Miracle-dz/UniFAR-FTUs huggingface dataset:
FLOW INJECTION DETERMINATION OF DOPAMINE BASED ON INHIBITED ELECTROCHEMILUMINESCENCE OF LUMINOL

ABSTRACT A flow injection method has been developed for the determination of dopamine based on its inhibition of the electrochemiluminescence of luminol. This method is simple and sensitive for dopamine detection. Under the selected experimental conditions, the decreased electrochemiluminescent intensity is linear with dopamine concentration in the range of 5.0 × 10−8–1.0 × 10−5 mol/L with a detection limit of 30 nmol/L. The relative standard deviation of eleven determinations is 1.9% for 1.0 × 10−6 mol/L dopamine. The proposed method has been applied to the detection of dopamine in pharmaceutical injections with satisfactory results.
Development and characterization of novel composite membranes for fuel cell applications

In this paper, we report a novel composite electrolyte membrane consisting of a polyethylene substrate and a Nafion ionomer. Polymer Electrolyte Membranes (PEMs) have been gaining increasing attention in the fuel cell industry due to their excellent proton conductivity and among them the Nafion membrane is by far the most widely used membrane electrolyte. However, it suffers from several drawbacks such as high fuel crossover and low mechanical strength, which lower the fuel cell performance and disturb the structural integrity. In order to deal with these problems, we have prepared a pore filling membrane that is composed of a porous substrate and a filling electrolyte. Nafion was used as a filling electrolyte and was impregnated into the pores of the porous substrate made up of ultra-high molecular weight polyethylene (UHMWPE). The UHMWPE backbone serves as a structural support and blocks the fuel crossover while the impregnated Nafion molecules provide the proton conducting path. A porous UHMWPE membrane with a porosity of approximately 66% was prepared, and the Nafion electrolyte was impregnated into the pores so that an NPE (Nafion–polyethylene composite) membrane was formed. Major accomplishments of this work are (a) the membrane is biaxially oriented and has higher tensile strength and modulus especially under wet conditions as well as better electrolyte conductivity because the resistivity in the system is reduced due to the development of a very thin (13 μm) film composite, and (b) the electrolytic membrane is economical because of the utilization of a lesser amount of ionomer. Systematic characterization of both porous polyethylene and the NPE composite has been performed using SEM, EDAX, XRD, XRF, porosity measurement, tensile tests, proton conductivity, and fuel cell performance tests.
Population kinetics of the fluorescing MNa center state in CaF2 upon fs laser excitation at 392 nm and 262 nm

We report on femtosecond (fs) laser experiments yielding the time constants τrel for the non-radiative relaxation from optically excited high energy MNa** states to the fluorescent MNa* state in CaF2 samples. The values obtained with the third and second harmonics of the fs laser amount to τrel (262 nm) = (3.0 ± 0.3) ps and to τrel (392 nm) = (1.0 ± 0.1) ps for the two selected MNa** states at 4.7 eV (262 nm) and 3.2 eV (392 nm) excitation energy, respectively. These time constants were derived from depletion processes of the fluorescence at 740 nm (MNa* state) using fs laser pulses of the NIR fundamental wavelength (785 nm) at variable delay relative to the UV fs laser pulses. In addition, photobleaching of the MNa centers upon UV fs laser irradiation is observed and simulated by assuming a constant fraction of MNa bleaching per pulse for a given laser fluence. This fraction ranges from 0.14% per pulse at 392 nm and 0.28mJ/cm2 to about 1% per pulse at about 6 mJ/cm2.
Preparation and Characterization of Heparin‐Stabilized Gold Nanoparticles

A simple method for preparing gold nanoparticles in aqueous solution has been developed by using glycosaminoglycan‐heparin as reducing and stabilizing agent and HAuCl4 as precursor. The obtained gold nanoparticles were characterized by UV‐vis spectroscopy, resonance light scattering spectroscopy (RLS), transmission electron microscopy (TEM) and electrophoresis technology. The influence of reactant concentration for the preparation of gold nanoparticles was investigated. The results indicated that the gold nanoparticles carried negative charges in the aqueous solution and the size and shape of the gold nanoparticles could be controlled by changing the concentration of the heparin. Moreover, the gold nanoparticles obtained with relatively high concentration of heparin were very stable and had relative narrow size distribution.
Low-loss InP-based photonic-crystal waveguides etched with Ar/Cl2 chemically assisted ion beam etching

