limited by the unpredictability of the structures and functions. Therefore, computational and data-driven pre-evaluation could enable more efficient NP-inspired drug development. Since NPs possess structural features that differ from synthetic compounds, models trained with synthetic compounds may not perform well with NPs. There is also an urgent demand for well-curated databases and user-friendly predictive tools. We presented a comprehensive online web platform (InflamNat, http://www.inflamnat.com/ or http://39.104.56.4/) for anti-inflammatory natural product research. InflamNat is a database containing the physicochemical properties, cellular anti-inflammatory bioactivities, and molecular targets of 1351 NPs that tested on their anti-inflammatory activities. InflamNat provides two machine learning-based predictive tools specifically designed for NPs that (a) predict the anti-inflammatory activity of NPs, and (b) predict the compound-target relationship for compounds and targets collected in the database but lacking existing relationship data. A novel multi-tokenization transformer model (MTT) was proposed as the sequential encoder for both predictive tools to obtain a high-quality representation of sequential data. Experimental results demonstrated that the proposed predictive tools achieved the desired performance in terms of AUC.

Office and retail interior fittings have a relatively short service life of 5-7 years. In this context, composite materials are often used, hindering possibilities of reuse or recycling. This research explores novel bio-composite materials and subsequently a construction method for CO2-neutral, circular interior fittings for office spaces. Based on the potential of fungal mycelium as a rapidly renewable, regenerative, affordable, low-carbon building material, bio-composite construction methods are explored in conjunction with timber-based additive manufacturing using continuous fibres. As mycelium has potentially excellent sound-absorbing properties but low load-bearing capacity, composite construction of timber veneer and mycelium allows to increase the structural capabilities of resulting components, while relying entirely on bio-based value chains. We describe the production process as well as the material development, including robotically aided processes for additive manufacturing of veneer reinforcement grids and compatibility studies of different mycelial species and substrates, and their bonding capabilities with veneer. We further present initial results on the mechanical characterization of the composite material, and its comparison to conventional mycelium composites. Minimal structural, acoustic, and functional requirements for different interior fitting elements are studied and compared to the characteristics of the proposed composite, highlighting the range of applications of the presented wood-mycelium composites.

Monolithic catalysts are widely used in industrial catalysis. However, in the preparation of monolithic catalyst, the most important catalyst coating has the problems of low upload rate and poor uniformity. In the present work, the effects of acid treatment of carrier on the upload rate and the effects of size of slurry and dispersant on the uniformity of coating were investigated. The weight loss rate and water absorption rate of cordierite, slurry stability, coating upload rate and catalytic performance were also tested. Characterization analysis was carried out by means of BET, SEM, Zeta potential, the laser grain-size analyzer. The results showed that the optimal performance of cordierite carrier could be obtained by heating the cordierite carrier with 20% HCl for 3 h; the water absorption rate could increase for more than 48.0%, and the upload rate could reach 14.5%. Pearson test showed that there was a moderate positive correlation between water absorption rate and upload rate. It was also found that reducing the particle size of the slurry (1.47 microns) and adding 4% dispersant PAA could effectively improve the stability of the suspension and the uniformity of the coating. When 20% HCl was used to pretreat, the toluene catalytic activity of the monolith catalyst prepared by cordierite increased, in which T10 and T90 both increased for about 5 ℃. At the same time, reducing particle size and adding dispersant could also promote the catalytic degradation efficiency to a certain extent.

