Detector Research Papers - Academia.edu (original) (raw)

The ALICE Forward Multiplicity Detector (FMD) is a silicon strip detector with 51,200 strips arranged in 5 rings, covering the range −3.4 < η < 5.1. It is placed around the beam pipe at small angles to extend the charged particle... more

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- Physics, Nuclear Physics, Mathematical Sciences, Physical sciences
- by Alan Bross
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- Detector

There are in excess of 20 million acres of bomb and artillery ranges under the control of the Department of Defense Ž. 2 Ž. DoD. Each year some 800,000 to 2,000,000 km are turned over to civilian private or commercial use. Some of this land Ž. is contaminated with buried unexploded ordnance UXO. These UXOs present a safety hazard and raise many environmental concerns. In addition to inaccurate locating, one of the most difficult aspects for the operator of an excavator is the inability to see the target ordnance while it is covered with soil and debris. This paper presents a system which is mounted to the arm of an excavator and is capable of detecting a buried UXO located in the path of an excavator's bucket. Also, the system is able to determine the precise location of the ordnance relative to the excavator's bucket. This information will allow the operator not only to avoid striking the ordnance during the digging operation, but also to expose the object by removing the soil around it. This technology is also capable of locating small UXO which can be buried within the spoil material. This technology has the potential to result in savings of millions of dollars in operating costs and prevent the damage or loss of equipment.

- by Leonhard Bernold
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- Engineering, Robotics, Data Analysis, Localization

We have determined complete polycldorinated biphenyl (PCB) congener assignments end weight percent distributions for all major ( > 0.5 wt % ) FCB components of that are resolved by DB-1 (polydimethylsiloxane) capillary C,-C columns. Aroclor components present between 0.05 and 0.5 wt % were also identified but not quantified. Quantitadon was done using a combination of GC-ELCD (Hall electrolytic conductivity detector) and GC-MS measurements. All 209 PCB congeners have been assigned to the 124 peaks that can be resolved on DB-I columns. The data support use of these eight Aroclors individually or in customized standards for calibrating the comprehensive, quantitative, congenerspecific PCB analyses that are necessary for accurate quantitation of the complex and often radically altered mixtures of PCBs typically found in the environment.

- by james Carnahan
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- Multidisciplinary, Gas Chromatography, Chemical Analysis, Polychlorinated Biphenyl

We have developed a polyaniline/carboxy-functionalized multiwalled carbon nanotube (PAn/MWCNTCOOH) nanocomposite by blending the emeraldine base form of polyaniline (PAn) and carboxy-functionalized multiwalled carbon nanotubes (MWCNT) in dried dimethyl sulfoxide (DMSO) at room temperature. The conductivity of the resulting PAn/MWCNTCOOH was 3.6 × 10 −3 S cm −1 , mainly as a result of the protonation of the PAn with the carboxyl group and the radical cations of the MWCNT fragments. Horseradish peroxidase (HRP) was immobilized within the PAn/MWCNTCOOH nanocomposite modified Au (PAn/MWCNTCOOH/Au) electrode to form HRP/PAn/MWCNTCOOH/Au for use as a hydrogen peroxide (H 2 O 2 ) sensor. The adsorption between the negatively charged PAn/MWCNTCOOH nanocomposite and the positively charged HRP resulted in a very good sensitivity to H 2 O 2 and an increased electrochemically catalytical current during cyclic voltammetry. The HRP/PAn/MWCNTCOOH/Au electrode exhibited a broad linear response range for H 2 O 2 concentrations (86 M-10 mM). This sensor exhibited good sensitivity (194.9 A mM −1 cm −2 ), a fast response time (2.9 s), and good reproducibility and stability at an applied potential of −0.35 V. The construction of the enzymatic sensor demonstrated the potential application of PAn/MWCNTCOOH nanocomposites for the detection of H 2 O 2 with high performance and excellent stability.

- by Rung-Ywan Tsai
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- Engineering, Analytical Chemistry, Technology, Electrochemistry

Miniaturized Golay cells based on tunneling displacement transducers were first produced at the Jet Propulsion Laboratory (JPL). The devices produced have performance characteristics comparable to the best thermal infrared detectors of comparable dimensions. This work describes a high yield wafer-scale process for fabrication of tunneling infrared detectors. The sensors produced have performance comparable to the best tunneling sensors made so far.

- by Choongsoo Shin
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- Materials Engineering, Mechanical Engineering, Tunneling, Thermal

Carbon monoxide (CO) generally referred to as the silent killer, arises from combustion of fuel with limited oxygen. This gas is a lighter than air and could be dangerous if inhaled in high quatity by humans. There is increase in the death rate yearly as a result carbon monoxide (CO) poisoning. To prevent this poisoning, it is important to build a detector that will assess the level of CO levels the room/environment so as to inform people of the CO concentrations level. The contructed device in this study was assembled using TGS 2442 sensor. It uses PIC16F917 microcontroller as the processor, in the configuration perform the task of converting the analogue input into a digital output which was shown on the LCD as the CO concentration in the room. The constructed circuit was used to determine the output voltage of CO emitted from petrol car, candle, diesel generator and petrol generator. Highest output voltage was obtained from candle light.

