Small Setup Research Articles

Comparison of positioning accuracy between personalized polyurethane foam with wing boards and negative pressure vacuum bag in radiotherapy for lung cancer

Objective To compare the positioning accuracy between personalized polyurethane foam with wing boards and negative pressure vacuum bag in radiotherapy for lung cancer using kilovoltage cone beam computed tomography (CBCT). Methods Thirty-nine patients with lung cancer who received chest radiotherapy in our hospital from 2015 to 2016 were enrolled as subjects. In those patients, 20 were immobilized by negative pressure vacuum bags (VB group) and the others by personalized polyurethane foam with wing boards (PF group). CBCT images were acquired weekly and registered with planning CT images. Setup errors in the left-right, superior-inferior, and anterior-posterior directions, three-dimensional (3D) displacement vector, and setup time were recorded. The margin of the planning target volume (PTV) was calculated using the Van Herk formula (2.5∑+ 0.7σ). Between-group comparison was made by paired t test. Results The PF group had a significant smaller setup error in the y-direction than the VB group (2.54±1.79 vs. 3.19±2.14 mm, P=0.03), while there were no significant differences in setup errors in the x-or z-direction between the two groups (1.80±1.48 vs. 1.90±1.41 mm, P=0.46; 2.14±1.75 vs. 2.25±1.75 mm, P=0.35). There were no significant differences in rotational setup errors in the Rx-, Ry-, or Rz-direction between the two groups (1.15°±0.76°vs. 1.15°±0.85°, P=0.50; 0.71°±0.60°vs. 0.72°±0.43°, P=0.45; 0.62°±0.54° vs. 0.46°±0.30°, P=0.06). The PTV margins in the x-, y-, and z-directions were expanded by 5.56, 8.57, and 7.02 mm, respectively, in the PF group, and by 5.62, 9.27, and 7.23 mm, respectively, in the VB group. The proportion of patients with 3D displacement vectors larger than 5 mm was 40% in the PF group and 45% in the VB group. Conclusions For patients undergoing radiotherapy for lung cancer, personalized polyurethane foam with wing boards can, to a certain extent, reduce the setup error in the superior-inferior direction and PTV margin expansion. Key words: Lung neoplasms/radiotherapy; Polyurethane foam; Vacuum bag; Setup errors; Margin

Direct power control for grid-connected doubly fed induction generator using disturbance observer based control

Abstract A disturbance observer based control method for a grid-connected doubly fed induction generator is presented in this study. The proposed control method consists of a state-feedback controller and a disturbance observer (DO). The DO is used to compensate for model uncertainties with the aim of removing the steady-state error. The control objective consists of regulating the stator currents instead of the rotor currents in order to achieve direct control of the stator active and reactive powers. Such a control scheme removes the need for an exact knowledge of the machine parameters to achieve accurate control of the stator active and reactive powers. The main advantage of this control method is ensuring a good transient performance as per the controller design specifications, while guaranteeing zero steady-state error. Moreover, the proposed control method was experimentally validated on a small scale DFIG setup.

Synthesis of titanium (IV) oxide composite membrane for hydrogen production through alkaline water electrolysis

Alkaline water electrolysis is one of the most efficient methods for the hydrogen production. In this method widely used as the asbestos membrane as a separator, but this material is hazardous for health, causing cancer, in order to limit the usage of an asbestos separator. In this present study, a novel TiO2 composite membrane was synthesized from polysulfone (PSF), PVP and titanium oxide (TiO2) by phase inversion precipitation technique. The synthesized membranes were characterized by FT-IR, FE-SEM and XRD techniques. Further, membranes electrolysis performance studied in in-house fabricated small scale alkaline water electrolyser experimental setup of a 10 cm2 cell. These synthesized membranes were effectively improved the hydrogen production rate and purity compared to conventional asbestos separators. A current density of 600 mA/cm2 along with 30 ml/min hydrogen with 99.9% purity was obtained when operating the cell in 30 wt% KOH and 80 °C at 2 V. In electrolysis process, various experimental parameters considered such as an effect of temperature (30–80 °C) and KOH concentration (5–30 wt %) were studied. Hydrogen quantity measured by liquid displacement unit, purity determined by ENDEE portable hydrogen gas analyzer and gas chromatographic (GC) techniques. These synthesized composite membranes are low cost and showed excellent electrochemical performance and stability in alkaline medium.