BackgroundThe partial pressure of oxygen (PaO2)/fraction of oxygen delivered (FIO2) ratio is the reference standard for assessment of hypoxemia in mechanically ventilated patients. Non-invasive monitoring with the peripheral saturation of oxygen (SpO2) is increasingly utilized to estimate PaO2 because it does not require invasive sampling. Several equations have been reported to impute PaO2/FIO2 from SpO2 /FIO2. However, machine-learning algorithms to impute the PaO2 from the SpO2 has not been compared to published equations.Research QuestionHow do machine learning algorithms perform at predicting the PaO2 from SpO2 compared to previously published equations?MethodsThree machine learning algorithms (neural network, regression, and kernel-based methods) were developed using 7 clinical variable features (n=9,900 ICU events) and subsequently 3 features (n=20,198 ICU events) as input into the models from data available in mechanically ventilated patients from the Medical Information Mart for Intensive Care (MIMIC) III database. As a regression task, the machine learning models were used to impute PaO2 values. As a classification task, the models were used to predict patients with moderate-to-severe hypoxemic respiratory failure based on a clinically relevant cut-off of PaO2/FIO2 ≤ 150. The accuracy of the machine learning models was compared to published log-linear and non-linear equations. An online imputation calculator was created.ResultsCompared to seven features, three features (SpO2, FiO2 and PEEP) were sufficient to impute PaO2/FIO2 ratio using a large dataset. Any of the tested machine learning models enabled imputation of PaO2/FIO2 from the SpO2/FIO2 with lower error and had greater accuracy in predicting PaO2/FIO2 ≤ 150 compared to published equations. Using three features, the machine learning models showed superior performance in imputing PaO2 across the entire span of SpO2 values, including those ≥ 97%.InterpretationThe improved performance shown for the machine learning algorithms suggests a promising framework for future use in large datasets.

Lignin, one of the most abundant natural polymers, has been extensively studied as liquid or solid additive in bituminous binders. Despite the fact the organosolv lignin in bitumen improves the overall resistance against oxidative aging, lignin could lead to binders of high thermal cracking sensitivity. In this study, a bio-based oil is implemented in a lignin modified bitumen to ameliorate characteristics, such as fatigue and thermal cracking resistance. Pressure aging vessel conditioning was applied to new binders formulated by different proportions of bio-oil to simulate the long-term aging. A series of rheological tests were performed. Based on the linear amplitude sweep test results, fatigue damage of lignin-bitumen could be reduced by increasing the oil content. According to relaxation test results, the addition of oil significantly decreased the ratio of residual stress and relaxation time. This study has shown preliminary conclusions on the use of bio-oil to improve the low-intermediate temperature performance of lignin-bitumen binders.

We demonstrate fiber few-mode interferometers based on a self-assembly surface corrugated grating using charged nano-particles. Initially, an abrupt taper (AT) was first created using a micro flame. The AT was then further outwardly stretched to make an elongated uniformed taper until the tapered diameter achieved a micron scale. The high order core modes (HOCMs) were excited at the AT and the optical path difference (OPD) among the modes was enlarged through the uniformed taper to achieve the few-mode interference effects seen. However, to significantly enhance the interference effects with higher extinction ratios (ER) over such a short length of interferometer, an external assisted grating was made using charged nanoparticles to form surface corrugated grating with a period, Λ, of approximately 14 μm. This intermediate period of the fiber grating was helpful in scattering and attenuating some unwanted high-order modes to change the optical characteristics of the few-mode interferometer (FMI). This FMI with a self-assembly fiber grating (SAFG) was further used to make fiber temperature sensors, with a maximum resonant wavelength shift of 4.6 nm, over a temperature range from 20–60 °C. The temperature sensitivity achieved was 112.6 pm/°C and the coefficient of determination, R2, was as high as 0.99, which revealed the high linearity of the results.

