Clean Room Laboratory Research Articles

Design of Three-Dimensional Virtual Simulation Experiment Platform for Integrated Circuit Course

The integrated circuit (IC) is a subject for which researchers need practical experience, but its experiment cost is high, the risk involved is high, and it is not easy to carry out experiments on a large scale. This paper designs a three-dimensional integrated circuit virtual experiment platform based on Unity3d. The platform uses the Unity3d and 3ds Max tools to build a three-dimensional model of instruments, equipment, electronic components, and ultra cleanroom laboratory scenes in an integrated circuit experiment. In addition, it uses C# script to develop the functions and three-dimensional simulation of general virtual instruments and equipment and deploys the experimental website using the frame of the jspxcms open source website. The experimental platform arranges the three-dimensional web file WebGL file in the cloud. Students can use video and text materials to acquire basic IC knowledge at any time and conduct IC virtual experiments safely, efficiently, and without constraints. At present, the platform has been tested and used in teaching and has received high praise and recognition from students.

Correlation of long-duration exposure and accelerated testing of protected silver mirrors.

The stability of two types of protected silver mirrors was studied by long-term exposure in a clean-room laboratory and mixed-flowing-gas (MFG) accelerated environmental test with two different gas concentrations. The two types of mirrors behaved very differently when exposed to the clean-room air for six years. The mirrors subjected to a reduced Battelle Class II MFG test protocol for 10 days exhibited similar corrosion mechanisms to those exposed to the clean-room air. With further testing of silver mirrors in both field exposures and MFG test conditions, it is feasible that the MFG-accelerated test method can be developed to quantitatively assess the durability of protected silver mirrors in ambient applications.

Spreading rate and dispersion behavior of evaporation-suppressant monolayer on open water surfaces: Part 1 – At zero wind stress

Effective evaporation suppression by a monolayer film is largely dependent on the maintenance of that film over as much of the water surface as practically possible. Hence, an autonomous system capable of adaptive re-application of monolayer according to the prevailing wind conditions in order to satisfy this requirement is highly desirable. Key to the design and functioning of a system of this nature is a fundamental understanding of the spatial movement/distribution characteristics of the monolayer material. To ‘bridge’ between centimeter-scale, clean room laboratory experimentation (e.g. with a Petri dish) and field conditions (i.e. hectare-scale open water storages), the spreading rate and dispersion behavior of different application quantities of octadecanol monolayer (in water-emulsion) was investigated on 0.3m, 2m and 6m diameter laboratory water tanks under zero wind stress. A standard formula for spreading is shown to be applicable to ‘bulk’ monolayer from a center point on circular, open water surfaces of scale 0.3m, 2m and 6m diameter. Under still conditions, monolayer spread (as expected) in a uniform circular pattern outwards, centered on the point of application. ‘Bulk’ application involved the placement of enough material to form layers 1×, 3× or 6× monomolecular. Hitherto this has not been demonstrated with either these ‘overdosed’ (3×, 6×) material quantities or at these scales, scales which come closer to those required for monolayer application for the evaporation mitigation of practical open water storages. An empirical relationship for spreading rate has been developed as a function of both time and storage size.

Spreading rate and dispersion behavior of evaporation-suppressant monolayer on open water surfaces: Part 2 – Under wind stress

Wind causes migration and eventual removal (dispersal or beaching) of evaporation-suppressing monolayer on open-water storages. Hence, an autonomous system capable of adaptive re-application of monolayer according to the prevailing wind conditions is highly desirable. Key to the design and functioning of such a system is a fundamental understanding of the spatial movement/distribution characteristics of the monolayer material. To ‘bridge’ between centimeter-scale, clean room laboratory experimentation (e.g. Petri dish–scale in a wind tunnel) and field conditions (i.e. hectare-scale open-water storages), the drift velocity and spreading behavior of C18OH monolayer (in water-emulsion), applied continuously during constant wind stress, were investigated on a 6m-diameter indoor water tank for wind speeds in the range 4–8m/s. Monolayer was found to spread in a teardrop shape initially, which evolved into a wedge shape whose close-to-straight edges were detectable visually due to the wave-damping effect of the monolayer. The internal angle of the wedge decreased with increasing wind speed, consistent with the force equilibrium between the lateral force of the monolayer spreading outwards and the increasing shear imposed with increasing wind speed. The relationship between internal angle of the wedge and wind velocity was a power law. The widely-accepted spreading kinetics formula was used to derive an empirical relationship for the drift velocity that is a power law with respect to the wind speed. This model was compared with the experimental data, with a modest degree of agreement.

