NATIONAL VACUUM CONFERENCE IRAN | Year:2012 | دوره:5 |Papers Count:53

DUE TO THE IMPORTANCE OF HIGH VACUUM TECHNOLOGY IN THE MASS SPECTROMETER PERFORMANCE ON ONE HAND AND WITH RESPECT TO THE INTERNATIONAL SANCTIONS ON IRAN WHICH LIMITS THE ACCESS TO ULTRA-HIGH VACUUM COMPONENTS LIKE ION PUMPS ON THE OTHER HAND, THIS PAPER DESCRIBES THE SPUTTER-ION PUMPS AND THEIR FUNCTION, AS WELL AS THE PROCEDURE OF REVIVING THE ION PUMPS IN MASS SPECTROMETER WHICH WAS CARRIED OUT FOR THE FIRST TIME IN THIS LABORATORY.

VERTICALLY ALIGNED CARBON NANOTUBES (VA-CNTS) WERE SYNTHESIZED BY CHEMICAL VAPOR DEPOSITION (CVD) USING COBALT (CO) CATALYST SUPPORTED BY ALUMINUM OXIDE (AL2O3) LAYER. A MIXTURE OF THE GASES OF ETHANOL VAPOR AND ARGON WAS USED DURING THE GROWTH. THE EFFECT OF THE RATE OF HYDROCARBON GAS (ETHANOL) ENTERING THE CHAMBER, ON THE LENGTH AND DENSITY OF CARBON NANOTUBES WERE STUDIED. WE FOUND THAT IN A FIXED PRESSURE OF 20 MMHG, BY INCREASING THE RATE OF ETHANOL VAPOR, THE DENSITY AND ALSO THE LENGTH OF NANOTUBES INCREASES UP TO APPROXIMATE RATE OF 1.6 MOL/MIN, AND THEN DECREASES FOR HIGHER RATES OF ETHANOL. ALSO, IT WAS FOUND THAT THE DIAMETER, LENGTH AND DENSITY OF THE NANOTUBES ARE CONTROLLED BY THE THICKNESS OF THE CATALYST LAYER. SCANNING ELECTRON MICROSCOPY (SEM) WERE UTILIZED TO PROVIDE INFORMATION OF THE LENGTH, DENSITY AND DIAMETER OF CNTS UNDER VARIOUS CONDITIONS.

IN THIS PAPER, ABSORBANCE PROPERTIES OF TI THIN FILMS MADE BY ELECTRON BEAM EVAPORATION METHOD IN HIGH VACUUM HAVE BEEN STUDIED. THESE SAMPLES ARE COATED ON GLASS AND QUARTZ SUBSTRATES. ABSORBANCE AND ABSORPTION COEFFICIENTS OF SAMPLES ARE MEASURED BY SPECTROPHOTOMETER THAT IS CONFIRMED BY OTHERS. ALSO, SEM AND EDX ARE TAKEN FOR GETTING BETTER DISCUSSIONS. THE SEM IMAGES PRESENT THE NUCLEATION STAGE OF SAMPLES.

ONE OF THE MOST IMPORTANT FACTORS FOR INCREASING LASER EFFICIENCY IS THE QUALITY OF OPTICAL ELEMENTS WHICH ARE USED IN LASER SYSTEMS. THE QUALITY OF THESE ELEMENTS IS DEPENDENT ON VARIOUS PARAMETERS SUCH AS SPECTRUM OF LASER LIGHT, ADHESION AND DAMAGE THRESHOLD. ANTI-REFLECTIVE COATINGS HAVE MANY APPLICATIONS IN OPTICS, FOR INSTANCE LASERS, LENSES AND SOLAR CELLS. IN THIS STUDY, WE HAVE BEEN INVESTIGATED DESIGN AND FABRICATION OF ANTI-REFLECTIVE FILTER FOR THE VISIBLE AND NEAR-INFRARED REGIONS OF ND:YAG LASER.

IN THIS PROJECT, SAMPLES OF LA0.6CA0.4FE0.8NI0.2O3 (LCFN OXIDE) WERE PREPARED BY SOL-GEL METHOD, AS A CATHODE MATERIAL OF SOLID OXIDE FUEL CELL. ALSO, THIN FILMS OF LCFN WERE PREPARED BY PULSED LASER DEPOSITION (PLD) ON SRTIO3 (STO) SUBSTRATES IN DIFFERENT PRESSURE OF OXYGEN. CRYSTAL STRUCTURE, MORPHOLOGY AND ELECTRICAL CONDUCTIVITY WERE STUDIED BY X-RAY DIFFRACTION (XRD), AFM AND FOR POINT PROBE METHOD, RESPECTIVELY.

NANOPARTICLES CU-FE BILAYERS FILMS WERE PREPARED BY DC-MAGNETRON SPUTTERING METHOD IN VACUUMED, AND USED AS CATALYST FOR GROWTH CNT(CARBON NANO TUBES).BY ATOMIC FORCE MICROSCOPY(AFM), X RAY DIFFRACTION(XRD), SCANNING ELECTRON MICROSCOPY(SEM) AND RAMAN SPECTROSCOPY, THE CATALYST AND CNTS WERE CHARACTERIZED. THE COMPARISON BETWEEN TWO KINDS OF GROWTH SHOWS THAT INCREASING THE CU NANOPARTICLES AS SUBSTRATE OF FE NANOPARTICLES WAS IMPRESSIVE ON QUALITY AND IMPROVEMENT OF GROWTH.

IN THIS RESEARCH ,BARIUM FLUORIDE THIN FILM WITH 180NM THICKNESS HAS BEEN PREPARED BY PHYSICAL VAPOR DEPOSITION ( PVD) IN VACUUM. MICROMETRIC ZN DOPED BAF2 FILM HAS BEEN ALSO PREPARED IN SLIGHTLY HIGHER VACUUM. XRD PLOT OF BAF2 FILMS SHOWS POLYCRYSTALLINE NATURE WITH (200) PREFERENTIAL PLANE. GRAIN SIZES WERE ESTIMATED TO BE~42 NM .THE STRUCTURAL PARAMETERS OF DOPED AND UNDOPED FILMS HAS BEEN COMPARED.THE OPTICAL TRANSMITTANCE SPECTRA AND THE PHOTOLUMINESCENCE (PL) SPECTRA OF THE BAF2 THIN FILMS ARE ALSO CONSIDERED.