Background The systemic therapy is currently recommended for patients with oligometastatic prostate cancer, however the prognosis has not been satisfactory. Therefore, it is necessary to explore more effective treatment to improve the prognosis. Oligometastatic prostate cancer is a special subgroup in patients with advanced cancer. The paragrim of treatment is shifting to a more aggressive approach. Stereotactic body radiotherapy (SBRT) is an emerging treatment alternative for patients with oligometastases with minimal toxic effects. What’s more, accumulating studies have proved safety as well as feasibility of radical prostatectomy and local or metastasis-directed radiotherapy for oligometastatic patients. The aim of this phase I prospective trial is to demonstrate the early evidence of safety and feasibility of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy for treating oligometastatic prostate cancer Methods The patients with oligometastatic prostate cancer received 1 month of neoadjuvant androgen deprivation therapy (ADT) followed by metastasis-directed radition and abdominal or pelvic radiotherapy. Then offer radical prostatectomy at the interval of 4-8 weeks after radiotherapy and adjuvant ADT for 2 years. The primary endpoints of the study are safety as assessed by CTCAE 5.0 grading scale and intraoperative and postoperative day-30 morbidity. Secondary endpoints include the positive rate of post-operative edge, biochemical progression-free survival (bPFS), postoperative continence and sexual function recovery, quality of life (QoL), overall survival (OS) and adverse reactions of ADT. Discussion This is the first, phase I trial assessing the safety and feasibility of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy treatment for patients with oligometastatic prostate cancer. If positive, the results of this trial may help to design subsequent phase II trials exploring the role of metastasis-directed radiation and neoadjuvant hormone and radiation therapy followed by radical prostatectomy in the randomized controlled study.

We evaluate the performance of Gaussian Modulated Coherent State (GMCS) Continuous-Variable QuantumKey Distribution (CV-QKD), in terms of secure key rate, at different detector bandwidths. We illustrate theadvantages and limitations of high-speed CV-QKD systems using a general noise model in which we considervarious noise sources and their dependence upon detection bandwidth. Experimentally, the feasibility of highspeed CV-QKD is demonstrated by using a GHz bandwidth balanced homodyne detector (BHD) establishedwith commercially available components. We provide secure key rates of transmitted and local local oscillatorschemes under various clock rates.

The spray forming of thick, dissimilar steel clad tubes with the objective of achieving a high integrity metallurgical bond across the cladding-substrate interface able to withstand residual stresses and subsequent thermo-mechanical processing was investigated by large scale experiments, modelling and extensive microstructural characterization including microscopy, X-ray tomography, neutron scattering and mechanical testing. The simulated residual stress distributions across the cladding-substrate interface, accounting for any as-sprayed porosity and the distribution of martensitic and retained austenite phases, were compared with neutron diffraction measurements and differences used to infer the load transfer behaviour and thus the mechanical integrity of the interface. The mechanical properties of the interfaces were then also measured directly by shear testing. The link between substrate pre-heating, the spray forming temperature, and the resulting preform temperature, porosity, phase fractions, residual stress, strength and integrity of the interface were established and quantified explicitly.

Dynamic liquid-liquid-liquid microextraction coupled with ion-pair liquid chromatography (IP-LC) and photodiode array detection was developed and used for the extraction and analysis of chlorinated phenoxyacetic acids (CPAs) and chlorophenols (CPs) from water samples. An organic extraction solvent mixture was chosen to simultaneously and effectively extract both CPAs and CPs from aqueous samples. The method detection limit (MDL) ranged from 0.06 to 0.45 µg L(-1) with good reproducibility. The relative standard deviations were in the range of 2.6-6.5% at lower spiked concentrations and 3.0-4.6% at higher concentrations. Good linearity of analytes was achieved in the range of 0.5-500 µg L(-1). The acceptable relative recoveries (82.9-112.4%) for environmental waters revealed the presence of negligible matrix effects in the case of real samples. The applicability of this newly developed method was illustrated by determinations of CPAs and CPs in environmental water samples.

The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mantid are described., 16 pages, 11 figures, accepted for publication in Nuclear Inst. and Methods in Physics Research A

Rate constants directly measured from GC-analyzed method for SmI2 reduction of alkyl halides were obtained. The rates increase in the orders of primary, secondary, tertiary RX and RCl < RBr < RI as expected. 2-Heptanone was chosen as the partner of alkyl halide in the samarium Barbier reaction. In the absence of HMPA, the reaction orders of alkyl halide and ketone were determined as first and zero order, respectively.