- by IAEME Publication
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- Concentration, Carbon Monoxide, Microcontroller, Detector
- by henrry henrry
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- Energy Conversion, Low Frequency, Membrane, Spectrum
- by Marion Essers
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- Instrumentation, X Rays, Quality Assurance, Transmission

A peak/RMS power detector with 40 dB dynamic range is presented. The simulated frequency response is flat to 60 GHz and the measured response is flat to 20 GHz. Analysis shows that the Meyer detector, originally developed as a peak detector, can be used for RMS detection with an error less than 0.5 dB over an approximately 20 dB range, comparable to the popular RF/microwave diode detector. The range for RMS detection is extended by cascading several stages of attenuators and detectors, leading to a circuit suitable for applications such as embedded RFIC test. The power detector is only 700 550 m 2 including all AC and DC bond pads.

- by William Eisenstadt
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- Power, Built in self test, RMS, Interconnection

MALDI-TOF MS is a soft ionization technique suitable for analysis of peptides, proteins, glycoproteins, oligosaccharides and oligonucleotides etc. In dairy sector, it can be used to analyze milk proteins, to identify adulteration in milk, isolation of phospholipids, characterization of proteins and enzymes of the microorganisms used in manufacture of cheese and other fermented products. In food industry, it can be used for evaluation and determination of fructo-oligosaccharides, inulins, certain pigments and flavor compounds present in different foods. This technique has found applications in a variety of disciplines including proteomics, glycomics, dairy, food, chemistry, biochemistry, microbiology, and physics. The purpose of this review is to summarize the contribution of the studies already performed with MALDI-TOF MS concerning dairy and related sectors.

- by Anil Kumar and +1
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- Bioengineering, Biochemistry, Bioinformatics, Chemistry

- by Anil Kumar
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- Bioengineering, Biochemistry, Bioinformatics, Chemistry

Analysis of water and sand samples was done by reflectance measurements using a mobile phone. The phone's screen served as light source and front view camera as detector. Reflected intensities for white, red, green and blue colors were used to do principal component analysis for classification of several compounds and their concentrations in water. Analyses of colored solutions and colorimetric reactions based on widely available chemicals were performed. Classification of iron(III), chromium(VI) and sodium salt of humic acid was observed using reflected intensities from blue and green light for concentrations 2-10 mg/l. Addition of complex forming sodium salt of ethylenediaminetetraacidic acid enabled the discrimination of Cu(II) ions in the 2-10 mg/l concentration range based on reflection of red light.

- by zafar iqbal
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- Analytical Chemistry, Water, Colorimetry, Principal Component Analysis

Being one of the most commonly used electrochemical mediators for analytical applications, Prussian Blue has found a wide use in the biosensor field during the last years. Its particular characteristic of catalysing hydrogen peroxide reduction has been applied in the construction of a large number of oxidase enzyme-based biosensors for clinical, environmental and food analysis.

- by Giuseppe Palleschi and +1
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- Analytical Chemistry, Biomedical Engineering, Electrochemistry, Nanotechnology

The method presented is applicable to the determination of organophosphorus (OP) pesticide residues in vegetable oils. The method performs in a single step an on-column extraction and cleanup of OP pesticide residues by means of a system of three cartridges. A solution of 1 g oil in n-hexane is loaded into an Extrelut-NT3 cartridge (large-pore diatomaceous material). The OP pesticide residues are extracted by eluting the cartridge with 20 mL acetonitrile, which is cleaned up by passing through a silica and a C18 cartridge connected on-line to the Extrelut NT-3 cartridge. A few milligrams of lipid is carried over into the eluate, which after concentration and solvent exchange is directly amenable to determination by gas chromatography (GC) with flame photometric detector with optical filter for phosphorus compounds (FPD-P). Recovery values for 45 OP pesticide residues are reported at two spiking levels. In the lower concentration range tested (0.09–0.60 mg/kg), satisfactory results (...

- by Antonella Ausili
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- Engineering, Environmental Engineering, Analytical Chemistry, Chromatography
- by Ma Ket
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- Analytical Chemistry, Forensic Science, Mass Spectrometry, Multidisciplinary

Colloidal quantum dot light-emitting devices (QD-LEDs) have generated considerable interest for applications such as thin film displays with improved color saturation and white lighting with a high color rendering index (CRI). We review the key advantages of using quantum dots (QDs) in display and lighting applications, including their color purity, solution processability, and stability. After highlighting the main developments in QD-LED technology in the past 15 years, we describe the three mechanisms for exciting QDs Á optical excitation, Fö rster energy transfer, and direct charge injection Á that have been leveraged to create QD-LEDs. We outline the challenges facing QD-LED development, such as QD charging and QD luminescence quenching in QD thin films. We describe how optical downconversion schemes have enabled researchers to overcome these challenges and develop commercial lighting products that incorporate QDs to achieve desired color temperature and a high CRI while maintaining efficiencies comparable to inorganic white LEDs (65 lumens per Watt). We conclude by discussing some current directions in QD research that focus on achieving higher efficiency and air-stable QD-LEDs using electrical excitation of the luminescent QDs.