We demonstrate low-loss photonic-crystal (PC) waveguides realized in InP by Ar/Cl2 based chemically assisted ion beam etching. The waveguides are obtained as line defects in a triangular lattice of holes etched through a three-layer InP/GaInAsP/InP heterostructure. By optimizing the etching parameters so that the physical and the chemical components are balanced we succeed in obtaining holes deeper than 2 μm even for a hole diameter as small as 220 nm. The quality of the PCs etched by two different process conditions is compared by using the shape and the position of one of the mode gaps as an assessment tool. The measured transmissions spectra indicate that the PC waveguides etched with an optimized process exhibit losses smaller than 1 dB/100 μm. This is to date the lowest loss value reported for PC waveguides in semiconductor heterostructures at optical communication wavelengths.
Purification and Some Properties of Cell-bound Lipase from Saccharomycopsis lipolytica

Two kinds of cell-bound lipases were purified from S. lipolytica with a total recovery of 8%. One was adsorbed and the other not to CM-Sepharose CL-6B at pH 5.0. The method of purification involved chromatography on CM-Sepharose CL-6B, DEAE-Sepharose CL-6B and Sephadex G-100 columns. Sodium dodecylsulfate-polyacrylamide gel electrophoresis of the purified lipases gave a single band. The purified Upases required an activator, such as oleic acid for hydrolysis of triglycerides. The Upases hydrolyzed tricaprylin at the largest initial rate and the optimum pH for hydrolysis of olive oil was about 8.0 under the experimental conditions. They were stable for 20 min below 37°C and in a pH range from 4.5 to 8.0 for 22 hr at 5°C. The molecular weight of Lipase I and II was estimated to be 39,000 and 44,000, respectively, and both Upases were a monomeric enzyme.
Particulate matter and downward flux in the Northern and Central Adriatic Sea

During four oceanographic cruises carried out in June 1996, February and June 1997, and February 1998, particulate matter characteristics and short-term downward fluxes measured with drifting sediment traps were studied in two areas of the Adriatic Sea. The investigated areas were located one south of the Po River delta, and the other in the central Adriatic between Pesaro and Ancona. In each area, a frontal system was detected and two stations inside and outside the front, i.e . in coastal and offshore areas, were selected. The particulate and dissolved matter revealed a higher concentration in the coastal areas with the highest values in the central Adriatic coastal zone in both February surveys. Total mass fluxes ranged within two orders of magnitude from 11 to 3139 r mg m d in the northern area and similarly from 20 to 3864 r mg r m r d in the southern one, with higher values in the coastal stations. The organic carbon accounted for 3-30% of total flux in the northern coastal station with higher values in June, whereas at the offshore station it ranged from 6 to 39% in summer, decreasing to values lower than 10% in February. In the southern zone the organic carbon content was less than 2% in winter and from 3 to 33% in summer. The organic carbon fluxes (1-82 and 6-71 r mg C m d in the northern and southern area) were comparable with others measured with drifting sediment traps in the same area, though much lower with respect to those measured with long-term moored sediment traps. The export of organic carbon from the photic layer (expressed as the percentage of primary production) in the northern area was less than 10% at the coastal station, reaching a maximum of 12% in the offshore area. In the central Adriatic area it was greater, with values reaching up to 66% at the coastal station in June 1996. The organic carbon loss via sedimentation from the POC pool was low ( i.e. <1.5% per day) at both stations in the northern zone, while in the southern area the export was generally greater, exceeding 10% in the offshore area.
From Interfacial Water to Macroscopic Observables: A Review