The rate constants for the electron transfer of samarium diiodide to 2-heptanal, 2-methyl valeraldehyde and diphenyl sulfoxide were obtained for the first time. The reaction is first order in these substrates and there are hints that the reaction rate has a strong steric dependence. HMPA exhibited a profound catalytic effect but t-BuOH did not. The effect of temperature on reaction rates was also obtained.

This article describes a newly developed pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) method for the determination of vulcanized chloroprene/nitrile rubber (CR/NBR) material. The pyrolysis products of nitrile rubber and chlorophrene are identified and a reaction mechanism is proposed. The peak ratio of 1-chloro-4-(1-chloroethenyl)-cyclohexene and benzonitrile is used for quantitative measurement of CR/NBR composition in vulcanized samples. Good linearity (r2=0.99) and recovery (99.1%) were obtained. A series of vulcanized CR/NBR blended rubber materials were analyzed using this method. Adequate agreement between the estimated and the actual CR composition of these commercial rubber material is thus determined.

This paper presents summary statistics and a preliminary analysis of the success rate of loan modifications made in 2010 and January 2011 to residential mortgages securitized in private-label residential mortgage-backed securities. We find that these more recent private-label loan modifications had a higher overall success rate, compared to similar modifications made in earlier years. Consistent with prior literature, having a fixed-rate mortgage, a prime mortgage, a higher Fair Isaac & Company (FICO) credit score, and/or a lower interest rate at origination were positively correlated with lower redefault rates post-modification. Borrowers with interest-only and teaser-rate loans performed slightly better than other borrowers after receiving loan modifications. Similarly, modifications of purchase loans did worse not only than plain vanilla refinance loans, but also worse than debt consolidation and cash out refinance loans. Modifications of private-label mortgages in the four “sand states” – Arizona, California, Florida, and Nevada – did better than modifications in other parts of the United States, although the difference was small. Surprisingly, modifications of fully documented loans performed worse, while modified no-documentation loans performed best. Finally, we confirm that capitalizations of arrears performed worse than interest rate reductions and principal modifications, with the latter appearing to be the most effective.

Objective Evidence from pivotal clinical trials conducted more than a decade ago supports the use of antithrombotic therapy, particularly warfarin, for stroke prevention in atrial fibrillation (AF). Despite the wide dissemination of this evidence since that time, there is anecdotal evidence that utilisation of therapy remains suboptimal, especially in the target elderly population, which is reflected in the development of practice tools such as the TAG Clinical Indicator ('Antithrombotics in AF' Indicator 1.6, 2007). Therefore, the objective of this study was to determine the current utilisation of antithrombotic therapy for elderly patients with AF in the local setting, and to compare this utilisation with the results of a prior audit (AUDIT 1), as well as against the recommendations of the TAG Clinical Indicator (TAG IND). Setting A major teaching hospital in Sydney, Australia. Method A retrospective audit (AUDIT 2) of medical records of hospital inpatients (aged 65 years, with a significant diagnosis of AF), pertaining to admissions over the 12-month period 1st June 2006-31st May 2007, was conducted. Main outcome measure Proportion of patients receiving antithrombotic therapy at the point of discharge from hospital. Results A total of 201 patients (mean age 79.8 ± 7.8 years) were reviewed in AUDIT 2. Most (85%) patients received antithrombotic therapy (vs. 79.2%, AUDIT 1), with "warfarin ± antiplatelets" most frequently (46.3%) used (vs. 34.5%, AUDIT 1), followed by "aspirin ± other antiplatelet" (33.3% AUDIT 2 vs. 43.1% AUDIT 1). Patients aged 80 years were significantly less likely to receive warfarin therapy, compared to those