Development of single step RT-PCR for detection of Kyasanur forest disease virus from clinical samples

BackgroundKyasanur Forest Disease (KFD), a tick borne flavivirus, which was earlier endemic to Karnataka state, India, has been confirmed and detected from neighboring states of Tamil Nadu, Maharashtra, Goa and Kerala states in India. Increased human and vector surveillance therefore becomes essential for the identification of KFD affected regions and control of further spread of the disease. Currently, available KFD detection assays include realtime RT-PCR and nested RT-PCR assays. Here we describe the development of a sensitive single step RT-PCR assay for the detection of KFD viral RNA. This can be easily used in any BSL-2 laboratory for screening of KFD suspected cases or for differential diagnosis of viral hemorrhagic fever panel. MethodThree primer sets were designed and checked for sensitivity using known dilutions of KFD viral RNA (Ranging from 106 copies to 10 copies). The primer set (2) was found to be most sensitive was selected and tested for specificity for Kyasanur forest disease virus (KFDV) by testing against zika, dengue, chikungunya, crimean congo hemorrhagic fever (CCHF), yellow fever, japanese encephalitis (JE) and west nile viruses. A total of 104 samples (human, monkey and tick positive and negative samples) were tested using this assay. ResultNo false positive or false negative results were seen for human, monkey or tick samples. The assay was specific for KFD and could detect upto 100 copies of KFD viral RNA. Discussion and conclusionThe previously published sensitive real time RT-PCR assay requires higher cost in terms of reagents and machine setup and technical expertise has been the primary reason for development of this assay. A single step RT-PCR is relatively easy to perform and more cost effective than real time RT-PCR in smaller setups in the absence of Biosafety Level-3 facility. This study reports the development and optimization of single step RT-PCR assay which is more sensitive and less time-consuming than nested RT-PCR and cost effective for rapid diagnosis of KFD viral RNA.

A Novel Approach Towards a Low Cost Peripheral Security System Based on Specific Data Rates

This paper proposes a method for data rate and specific signal format based peripheral security system which can also be used for authorization and recognition functions. This arrangement can be used for security management and monitoring of entry in a large peripheral area. Generally conventional peripheral security systems based on RF modules focus on power level or specific signal measurement, but those methods may suffer from jamming and are prone to hacking. In the proposed method, identification of authorized person depends upon exchange of certain fixed data rates between transmitter and receiver modules. Exchange of data is initiated by the first layer of security provided by IR sensor, and therefore this system can provide better protection from jamming devices or hacking. Results defined from the validation of small setup of hardware module also cross verifies the proposed approach.

Temperature quenching in LAB based liquid scintillator

The effect of temperature changes on the light output of LAB based liquid scintillator is investigated in a range from -5 to 30,^{circ }C with alpha -particles and electrons in a small scale setup. Two PMTs observe the scintillator liquid inside a cylindrically shaped aluminum cuvette that is heated or cooled and the temperature dependent PMT sensitivity is monitored and corrected. The alpha -emitting isotopes in dissolved radon gas and in natural Samarium (bound to a LAB solution) excite the liquid scintillator mixtures and changes in light output with temperature variation are observed by fitting light output spectra. Furthermore, also changes in light output by compton electrons, which are generated from external calibration gamma -ray sources, is analysed with varying temperature. Assuming a linear behaviour, a combined negative temperature coefficient of {(-0.29 pm 0.01)}{,%/^{circ }}hbox {C} is found. Considering hints for a particle type dependency, electrons show {(-0.17 pm 0.02)}{,%/^{circ }}hbox {C}, whereas the temperature dependency seems stronger for alpha -particles, with {(-0.35 pm 0.03)}{,%/^{circ }}hbox {C}. Due to a high sampling rate, a pulse shape analysis can be performed and shows an enhanced slow decay component at lower temperatures, pointing to reduced non-radiative triplet state de-excitations.