IN THIS RESEARCH, A HOT CATHODE PLASMA SOURCE WAS MADE AND THE PLASMA FORMATION IN HIGH VACUUM REGIME (RANGE OF 10-3 TO 10-4 MBAR) WAS STUDIED BY APPLYING MAGNETIC FIELD BY MEANS OF PERMANENT MAGNETS ASSEMBLY. EFFECTS OF VARIOUS CONTROL PARAMETERS SUCH AS WORKING PRESSURE, DISCHARGE VOLTAGE AND EXTERNAL ELECTRON SOURCE (HOT TUNGSTEN FILAMENT) ON PLASMA DENSITY WERE INVESTIGATED. AT A DISCHARGE VOLTAGE OF 57 VOLT, MAGNETIC FIELD OF ABOUT 200 GAUSS, FILAMENT CURRENT OF 18 AMPERE, 130 MILIAMPERE FOR DISCHARGE CURRENT WAS OBTAINED AT A PRESSURE OF 1.2×10-4 MBAR.

IN THE PRESENT STUDY THE EFFECT OF NITROGEN BOMBARDMENT ON THE STRUCTURE OF TITANIUM SURFACE AND CORROSION RESISTANCE HAVE BEEN INVESTIGATED. IN THIS EXPERIMENT 30 KEV NITROGEN ION BEAM OF 5´1017 TO 1´1018 IONS/CM2 FLUENCE WAS USED. CRYSTALLINE STRUCTURE AND CRYSTALLINE SIZE OF THE DIFFERENT SAMPLES WAS STUDIED BY X-RAY DIFFRACTION ANALYSIS. THE ROUGHNESS VARIATIONS BEFORE AND AFTER BOMBARDMENT WERE OBSERVED BY ATOMIC FORCE MICROSCOPY. THE CORROSION TEST WAS USED TO COMPARE THE CORROSION RESISTANCE OF TITANIUM BEFORE AND AFTER BOMBARDMENT. THE SURFACE MORPHOLOGY OF THE SAMPLES WAS INVESTIGATED BY SCANNING ELECTRON MICROSCOPY THE RESULTS SHOWED THAT CRYSTALLINE SIZE CHANGES BECAUSE OF ION BOMBARDMENT HAS A SUBSTANTIAL EFFECT ON THE IMPROVEMENT OF TITANIUM RESISTANCE AGAINST CORROSION.

TI DOPED CU3N (TI:CU3N) THIN FILMS WERE DEPOSITED ON SI(111), QUARTZ, GLASS SLIDE AND STAINLESS STEEL SUBSTRATES USING A BINARY TI13CU87 ALLOYED TARGET BY REACTIVE DC MAGNETRON SPUTTERING AT NITROGEN AMBIENT. THIS STUDY PROVIDES INSIGHT INTO THE IMPORTANCE OF NITROGEN PRESSURE ON THE CHARACTERISTIC OF THE AS-DEPOSITED TI: CU3N THIN FILMS. STRUCTURAL PROPERTY OF THESE FILMS IS IDENTIFIED BY X-RAY DIFFRACTION (XRD) TECHNIQUE. THE OBSERVED PHASES ARE; CUBIC STRUCTURE OF TI DOPED CU3N (TI: CU3N) AND FCC STRUCTURE OF CU. THE ELECTRICAL RESISTIVITY OF THE FILMS, DEDUCED FROM MEASUREMENT USING FOUR- POINT PROBE, WAS DEPENDING ON FILMS’ STRUCTURE AND CHEMICAL COMPOSITION. FILMS’ HARDNESS, MEASURED BY VICKERS’S MICROHARDNESS TEST, WAS STRONGLY DEPENDING ON FILMS’ COMPOSITION. REFRACTIVE INDEX (N), EXTINCTION COEFFICIENT (K) AND FILM THICKNESS (D) ARE CALCULATED USING VISNEAR IR TRANSMITTANCE. SEMICONDUCTING TRANSITION PROCESS AND BANDGAP VALUE ARE EXTRACTED FROM ABSORPTION COEFFICIENT. TI ADDITION AND SUBSEQUENT EXCESS OF INTERSTITIAL NITROGEN (N-RICH) RESULT IN LATTICE CONSTANT EXPANSION IN COMPARISON WITH TI FREE CU3N AND OPTICAL ENERGY GAP WIDENING.

IN THIS STUDY, THIN FILMS OF NICKEL AND SILVER HAVE BEEN DEPOSITED ON GLASS SUBSTRATE BY UNBALANCED MAGNETRON SPUTTERING METHOD WITH 50 AND 100NM THICKNESSES, RESPECTIVELY. NICKEL WAS USED FOR INCREASING SILVER ADHESION TO GLASS SUBSTRATE. SAMPLES WERE ANNEALED AT TEMPERATURES OF 100, 200 AND 300OC. SCANNING TUNNELING MICROSCOPY (STM) WAS USED FOR INVESTIGATING SURFACE MORPHOLOGY OF SAMPLES. STM RESULTS DEMONSTRATE THAT INCREASING TEMPERATURE LEAD TO AN INCREASE IN GRAIN SIZE OF SILVER SURFACE.

VACUUM FRYING PROCESS IS A GOOD WAY TO PROVIDE BETTER QUALITY CHIPS. IN THIS PAPER WE CONTROL PROCESS PARAMETERS AND FINAL PRODUCT, USING THE ARTIFICIAL NEURAL NETWORKS (ANN) TO IMPROVE VACUUM FRYING. FOOD ENGINEERS CONCERN INCREASE OR DECREASE IN THE PRODUCTION PROCESS PARAMETERS OF CHIPS. IN THIS STUDY, THE MODELING PROCESS IS OBTAINED BY EXPERIMENTAL DATA AT THREE TEMPERATURES 118, 132 AND 144O C AND VACUUM PRESSURES 16.6 KP, 9.89 KP AND 3.12 KP TO FRY POTATOES AND CHIPS. THE RESULTS SUGGEST A STRONG MODEL TO PREDICT OUTPUTS OF THE SYSTEM. ARTIFICIAL NEURAL NETWORK IS USED TO OPTIMIZE THE VACUUM FRYING CONDITIONS TO OBTAIN THE BEST QUALITY.

