188 research outputs found
Bio-analytical method validation and its importance in pharma research - A review article
Bioanalytical method based on a variety of physico-chemical and biological techniques such as chromatography, immunoassay and mass spectrometry, must be validated prior to and during use to give confidence in the results generated. It is the process used to establish that a quantitative analytical method is suitable for biomedical applications. Bioanalytical method validation includes all of the procedures that demonstrate that a particular method used for quantitative measurement of analytes in a given biological matrix, such as blood, plasma, serum, or urine is reliable and reproducible for the intended use. The present manuscript focuses on the consistent evaluation of the key bioanalytical validation parameters is discussed: accuracy, precision, sensitivity, selectivity, standard curve, limits of quantification, range, recovery and stability. These validation parameters are described, together with an example of validation methodology applied in the case of chromatographic methods used in bioanalysis, taking in account to the recent Food and Drug Administration (FDA) guidelines and EMA guid
Use of CR-39 films for nuclear radiation shielding efficacy evaluation of lining materials for combat vehicles
All materials provide, to a lesser or greater extent, shielding against
nuclear radiations. Armoured fighting vehicles (AFVs) have steel as the structural
material, which appears to be a reasonably good gamma and neutron shield material
but a shield of pure iron would not be equally effective against whole range of
neutron energies as it has a few resonances in electron volt range, and it reduces
energy of fast neutrons to lower energy neutrons. These neutrons will be absorbed
through radiative capture and emit gamma radiations. Thus it is essential that an
effective shield should contain a large amount of moderating material, hydrogen
being preferred with low atomic number materials (B, C, Li) and lead (Pb) to ensure
that the neutrons do not diffuse at intermediate energies in the shield as well as
gamma attenuation will also take place.
In order to have a suitable shield material for armoured vehicles which serves as
neutron and gamma radiation attenuator, polyethylene polymer with fillers lining
materials are preferred. These materials were evaluated against gamma and fast
neutrons using radioactive sources for suitability to fitment into combat vehicle as
per the requirement of protection factor values. The detector for gamma radiation
was used as Nal(Tl) while for neutron, CR-39 film was used.Use of CR-39 films for nuclear radiation shielding efficacy evaluation of lining
materials for combat vehicles
Deepak Gopalani1*, A S Jodha1, M K Das1, R K Singh2 and G L Baheti1
1Defence Laboratory, Jodhpur-342 011, Rajasthan, India
2Defence Material & Store Research & Developement Establishment, Kanpur-208 013,
Uttar Pradesh, India
E-mail : [email protected] Laboratory, Jodhpur-342 011, Rajasthan, India
2Defence Material & Store Research & Developement Establishment, Kanpur-208 013,
Uttar Pradesh, Indi
Management Of Subclinical Hypothyroidism Through Ayurveda: A Case Study
Hypothyroidism falls within the domain of dhatvagni mandyajanya vyadhi, which is characterized by impaired metabolism at the Dhatu (tissue) level. A sedentary lifestyle combined with high-calorie foods that require little energy expenditure can be the cause of a disrupted metabolism. This case of subclinical hypothyroidism is selected due to its prevalence in the community. A female patient aged 29 years, a nurse by profession presented with chief complaints of fatigue, weight gain, hair loss, irregular menstrual periods, and puffiness of face for four years. She was diagnosed with subclinical hypothyroidism with increased serum thyroid-stimulating hormone levels. A treatment plan was planned according to the clinical symptoms of the patient. She was treated with ayurvedic internal medications for a period of six months along with udhvartana treatment externally. The combined action of Ayurveda medicines along with udhvartana showed significant relief in the symptoms clinically along with the reduction in the thyroid hormone levels
N 2-(7-Bromo-9-butyl-9H-carbazol-2-yl)-9,9-diethyl-N 2,N 7,N 7-triphenyl-9H-fluorene-2,7-diamine
In the title molecule, C51H46BrN3, the central fluorene residue is planar (r.m.s. deviation = 0.0203 Å), as is the carbazole system (r.m.s. deviation = 0.0154 Å), and these groups are almost orthogonal [dihedral angle = 79.72 (3)°]. The three-dimensional architecture is consolidated by C—H⋯π interactions. The butyl substituent is disordered with two sites resolved for the terminal propyl atoms; the major component had a site-occupancy factor of 0.686 (3)
Production Process Modelling Architecture to Support Improved Cyber-Physical Production Systems