The preparation, characterization and application of glycol aqueous base graphene oxide nanofluid

Enhancement of the heat transfer of the cold side is one of the approaches to improve the performance of thermoelectric generator systems (TEGs). In order to investigate viability and further performance of the TEG for waste heat recovery in industry area, a small low-temperature waste heat thermoelectric generator setup has been constructed with graphene oxide (GO) nanofluids as coolants in the paper. The results showed excellent stability of GO nanofluids through the preparation of two-step method to be applied in the TEGs .The highest open output voltage of TEG system were obtained by 0.15% weight fraction of GO nanofluids as coolant when the temperature difference (△T) was designed at 95K and the hot side temperature was fixed at 373K in the TEGs. Compared with conventional glycol-water base fluid as coolant, the highest open voltage enhancement ratio has reached 65.26% in the TEGs.

Designing number of Kanban in glove box assembly

For many decades, Just-In-Time manufacturing and lean manufacturing have adopted kanban system as a mean to control inventory and production. A number of tagged kanban cards represents inventory of the system, whereas untagged kanban cards equate to production orders. The ideal conditions are a consistent product mixed with a small production lot size and minimum setup time. Such conditions are difficult to obtain even in many automotive assembly lines similar to a case study. The case study assembly line is a glove box assembly production line that assembles two plastic parts and wields them together with a vibration machine after positioning in a mold designed for different products. Because of storage equipment, each kanban card represents 60 identical glove boxes. Therefore, a production engineer re-schedules the production planning to minimize the numbers of changeover without any effect on downstream. This ad hoc production scheduling leads to urgent production orders and interruption of lot size. As a result, the factory embeds historical data into a computer simulation that accounts for current molds, receiving time, and numbers of pending kanban cards, as well as number of storage equipment. The results of this simulation reveals that scheduling criteria and suggest a suitable lot size if the factory decides to change a storage equipment.

Energy Efficient Communication Using Reconfigurable Directional Antenna in MANET

Mobile Ad Hoc Networks (MANET) are autonomous, infrastructure less and self-configuring networks. MANETs has gained lots of popularity due to on the fly deployment i.e. small network setup time and ability to provide communication in obstreperous terrains. Major challenges in MANETs include routing, energy efficiency, network topology control, security etc. Primary focus in this article is to provide method and algorithm to ensure significant energy savings using re-configurable directional antennas. Significant energy gains can be clinched using directional antenna. Key challenges while using directional antenna are to find destination location, antenna focusing, signal power and distance calculations. Re-configurable directional antenna can ensure significant energy gains if used intelligently. This article provides a brief insight into improved energy savings using re-configurable directional antennas and an associated algorithm.

Unified static-fatigue pull-through capacity equations for cold-formed steel roof battens

This paper investigates the fatigue pull-through capacity of cold-formed steel roof batten to rafter or truss connections based on static and constant amplitude cyclic tests. In order to represent all steel roof battens used worldwide, test battens were made using 0.75 and 0.95mm G550 and 0.80 and 1.00mm G300 cold-formed steel sheets. Each batten type was tested with 10g and 12g metal self-drilling screws that are commonly used to fasten steel roof battens to rafters or trusses. Tests were conducted using a small scale two-span batten test set-up as recommended by past research studies and simulated wind uplift loading on roof battens. Test results showed that cyclic wind uplift loading significantly reduced the pull-through capacities of steel roof battens, and thereby highlighted the need for accurate fatigue design rules. Therefore, a single-term exponential model was developed to determine the fatigue pull-through capacity reduction factors and was combined with the current static pull-through capacity equations to determine both static and fatigue pull-through capacities of steel roof battens subjected to wind uplift loading. The unified static-fatigue pull-through capacity equations were then verified using further constant amplitude cyclic tests of industrial steel roof battens. The proposed unified equations will facilitate effective designs of cold-formed steel roof battens without conducting the prototype Low-High-Low cyclic tests of roof assemblies.