The scientific community has always been fascinated by the properties of water and, consequently, a number of investigations continue to address this ubiquitous fluid responsible for life on this planet. Interfacial water plays an important role in a number of physical phenomena that include protein-folding, structure/function relationships in enzymes, the design of nano-fluidic devices, and even macroscopic effects including drag reduction. Interfacial water is attracting renewed interest because of applications such as electrical double layer capacitors, and also for the microbial conversion of cellulose to biofuels. Current scientific explorations regarding interfacial water take advantage of innovations in experimental capabilities, theoretical models and computational tools. Particular attention has been devoted recently to uncovering the relationships between macroscopic properties, often summarized under the hydrophobic/hydrophilic characterization of solid surfaces, to the atomic-level behaviour of water near interfaces. The goal of the present review is to compile recent results obtained along these research objectives, for the most part obtained by simulation studies, to discuss some experimental techniques that appear most adequate to validate the simulation results (specular X-ray reflectivity, ultrafast IR spectroscopy, atomic force microscopy, and others), and to propose possible research topics to further develop this field. Because of our recent interests, the surfaces considered herein are mainly oxides.
Proficiency testing and other interactive measures to enhance analytical quality in soil and plant laboratories

Abstract Clients are increasingly seeking enhanced accuracy and precision from soil and plant testing laboratories. Commitment to good laboratory practice is essential, but gains in analytical quality often depend upon inputs from peers through collaborative networks, proficiency programs and laboratory accreditation. Examples of laboratory networks are given, while proficiency programs receive attention with respect to scope, frequency and the statistical assessment of data. Those with a national/regional focus have proliferated with some consolidation warranted. Recent interlaboratory proficiency data from Indonesia and occasional audits of other proficiency programs have been used to reinforce the benefit of non‐parametric statistical procedures for the identification of outlying laboratories, and to suggest greater uniformity in statistical approaches. There is brief mention of formal laboratory accreditation by national providers such as the National Association of Testing Authorities (NATA) in Australia. A disappointing finding was that co‐efficients of variation (CVs) for most soil and plant methods reported in interlaboratory proficiency programs exceed predicted CVs derived from the Horwitz equation. Examples of improving method performance over time are given for two interlaboratory proficiency programs, but grand CVs associated with three successive ASPAC's soil proficiency programs remain static at around 16%. The soil and plant laboratory industry must succeed with its efforts to improve analytical performance, as failure may encourage entities outside the industry to intervene.
The optimization of FTIR spectroscopy combined with partial least square for analysis of animal fats in quartenary mixtures

Four types of animal fats, namely lard (LD) and body fats of lamb (LBF), cow (Cow-BF) and chicken (Ch-BF), in quaternary mixtures were quantitatively analyzed using FTIR spectroscopy in combination with multivariate calibration of partial least square (PLS). The animal fats, either individual or in quaternary mixtures, were subjected to horizontal total attenuated total reflectance (HATR) as sample handling technique and scanned at mid-infrared region (4000–650 cm–1) with resolution of 4 cm–1 and with 32 interferograms. PLS calibration revealed that the first derivative FTIR spectrum was well suited for the correlation between actual value of LD and FTIR calculated value. The other animal fats (LBF, Cow-BF and Ch-BF) were better determined using normal FTIR spectra. The coefficient of determination (R2) obtained using the optimized spectral treatments was higher than 0.99. The root mean standard error of calibration (RMSEC) values obtained were in the range of 0.773–1.55. Analysis of animal fats using FTIR spectroscopy allows rapid, no excessive sample preparation, and can be regarded as “green analytical technique” due to the absence of solvent and chemical reagent used during the analysis.
EFFECT OF LONG-TERM SEWAGE SLUDGE APPLICATION ON THE DISTRIBUTION OF NUTRIENTS IN MAIZE (ZEA MAYS L.)