- by Gerasimos Konstantatos
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- Materials Science, Thermodynamics, Technology, Packaging

Two compact optoelectronic fluorimetric devices operating according to the paired-emitter-detectordiode concept have been developed. The fluorimetric detector, fabricated of three light emitting diodes only, has been applied for the development of fluorimetric optosensor by further integration with sensing solid phase. In these investigations as a model analyte and as a model sensing layer useful for solid phase spectrometry, riboflavin and C18-silica have been chosen, respectively. Both developed analytical devices have been applied for non-stationary fluorimetric measurements performed under conditions of flow injection analysis. The presented flow-through detector and sensor operating under given flow conditions offer riboflavin determination in mg L −1 and g L −1 ranges of concentration, respectively.

- by Marta Pokrzywnicka and +1
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- Analytical Chemistry, Sensor, Flow analysis, Fluorimetry

This review focuses on chemical and biochemical analysis systems using pressure-driven microfluidic devices or microchips. Liquid microspace in a microchip has several characteristic features, for example, short diffusion distances, high specific interfacial area and small heat capacity. These characteristics are the key to controlling micro unit operations and constructing new integrated chemical systems. By combining multiphase laminar flow and the micro unit operations, such as mixing, reaction, extraction and separation, continuous flow chemical processing systems are realized in the microchip format. By applying these concepts, several different analysis systems were successfully integrated on a microchip. In this paper, we introduce the microchip-based chemical systems for wet analysis of cobalt ion, multi-ion sensors, immunoassay, and cellular analysis. 

- by Manabu Tokeshi
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- Biochemistry, Lab On A Chip, Advanced Drug Delivery Research, Laminar Flow

The web page has become a great environment for those with malicious intent to perform some unwanted activities or launch attack. The attackers normally embed the malicious contents in the compromised web page or inject links to fake web pages they have created. Unhappily attacks are becoming more sophisticated by using complicated techniques to evade detection. The victim's system can be infected by just a single visit to a web page and the attack sometimes can be silent and unnoticeable. Often, the attacker focuses on a web site that has become the centre of attention, and then exploits the system's vulnerabilities and launches the attack. Objective: To provide a lightweight framework for malicious web page detection in order to reduce the threats of the web-based attacks and mitigate the risk. Results: Comparing with different approaches, our experiment with real world data set has shown a significant result, and our approach is able to reach 97% detection. Conclusion: We have proposed a framework for identifying a malicious web page as either benign or malicious using supervised machine learning techniques. The malicious web page has been characterized by a vector of discriminative features, and based on HTTP response we have collected two groups of features, the URL string lexical features and the page content features. When comparing with other works, the proposed framework effectively mitigates threats and less execution overhead. attention so far. This work is continuing to add some values to the malware field combat by mitigating some threats, and improve performance by enhancing the detection rate.

We are reporting fabrication and characterization of electrochemical sucrose biosensor using ultra-microelectrode (UME) for the detection of heavy metal ions (Hg(II), Ag(I), Pb(II) and Cd(II)). The working UME, with 25 microm diameter, was modified with invertase (INV, EC: 3.2.1.26) and glucose oxidase (GOD, EC: 1.1.3.4) entrapped in agarose-guar gum. The hydrophilic character of the agarose-guar gum composite matrix was checked by water contact angle measurement. The atomic force microscopy (AFM) images of the membranes showed proper confinement of both the enzymes during co-immobilization. The dynamic range for sucrose biosensor was achieved in the range of 1 x 10(-10) to 1 x 10(-7)M with lower detection limit 1 x 10(-10)M at pH 5.5 with 9 cycles of reuse. The spectrophotometric and electrochemical studies showed linear relationship between concentration of heavy metal ions and degree of inhibition of invertase. The toxicity sequence for invertase using both methods was observed as Hg(2+)&amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;Pb(2+)&amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;Ag(+)&amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;Cd(2+). The dynamic linear range for mercury using electrochemical biosensor was observed in the range of 5 x 10(-10) to 12.5 x 10(-10)M for sucrose. The lower detection limit for the fabricated biosensor was found to be 5 x 10(-10)M. The reliability of the electrochemical biosensor was conformed by testing the spike samples and the results were comparable with the conventional photometric DNSA method.