Pre-Concentration and Determination of Molybdenum in the Rouge River, Michigan, USA, with Graphite Furnace Atomic Absorption Spectrometry

Molybdenum is an essential element to humans because of its role in several enzymes, and its occurrence in natural waters is of significance from environmental and biochemical standpoints. Owing to the low concentration of molybdenum in natural waters, pre-concentration is required prior to its determination with atomic spectroscopic techniques. This paper reports on the pre-concentration and determination of molybdenum in the Rouge River, Michigan, USA with graphite furnace atomic absorption spectrometry (GFAAS). Sample preparation and pre-concentration were performed using ultra-trace analysis methodology in a class 100 clean room laboratory. The molybdenum was pre-concentrated on a Bio-Rad Chelex® 100 resin, followed by elution from the resin with ammonia solution. Subsequently, the single-point standard addition method was used, and the absorbance owing to molybdenum was measured at 313.3 nm. An overall concentration factor of ten was realized for the final pre-concentrated volume, and the results from several sampling locations on the four branches of the Rouge River yielded molybdenum concentrations ranging from 1.98 to 4.21 ug·L-1 with an overall average of 2.94 ug L-1. The precision of the results, based on quintuplet determinations from each sampling site, varied between 6.1 to 8.8 %relative standard deviation (%RSD). Although the concentration of molybdenum in the Rouge River is in line with the lower reported molybdenum levels in the US and world rivers, it is higher than the level that arises from natural sources only and therefore has anthropogenic causes.

68Ga-markierte Peptide für klinische Studien

SummaryThe AMG implies far-reaching implications for the synthesis of new radiopharmaceuticals for clinical trials. Aim, methods: As a part of the DFG-funded Clinical Research Group (KFO 179) a project designated „Immuno-PET for assessment of early response to radiochemotherapy of advanced rectal cancer“ was initiated. This trial is focused on a trivalent bispecific humanized monoclonal antibody, and a 68Ga-labeled peptide. Following the new regulatory framework we established a GMPcompliant cleanroom laboratory and applied for a manufacturing permission. Results: During the project constructural, personnel and organizational conditions for a successful application were established, including a quality management system. A GMP-conform cleanroom laboratory class C was constructed, equipped with a two-chamber lock. The actual manufacturing is performed in a closed system with subsequent sterile filtration. The manufacturing processes have been automatised and validated as well as the necessary quality controls. The manufacturing permission was granted after an official inspection. Conclusions: The new German Drug Act is considered as a break in the production practice of nuclear medicine. The early involvement and communication with the authorities avoids time-consuming and costly planning errors. It is much to be hoped that the new legal situation in Germany will not cause serious impairments in the realization of clinical trials in German nuclear medicine.

The Petri Project Pipeline for Education, Training Resources, and Innovation

Northampton Community College, in collaboration with industry, workforce, and secondary school partners, developed a multifaceted, replicable approach to meet the regional biotechnology workforce needs. Credit-bearing, career-latticed specialized diplomas and a cutting edge clean room laboratory provide a quick entrée option into a high growth industry in our region.

Abstract Additional informationNotes on contributors S Ahmad completed his master's degree from Allahabad University, Allahabad and PhD from BITS, Pilani in 65 and 70 respectively. This was followed by a brief teaching assignment at BITS, Pilani for about four years. He has been involved in R&D activities in the areas of microwave and millimeter wave semiconductor devices and technology, high power laser source packaging, Micro-electro-mechanical Systems (MEMS) and Micro Sensor Technology in the present organization for more than three decades. A clean room laboratory, equipped with modern device processing and characterization facilities, was set up by him to undertake sponsored projects in microwave and millimeter wave semiconductor device development. Later on, the laboratory was augmented with additional facilities for undertaking development work in the area of high power laser source packaging and MEMS micro sensors. Silicon Baritts, Impatts, high power CW laser sources, piezo-resistive pressure sensors, acoustic sensors, capacitive pressure sensors, RF switch, polysilicon load cells like products were developed in various programmes under his supervision. Device design activity started in his team using numerical solutions of charge carrier transport equations under practical boundary conditions. These efforts have resulted in about 60 publications in national and international journals and nine patents. Development of MEMS based chemical and biosensors, RF MEMS and inertial sensors are his current areas of interest. Dr Ahmad is presently coordinating the CSIR Network Program on MEMS and Micro Sensors in which nine laboratories are actively participating. Dr Ahmad is a Fellow of IETE and the Principal Hony. Editor of IETE Journal of Research. Dr S Ahmad is recipient of 19th RL Wadhwa Memorial Gold Medal Award from IETE. Dr Ahmad was Director of Central Electronics Engineering Research Institute, Pilani up to October 2003 and after that he is serving CSIR as Director Grade Scientist in Pilani.