The distribution of the nutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and iron (Fe) in maize (Zea mays L.) was studied in a long-term sewage sludge field application in an acid coarse sandy soil at Bordeaux, France. Sewage sludge had been applied since 1974 at 100 t (dry weight) ha−1 per 2 years (SS 100) in plots cultivated annually with maize. Treatment with farmyard manure (FYM) at 10 t (dry weight) ha−1 per year and mineral fertilization served as control. Five plants per treatment were investigated at six different growth stages. The plants were separated into their different organs and the distribution of nutrients was determined in up to 12 different plant parts. Sludge application did not significantly influence the nutrient partitioning in maize, but improved slightly the plants' nutrient status compared with the FYM treatment. Grain yield was similar for both treatments. The values for N, P, K, Ca, Mg and Fe content in sludge-treated plants were in the recommended range for optimal growth. Thus, sewage sludge would be a valuable source for maize nutrition even after long-term application, if the critically high copper (Cu) and zinc (Zn) concentrations, previously reported in these sludge-amended plants, could be avoided by the use of sludge low in these elements.
Stationary current generated from photocycle of a hybrid bacteriorhodopsin/quantum dot bionanosystem

Bacteriorhodopsin (bR) is a promising biomaterial for broad potential applications in optical and optoelectronic devices. Upon the original photochemical cycle of bR, for the first time we construct a hybrid bR/quantum dot (QD) bionanosystem and a stationary current is generated from the modified photocycle. We propose a model to explain that QDs could act as nanoscaled light sources embedded in bR to assist its generation of a stationary photocurrent, which is completely different from the reported transient spikes from the bR’s photocycle. It opens the horizon for optical devices other than those reported up to date.
The atomic structure of two intermetallic compounds

The two intermetallic compounds Mg2Si and AlSb have been examined by the X-ray spectrometer with the following results: - Mg2Si. - A face centred cubic lattice of silicon atoms of side 6.391A symmetrically intermeshed with a simple cubic lattice of magnesium atoms of side 3.19A. There are eight magnesium atoms situated within each face centred cube of silicon atoms, dividing the four cubic diagonals in the ratio 1:3 and 3:1. Density from X-ray data 1.95±0.05 gms. /c.c. The magnesium atoms are separated by the same distance as in the pure metal. The sum of the "radii" of silicon and magnesium atoms is equal to the distance between these atoms in the compound. AlSb. - A face centred cubic lattice of antimony of side 6.126A intermeshed with an indentical lattice of aluminium atoms; the corner of the latter dividing the cubic diagonal of the former in the ratio of 1:3. Density from X-ray data 4.23±0.04 gms. /c.c. The molecular volume of the compound is greater than the sum of the atomic volumes of its constituents. The increase in volume observed by the method of X-ray analysis agrees with that obtained by other methods of measurement. The volume of the lattice on which the antimony atoms are arranged is 4 per cent. less than the volume of the face centred rhomb found in pure antimony. The molecular volume of the compound is accordingly 4 per cent. less than twice the atomic volume of antimony. The closest distance of approach of aluminium and antimony atoms is 2.65A, which is less than the sum of their "radii" as determined from the pure metals.
Calculation of solid-fluid phase equilibria for systems of chain molecules

We study the first order solid-fluid phase transition of a system of semi-flexible Lennard-Jones chains using molecular dynamics simulations. Thermodynamic integration methods are used to calculate the free energy of the solid and fluid phases. The solid phase free energy per chain can be calculated to an accuracy of ±0.03kBT with relative ease. The Gibbs-Duhem integration technique is used to trace out the complete melting curve, starting with a single point on the curve obtained from the free energy calculations. For the short chains studied here, we find that increasing the chain length stabilizes the solid phase; i.e., it raises the melting temperature at fixed pressure, and lowers the density at the transition at fixed temperature. Gibbs-Duhem integration was used also to investigate the effects of chain stiffness on the transition. We find that increasing the stiffness also acts to stabilize the solid phase. At fixed temperature, the transition is shifted to lower pressure and lower density with increasing chain stiffness. Further, we find that the density gap between solid and fluid broadens with increasing chain stiffness.
Communicating with Raspberry Pi via MAVLink

This paper explains how to connect and configure a Raspberry Pi so that it is able to communicate with a Pixhawk flight controller using the MAVLink protocol over a serial connection. This can be used to perform additional tasks such as image recognition which simply cannot be done by the Pixhawk due to the memory requirements for storing images.
Effects of Weakly Electrolyzed Water on Properties of Japanese Wheat Noodles (Udon)