- by Vijayamohanan Pillai and +1
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- Analytical Chemistry, Biomedical Engineering, Water, Biosensors

In this study preparation and thermal, electrochemical, photophysical properties of the compounds are reported. New series of compounds consisting of 4-Allylamino-N-4-aminobenzenesulfonamide-1, benzenesulfonamide-1,8-naphthalimide and 4-Allylamino-N-4-amino-N-(2pyrimidinyl) benzenesulfonamide-1,8-naphthalimide were synthesized via sonic method from intermediate 4-nitro-1,8naphthalimide by imidation, reduction and allylation reactions. These compounds were characterized by thin layer chromatography (TLC), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR), 1 Hnuclear magnetic resonance ( 1 HNMR), 13 C-NMR, liquid chromatography, UV-Vis spectroscopy and fluorimetry. New acceptor-donor compounds were obtained with the photoluminescence quantum yields (PLQY) of 33.68-79.70% in solution and 0.85-3.39% in non-doped solid film. The synthesized dyes absorb electromagnetic radiation in the range of 434-440 nm and emit solid films exhibited fluorescence in the range of 561-614 nm. The ionization potentials of the synthesized dyes were found to range from 6.00 eV to 6.09 eV.

- by Hiroshi Maezawa
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- Materials Engineering, Organic Chemistry, Near Infrared, Multidisciplinary

A superconductor single photon detector based on NbN nanowire was fabricated using electron beam lithography (EBL) and reactive ion etching (RIE) for infrared photon detection. When biased well below its critical current at 4.2 K, NbN nanowire is very sensitive to the incident photons. Typical telecommunication photons with a wavelength of 1550 nm were detected by this detector. Data analysis indicates the repeating rate of the device with 200 nm NbN nanowire may be up to 100 MHz, and the quantum efficiency is about 0.01% when biased at 0.95I c .

- by Labao Zhang
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- Data Analysis, Electron Beam Lithography, Multidisciplinary, Nanowires

A remote monitoring system based on a piezoelectric quartz crystal (SPQC) sensor was developed for the determination of the bacteria population in raw milk. The system employs the Windows XP server operating system, and its programs for data acquisition, display and transmission were developed using the LabVIEW 7.1 programming language. The circuit design consists of a circuit with a piezoelectric quartz crystal (SPQC) and a pair of electrodes. This system can provide dynamic data monitoring on a web-page via the Internet. Immersion of the electrodes in a cell culture with bacteria inoculums resulted in a change of frequency caused by the impedance change due to microbial metabolism and the adherence of bacteria on the surface of the electrodes. The calibration curve of detection times against density of bacteria showed a linear correlation coefficient (R 2 = 0.9165) over the range of 70-10 6 CFU ml −1 . The sensor could acquire sufficient data rapidly (within 4 h) and thus enabled real-time monitoring of bacteria growth via the Internet. This system has potential application in the detection of bacteria concentration of milk at dairy farms.

- by Ching-fu Lee
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- Analytical Chemistry, Biomedical Engineering, Biosensors, Electrochemistry

Comprehensive two-dimensional gas chromatography (GC×GC) is a powerful technique which can enable a great increase in GC peak capacities. However, since secondary-column separations are very rapid, detectors with a fast acquisition rate are mandatory. Such a requirement has certainly limited the use of the quadrupole mass spectrometer in the GC×GC field. The present research is focused on the evaluation of a novel rapid-scanning quadrupole mass spectrometry (qMS) detector, characterized by a 20 000 amu/s scan speed and a 50 Hz scan frequency, using a 290 amu mass range (40-330 m/z). The performance of the MS system was assessed by analyzing mixtures of 24 allergens, as well as a perfume sample, through GC×GC/qMS. The MS parameters evaluated at different acquisition rates (50, 33, and 25 Hz), as well as in the (simultaneous) scan/selected ion monitoring (SIM) mode, were the number of data points per peak, mass spectrum quality, peak skewing, and sensitivity. Two GC×GC/qMS methods, using the 50 Hz acquisition rate and the scan/SIM mode, were validated. Both methods provided similar results in terms of repeatability, accuracy, and linearity, while a great increase in sensitivity was observed (ca. a factor of 10) under scan/SIM conditions. The validated method proved to be suitable for the analysis of perfume allergens, according to the requirements of Directive 2003/15/EC.

- by Luigi Mondello
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- Chemical Engineering, Analytical Chemistry, Perfume, Mass Spectrometry
- by chhaya gupta
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- Computer Science, Artificial Intelligence, Face Detection, Detector

Matrix ion suppression/enhancement is a well-observed and discussed phenomenon in electrospray ionization mass spectrometry. Nonuniform matrix ion suppression/ enhancement across different types of samples in an analytical run is widely believed to be well compensated for by using a stable isotope-labeled internal standard (SIL-IS) in bioanalysis using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Therefore, the risk of nonuniform matrix ion suppression/ enhancement is usually deemed low when an SIL-IS is used. Here, we have identified, evaluated, and proposed solutions to control bioanalytical risks from nonuniform matrix ion suppression/enhancement even with an SIL-IS through a case study using omeprazole. Two lots of human blank urine were tested, and ion enhancement of about 500% for omeprazole was observed in one lot but not in the other. When a quadratic regression model had to be used, the assay failed the industry acceptance criteria due to unacceptable positive bias for the middle and high quality control (QC) samples. The failure was attributed to different extents of matrix ion enhancement between the standards (STDs) and QCs, which resulted in the misaligned results from the regression model. It was concluded that, for the same amount of drug, nonuniform ion enhancement for different types of samples (STD or QC) resulted in different ion intensities, therefore leading to different response behaviors (linear or nonlinear) at the mass spectrometer detector. A simplified mathematical model was used to evaluate the risk when unmatched response models occurred for different types of samples. A diagnostic factor Q (Q) X ULOQ (-A/B)) was proposed to monitor the risks, where X ULOQ is the upper limit of quantitation of the assay, A is the quadratic slope of the curve, and B is the linear slope of the curve. The potential maximum errors were estimated on the basis of the mathematical model for different scenarios, and Q values were given to control the risks under these conditions for bioanalysis using LC-MS/MS.