TITANIUM FOAMS NOT ONLY POSSESS WIDE APPLICATION IN MILITARY, BUT ALSO IN BIOMEDICAL ENGINEERING BECAUSE OF ITS HIGH STRENGTH TO DENSITY RATIO, EXCELLENT CORROSION RESISTANCE AND GOOD BIOCOMPATIBILITY. HIGH REACTIVITY OF TITANIUM POWDERS IS THE FIRST PROBLEM WE ENCOUNTER IN ORDER TO UTILIZING PURE TITANIUM. HENCE, IN THIS STUDY A NEW METHOD FOR FABRICATION OF TITANIUM FOAMS HAS BEEN PROPOSED. THEN, THERMAL BEHAVIOR OF TITANIUM DURING HEATING IN ARGON, NITROGEN AND VACUUM HAS BEEN INVESTIGATED USING SIMULTANEOUS THERMAL ANALYZER (STA), X-RAY DIFFRACTION (XRD) AND ENERGY DISPERSIVE SPECTROSCOPY (EDS). STRUCTURAL PROPERTIES OF THE FOAMS FABRICATED USING THIS NOVEL METHOD HAS BEEN INVESTIGATED USING SCANNING ELECTRON MICROSCOPY (SEM). RESULTS SHOWED THAT USING VACUUM ATMOSPHERE GREATLY DECREASED OXIDE PHASES FORMED ON THE SURFACE OF THE FOAMS. TITANIUM HYDRIDE HAS TWO STEP DECOMPOSITION IN VACUUM, ARGON AND NITROGEN ATMOSPHERES.

IN THIS RESEARCH, AT FIRST RF SPUTTERING METHOD WAS USED TO GROW THIN FILMS OF NICKEL ON THE GLASS LAME SUBSTRATE AND THEN THE FILMS WERE ANNEALED AT DIFFERENT TEMPERATURES IN PURE OXYGEN AT ATMOSPHERIC PRESSURE .ACCORDING TO IMAGES ANALYSIS OF SCANNING ELECTRON MICROSCOPY (SEM),THE PRODUCED NANOSTRUCTURES HAVE NANOROD SHAPE WITH DIAMETER OF ABOUT 30 - 40 NM. A BAND GAP ENERGY BETWEEN 3.7 TO 3.8 EV IS MEASURES BASED ON OPTICAL MEASUREMENTS. IN ADDITION, IT WAS ALSO FOUND THAT CONTACT ANGLE OF UNANNEALED SPECIMEN, WAS110OC INDICATING HYDROPHOPIC SURFACE AND REDUCE TO 33OC FOR THE ANNEALED SAMPLE AT 300OC SHOWING ITS STATE HYDROPHILICITY.

THE CADMIUM TELLURIDE THIN FILMS WITH THE THICKNESS OF 650 NM WERE DEPOSITED ON GLASS SUBSTRATE BY VACUUM THERMAL EVAPORATION TECHNIQUE. IN THE PRESENT INVESTIGATION, THE EFFECT OF SUBSTRATE TEMPERATURE ON THE STRUCTURAL PROPERTIES OF THE PREPARED SAMPLES WAS STUDIED. THE STRUCTURAL ANALYSIS WAS CARRIED OUT BY X-RAY DIFFRACTION (XRD) AND FIELD EFFECT SCANNING ELECTRON MICROSCOPY (FESEM) TECHNIQUES. CALCULATION OF STRUCTURAL PARAMETERS REVEALED THE INCREASE OF THE CRYSTALLITE SIZE UPON INCREASING THE SUBSTRATE TEMPERATURE. IT WAS ALSO OBSERVED THAT THE LAYERS CRYSTALLINITY IMPROVED DUE TO THE INCREASE IN SUBSTRATE TEMPERATURE.

WE ARE REPORTING ON THE DESIGN AND SIMULATION OF A CURVED POSITRON-TRANSPORTATION SYSTEM FOR DOPPLERBROADENING POSITRON SPECTROSCOPY PURPOSES, WITH THE USE OF CST SIMULATION SOFTWARE. POSITRON SPECTROSCOPY IS WIDELY USED IN SURFACE SCIENCE AND NANOSCIENCE. IN THE PRESENT SYSTEM POSITRONS TRAVEL 114 CENTIMETER FROM THE MODERATOR TO THE TARGET ON A CURVED TRAJECTORY WITH THE RADIUS OF 150 CM. THIS SYSTEM IS EXPECTED TO DELIVER BEAMS AT THE TARGET WITH THE CROSS SECTION DIAMETER 0.16 TIMES SMALLER THAN THAT AT THE MODERATOR. IN ADDITION, THE BEAM ENERGY WOULD BE RANGING FROM 200 EV TO 20 KEV.

IN THIS RESEARCH, ZNO NANOWIRES WITH HIGH QUALITY WERE SYNTHESIZED BY USING THERMAL OXIDATION OF METALLIC ZN FILMS. METALLIC ZN FILMS WITH THE THICKNESS OF 250NM WERE DEPOSITED ON GLASS SUBSTRATE BY PVD TECHNIQUE IN VACUUM. THE DEPOSITED ZINC FILMS WERE ANNEALED IN AIR AT TEMPERATURE OF 600OC FOR 30MIN, 1 H AND 2 H IN THE TUBULAR FURNACE. SURFACE MORPHOLOGIES WERE CHARACTERIZED BY SCANNING ELECTRON MICROSCOPY AND RESULTS INDICATED THAT WITH INCREASING OXIDATION TIME, THE DIMENSION OF ZNO NANOWIRES INCREASES.EDX RESULTS REVEALED THAT ONLY ZN AND O ARE PRESENT IN THE SAMPLE, INDICATING A COMPOSITION OF PURE ZNO. XRD ANALYSES DEMONSTRATED THAT ZNO NANOWIRES HAVE A WURTZITE STRUCTURE WITH ORIENTATION OF (002).

IN THIS PAPER, THE TOLERANCES OF TURBOMOLECULAR HIGH VACUUM PUMP HAS BEEN INVESTIGATED. AT FIRST, THE TOLERANCE ANALYSIS METHODS ARE INTRODUCED. THEN, THE DIRECT LINEAR METHOD IS APPLIED TO ANALYZE THE MANUFACTURING AND ASSEMBLING TOLERANCES OF PARTS OF THIS PUMP.