The dispersal capabilities of most plant species remain unknown. However, gaining basic dispersal information is a critical step for understanding species' geographical distributions and for predicting the likely impacts of future climate change. Dispersal mechanisms can indicate short- or long-distance dispersers, and highlight important biological interactions. To predict dispersal mechanisms for species where information is limited, we used generalized linear mixed models with basic life-history and ecological traits. Sets of models were created (using Australian species) for six dispersal categories: wind, unassisted, water, ant, vertebrate-ingestion and vertebrate-attachment dispersal mechanisms. We validated our models on the dispersal mechanisms of 50 Australian, 30 Californian, 30 Swiss plant species and a global compilation of 70 species. Growth form, seed mass and vegetation type were the main predictor variables. Our models predicted dispersal mechanisms for Australian and Californian plant species equally well (c. 70% correct) and to a lesser extent for the Swiss flora (c. 50% correct). Our models predicted observed dispersal mechanisms (c. 50% correct) equally well to inferred dispersal mechanisms (based on seed morphology). Synthesis. Our approach of using easily obtainable traits for predicting dispersal mechanisms of species allows dispersal information to be predicted for species where little is known. From here, the application of realistic dispersal curves to the predicted dispersal mechanisms will further understanding on the dispersal capabilities of species. © 2010 The Authors. Journal compilation © 2010 British Ecological Society.

Comparing the borrowing trends of owner-occupants versus investors in small multifamily properties reveals that investors may not engage in as much risky behavior as public sentiment leads one to expect. The authors investigate data from Southern New England and debunk several myths about the “irresponsible investor.”

The use of multidimensional fluorescence for detecting the effects of select pollutants on algal fluorescence and production is demonstrated. Multidimensional fluorescence is ideally suited to rapidly measure algal fluorescence generated by both chlorophyll a and accessory pigments, as well as any changes induced by pollutants. Laboratory cultured and natural algae samples from classes Chlorophyceae, Bacillariophyceae, and Cyanophyceae were exposed to substituted nitroaromatics and fluorescence spectra of the algae recorded. Notable spectroscopic changes and fluorescence quenching were observed. In addition, a novel method for rapidly preconcentrating dilute natural marine samples is described.

Four compounds were isolated from the root bark of Tripterygium wilfordii . One of them is a new compound whose structure was proved to be 1-hydroxy-2,5,8-trimethyl-9-fluorenone. The others were identified as 3-hydroxy-2-oxo-D: A-friedoolean-3-en-29-oic acid, oleana-11,13(18)-dien-3-one and 3-furoic acid, and their presence in this species is reported for the first time.

Daily serum sex hormone binding globulin (SHBG) levels were measured during normal ovulatory menstrual cycles in ten women between the ages of 23 and 34 by the method of precipitation with ammonium sulfate. The results showed that the mean SHBG levels in a cycle were quite different among individuals, but that the SHBG levels were constant during a certain menstrual cycle. Neither SHBG peaks on day LH-0 (52.64 +/- 19.89 nmol/L) (x +/- SD) nor the mean SHBG levels between the follicular phase (57.10 +/- 17.64 nmol/L) and luteal phase (64.75 +/- 23.42 nmol/L) show any significant differences. The correlations between the mean SHBG levels and the mean concentrations of progesterone (P), estradiol (E2) and androstenedione during the menstrual cycles were insignificant, whereas the mean SHBG levels during the follicular and luteal phase and on LH-0 day were significantly correlated with the mean concentrations of testosterone (t = 0.474; p less than 0.05). In ten women between the ages of 25 and 34, serum SHBG, E2, P, and levonorgestrel (LNG) levels were measured once on day 20-21 of the pretreatment cycle and 3 times/week during the 1st, and 2 times/week during the 6th treatment cycle after insertion of a levonorgestrel-releasing IUD (LNG-IUD). The mean value of SHBG in the pretreatment blood samples (62.09 +/- 23.09 nmol/L) was higher than that after insertion of the LNG-IUD (41.82 +/- 20.50 nmol/L), though the difference was not significant (p greater than 0.05). The correlation between LNG and SHBG was highly significant (r = 0.89, p less than 0.01). The significance of this correlation and the degree of suppression of ovarian function are discussed.