With the proliferation of intelligent networks in industrial environments, manufacturing SME’s have been in a continuous search for integrating and retrofitting existing assets with modern technologies that could provide low-cost solutions for optimizations in their production processes. Their willingness to support a technological evolution is firmly based on the perception that, in the future, better tools will guarantee process control, surveillance and maintenance. For this to happen, the digitalization of valuable and extractable information must be held in a cost-effective manner, through contemporary approaches such as IoT, creating the required fluidity between hardware and software, for implementing Cyber-Physical modules in the manufacturing process. The goal of this work is to develop an architecture that will support companies to digitize their machines and processes through an MDA approach, by modeling their production processes and physical resources, and transforming into an implementation model, using contemporary CPS and IoT concepts, to be continuously improved using forecasting/predictive algorithms and analytics.authorsversionpublishe
Task-specific information for imaging system analysis
ABSTRACT We present a novel method for computing the information content of an image. We introduce the notion of task-specific information (TSI) in order to quantify imaging system performance for a given task. This new approach employs a recently-discovered relationship between the Shannon mutual-information and minimum estimation error. We demonstrate the utility of the TSI formulation by applying it to several familiar imaging systems including (a) geometric imagers, (b) diffraction-limiter imagers, and (c) projective/compressive imagers. Imaging system TSI performance is analyzed for two tasks: (a) detection, and (b) classification
Efficiency of Energy Conversion in Thermoelectric Nanojunctions
Using first-principles approaches, this study investigated the efficiency of
energy conversion in nanojunctions, described by the thermoelectric figure of
merit . We obtained the qualitative and quantitative descriptions for the
dependence of on temperatures and lengths. A characteristic temperature:
was observed. When , . When , tends to a saturation value. The dependence of
on the wire length for the metallic atomic chains is opposite to that for
the insulating molecules: for aluminum atomic (conducting) wires, the
saturation value of increases as the length increases; while for
alkanethiol (insulating) chains, the saturation value of decreases as the
length increases. can also be enhanced by choosing low-elasticity bridging
materials or creating poor thermal contacts in nanojunctions. The results of
this study may be of interest to research attempting to increase the efficiency
of energy conversion in nano thermoelectric devices.Comment: 2 figure
Effect of Thermoelectric Cooling in Nanoscale Junctions
We propose a thermoelectric cooling device based on an atomic-sized junction.
Using first-principles approaches, we investigate the working conditions and
the coefficient of performance (COP) of an atomic-scale electronic refrigerator
where the effects of phonon's thermal current and local heating are included.
It is observed that the functioning of the thermoelectric nano-refrigerator is
restricted to a narrow range of driving voltages. Compared with the bulk
thermoelectric system with the overwhelmingly irreversible Joule heating, the
4-Al atomic refrigerator has a higher efficiency than a bulk thermoelectric
refrigerator with the same due to suppressed local heating via the
quasi-ballistic electron transport and small driving voltages. Quantum nature
due to the size minimization offered by atomic-level control of properties
facilitates electron cooling beyond the expectation of the conventional
thermoelectric device theory.Comment: 8 figure
Molecular design and control of fullerene-based bi-thermoelectric materials
Molecular junctions are a versatile test bed for investigating nanoscale thermoelectricity and contribute to the design of new cost-effective environmentally friendly organic thermoelectric materials. It was suggested that transport resonances associated with discrete molecular levels could play a key role in thermoelectric performance, but no direct experimental evidence has been reported. Here we study single-molecule junctions of the endohedral fullerene Sc3N@C8 connected to gold electrodes using a scanning tunnelling microscope. We find that the magnitude and sign of the thermopower depend strongly on the orientation of the molecule and on applied pressure. Our calculations show that Sc3N inside the fullerene cage creates a sharp resonance near the Fermi level, whose energetic location, and hence the thermopower, can be tuned by applying pressure. These results reveal that Sc3N@C80 is a bi-thermoelectric material, exhibiting both positive and negative thermopower, and provide an unambiguous demonstration of the importance of transport resonances in molecular junctions
- …