scholarly journals Light-Dependent Resistors as Dosimetric Sensors in Radiotherapy

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1568 ◽  
Author(s):  
Juan Román-Raya ◽  
Isidoro Ruiz-García ◽  
Pablo Escobedo ◽  
Alberto J. Palma ◽  
Damián Guirado ◽  
...  
Keyword(s):  
Quality Control ◽  
Ionization Chamber ◽  
Low Cost ◽  
Complete Characterization ◽  
Readout System ◽  
Drift Correction ◽  
Ionization Chambers ◽  
The Common ◽  
Dose Measurements

Safe quality control of radiotherapy treatments lies in reliable dosimetric sensors. Currently, ionization chambers and solid-state diodes along with electrometers as readout systems are accomplishing this task. In this work, we present a well-known and low-cost semiconductor sensor, the light-dependent resistor (LDR), as an alternative to the existing sensing devices for dosimetry. To demonstrate this, a complete characterization of the response to radiation of commercial LDRs has been conducted in terms of sensitivity, reproducibility and thermal correction under different bias voltages. Irradiation sessions have been applied under the common conditions in radiotherapy treatments using a hospital linear accelerator. Moreover, the same electrometer used for the ionization chamber has also been successfully used for LDRs. In comparison with the sensitivity achieved for the ionization chamber (0.2 nC/cGy at 400 V bias voltage), higher sensitivities have been measured for the proposed LDRs, ranging from 0.24 to 1.04 nC/cGy at bias voltages from 30 to 150 V, with a reproducibility uncertainty among samples of around 10%. In addition, LDR temperature dependence has been properly modeled using the simple thermistor model so that an easy thermal drift correction of dose measurements can be applied. Therefore, experimental results show that LDRs can be a reliable alternative to dosimetric sensors with the advantages of low size, affordable cost and the fact that it could be adopted with minimal changes in routine dosimetry quality control since the same readout system is fully compatible.

Preparation and Characterization of Naturally Scented Candles Using the Lemongrass (Cymbopogon citratus) Essential Oil

2020 ◽  
Vol 977 ◽  
pp. 212-217
Author(s):  
Hoang Danh Pham ◽  
Tri Nhut Pham ◽  
Do Thi Kim Nga ◽  
Ngan Thi Thu Nhung ◽  
Tri Duc Lam ◽  
...  
Keyword(s):  
Citric Acid ◽  
Essential Oil ◽  
Essential Oils ◽  
Health Effects ◽  
Low Cost ◽  
Cymbopogon Citratus ◽  
Natural Sources ◽  
The Common ◽  
Lemongrass Essential Oil

At present, there are many different forms of relaxation and aromatic candles are one of the common forms. Scented candles not only provide background lighting but also help promoting a feeling of wellness. This study attempts to produce scented candles from natural sources such as soy wax, beeswax, and natural essential oils to bring the most practical benefits to the users. The produced candle should be long lasting, low cost and causes no health effects. The composition of scented candles included 60% beeswax, 30% soy wax, 8% lemongrass essential oil, 1% citric acid, and 1% ethanol.

Colex

Terminology ◽  
2006 ◽  
Vol 12 (2) ◽  
pp. 261-280 ◽  
Author(s):  
Brigitte Orliac
Keyword(s):  
Statistical Tests ◽  
Complete Characterization ◽  
Grammatical Relations ◽  
The Common ◽  
High Level

We present a method for extracting verb + noun collocations from specialized corpora based on the lexical functions of the Meaning-Text Theory. Lexical functions offer a complete characterization of verbal collocations. They cover the three grammatical relations that obtain between a verb and its arguments and provide high-level semantic descriptors to represent the meanings of the common verbal collocates of terms. Our system uses morphosyntactic patterns to extract verb–argument relations from a parsed corpus of computer texts. We then apply two statistical tests to isolate the true collocations in the list of syntactically extracted combinations. While the better of the two statistical tests identifies collocations with a precision of 71 %, we argue that a semantic filtering of the combinations, based on their ability to be encoded as standard lexical functions, could achieve higher precision.