A double-blind comparative study of clomipramine and fluvoxamine was performed in 50 patients suffering from anxiety disorders (DSM-III). Patients were treated for 6 weeks with either 150 mg of clomipramine or 100 mg of fluvoxamine. The results show that both drugs at the dosages used are equipotent in reducing anxiety symptoms as assessed with the Hamilton Anxiety Scale and the Spielberger State-Trait Anxiety Inventory. Clomipramine differed from fluvoxamine in its efficacy with respect to associated depressive symptomatology in that it had a more pronounced effect on the Self Rating Depression Scale. The results support the hypothesis that brain serotonergic pathways are implicated in the pathophysiology of anxiety disorders, particularly in agoraphobia and panic disorders.

The design and preliminary charaterization of a novel fiber optic-based fluorimeter are reported. It includes a white light source, optical fibers for light transmission and an intensified photodiode array for detection. A bifurcated sensing configuration is used to transmit excitation and emission radiation to and from the analyte solution. Detection limits in the nanomolar range are reported for several test compounds.

A double-blind placebo-controlled study of 5-HTP and clomipramine was carried out on 45 patients suffering from anxiety disorders (DSM-III). Clomipramine has shown to be effective in that it induced significant improvement on all rating scales as compared to placebo. 5-HTP showed a moderate reduction of the symptomatology on the 90-item symptoms checklist (SCL-90) and the State Scale of the Spielberger State-Trait Anxiety Inventory. Clomipramine and 5-HTP differed in their efficacy in that 5-HTP did not affect the associated depressive symptomatology. The results support the hypothesis that brain serotonergic pathways are involved in the pathogenesis of anxiety disorders, particularly in agoraphobia and panic disorders.

The performance of a high‐pressure xenon arc lamp is enhanced by application of a combination of two techniques which (1) reduces noise due to arc wander and (2) increases the lamp intensity. Fluctuations in lamp intensity due to arc wander are minimized by the superimposition of an alternating current (ac) on the direct‐current (dc) source voltage in conjunction with detector averaging. Lamp intensity is increased by the application of a static magnetic field to the arc plasma. Arc stability and intensity are monitored indirectly by measuring arc‐excited Rhodamine B fluorescence. Data illustrating the effects of each technique individually and in combination are presented. Lamp output is typically maintained to less than 1% relative standard deviation while intensity is increased by as much as 127%.

Fiber optic remote sensing is a growing area of analytical chemistry. The application of such technology promises to augment much of today's process control, in-vivo medical diagnostics and environmental instrumentation. The use of optical fibers in chemical analysis is an attractive choice for many reasons. These include immunity to electromagnetic and RF interferences, low attenuation, ruggedness, and of course suitability for in-situ on line monitoring in hazardous and/or remote environments. Fluorescence spectroscopy is an inherently sensitive technique; however, single wavelength measurements can be limited for analysis of complicated multicomponent samples. In this regard, multidimensional fluorescence can be used to obtain additional information about the sample. In multidimensional fluorescence, the fluorescent measurement involves the use of multiple luminescence parameters to increase the specificity of the measurement. In this paper, the use of a newly designed fiber optic based multidimensional fluorometer to study the effects of various environmental pollutants on the spectral characteristics of marine phytoplankton is demonstrated.

Fluorescence spectroscopy is an inherently selective technique; however, single wavelength measurements can be limited for the analysis of complicated multicamponent samples or even a simple mixture with overlapping emission spectra. To overcome this limitation, multidimensional fluorescence measurements can beused to obtain additional information about the sample. The multidimensionalfluorescence measurement involves the use of multiple parameters to increase thespecificity of the measurement. In this laboratory, we are especially interestedin multiparametric measurements such as the Excitation -Emission Spectrum.In this paper a fiber optic based multidimensional fluorometer is examined along with a portable multichannel fluorometer in terms of sensitivity. Inaddition, specific applications incorporating the excitation- emission matrix arepresented. i. INTRODUCTION 1.1 MULTIDIMENSIONAL FLUOR The acceptance of fluorescence spectroscopy as an analytical technique is well documented in several texts 1 -3.

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