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1.
Rev Sci Instrum ; 95(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38758770

ABSTRACT

A differential scanning calorimeter was designed to study the thermal analysis of the materials for the nuclear reactor/allied facilities. The hardware and software were developed for measuring the calorimetric signals and had various features for the thermal analysis of the material. The processing of calorimetric signals was carried out by a programmable system-on-chip. Using a programmed temperature profile, the differential scanning calorimeter setup was tested, calibrated, and validated with standard aluminum and indium metal samples. It was found that the obtained results agree with the literature values. The methodology for the experiment was optimized. Various experiments were carried out, and the thermal analysis of different materials for nuclear reactors was investigated and studied. The instrumentation is also compact, accurate, reliable, and cost-effective for the thermal analysis of materials.

2.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37862516

ABSTRACT

Liquid sodium is the heat transport medium in fast breeder reactors due to its favorable chemical, physical, and nuclear properties. Wetting of liquid sodium with the material of reactor components is essential for the effective functioning of the reactor. Liquid sodium wetting plays a crucial role, such as in (i) heat transfer and (ii) image reconstruction under sodium ultrasonic scanners. Contact angle is the inverse measure of the wetting of liquids over solid surfaces. A contact angle measurement system was set up in an inert atmosphere glow box to study the wetting behavior of liquid sodium on reactor materials. The contact angle of liquid sodium on nickel surface was measured as a function of temperature, and the results obtained were found to be in good agreement with the literature values. The contact angle of liquid sodium on SS316LN as a function of temperature was measured for the first time using this facility.

3.
Cureus ; 14(10): e30142, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36381703

ABSTRACT

Angioedema is the diffuse edematous swelling of the soft tissues that most commonly involves the submucosal and subcutaneous connective tissues. It can also affect the connective tissues of the respiratory and gastrointestinal tract. The most common pathogenesis is the degranulation of mast cells, leading to histamine release and increased vascular permeability. The immunoglobulin E (IgE)-mediated hypersensitivity reactions are triggered by foods, preservatives such as sodium benzoate used in peanut butter, dust, drugs like angiotensin-converting enzyme inhibitors (ACE) like captopril, enalapril, lisinopril and pollens, and contact allergies started by prolonged contact with dental rubber dams and cosmetics. Hereditary factors such as quantitative reduction of C1 esterase inhibitor (C1-INH) deficiency and dysfunctional C1 esterase inhibitor (C1-INH) are also postulated in its etiopathogenesis. In addition, lymphoproliferative disorders, bacterial or viral infections, lupus erythematosus, and minor trauma from dental procedures may precipitate an angioedema attack.

4.
Rev Sci Instrum ; 93(4): 044105, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35489907

ABSTRACT

An isopiestic experimental facility for the measurement of vapor pressures has been designed, fabricated, and commissioned. Using the vapor pressure data as a function of temperature, useful thermodynamic properties of alloys and compounds of interest can be derived. The isopiestic facility comprises a pair of furnaces, temperature controllers, thermocouple movement mechanism, user interface, and data collection. Four such experimental setups have been commissioned. This experimental facility is useful to determine the vapor pressures of a volatile component over the condensed phases as a function of temperature and composition. Using the vapor pressure data, the thermodynamic properties of various systems can be determined. The experimental setup was validated by a Pr-Cd isopiestic run, and the results are compared with the data reported in the literature.

5.
Sensors (Basel) ; 20(11)2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32492971

ABSTRACT

Over the past few years, unmanned aerial vehicles (UAV) or drones have been used for many applications. In certain applications like surveillance and emergency rescue operations, multiple drones work as a network to achieve the target in which any one of the drones will act as the master or coordinator to communicate, monitor, and control other drones. Hence, drones are energy-constrained; there is a need for effective coordination among them in terms of decision making and communication between drones and base stations during these critical situations. This paper focuses on providing an efficient approach for the election of the cluster head dynamically, which heads the other drones in the network. The main objective of the paper is to provide an effective solution to elect the cluster head among multi drones at different periods based on the various physical constraints of drones. The elected cluster head acts as the decision-maker and assigns tasks to other drones. In a case where the cluster head fails, then the next eligible drone is re-elected as the leader. Hence, an optimally distributed solution proposed is called Bio-Inspired Optimized Leader Election for Multiple Drones (BOLD), which is based on two AI-based optimization techniques. The simulation results of BOLD compared with the existing Particle Swarm Optimization-Cluster head election (PSO-C) in terms of network lifetime and energy consumption, and from the results, it has been proven that the lifetime of drones with the BOLD algorithm is 15% higher than the drones with PSO-C algorithm.