The total leucocyte count: its utility in dengue

Background: Dengue infections are public health concerns in India, where they occur in epidemics and have a high mortality in the advanced stages. Clinical features are nonspecific, and diagnosis is supported by lab features. One of these lab tests include total leucocyte count-easily available, simple and cost effective which is useful in small rural set ups for early diagnosis and prognosis of dengue. The aim of this study is to analyse the total leucocyte count patterns in dengue and assess its utility as early marker of dengue and prognosticator of severe dengue.Methods: A total of 132 serologically proven cases of dengue with total white cell counts (blood counts obtained by Automated hematology analyser) during November 2016 were analysed.Results: In our study, most cases were noted in the younger age group with a male predominance. The range of total leucocyte count was 1.1x109 /l to 14.3x109/l. Most (55%) had normal counts, leucopenia was noted in 36%, had an equal distribution in all ages and both sexes. 82% had mild leucopenia,52% of leucopenia cases were associated with severe thrombocytopenia. Almost half (47%) of leucopenia cases were NS1 positive while only 15% were antibody positive.59% of NS1 positive had leucopenia in contrast to 13% of antibody positive cases. While leucopenia was mostly (55%) associated with neutrophilia, lymphocytosis was seen in 74% of cases with a normal leucocyte count.Conclusions: Total leucocyte count is one of the simple, easily available, cost effective tests useful in small rural set ups for early diagnosis and prognosis in dengue and helps reduce the morbidity and mortality of dengue.

Human small bowel as a useful tool to investigate smooth muscle effects of potential therapeutics in organophosphate poisoning

Isolated organs proofed to be a robust tool to study effects of (potential) therapeutics in organophosphate poisoning. Small bowel samples have been successfully used to reveal smooth muscle relaxing effects. In the present study, the effects of obidoxime, TMB-4, HI-6 and MB 327 were investigated on human small bowel tissue and compared with rat data. Hereby, the substances were tested in at least seven different concentrations in the jejunum or ileum both pre-contracted with carbamoylcholine. Additionally, the cholinesterase activity of native tissue was determined. Human small intestine specimens showed classical dose response-curves, similar to rat tissue, with MB 327 exerting the most potent smooth muscle relaxant effect in both species (human EC50=0.7×10−5M and rat EC50=0.7×10−5M). The AChE activity for human and rat samples did not differ significantly (rat jejunum=1351±166 mU/mg wet weight; rat ileum=1078±123 mU/mg wet weight; human jejunum=1030±258 mU/mg wet weight; human ileum=1293±243 mU/mg wet weight). Summarizing, our isolated small bowel setup seems to be a solid tool to investigate the effects of (potential) therapeutics on pre-contracted smooth muscle, with data being transferable between rat and humans.

Development of a Video-Microscopic Tool To Evaluate the Precipitation Kinetics of Poorly Water Soluble Drugs: A Case Study with Tadalafil and HPMC.

Many drug candidates today have a low aqueous solubility and, hence, may show a low oral bioavailability, presenting a major formulation and drug delivery challenge. One way to increase the bioavailability of these drugs is to use a supersaturating drug delivery strategy. The aim of this study was to develop a video-microscopic method, to evaluate the effect of a precipitation inhibitor on supersaturated solutions of the poorly soluble drug tadalafil, using a novel video-microscopic small scale setup. Based on preliminary studies, a degree of supersaturation of 29 was chosen for the supersaturation studies with tadalafil in FaSSIF. Different amounts of hydroxypropyl methyl cellulose (HPMC) were predissolved in FaSSIF to give four different concentrations, and the supersaturated system was then created using a solvent shift method. Precipitation of tadalafil from the supersaturated solutions was monitored by video-microscopy as a function of time. Single-particle analysis was possible using commercially available software; however, to investigate the entire population of precipitating particles (i.e., their number and area covered in the field of view), an image analysis algorithm was developed (multiparticle analysis). The induction time for precipitation of tadalafil in FaSSIF was significantly prolonged by adding 0.01% (w/v) HPMC to FaSSIF, and the maximum inhibition was reached at 0.1% (w/v) HPMC, after which additional HPMC did not further increase the induction time. The single-particle and multiparticle analyses yielded the same ranking of the HPMC concentrations, regarding the inhibitory effect on precipitation. The developed small scale method to assess the effect of precipitation inhibitors can speed up the process of choosing the right precipitation inhibitor and the concentration to be used.