Deposition and Evaluation of Micro-Crystalline Silicon for Use in Photoconducting Antennas

ABSTRACTThe importance of micro-crystalline silicon (μc-Si:H) for the photo-conducting dipole antenna application is investigated in this paper. The structural and optical properties of gc-Si:H films prepared by plasma enhanced chemical vapor deposition are studied with Raman spectra, scanning electron microscope, and ellipsometer measurements. The influence of grain size and defects on the opto-electronic characteristics of the photo-conducting dipole antenna is discussed. A sample of the antenna fabricated in our clean room laboratory is reported.

Multi-element speciation of trace metals in fresh water adapted to plasma source mass spectrometry

A method for speciation of trace metals at natural concentration levels has been developed. The speciation is carried out in a cleanroom laboratory and the determination is performed with an ICP-MS. The method is based on fractionation of metal species on three adsorbents. Chelex-100, Sep-Pak C-18 and Fractogel DEAE. The method distinguishes between labile complexes, non-polar organic adsorbable matter and ion exchangeable substances. The filtered water samples are pumped through columns with the adsorbents. Following a prefraction, samples for determination of metal concentrations are taken. The adsorbents are not eluted. After extensive cleaning, the used adsorbents have blank values that are low enough for trace metal analysis in fresh water. Concentration and speciation data for Al, Cd, Co, Cu, Fe, Pb, Mn, Mo, Ni and Zn are obtained.

Lead in Atlantic surface waters as a tracer for atmospheric input

The present report provides information about lead concentrations in Atlantic surface waters over a wide geographical range. Differential pulse anodic stripping voltammetry (DPASV) was applied for the analysis of lead in surface water of the Atlantic Ocean. Sampling on board of the research vessel Polarstern was performed from the bow boom of the ship but also with a newly installed snorkel system which allowed continuous sampletaking. In both cases special precautions were taken in order to avoid contamination by the ship. A limited number of samples could immediately be measured aboard Polarstern in a newly constructed clean room laboratory container. A part of the samples had to be irradiated before the voltammetric measurement. In 1989 lead concentrations in the North Atlantic between 22° N and 46° N continuously increased from 42.5 pmol/kg up to 147 pmol/kg. The comparison with results from a cruise in 1981 shows that the lead concentration in the eastern North Atlantic has diminished by more than 50%. A similar trend is documented for the consumption of alkyl leaded gasoline in the United States of America. Seawater samples from a cruise in 1990 exhibited a very low background concentration of 6.1–14 pmol/kg Pb in the middle Atlantic, while higher values were measured in the Intertropical Convergence Zone (ITCZ). In a certain area of the Atlantic Ocean lead has been identified as a tracer for terrigenous input, in another area, however, as a transient tracer for anthropogenic input. This demonstrates that atmospheric input of lead into the surface water of the Atlantic can have different origins.

Influence of laboratory environment on the precision and accuracy of trace element analysis.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfluence of laboratory environment on the precision and accuracy of trace element analysisS. B. Adeloju and A. M. BondCite this: Anal. Chem. 1985, 57, 8, 1728–1733Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://doi.org/10.1021/ac00285a050RIGHTS & PERMISSIONSArticle Views156Altmetric-Citations29LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (679 KB) Get e-Alerts Get e-Alerts

Sample Preparation in Determination of Lead in Garden Vegetables by Flame Atomic Absorption Spectrophotometry

Dry and wet ashing methods have been used in the analysis of garden vegetables for Pb. The reliability of wet ashing has been verified by the method of standard additions. Comparison of dry and wet ashing showed good agreement for a variety of garden vegetables. Sample size was more strictly limited for the wet-ashed samples, which led to lower sensitivity. Vegetable samples are commonly analyzed for a number of trace elements, which introduces additional constraints on sample preparation, notably because of Cd loss on dry ashing. Pretreatment with HNO3/H2SO4 ash aid eliminated Cd loss. Reliability of dry ashing with pretreatment was shown with NBS SRM Orchard Leaves, Pine Needles, Spinach, and Tomato Leaves. The analysis was insensitive to ashing temperature in the range 480-625 degrees C. A practical detection limit for the method is about 2 ppm Pb, dry weight basis (DWB). Care must be exercised to avoid contamination of the sample with lead at this level by improper handling. Segregation and acid washing of glassware and protection of the sample from contact with any object not demonstrably clean was necessary. No evidence was found of Pb contamination at this level from tap water washing of fresh vegetables, forced-air oven drying, or grinding with mortar and pestle. No special clean room facilities or laboratory air purification measures were used. Sensitivity was increased 3-fold by extraction with dithizone in CHCl3 followed by back-extraction into dilute HCl. Detection limits were not improved, however, because of variation in the extraction results. The instrumental method for assessing effective correction for back-ground absorbance showed adequate compensation, although comparison of direct and extractive determinations showed a small but significant difference between the methods of about 1 ppm Pb (DWB).