IN THIS PAPER, OPTIMIZE OF LASER DAMAGE THRESHOLD FOR TIO2 THIN FILMS BY ANNEALING PROCESS IN ANNEALING OVEN IS INVESTIGATED. COATING WAS DONE BY ELECTRON GUN EVAPORATION. THEN, SAMPLES WERE ANNEALED IN 300, 400 AND 600OC, IN VACUUM FOR 2 HOUR. THEN, LASER DAMAGE THRESHOLD OF THE SAMPLES WAS MEASEURED. WE, ALSO, MEASURED OF OPTICAL SPECTRA AND ROUGHNESS BY SPECTROPHOTOMETER AND SPM .WE FIND THAT DAMAGE THRESHOLD AND ROUGHNESS OF THE SAMPLES ARE INCREASED BY INCREASE ANNEALING TEMPERATURE. TRANSMITTANCES OF THE SAMPLES ARE INCREASED BY INCREASE ANNEALING TEMPERATURE, TOO. IT CAUSED BY DIFFERENCE IN COEFFICIENT OF REFRACTION.

IN THIS RESEARCH MICRO AND NANO STRUCTURES OF ZINC OXIDE HAVE BEEN PREPARED ON SILICON SUBSTRATES BY RF MAGNETRON SPUTTERING AT TWO DIFFERENT TEMPERATURES. IN THE FIRST EXPERIMENT, IN WHICH THE SILICON SUBSTRATE WAS COVERED WITH A THIN ZN LAYER, AND HOLD IN A TEMPERATURE OF 200OC DURING DEPOSITION, THE STRUCTURES WERE IN THE SHAPE OF NANORODS GROWN VERTICALLY ALIGNED AND CLOSELY PACKED. IN THE SECOND EXPERIMENT THAT THE STRUCTURES WERE GROWN ON THE SILICON SUBSTRATE HOLD AT 100OC, THE PRODUCTS WERE IN THE FORM OF MICRO-RODS WITH CIRCLE CROSS SECTION. COMPARISON OF THE PHOTOLUMINESCENCE SPECTRA SHOWED THAT THE EMISSION OF NANORODS IN GREEN AND BLUE REGIONS IS NEARLY 4.5 TIMES THE EMISSION OF MICRO-RODS.

THE MAIN RECORDING MATERIAL FOR RECORDING HOLOGRAPHIC OPTICAL ELEMENTS (HOE) IS DICHROMATED GELATIN (DCG.) THE DRAWBACK OF DCG IS ITS LOW ENERGETIC SENSITIVITY AND LIMITED SPECTRAL RESPONSE. SILVER HALIDE SENSITIZED GELATIN (SHSG) TECHNIQUE HAS BECOME MORE INTERESTING SINCE THE INTRODUCTION OF NEW ULTRA-FINE-GRAIN SILVER HALIDE (AGHAL) EMULSIONS. IN THIS TECHNIQUE SILVER HALIDE MATERIALS CAN BE PROCESSED IN SUCH A WAY THAT THE FINAL HOLOGRAM HAS PROPERTIES LIKE A DCG HOLOGRAM. IN PARTICULAR, HIGH SPATIAL-FREQUENCY FRINGES ASSOCIATED WITH HOE OF REFLECTION TYPE ARE DIFFICULT TO CONSTRUCT WHEN SHSG PROCESSING METHODS ARE EMPLOYED. THE MAIN ADVANTAGE OF SHSG TECHNIQUE IS THAT HIGH-SENSITIVITY RECORDING CAN BE PERFORMED WITH LASER BEAM ANYWHERE WITHIN THE VISIBLE SPECTRUM. THEREFORE AN OPTIMIZED PROCESSING TECHNIQUE FOR REFLECTION HOE RECORDED IN THE NEW AGHAL MATERIALS IS INTRODUCED AND FINALLY WITH DRYING IN VACUUM OVEN, DIFFRACTION EFFICIENCY OF MORE THAN 50% IS OBTAINED FOR REFLECTION GRATINGS OF 5120 LINES.MM-1.

NANOSTRUCTURE THIN FILMS OF BOROMOALUMINIUM-PHTHALOCYANINE (BRALPC) AND PBPHTHALOCYANINE (PBPC) WERE IN ORDER DEPOSED ON A GLASS SUBSTRATE BY ELECTERON BEAM GUN (EBG) TECHNIQUE. SANDWICH DEVICE COMPOSED OF HETEROJUNCTION OF BRALPC AND PBPC (AL/BRALPC/PBPC/AL) WERE PREPARED IN OUR LABORATORY. THE AC ELECTRICAL BEHAVIOR OF HETEROJUNCTION DEVICES OBSERVED OVER THE FREQUENCY RANGE 102-105HZ AND TEMPERATURE RANGE 303 TO 403 K. CAPACITANCE AND DISSIPATION FACTORS (TAND) DECREASE WITH INCREASING FREQUENCY AND INCREASE WITH INCREASING TEMPETURE. THE OBTAINE RESULTS FROM MEASUREMENTS DESCRIBED BY THE THEORY OF SIMMONS ET AL.

IN THIS PAPER, SYNTHESIS OF WO3-X THIN FILMS AND THEIR OPTICAL, STRUCTURE AND SURFACE PROPERTIES HAVE STUDIED. FIRST, WO3 THIN FILMS WERE DEPOSITED BY THERMAL EVAPORATION UNDER VACUUM CONDITION ON GLASS SUBSTRATES. THEN, THE DEPOSITED SAMPLES WERE ANNEALED UNDER ATMOSPHERE AT 400OC FOR 1 H. AFTER THIS, THEY WERE REDUCED UNDER PURE HYDROGEN ENVIRONMENT AT 500OC FOR DIFFERENT TIME DURATION OF 0-480 MIN TO PRODUCE WO3-X COMPOSITION. THE SAMPLES WITH DIFFERENT REDUCTION TIME UNDER H2 WERE ANALYZED BY XRD, UV-VISIBLE SPECTROPHOTOMETER AND AFM. XRD SPECTRA SHOWED THAT THE SAMPLES BEFORE THE REDUCTION PROCESS DO NOT HAVE ANY WO3-X STRUCTURE, BUT AFTER THE REDUCTION PROCESS, WO2.8 CRYSTALLINE PHASE WAS FORMED. BY INCREASING THE REDUCTION TIME, THE INTENSITY OF WO2.8 PHASE WAS INCREASED. TRANSMITTANCE AND REFLECTANCE MEASUREMENTS OF THE SAMPLES AT 500 AND 1100 NM WAVELENGTH INDICATED THAT BEFORE THE REDUCTION PROCESS THE SAMPLES WERE TRANSPARENT, WHILE AFTER THE REDUCTION PROCESS THEY BECOME DARK AND THEIR REFLECTANCE WERE INCREASED IN IR REGION.