- by Guowen Liu
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- Chemical Engineering, Analytical Chemistry, Mass Spectrometry, Bias

A single flux quantum (SFQ) pulse coincidence detector based on resistively shunted nonhysteretic Josephson junctions was designed and simulated. The coincidence detector generates an SFQ pulse when the delay between the arrival of SFQ pulses at its two inputs is less than the coincidence threshold. Simulations indicate that the minimum coincidence threshold time can be as short as 400 f 200 fs assuming Josephson junction characteristic voltages of 1 mV, overdamped dynamics and 4.2 K operating temperatures. Circuit architectures exploiting this gate are suggested. Estimates of the effects of thermal noise on resolution are presented indicating the potential for various time domain measurements with sub-picosecond resolution.

- by Peter Rosenthal
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- Materials Engineering, Condensed Matter Physics, Measurement, Temperature

Introduction Flat detector computed tomography (FDCT) is an imaging tool that generates three-dimensional (3-D) volumes from data obtained during C-arm rotation using CT-like reconstruction algorithms. The technique is relatively new and, at current levels of performance, lags behind conventional CT in terms of image quality. However, the advantage of its availability in the interventional room has prompted neuro-radiologists to identify clinical settings where its role is uniquely beneficial. Methods We performed a search of the online literature databases to identify studies reporting experience with FDCT in interventional neuro-radiology. The studies were systematically reviewed and their findings grouped according to specific clinical situation addressed. Results FDCT images allow detection of procedural complications, evaluation of low-radiopacity stents and assessment of endosaccular coil packing in intra-cranial aneurysms. Additional roles are 3-D angiography that provides an accurate depiction of vessel morphology with low concentrations of radiographic contrast media and a potential for perfusion imaging due to its dynamic scanning capability. A single scan combining soft tissue and angiographic examina-tions reduces radiation dose and examination time. Ongoing developments in flat detector technology and reconstruction algorithms are expected to further enhance its performance and increase this range of applications.

- by James Byrne
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- Computed Tomography, Image Quality, Complication, Neuroradiology

Functionalizing surface enhanced the molecular sensing ability of a fabricated nanopore by increasing the translocation duration time for a short double-stranded DNA. The surface of nanopore was derivatized with ␥-aminopropyltriethoxysilane and the positively charged surface attracted DNA molecules when they were in the vicinity of nanopore. The translocation duration time of DNA increased due to the strong electrostatic interaction and it enabled us to detect a short double-stranded DNA (<1 kbp) that is under the size limit of a conventional solid state nanopore sensor. Both 539 and 910 bp double-stranded DNAs were analyzed with the surface functionalized nanopore and their translocation kinetics are presented in this work. The new feature of the surface modified nanopore that can detect short double-stranded DNA molecules could readily be applied for a rapid label-free diagnostic analysis in a Lab-On-a-Chip type DNA sensor.

- by KUIHYUN KIM
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- Analytical Chemistry, Biomedical Engineering, Biosensors, Sensor

From cell phones to biomedical systems, modern life is inexorably dependent on the complex convergence of technologies into stand-alone products designed to provide a complete solution in small, highly integrated systems with computing, communication, biomedical and consumer functions. The concept of system-on-package (SOP) originated in the mid-1990s at the NSF-funded Packaging Research Center at the Georgia Institute of Technology. This can be thought of as a conceptual paradigm in which the package, and not the bulky board, as the system and the package provides all the system functions in one single module, not as an assemblage of discrete components to be connected together, but as a continuous merging of various integrated thin film technologies in a small package. In the SOP concept, this is accomplished by codesign and fabrication of digital, optical, RF and sensor functions in both IC and the package, thus distinguishing between what function is accomplished best at IC level and at package level. In this paradigm, IC's are viewed as being best for transistor density while the package is viewed as being best for RF, optical and certain digital-function integration. The SOP concept is demonstrated for a conceptual broad-band system called an intelligent network communicator (INC). Its testbed acts as both a leading-edge research and teaching platform in which students, faculty, research scientists, and member companies evaluate the validity of SOP technology from design to fabrication to integration, test, cost and reliability. The testbed explores optical bit stream switching up to 100 GHz, digital signals up to 5-20 GHz, decoupling capacitor integration concepts to reduce simultaneous switching noise of power beyond 100 W/chip, design, modeling and fabrication of embedded components for RF, microwave, and millimeter wave applications up to 60 GHz. This article reviews a number of SOP technologies which have been developed and integrated into SOP test bed. These are 1) convergent SOP-based INC system design and architecture, 2) digital SOP and its fabrication for signal and power integrity, 3) optical SOP fabrication with embedded actives and passives, 4) RF SOP for high Q-embedded inductors, filters and other RF components, 5) mixed signal electrical test, 6) mixed signal reliability, and 7) demonstration of SOP by INC prototype system.