Reducing CO2 Flow Using Foams

As part of the MiReCOL three-year European project (www.mirecol-co2.eu) on storage remediation technologies, we studied in the laboratory the capacity of foams to reduce gas flow for CO2-brine systems in rock core sample with common surfactants, as a function of interstitial velocity and gas to water fraction. Two different types of experimental set-up are used. They both allow local measurement of the water saturation for low and high pressure/temperature condition. A small MRI core-flood set-up is used to perform experiments at 35°C and 10 bars pore pressure, in CO2 non-dense condition. In order to work under reservoir condition, at 40°C and 130 bars, with dense super-critical CO2 we used a classical core-flood system coupled to an X-ray detection set-up.All experiments were carried out in similar Clashach sandstones with permeability between 220 and 1500 mD, and porosity in the range 10-20%. The gas and the surfactant-brine solution were co-injected at the core inlet face with a gas fraction around 0.7. We vary the interstitial velocity within two decades from about 3 ft/day up to 100 ft/day.The performance of the generated foams was evaluated from the relative foam viscosity, the ratio of the measured pressure drop in the presence of foam to the pressure drop in single phase condition for the same interstitial velocity. Whatever the pressure and permeability/porosity, the relative foam viscosity can be described as a power law vs. the shear rate evaluated from the interstitial velocity, permeability and porosity. The exponent is close to -1 describing the shear-thinning behavior.

Milestone for flow chemistry

Although continuous flow chemistry—wherein molecules are made in a continuous process rather than in batches—has gained ground in academic labs, its adoption by industry and contract manufacturing labs has been comparatively slow. Now, chemists at Eli Lilly & Co. report a continuous manufacturing process for the chemotherapy drug candidate prexasertib monolactate monohydrate. Notably, the synthesis uses current Good Manufacturing Practices (cGMPs), linking each stage in the continuous manufacturing process to quality-control systems (Science 2017, DOI: 10.1126/science.aan0745). Kevin P. Cole, the report’s lead author, explains that the chemists used continuous manufacturing because they needed to make only 24 kg of the compound. Making the drug candidate in batch equipment would have required an extensive cleanup afterward because the compound is potent and cytotoxic. The small flow setup can be dedicated to making this single compound and discarded, if necessary, at no great cost. Also, the flow process included a step involving

Determination of Mechanical Properties of Metallic Materials from Very Small Volumes by Means of Small Punch Test

The paper summarizes capabilities of the small punch tests on miniature disc specimens from metallic materials. Results obtained by small punch tests can be correlated with mechanical properties determined by conventional or other miniature tests. Three basic types of small punch test setup: i) static/fracture, ii) creep and iii) stress relaxation are described and the basic quantities that can be obtained are shown. Relations for an assessment of conventional mechanical properties from quantities obtained by small punch test are presented.

A Novel Method for Fragmentation Studies in Particle Therapy: Principles of Ion Identification.