The effect of weakly electrolyzed water (anode water and cathode water) on the properties of Japanese wheat noodles was examined. Instrumental measurements and sensory tests of the cooked noodles revealed that noodles made by kneading wheat flour with anode water were harder and springier than those made by kneading wheat flour with tap water. This suggests that anode water provides a favorable texture to the cooked noodles. Anode water promoted the dissolution of gliadin and glutenin subunits which participate in the formation of gluten-matrix, so that the texture of cooked noodles was improved by kneading the wheat flour with this water. When noodles were cooked in either anode water or cathode water, they showed less springiness compared with those cooked in tap water. The use of either anode or cathode water for cooking changed the gelatinization condition of starch, which affects the texture of the cooked noodles.
Correction for nonlinear fluctuating background in monovariable analytical systems

A method to correct for fluctuating nonlinear background is suggested. The method is evaluated by experimental near-IR spectroscopy and by computer experiments that cover a wide range of possible variables. The current presentation of the method is suitable for monovariable analytical systems, such as mixtures in which the concentration of only one component is varied (and, as a result, the solvent's concentration changes accordingly). In spectroscopic applications, the concentration of an unknown sample can be determined from its spectrum and the spectra of two known reference samples, even though each individual spectrum has a different and nonlinear baseline. The method has been examined for polynomial baselines, up to the eighth degree. The method can handle extreme baseline fluctuations and is stable in a considerably wide range of the relevant parameters. Small deviations from monovariability cause only a slight (and linear) increase in analysis error, which means that the proposed algorithm is resistant to variable and unknown contamination.
EFFECTS OF COMBINED WATER COOKING–VACUUM COOLING WITH WATER ON PROCESSING TIME, MASS LOSS AND QUALITY OF LARGE PORK HAM

The catering system of pork ham is normally a cook-chill system, which is based on the full cooking of pork ham followed by chilling. In order to obtain large pork ham with high quality and safety, a novel method was developed in this work, i.e., combined water cooking-vacuum cooling with water (immersion vacuum cooling) (WC+VW). The effects of WC+VW on processing time, mass loss and quality of large pork ham were evaluated by comparing them with those of four traditional pork ham processing methods, i.e., dry air cooking combined with air blast cooling (DAC+AB), dry air cooking combined with cold room cooling (DAC+CR), wet air cooking combined with air blast cooling (WAC+AB) and wet air cooking combined with cold room cooling (WAC+CR). WC+VW achieved the shortest processing time, resulting from the shortest time of vacuum cooling with water (308.0 min). Furthermore, present results showed that WC+VW could produce mass loss and quality of large pork ham comparable to those of the four traditional processing methods.
Nylon Nanofibrous Biosensors for Glucose Determination

Nanofibrous membranes have been produced by electrospinning to develop first generation glucose biosensors. The direct immobilization of glucose oxidase onto the polyamide nanofibrous surfaces by drop coating revealed a simple and efficient method for the development of sensitive, stable, and reproducible electrochemical biosensors. The biosensor showed a linear response over the range 1–9×10−3 glucose (R2=0.9997) with a sensitivity of 1.11 μA/mM and a limit of detection of 2.5×10−6 M (S/N=3). The uncertainty of repeatability was 2% (RSD%, n=30). After one month of storage, the signal decreased of 35%. The recovery of glucose, evaluated in real samples of honey, was 98% (RSD%=1%, n=3).
An Estimate of Some Statistical Properties of Extinction signals in dilute and concentrated suspensions of monosized spherical particles

A statistical analysis is made for the extinction of radiations in suspensions, whereby the whole range of possible particle concentrations is covered. The extinction signals are characterized by their average value and by a characteristic length of fluctuation. For simplicity, the considerations are restricted to geometric ray propagation in dispersions of perfectly absorbent, monosized spherical particles. An extinction equation is derived, which reduces to Lambert-Beer's law in the limit of low particle concentrations. For higher concentrations, significant deviations from Lamberg-Beer's law due to steric particle-particle interactions are predicted. The characteristic length of the fluctuations is a function of particle diameter and transmission and has a broad minimum with medium transmissions, allowing for maximum resolution with measurements in this range.