- by Manos M Tentzeris
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- Communication, Antennas, Packaging, Embedded Systems

Purpose The purpose of this study was to analyze the length variations of the pancreas using computed tomography (CT) and establish a database for short pancreas. Methods We retrospectively reviewed CT examinations of 228 adults and rated pancreatic lengths qualitatively on a scale of 1-3 using transverse images. 1, normal pancreas length; 2, mildly short pancreas; and 3, markedly short pancreas. The length of the pancreas from head to tail was also measured using the "curved line tool" through the midline of the organ on curved planar reconstructed (CPR) images. The pancreatic neck-tail length and the abdominal radius were measured on transverse images, and the ratio of pancreatic neck-tail length to abdominal radius was calculated to avoid the eVect of body mass diVerences. All data were analyzed statistically. Results The pancreas length was normal (group 1) in 180 (78.9%) patients, mildly short (group 2) in 38 (16.7%), and markedly short (group 3) in 10 (4.4%). The average pancreatic length on CPR evaluation was 207.5 § 19.1 mm in group 1, 168.9 § 8.5 mm in group 2, and 135.1 § 10.7 mm in group 3. There were statistically signiWcant diVerences between three groups. Although it was not statistically sig-niWcant, percentage of diabetes mellitus was higher in group 3 (20%) than other two groups (13.2% in group 2, and 8.9% in group 1). Conclusions CT examination of the pancreas is an eVective imaging method to classify the pancreatic length and to detect short pancreas. We suggest that pancreatic length variations should be reported on routine abdominal CT examinations.

- by Murat Acar
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- Surgery, Evaluation, Treatment, Medicine

We have developed a sensor concept capable of discriminating environments that induce proteins to enter unfolding intermediate states. Such a sensor detects the presence of environmental stressors such as chemical agents in aqueous media, thermal stress or the presence of ionizing or non-ionizing radiation by monitoring the conformation state of a "sensor protein". In this paper, we demonstrate the concept by using surface plasmon resonance to monitor binding of thermally and chemically stressed sensor proteins to a chaperone, ␣-crystallin, bound to the sensor surface. Citrate synthase and insulin were used as example sensor proteins to detect the presence of thermal stress and chemical stress, respectively.

- by Marcela Bilek
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- Analytical Chemistry, Biomedical Engineering, Crystallography, Protein Folding

Mamta Jangra, Gobinda Majumder, Mandar Saraf, B. Satyanarayana, R.R. Shinde, Suresh S Upadhya, Vivek M Datar, Douglas A. Glenzinski, Alan Bross, Anna Pla-Dalmau, Vishnu V. Zutshi, Robert Craig Group and E Craig Dukes f Homi Bhabha National Institute, Mumbai-400094, India Tata Institute of Fundamental Research, Mumbai-400005, India The Institute of Mathematical Sciences, Chennai-600113, India Fermi National Accelerator Laboratory, IL 60510, United States Northern Illinois University, IL 60510, United States Virginia University, VA, United States

- by Alan Bross
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- Physics, Instrumentation, Detector

The growing technology in the world is rapidly transforming the way people lead their lives. Industrialization and urbanization have brought an enormous increase in sedentary lifestyle to the modern world. Indulged in technology, people are often found abandoning their good posture and being hunched over for really long hours. Good posture is of utmost importance for leading a healthy lifestyle and it is said that back pain is the third most common reason for people to visit the doctor. Yet, knowingly or unknowingly, people compromise on one of the most essential traits of what makes them human; the ability to walk upright. The aim of this paper is to provide a feasible solution to this problem by presenting a wearable device that recognizes the posture of the person and sends live data on the phone through an app. It records the posture and classifies it as Good, Okay or Bad. It also gives the statistics and overall feedback of how it can be improved.