In carbon ion beam radiation therapy, fragmentation processes within the patient lead to changes in the composition of the particle field with increasing depth. Consequences are alterations of the resulting dose distribution and its biological effectiveness. To enable accurate treatment planning, the characteristics of the ion spectra resulting from fragmentation processes need to be known for various ion energies and target materials. In this work, we present a novel method for ion type identification using a small and highly flexible setup based on a single detector and designed to simplify measurements and overcome current shortages in available fragmentation data. The presented approach is based on the pixelated, semiconductor detector Timepix. The large number of pixels with small pitch, all individually calibrated for energy deposition, enables detection and visualization of single particle tracks. For discrimination among different ion species, the pattern recognition analysis of the detector signal is used. Fragmentation spectra resulting from a primary carbon ion beam at various depths of tissue-equivalent material were studied to identify different ion species in mixed particle fields. The performance of the method was evaluated quantitatively using reference data from an established technique. All ion species resulting from carbon ion fragmentation in tissue-equivalent material could be separated. For measurements behind a 158-mm-thick water tank, the relative fractions of H, He, Be, and B ions detected agreed with corresponding reference data within the limits of uncertainty. For the relatively rare lithium ions, the agreement was within 2.3 Δref (uncertainty of reference). For designated configurations, the presented ion type identification method enables studies of therapeutic carbon ion beams with a simple, small, and configurable detection setup. The technique is promising to enable online fragmentation studies over a wide range of beam and target parameters in the future.

Development of Data Acquisition Set-up for Steady-state Experiments

For short duration experiments, generally digitized data is transferred for processing and storage after the experiment whereas in case of steady-state experiment the data is acquired, processed, displayed and stored continuously in pipelined manner. This requires acquiring data through special techniques for storage and on-the-go viewing data to display the current data trends for various physical parameters. A small data acquisition set-up is developed for continuously acquiring signals from various physical parameters at different sampling rate for long duration experiment. This includes the hardware set-up for signal digitization, Field Programmable Gate Arrays (FPGA) based timing system for clock synchronization and event/trigger distribution, time slicing of data streams for storage of data chunks to enable viewing of data during acquisition and channel profile display through down sampling etc. In order to store a long data stream of indefinite/long time duration, the data stream is divided into data slices/chunks of user defined time duration. Data chunks avoid the problem of non-access of server data until the channel data file is closed at the end of the long duration experiment. A graphical user interface has been developed in Lab VIEW application development environment for configuring the data acquisition hardware and storing data chunks on local machine as well as at remote data server through Python for further data access. The data plotting and analysis utilities have been developed with Python software, which provides tools for further data processing. This paper describes the development and implementation of data acquisition for steady-state experiment.

Bayes tests of independence for contingency tables from small areas

In this paper we study pooling effects in Bayesian testing procedures of independence for contingency tables from small areas. In small area estimation setup, we typically use a hierarchical Bayesian model for borrowing strength across small areas. This techniques of borrowing strength in small area estimation is used to construct a Bayes test of independence for contingency tables from small areas. In specific, we consider the methods of direct or indirect pooling in multinomial models through Dirichlet priors. We use the Bayes factor (or equivalently the ratio of the marginal likelihoods) to construct the Bayes test, and the marginal density is obtained by integrating the joint density function over all parameters. The Bayes test is computed by performing a Monte Carlo integration based on the method proposed by Nandram and Kim (2002).

Development of Small Pressure Sensing Unit using Nano-Materials

Precise measurement of low and high pressures for various types of applications has always been a challenge. Various types of nano-materials exhibit the property of change in electrical resistance upon the application of pressure. In this paper, we develop a handy pressure sensing unit for measuring minor changes in pressures by measuring changes in electrical resistance of the compressed nano-materials. The unit consists of a cylindrical arrangement upon which load is applied. This cylinder is connected with a Data Acquisition System (DAQ) to obtain the variations in voltage. We used multi walled carbon nanotubes (MWCNTs) as the transducer. Considering that the inner structure of these nanotubes is hollow, the vacant spaces allow larger flow of current through them. The experiment has been conducted using a small setup in which nearly 5 mg of MWCNTs were used and static pressure was varied from 150 gm to 5.13 kg in steps. The experiment was conducted for both loading and unloading cycles. It has been observed that when the external pressure increased from 0 to 1.2MPa, the electrical resistance fell by nearly 65% from 5.434 Ohm to 1.889 Ohm. The results obtained during present study are very useful in estimating the unknown external static loads by calibrating them with change in electrical resistance or voltage drop across the setup.