Technical Note: Design and characterization of a large diameter parallel plate ionization chamber for accurate integral depth dose measurements with proton beams

2020 ◽  
Vol 47 (7) ◽  
pp. 3214-3224 ◽  
Author(s):  
Jonathan B. Farr ◽  
Vadim Moskvin ◽  
Renin C. Lukose ◽  
Weiguang Yao ◽  
Frank Schwamm
Keyword(s):  
Ionization Chamber ◽  
Parallel Plate ◽  
Large Diameter ◽  
Technical Note ◽  
Proton Beams ◽  
Depth Dose ◽  
Dose Measurements

scholarly journals Assessment of dosimetric parameters in mammography employing a homemade ionization chamber

2016 ◽  
Vol 12 (12) ◽  
Author(s):  
Jonas Oliveira da Silva ◽  
Linda V. E. Caldas
Keyword(s):  
Quality Control ◽  
Ionization Chamber ◽  
Early Stage ◽  
Low Cost ◽  
Control Program ◽  
Sensitive Volume ◽  
X Rays ◽  
Quality Control Program ◽  
Air Kerma ◽  
Breast Phantom

X-ray mammography examination is the reference tool to discover breast cancer in an early stage. The mammography unit must follow an accurate quality control program that covers both patient and staff radiation protection. Plane parallel ionization chambers are the reference instrument for dosimetry in mammography beams, but they can represent higher cost for small clinics in countries as Brazil. In this work, it is presented a low cost ionization chamber for mammography X-rays energy range dosimetry developed at IPEN.  The homemade ionization chamber has a sensitive volume of 6.0 cm3 and it was utilized to execute quality control tests in two distinct mammography systems: a GE Senographe DMR-plus and a Philips VMI Graph Mammo. The setups for the tests performed agreed with the IAEA HHS 2 and 17 recommendations. A breast phantom of various PMMA thicknesses was utilized in this work. The homemade ionization chamber performance was compared to that of a commercial one. The maximum difference between the incident air kerma measured with the reference ionization chamber and the developed one was only 5.62% for the GE equipment and only 4.42% for the Philips equipment. The homemade ionization chamber presented an excellent performance in incident air kerma and HVL measurements for the radiographic techniques utilized in the present work. All the results obtained were within IAEA specifications.

scholarly journals Electrochemical Detection and Characterization of Nanoparticles with Printed Devices

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 47 ◽  
Author(s):  
Daniel Martín-Yerga
Keyword(s):  
Quality Control ◽  
Electrochemical Detection ◽  
Chemical Nature ◽  
Low Cost ◽  
Cost Effective ◽  
Innovative Methods ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
User Friendly

Innovative methods to achieve the user-friendly, quick, and highly sensitive detection of nanomaterials are urgently needed. Nanomaterials have increased importance in commercial products, and there are concerns about the potential risk that they entail for the environment. In addition, detection of nanomaterials can be a highly valuable tool in many applications, such as biosensing. Electrochemical methods using disposable, low-cost, printed electrodes provide excellent analytical performance for the detection of a wide set of nanomaterials. In this review, the foundations and latest advances of several electrochemical strategies for the detection of nanoparticles using cost-effective printed devices are introduced. These strategies will equip the experimentalist with an extensive toolbox for the detection of nanoparticles of different chemical nature and possible applications ranging from quality control to environmental analysis and biosensing.