- by Greeshma Karanth
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- Computer Science, Internet of Things, Detector
- by Erno Lindner
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- Chemistry, Analytical Chemistry, Medicine, Quantitative analysis

Nanomaterials -nanoparticles analysis and behaviours for different applications such as medical, biotechnology and environmental ones View project Potential ecological risk and human risk of heavy metal concentration in road dust from... more

- by Mohammed Baalousha
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- Engineering, Technology, Light Scattering, Nanoparticle

The research reported in this paper has focused on the different modes of heat transfer – conductive (to the substrate), conductive and convective (to the environment) and radiative (to the environment) – from an on-chip resistance temperature detector (RTD). The study has been carried out at various input voltages, various pressures ranging from atmospheric to vacuum, and for two classes of platforms for the device – thermal insulators (glass wool and ceramic), and a thermal conductor (aluminum block). The transient temperature–time response of the RTD under the various conditions stated above was recorded. A heat transfer model approximately accounting for all the modes of heat transfer was introduced. The calibration parameters of the model allowed us to quantify the different modes of heat transfer. The model uncovers the fact that the heat losses to the environment via conduction and convection are almost as much as the heat lost by radiation (radiative effects were unequivocally confirmed experimentally). Compared to these losses, conductive heat losses from the RTD to its underlying substructure are far more dominant (almost five times). We also give an analysis originating from the exact form of conservation of energy and demonstrate that the use of the simplified model has led to the most dominant heat transfer mode of conduction to the substrate being underestimated by no more than 7.89% (at the highest input power tested).

- by Abhijit Bhattacharyya
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- Mechanical Engineering, Conduction, Modeling, Heat Transfer

A novel nonenzymatic glucose sensor was developed based on the renewable Ni nanoparticle-loaded carbon nanofiber paste (NiCFP) electrode. The NiCF nanocomposite was prepared by combination of electrospinning technique with thermal treatment method. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that large amounts of spherical nanoparticles were well dispersed on the surface or embedded in the carbon nanofibers. And the nanoparticles were composed of Ni and NiO, as revealed by energy dispersive X-ray spectroscopy (EDX) and X-ray powder diffraction (XRD). In application to nonenzymatic glucose determination, the renewable NiCFP electrodes, which were constructed by simply mixing the electrospun nanocomposite with mineral oil, exhibited strong and fast amperometric response without being poisoned by chloride ions. Low detection limit of 1 μM with wide linear range from 2 μM to 2.5 mM (R = 0.9997) could be obtained. The current response of the proposed glucose sensor was highly sensitive and stable, attributing to the electrocatalytic performance of the firmly embedded Ni nanoparticles as well as the chemical inertness of the carbon-based electrode. The good analytical performance, low cost and straightforward preparation method made this novel electrode material promising for the development of effective glucose sensor.

- by Zhitao Wang
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- Analytical Chemistry, Biomedical Engineering, Electrochemistry, Carbon

A direct fluorescence polarization (FP) assay strategy, dedicated to the small molecule sensing and based on the unique induced-fit binding mechanism of end-labelled nucleic acid aptamers, has been recently developed by our group. Small target binding has been successfully converted into a significant increase of the fluorescence anisotropy signal presumably produced by the reduction of the local motional freedom of the dye. In order to generalize the approach, a rational FP sensor methodology was established herein, by engineering instability in the secondary structure of an aptameric recognition element. The antiadenosine DNA aptamer, labelled by a single fluorescein dye at its 3 extremity, was employed as a model functional nucleic acid probe. The terminal stem of the stem-loop structure was shortened to induce a destabilized/denatured conformation which promoted the local segmental mobility of the dye and then a significant depolarization process. Upon target binding, the structural change of the aptamer induced the formation of a stable stem-loop structure, leading to the reduction of the dye mobility and the increase in the fluorescence anisotropy signal. This reasoned approach was applied to the sensing of adenosine and adenosine monophosphate and their chiral analysis.

- by Béatrice Roy
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- Analytical Chemistry, Design, Biomedical Engineering, Biosensors

A conductometric sensor using microtubules of polyaniline as transducer cum immobilization matrix is reported, capable of detecting ethanol in liquid phase. Enzyme ADH (alcohol dehydrogenase) and its coenzyme NAD + have been used to improve the selectivity of the sensor. The sensor concept is based on the protonation of the polyaniline by the hydrogen ion produced in the enzyme-catalyzed reaction, leading to changes in the electrical conductance of the polyaniline. The sensor works well on the physiological pH, can detect ethanol as low as 0.02% (v/v) (0.092 M) and has a linear trend at par healthcare guidelines. The sensor responses were measured in various permutation and combination of enzyme and coenzyme concentrations and site of immobilization. The sensor shows minor interference with other functional groups and alcohols. The possible causes for such interference have been discussed.

- by Amrendra Ajay
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- Analytical Chemistry, Biomedical Engineering, Electrochemistry, Nanotechnology

Axisymmetric drop-shape analysis-no apex (ADSA-NA) is a recent drop-shape method that allows the simultaneous measurement of contact angles and surface tensions of drop configurations without an apex (i.e., a sessile drop with a capillary protruding into the drop). Although ADSA-NA significantly enhanced the accuracy of contact angle and surface tension measurements compared to that of original ADSA using a drop with an apex, it is still not as accurate as a surface tension measurement using a pendant drop suspended from a holder. In this article, the computational and experimental aspects of ADSA-NA were scrutinized to improve the accuracy of the simultaneous measurement of surface tensions and contact angles. It was found that the results are relatively insensitive to different optimization methods and edge detectors. The precision of contact angle measurement was enhanced by improving the location of the contact points of the liquid meniscus with the solid substrate to subpixel resolution. To optimize the experimental design, the capillary was replaced with an inverted sharp-edged pedestal, or holder, to control the drop height and to ensure the axisymmetry of the drops. It was shown that the drop height is the most important experimental parameter affecting the accuracy of the surface tension measurement, and larger drop heights yield lower surface tension errors. It is suggested that a minimum nondimensional drop height (drop height divided by capillary length) of 1.7 is required to reach an error of less than 0.2 mJ/m 2 for the measured surface tension. As an example, the surface tension of water was measured to be 72.46 (0.04 at 24°C by ADSA-NA, compared to 72.39 (0.01 mJ/m 2 obtained with pendant drop experiments.