IN THIS RESEARCH, A CARBON TARGET HAS BEEN INCIDENT BY ARGON ION BEAMS UNDER VARIOUS ANGLES. SURFACE SPUTTERING EFFICIENCY, DISTRIBUTION, AND PENETRATION DEPTH OF ARGON BEAM HAVE BEEN DETERMINED AND STUDIED. SRIM-TRIM 2008 SOFTWARE HAS BEEN USED FOR CALCULATING THE DISTRIBUTION PARAMETERS AND MODELING OF THE IONS PENETRATION. THE RESULTS SHOW THAT BY INCREASING THE ANGLE OF INCIDENT BEAM, THE PENETRATION DEPTH DECREASES AND ARGON IONS HAVE THE SURFACE DISTRIBUTION. IN ADDITION, THE RESULTS SHOW THAT THE SPUTTERING EFFICIENCY INCREASES WHEN THE INCIDENT ANGLE INCREASES.

THE COATING MACHINE “BALZERS BAK760” IS USED TO MAKE OF THIN FILMS BY PHYSICAL EVAPORATION METHOD OR PHYSICAL VAPOR DEPOSITION METHOD (PVD). THE ROTATION UMBRELLA OF THIS MACHINE IS DESIGNED SO THAT INTERVAL SUBSTRATES OF ELECTRON GUN ARE SYMMETRIC. FOR THE STEADY ACCUMULATION LAYER ON THE SUBSTRATE, THE UMBRELLA MUST ROTATE WITH A CERTAIN SPEED. THIS UMBRELLA IS DESIGNED TO COATING OF FLAT SUBSTRATES OR SUBSTRATES WITH VERY LARGE RADIUS OF CURVATURE (THAT IN SMALL SIZE ARE SEEMS FLAT). FOR COATING ON THE SUBSTRATES WITH DIFFERENT SHAPES, SHOULD BE DESIGNED AND MADE OF DIFFERENT UMBRELLAS AND HOLDERS. IN THIS PAPER HAVE BEEN REPORTED THE DESIGN AND CONSTRUCTION OF THREE UMBRELLA AND HOLDERS FOR COATING OF CYLINDRICAL SUBSTRATES AND GAUSSIAN MIRRORS.

FE3O4 NANOPOWDERS WITH DOPING ZN IN VARIOUS MOLAR RATIOS (ZN/FE=0, 0.025, 0.05, 0.075, 0.1, 0.125) WERE SYNTHESIZED BY CO-PRECIPITATION METHOD AND DRIED UNDER VACUUM ENVIRONMENT. THE CRYSTALLINE STRUCTURES WERE INVESTIGATED BY X-RAY DIFFRACTION (XRD), FOURIER TRANSFORM INFRARED SPECTROMETRY’S (FTIR) AND TRANSMISSION ELECTRON MICROSCOPY (TEM).THE X-RAY DIFFRACTION PATTERN INDICATE THE FABRICATION OF FE3O4 IN ALL OF THE SAMPLES. THE TEM IMAGES REVEAL UNIFORM DISPERSION’S SIZE AND SPHERICAL FORM FOR FE3O4: ZN NANOPARTICLES.

MOST LOSSES OF THE PADDY OCCURRED IN DRYING AND MILLING PROCESS THAT CAN BE REDUCED BY OPTIMIZING THE DRYING PROCESS. IN THIS STUDY, PADDIES HAVE BEEN TRANSFERRED TO A VACUUM CHAMBER AFTER EVERY DRYING STEP. DURING THE RELAXATION PERIOD IN THE VACUUM CHAMBER, HEAT TRANSFER WITHIN THE RICE GRAIN OCCURS SLOWLY FOR MINIMIZING THE THERMAL AND MOISTURE STRESSES. BASED ON THE RESULTS OBTAINED IN THIS STUDY, A REDUCED PRESSURE DURING THE RELAXATION STAGE SIGNIFICANTLY INFLUENCES THE RICE GRAIN BREAKAGE. THE OPTIMIZED COMBINATION OF TIME, TEMPERATURE AND PRESSURE FOR THE NEMAT RICE VARIETY OBTAINED 5 HR, 60OC AND 0.6 ATM, RESPECTIVELY.

UTILIZING ELECTRON BEAM EVAPORATION TECHNIQUE, ZNO LAYER IS DEPOSITED ON SODA LIME GLASS SUBSTRATE AND THEN ANNEALING AT 500OC FOR 2 HOURS, THEN PT ELECTRODE WAS COATED ON DIFFERENT ZNO LAYER SAMPLES WITH THE SAME METHOD AND EVENTUALLY WERE USED AS GAS SENSORS. SENSORS WERE EXPOSED TO VAPORS OF DIFFERENT ALCOHOLS I.E , ETHANOL, METHANOL, PROPANOL AND BUTANOL. CHANGE IN SENSITIVITY OF SENSORS BY INCREASE IN CONCENTRATION OF THE ALCOHOLS WAS INVESTIGATED.

IN THIS PAPER, SOME PATHOGENIC MICROORGANISMS, INCLUDING CLOSTRIDIUM BOTULINUM ARE INTRODUCED THAT THEY CAN GROW AND MULTIPLY AND CAUSE SPOILAGE IN VACUUM CONDITIONS INSIDE OF CANNED FOODS. CONSUMPTION OF FOOD CONTAMINATED WITH THIS TOXIN CAN BE DANGEROUS MICROORGANISMS THAT CAUSE DISEASE BY OBSERVING SOME SIMPLE TIPS, WHICH CAN BE PREVENTED.

IN THIS PAPER A REPORT OF SIMULATION AND CONSTRUCTION AND EARLY DEVELOPMENTAL STAGES OF A THERMIONIC ELECTRON EMITTER ALONG WITH ACCOMPANYING ELECTRON OPTICS INCLUDING ELECTROSTATIC LENSES NECESSARY FOR ACCELERATING ELECTRONS, PASSING THEM THROUGH APERTURES AND FORMING AN ELECTRON BEAM AS WELL AS MAGNETIC FOCUSING LENSES FOR INCREASING POWER DENSITY OF THE BEAM IS GIVEN. THE COMPUTATIONAL CODE SIMION3D8. 0 MAY BE USED TO CORRECT THE CANONICAL PROPERTIES OF ELECTROSTATIC LENSES AND CALCULATE THE IMPOSED VOLTAGES ON OPTICAL COMPONENTS OF THE ELECTRON GUN. IN THESE GUN A 0. 3 MM TUNGSTEN WIRE HAVING A SHARP EMITTING AREA AT THE TOP IS USED AS A CATHODE. A DIRECT CURRENT WAS USED TO HEAT THE CATHODE. AN ELECTROMAGNETIC COIL IS USED FOR FOCUSING THE BEAM ONTO THE WORK PIECE. WE ACHIEVED TO A BEAM WITH FINAL EMISSION CURRENT OF 212 MA AND FINAL RADUSE OF 1.5 MM.