Experimental Characterization of Mechanical Behavior of Cord-Rubber Composites

1982 ◽  
Vol 10 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. Kumar ◽  
C. W. Bert
Keyword(s):  
Response Characteristic ◽  
Cord Compression ◽  
Complete Characterization ◽  
Strain Response ◽  
Strain Gages ◽  
Experimental Characterization ◽  
Rubber Composites ◽  
Stress Strain ◽  
Strain Data

Abstract Unidirectional cord-rubber specimens in the form of tensile coupons and sandwich beams were used. Using specimens with the cords oriented at 0°, 45°, and 90° to the loading direction and appropriate data reduction, we were able to obtain complete characterization for the in-plane stress-strain response of single-ply, unidirectional cord-rubber composites. All strains were measured by means of liquid mercury strain gages, for which the nonlinear strain response characteristic was obtained by calibration. Stress-strain data were obtained for the cases of both cord tension and cord compression. Materials investigated were aramid-rubber, polyester-rubber, and steel-rubber.

Isolation and characterization of oleochemical compounds from watermelon seed

2020 ◽  
Vol 10 (4) ◽  
pp. 79-82
Author(s):  
Madhubhushan M ◽  
Seshaiah S ◽  
Chandrudu J ◽  
Sagar R ◽  
Akila CR
Keyword(s):  
Cutting Tool ◽  
Citrullus Lanatus ◽  
Fatty Esters ◽  
Mineral Oils ◽  
Light Yellow ◽  
Isolation And Characterization ◽  
The Common ◽  
Set Up ◽  
Natural Gradation

The common watermelon item (Citrullus lanatus) seeds were gained from castoffs verdant nourishments for use by decorating, sun ventilation and pulverizing. Light yellow-toned oil was gotten by dissolvable withdrawal using oil atmosphere and the going with traits were gotten using oil ether: pH, refractive rundown, thickness, dissolvable miscibility, coagulating temperature, fire nature, express gravity, streak point and warmth of consuming. With a shallow level of unsaturation, stepped level of smoothness, and proximity of raised degree of the sensible proportion of free unsaturated fats. The low assessment of the solidifying temperature of the oil offered a hint that the oil can be managed in various areas paying little heed to the qualification in temperature. The following level of linoleic destructive of the oil offers a hint of natural gradation of solidarity. Fatty esters are increasing expanding significance as a biodegradable swap for mineral oils. In some request regions, for example, cutting tool oil, gearbox, pressure-driven oils, and greases for raw petroleum creation, the oleochemical items are set up. Nonetheless, certain particular wellsprings of fatty esters are hitherto to be abused for this comparative reason. This exploration subsequently tests into one of the less used wellsprings of fatty esters in watermelon. The oil from the kernels demonstrations a top-notch yield presents significant utilitarian gatherings for change and thus was utilized to set up an assortment of oleochemicals which demonstrated excellence materials in contrast with the routinely utilized oils feed frameworks for oleochemicals after portrayal. The photopolymers acquired indicated piercing vinyl protons for consistent polymerize.

Characterization of CMOS Structures (0.6 µm process) Submitted to HBM and COM ESD Stress Tests

1997 ◽  
Author(s):  
G. Meneghesso ◽  
E. Zanoni ◽  
P. Colombo ◽  
M. Brambilla ◽  
R. Annunziata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrostatic Discharge ◽  
Stress Test ◽  
Complete Characterization ◽  
Stress Tests ◽  
Test Procedures ◽  
Emission Microscopy ◽  
Fast Rise ◽  
Scanning Electron

Abstract In this work, we present new results concerning electrostatic discharge (ESD) robustness of 0.6 μm CMOS structures. Devices have been tested according to both HBM and socketed CDM (sCDM) ESD test procedures. Test structures have been submitted to a complete characterization consisting in: 1) measurement of the tum-on time of the protection structures submitted to pulses with very fast rise times; 2) ESD stress test with the HBM and sCDM models; 3) failure analysis based on emission microscopy (EMMI) and Scanning Electron Microscopy (SEM).

Emerging Techniques for the Characterization of Nano-Mechanical Properties of Integrated Circuit Components

2008 ◽  
Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Manufacturing Process ◽  
Solder Bumps ◽  
Initial Work ◽  
Circuit Components ◽  
Materials Used

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.

Sign in / Sign up

Export Citation Format

Share Document