6.
Med Eng Phys ; 42: 105-110, 2017 04.
Article in English | MEDLINE | ID: mdl-28159450

ABSTRACT

Hermetic electrical feedthroughs are essential for safe and functional active implantable biomedical devices and for a wide range of other applications such as batteries, supercapacitors, OLEDs and solar cells. Ceramics and metals have previously been the materials of choice for encapsulations, while polymers have advantages of ease of mass production and end user compatibility. We demonstrate a laser sealing technology that gives hermetic, mechanically strong feedthroughs with low electrical resistance in a polyetheretherketone (PEEK) encapsulation. The conductive pathways are wires and sputtered thin films. The water vapor transmission rate through the fabricated encapsulations is comparable to that of PEEK itself.


Subject(s)
Ketones/chemistry , Lasers , Polyethylene Glycols/chemistry , Prostheses and Implants , Benzophenones , Capsules , Electric Impedance , Polymers , Stress, Mechanical
7.
CALPHAD ; 44: 14-20, 2014 Mar.
Article in English | MEDLINE | ID: mdl-25540474

ABSTRACT

Cadmium vapor pressures were determined over Ce-Cd samples by an isopiestic method. The measurements were carried out in the temperature range from 690 to 1080 K and over a composition range of 48-85 at% Cd. From the vapor pressures thermodynamic activities of Cd were derived for all samples at their respective sample temperatures, and partial molar enthalpies of Cd were obtained from the temperature dependence of the activities. With these partial molar enthalpies the Cd activities were converted to a common temperature of 823 K. By means of a Gibbs-Duhem integration Ce activities were calculated, using a corresponding literature value for the two-phase field (CeCd11+L) as integration constant. Finally integral Gibbs energies were calculated for the composition range 48-100 at% Cd with a minimum value of -37 kJ g-atom-1 at 823 K in the phase CeCd. Phase boundaries of the intermetallic compounds CeCd, CeCd2, Ce13Cd58, and CeCd11 were estimated from the vapor pressure measurements and from SEM analyses.

8.
J Alloys Compd ; 610(100): 676-683, 2014 Oct 15.
Article in English | MEDLINE | ID: mdl-25328283

ABSTRACT

Vapour pressure measurements were performed in terms of a non-isothermal isopiestic method to determine vapour pressures of Cd in the system Cd-Gd between 693 and 1045 K. From these results thermodynamic activities of Cd were derived as a function of temperature for the composition range 52-86 at.% Cd. By employing an adapted Gibbs-Helmholtz equation, partial molar enthalpies of mixing of Cd were obtained for the corresponding composition range, which were used to convert the activity values of Cd to a common average sample temperature of 773 K. The relatively large variation of the activity across the homogeneity ranges of the phases Cd2Gd and Cd45Gd11 indicates that they probably belong to the most stable intermetallic compounds in this system. An activity value of Gd for the two phase field Cd6Gd+L was available from literature and served as an integration constant for a Gibbs-Duhem integration. Integral Gibbs energies are presented between 51 and 100 at.% Cd at 773 K, referred to Cd(l) and α-Gd(s) as standard states. Gibbs energies of formation for the exact stoichiometric compositions of the phases Cd58Gd13, Cd45Gd11, Cd3Gd and Cd2Gd were obtained at 773 K as about -19.9, -21.1, -24.8, and -30.0 kJ g atom-1, respectively.

9.
Article in English | MEDLINE | ID: mdl-26029745

ABSTRACT

Geographic disparities in access to and outcomes in transplantation have been a persistent problem widely discussed by transplant researchers and the transplant community. One of the alleged causes of disparities in the United States is administratively determined organ allocation boundaries that limit organ sharing across regions. This paper applies mathematical programming to construct alternative liver allocation boundaries that achieve more geographic equity in access to transplants than the current system. The performance of the optimal boundaries were evaluated and compared to that of current allocation system using discrete event simulation.

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