GIVEN THE FACT THAT THE GOAL OF THE CURRENT PAPER IS BOTH TO STUDY HOW STRUCTURAL PARAMETERS DEPEND ON GROWTH PARAMETERS AND TO INTRODUCE OPTIMUM POINT, THE TIME OF THE GROWTH AND METHANE GAS RATIO TO TOTAL ENTRANCE GAS IN SYSTEM (CH4/CH4+H2) WERE CHOSEN AS INDEPENDENT PARAMETERS AND CHANGES OF THE STRUCTURAL PARAMETERS LIKE SURFACE AVERAGE ROUGHNESS, CRYSTALLITY PERCENT AND DIAMOND CRYSTAL SIZE HAVE BEEN STUDIED REGARDING THESE PARAMETERS. IN THIS PROJECT, HFCVD SYSTEM HAS BEEN EMPLOYED AS PROCESS, CH4 AS CARBURIZED GAS AND H2 AS A DILUTING GAS.

VACUUM COOLING IS A RAPID EVAPORATIVE COOLING TECHNIQUE, WHICH CAN BE APPLIED TO SPECIC FOODS AND IN PARTICULAR VEGETABLES .INCREASED COMPETITIVENESS TOGETHER WITH GREATER CONCERNS ABOUT PRODUCT SAFETY AND QUALITY HAS ENCOURAGED SOME FOOD MANUFACTURERS TO USE VACUUM COOLING TECHNOLOGY .THE ADVANTAGES OF VACUUM COOLING INCLUDE SHORTER PROCESSING TIMES, CONSEQUEN TENERGY SAVINGS, IMPROVED PRODUCT SHELF LIFE, QUALITY AND SAFETY. RECENT RESEARCH HAS HIGHLIGHTED THE POSSIBLE APPLICATIONS OF VACUUM COOLING FOR COOLING MEAT AND BAKERY PRODUCTS, FRUITS AND VEGETABLES. IT IS CONCLUDED THAT WHILE VACUUM COOLING REMAINS A HIGHLY SPECIALIZED COOLING TECHNIQUE, WITH CONTINUING RESEARCH ITS APPLICATION MAY MAKE ITS USE IN THE FOOD AND VEGETABLE PROCESSING INDUSTRIES MORE COMPETITIVE AND WIDESPREAD. THIS PAPER FIRST DISCUSSES THE PRINCIPLES AND EQUIPMENT OF VACUUM COOLING AND CRITICALLY AND ANALYSES THE ADVANTAGES AND DISADVANTAGES OF THIS TECHNIQUE.

IN THIS PAPER, THE DIRECT LINEAR METHOD (DLM) IS APPLIED TO ANALYZE THE TOLERANCES OF PARTS OF TURBOMOLECULAR HIGH VACUUM PUMP. HERE THE MANUFACTURING TOLERANCES OF FIVE PARTS OF PUMP WHICH INCLUDE: SHELL, STATOR, HEAD, ROTOR SHAFT AND ROTOR BLADES ALONG AXESSYMMETRIC AXES ARE OBTAINED.

IN ORDER TO STUDY THE STRUCTURAL PROPERTIES OF ELECTRON BOMBARDED SILVER NANOPARTICLES COATED ON ALUMINA TEMPLATE, SAMPLES PLACED INTO A VACUUM CHAMBER EQUIPPED WITH AN ELECTRON GUN. IN THIS ARTICLE, THE PROCESS OF AG DEPOSITION WITH ION BEAM SPUTTERING METHOD AND ELECTRON BOMBARDMENT WERE SIMULTANEOUSLY. TO STUDY THE EFFECT OF ELECTRON BOMBARDMENT ON AG NANOPARTICLE STRUCTURE SCANNING ELECTRON MICROSCOPY (SEM) AND X-RAY DIFFRACTION ANALYSIS (XRD) WERE PERFORMED.

REACTIVE GASES ARE USED FOR A LARGE VARIETY OF OXIDE AND FLUORIDE COMPOUNDS TO KEEP FILM STOICHIOMETRY. IN REGARD TO THE DEPOSITION OF MGF2 BY ELECTRON BEAM EVAPORATION, USING REACTIVE GASES IS NOT NECESSARY. MGF2 THIN FILM WITH A THICKNESS OF 92 NM WAS DEPOSITED ON GLASS SUBSTRATE. THE OPTICAL, CHEMICAL, AND STRUCTURAL PROPERTIES OF THE DEPOSITED MGF2 FILMS WERE INVESTIGATED BY USING SPECTROPHOTOMETER, X-RAY PHOTOELECTRON SPECTROSCOPY (XPS), AND ATOMIC FORCE MICROSCOPY (AFM).

FABRICATION OF INDIUM OXIDE NANOWIRES BY THERMAL EVAPORATION WITHOUT ANY CATALYST, IN HORIZONTAL TUBULAR FURNACE SUCCESSFULLY HAS BEEN PERFORMED. THE GROWN NANOWIRES ARE 75NM-150NM IN DIAMETER AND SEVERAL MICRONS IN LENGTH. GROWTH MECHANISM OF THESE NANOWIRES WAS DISCUSSED BY MADE ANALYSIS AND IT WAS FOUND OUT THAT VS MECHANISM CAUSES LATERAL GROWTH OF NANOWIRES. FOR PREVAILING OF INDIUM OXIDE HIGH EVAPORATION TEMPERATURE AND NEED TO HIGH DEGREE FURNACES, THESE NANOWIRES HAVE BEEN MATERIALIZED IN RELATIVELY LOW VACCUM.