- by Ali Kalantarian
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- Experimental Design, Multidisciplinary, Contact angle, Shape

Two ordinary green light-emitting diodes used as light emitter and detector coupled with simple voltmeter form a complete, cost-effective prototype of a photometric hemoglobinometer. The device has been optimized for cuvette assays of total hemoglobin (Hb) in diluted blood using three different chemical methods recommended for the needs of clinical analysis (namely Drabkin, lauryl sulfate, and dithionite methods). The utility of developed device for real analytics has been validated by the assays of total Hb content in human blood. The results of analysis are fully compatible with those obtained using clinically recommended method and clinical analyzer.

- by Łukasz Tymecki
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- Engineering, Biological Sciences, Photometry, Cost effectiveness

An open channel scrubber is proposed as a miniature fieldable gas collector. The device is 100 mm in length, 26 mm in width and 22 mm in thickness. The channel bottom is rendered hydrophilic and liquid flows as a thin layer on the bottom. Air sample flows atop the appropriately chosen flowing liquid film and analyte molecules are absorbed into the liquid.

- by Shin-Ichi Ohira
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- Algorithms, Analytical Chemistry, System Integration, Environmental Monitoring

An imprinted polymer modified hanging mercury drop electrode (HMDE) in Model 303A system in conjunction with a PAR Model 264A Polarographic Analyzer/Stripping Voltammeter has been used for the selective analysis of a diquat herbicide viz., 5,6-dihydropyrazino[1,2,3,4-[lmn]-1,10-phenanthrolinium dichlorides in differential pulse cathodic stripping voltammetry mode. Complex aqueous samples (drinking water and agricultural soil suspension), spiked with a diquat herbicide, were directly analyzed by the adsorptive accumulation of the analyte over the working electrode (accumulation potential À 0.8 V (vs. Ag/AgCl), accumulation time 120 s, pH 7.0, supporting electrolyte 0.1 M KCl, scan rate 10 mV s À1 , pulse amplitude 25 mV). The limit of detection for diquat herbicide was found to be 0.34 nmol L À1 (0.1 ppb, RSD 2%, S/N 2).

- by Dhana Lakshmi
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- Analytical Chemistry, Biomedical Engineering, Electrochemistry, Creatine

X-ray fluorescence (XRF) analysis is one of the most widely used techniques for material analysis in the field of cultural heritage, thanks to its non-destructive and multi-elemental character and also to the possibility of using portable instrumentations. The need of compact systems for in situ analyses results generally in a worse, more limited performance: the detection of low-Z elements is the most affected aspect. In this article, we present a custom-realised portable XRF spectrometer developed in Florence at the LABEC laboratory of Istituto Nazionale di Fisica Nucleare (INFN), in collaboration with ICVBC of Consiglio Nazionale delle Ricerche (CNR). The system features a high efficiency for a wide range of elements, even at low Z (down to sodium), thanks to the use of two tubes with different anodes and to the presence of a continuous helium flow in front of the tubes and the detector, in order to enhance transmission of both primary and characteristic X-rays. After a detailed description of the spectrometer, the experimental characterisation of its performance is presented: efficiency curves obtained from the analysis of thin standards are reported, together with minimum detection limits for some elements in a thick target of medium-low density matrix. Examples of measurements, which demonstrate the capability and effectiveness of this spectrometer, are also reported.

- by P. Mandò and +1
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- Density, Instrumentation, Mathematical Sciences, Physical sciences

We analyze theoretically the properties of the recently introduced and experimentally demonstrated converter of frequency to power. The system is composed of a hybrid single-electron box with normal island and superconducting lead, and the detector of the energy flow using a thermometer on a normal metal bolometer. Here we consider its potential for metrology. The errors in power arise mainly from inaccuracy of injecting electrons at the precise energy equal to the energy gap of the superconductor. We calculate the main systematic error in form of the excess average energy of the injected electrons and its cumulants, and due to sub-gap leakage. We demonstrate by analytic and numerical calculations that the systematic error in detection can, in principle, be made much smaller than the injection errors, which also, with proper choice of system parameters, can be very small, < 1%, at low enough temperature. Finally we propose a simplified configuration for metrological purposes.

- by Marco Marín Suárez
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- Physics, Computational Physics, Superconductivity, Metrology