THE MOLYBDENUM NITRIDE COATING WAS PRODUCED BY NITROGEN ION IMPLANTATION INTO MOLYBDENUM LAYER DEPOSITED ON THE STAINLESS STEEL 316. AT FIRST, MOLYBDENUM IS DEPOSITED ON THE STAINLESS STEEL BY ION BEAM SPUTTERING METHOD. THE THICKNESS OF AS-DEPOSITED MO FILMS FOR THE SUBSTRATES PREPARED AT 12 MIN WAS 500 NM. THEN NITROGEN IONS OF 30 K EV WITH THE DOSE OF 1´1017, 8´1017 AND 12´1017 N+ IONS CM-2 WERE IMPLANTED IN AS-DEPOSITED FILMS. CRYSTALLINE STRUCTURE AND TOPOGRAPHY OF THE SURFACE ARE INVESTIGATED BY GLANCING INCIDENT X-RAY DIFFRACTION (GI XRD) AND ATOMIC FORCE MICROSCOPY (AFM) RESPECTIVELY. CORROSION TESTS SHOWED CONSIDERABLE IMPROVEMENT OF CORROSION PERFORMANCE OF MOLYBDENUM LAYER BY NITROGEN ION IMPLANTATION AND ALSO WITH INCREASE OF ION DOSES.

POROUS SILICON ARE PREPARED FROM P-TYPE SI WAFER BY ELECTROCHEMICAL METHOD WITH ETCHING TIMES OF 10, 20, 30, 40 MIN. SEM TOP AND CROSS SECTION VIEWS ARE MEASURED AND SHOWED THAT WITH INCREASING ETCHING TIME, THICKNESS OF POROUS LAYER AND POROSITY INCREASES. ALSO, ABSORBANCE OF SAMPLES IS DECREASED WITH INCREASING ETCHING TIME.

CARBON NANOTUBES WERE GROWN ON A THIN IRON CATALYST LAYER IN A CHEMICAL VAPOR DEPOSITION REACTOR (CVD) BY CHAMBER PRESSURE OF 10 MMHG. IN THIS PAPER WE REPORTED THE GROW OF CARBON NANOTUBES BY USING 1NM IRON CATALYST ON ALUMINUM OXIDE BUFFER AL2O3 LAYER OF SI P-TYPE (100) SUBSTRATE AND ETHANOL VAPOR AS CARBON SOURCE AND ARGON CARRIER GAS IN A THERMAL CHEMICAL VAPOR DEPOSITION(CVD). WE STUDIED CHAMBER TEMPERATURE ON LENGTH AND QUALITY OF CARBON NANOTUBES. THE RESULTS EXPLAINED THAT IN 10 MMHG PRESSURE, THE TEMPERATURE FOR OPTIMUM CARBON NANOTUBES GROWTH BY ETHANOL VAPOR AND IRON CATALYST IS 655OC. SCANNING ELECTRON MICROSCOPY (SEM) SHOWS CARBON NANOTUBES IN THIS TEMPERATURE HAVE BETTER LENGTH AND QUALITY.

RESPONSE SURFACE METHODOLOGY WAS USED FOR OPTIMIZATION OF OSMO-VACUUM DRYING OF PEAR. THE EFFECT OF DRYING TEMPERATURE(50-70OC), VACUUM PRESSURE(10-30 KPA) AND DRYING TIME(180-300 MIN) AS INDEPENDENT VARIABLES WERE INVESTIGATED ON THE MOISTURE CONTENT, SHRINKAGE AND REHYDRATION RATIO OF PEAR SLICES AS DEPENDENT VARIABLES(RESPONSES). THE OPTIMUM OSMO-VACUUM DRYING CONDITIONS FOR MINIMUM MOISTURE CONTENT AND SHRINKAGE AND MAXIMUM REHYDRATION RATIO WERE 56OC DRYING TEMPERATURE, 10 KPA VACUUM PRESSURE AND 250 MIN DRYING TIME. AT THIS OPTIMUM CONDITIONS MOISTURE CONTENT, SHRINKAGE AND REHYDRATION RATIO WERE FOUND TO BE 23%, 67% AND 1.45, RESPECTIVELY.

MOLYBDENUM (MO) THIN FILMS ARE DEPOSITED USING RF SPUTTERING TECHNIQUE, AND THE EFFECT OF OPERATIONAL PRESSURE AND RF POWER ON RESISTIVITY OF THE FILMS IS INVESTIGATED. POINT OF MINIMUM RESISTIVITY IS SELECTED TO SPUTTER A THIN LAYER OF MO ON TOP OF A PRE-FABRICATED SILICON FIELD EMITTER ARRAY (SI-FEA). GEOMETRIC AND FIELD EMISSION PROPERTIES OF THE ARRAYS ARE INVESTIGATED BEFORE AND AFTER MO DEPOSITION. IT IS SHOWN THAT THE MO COVERED ARRAY SHOWS BETTER EMISSION PROPERTIES AND LOWER TURN ON FIELD, COMPARED TO THE SIMPLE SI-FEA.

SILVER THIN FILMS WERE DEPOSITED BY ION BEAM SPUTTERING TECHNIQUE IN THE RANGE OF 100-400OC SUBSTRATE TEMPERATURE. THE SURFACE TOPOGRAPHY OF THE FILMS WAS CHARACTERIZED USING SCANNING ELECTRON MICROSCOPY (SEM). MEANWHILE, THE FRACTAL THEORY HAS BEEN USED FOR THE TREATMENT OF SURFACE ROUGHNESS. DIFFERENTIAL BOX COUNTING METHOD WAS USED FOR CALCULATION OF FRACTAL DIMENSION AND MULTIFRACTAL PARAMETERS OF THE FILMS. IN ORDER TO IMPROVE VISUALIZE CHARACTERISTICS OF THE IMAGES BOTH 2D AND 3D SEM IMAGES WERE USED.

THE UNDERSTANDING OF THE PARAMETERS WHICH AFFECTS THE FILM THICKNESS DISTRIBUTION AND THE TARGET BEHAVIOR DURING DEPOSITION AND THE WAY IT AFFECTS FILM PROPERTIES WILL UNEQUIVOCALLY IMPROVE COATINGS PROPERTIES. THIS PAPER EXAMINES THE DEPOSITION OF CU COATING IN BOTH HIGH AND VERY LOW RANGE OF PRESSURE, EXPERIMENTALLY. THE THICKNESS DISTRIBUTION OF THE ALUMINUM COATING HAS BEEN STUDIED USING DC MAGNETRON SPUTTERING METHOD, TOO. THE EXPERIMENTAL RESULTS COMPARE WELL WITH THOSE OBTAINED BY THEORETICAL METHODS GIVEN THE DC MAGNETRON SPUTTERING MODELS USED FOR THE STUDY. IN BOTH PRESSURE RANGES, FILM UNIFORMITY DEPENDS ON THE LOCATION OF THE SUBSTRATE. THE EFFECT OF PRESSURE, TARGET MATERIAL AND CURRENT ON THE SCATTERING IS ILLUSTRATED DIAGRAMMATICALLY AND THE VALIDITY OF PRESENTED MODEL IN BOTH PRESSURE RANGES ARE PROVED.

SIO2 THIN LAYERS IN THICKNESSES (1, 5, 10, 18 NM) ON THE TIO2 THIN LAYER IN THICKNESS 79 NM DEPOSITED BY REACTIVE RF SPUTTERING TECHNIQUE. THE DEPOSITED FILMS WERE ANNEALED AT (200, 300, 400, 500, 600OC). THE SURFACE PROPERTIES OF THIN FILMS BY ATOMIC FORCE MICROSCOPY (AFM), SURFACE CHEMICAL COMPOSITION BY X-RAY PHOTOELECTRON SPECTROSCOPY (XPS), PHOTOCATALYTIC TIO2 UNDERLAYER BY THE UV LIGHT IRRADIATION AND HYDROPHILIC PROPERTIES OF THE FILMS, WERE STUDIED.

IN THIS ARTICLE A QUADRUPOLE MASS FILTER WITH HYPERBOLIC CROSS SECTION WILL BE DESIGNED. THIS FILTER HAS BEEN SIMULATED WITH SIMION3D VERSION07 SOFTWARE AND HAS BEEN OPTIMIZE FOR TRANSMISSION OF HELIUM GAS IONS IN THE FIRST AND THIRD STABILITY ZONES. ALSO THE EFFECT OF CHANGE IN THE ION BEAM REDUCE, ENERGY AND ITS ANGULAR DISTRIBUTION ON THE RESOLVING POWER AND PERCENTAGE OF TRANSMISSION EFFICIENCY OF THIS MASS FILTER WITH A=0.237 AND Q=0.706 PARAMETERS IN THE FIRST STABILITY ZONE AND A=3.16 AND Q=3.23 PARAMETERS IN THE THIRD STABILITY ZONE, HAS BEEN STUDIED.

THE PRINCIPLE OF VACUUM COOLING IS BASED ON RAPID EVAPORATION OF PART OF THE MOISTURE OF THE PRODUCT UNDER VACUUM. VACUUM COOLING CAN BE USED TO SHORTEN PROCESSING TIME, EXTEND PRODUCT SHELF LIFE, AND IMPROVE PRODUCT QUALITY AND SAFETY. IN AGRICULTURAL INDUSTRY IS USED VACUUM COOLING TO REMAIN LONG TIME AS FRESH FOR VEGETABLES AND MUSHROOM. THE CONCERN FOR FOOD SAFETY HAS MADE FOOD MANUFACTURERS TO EXPLORE NEW METHODS TO COOL IN THE FOOD INDUSTRY.

THE INTEREST IN DUSTY PLASMA RESEARCH, WHICH IS A RELATIVELY NEW FIELD IN PLASMA PHYSICS, HAS INCREASED WITH THE DEVELOPMENT OF MICROELECTRONICS. THE DUST PARTICLES APPEAR AS POLLUTANT IN THIS INDUSTRIAL PROCESSING. RECENTLY, HOWEVER, THEY ARE SEEN FROM A DIFFERENT POINT OF VIEWS – THEY CAN BE USEFUL IN COATINGS VARIOUS TECHNOLOGIES FOR MICROELECTRONIC, OPTIC, ELECTRO-OPTIC INDUSTRIAL. IN THIS INVESTIGATION WE HAVE CONCENTRATED ON COATING OF DUST PARTICLES BY ZNO: AL THIN FILM. DUST PARTICLES IN THE INVESTIGATION ARE ZN, AL. THIN FILMS ARE FABRICATION BY COMBINATION OF PLASMA SPUTTERING ZN, AL AND THERMAL OXIDATION. THESE THIN FILMS HAVE SPECIAL PHYSICAL PROPERTIES, SUCH AS LARGE BOND STRENGTH, ZNO THIN FILMS EXHIBIT HIGH TRANSPARENCY IN VISIBLE REGION AND LOW ELECTRICAL RESISTIVELY. THE ELECTRICAL AND OPTICAL PROPERTIES OF ZNO: AL THIN FILMS WERE EVALUATED BY XRD, RBS, THE LINEAR FOUR POINT PROBE METHOD AND VISIBLE SPECTROSCOPY. 85.45.BZ VACUUM MICROELECTRONIC DEVICE CHARACTERIZATION, DESIGN, AND MODELING.

NANOBELTS HAVE BEEN SUCCESSFULLY GROWN BY PHYSICAL VAPOR DEPOSITION METHOD IN A TUBE FURNACE. TELLURIUM POWDER WAS EVAPORATED AT A TEMPERATURE OF 360OC AND A PRESSURE OF 10-2 MBAR, AND WAS CONDENSED ON SUBSTRATES AT 212–231OC, IN THE DOWNSTREAM OF ARGON GAS FLOW. THE PRODUCTS WERE CHARACTERIZED BY FIELD EMISSION SCANNING ELECTRON MICROSCOPY (FESEM). THE FESEM IMAGES REVEALED THAT IN LOWER TEMPERATURES THE SURFACE IS MOSTLY COVERED WITH NANORODS AND NANOWIRES WITH DIAMETERS RANGING FROM 100 TO 150 NM, WHILE IN HIGHER TEMPERATURES SOME 2D STRUCTURES AND NANOBELTS HAVE GROWN ON THE SURFACE AS WELL.

DIRECTIONAL SOLIDIFICATION PROCESS IS ONE OF THE CONTROLLED SOLIDIFICATION METHODS FOR DEVELOPING DIRECTIONAL GRAIN STRUCTURE IN ENGINEERING PARTS. IN THE PRESENT WORK, A LABORATORY-SCALE DIRECTIONAL SOLIDIFICATION SYSTEM BASED ON BRIDGMAN METHOD WAS DESIGNED AND MANUFACTURED. THIS SYSTEM WAS USED FOR DIRECTIONAL SOLIDIFICATION OF IN792 NICKEL-BASED SUPERALLOY UNDER VACUUM AND ATMOSPHERIC CONDITIONS. MICRO- AND MACROSTRUCTURE OF SPECIMENS WERE INVESTIGATED AND THE EFFECT OF VACUUM ON QUALITY OF THE CAST PARTS WAS STUDIED.

IN THIS PAPER, POWDER OF BA0.5SR0.5CO0.8FE0.2O3-Δ (BSCF OXIDE) WERE PREPARED BY SOL-GEL METHOD FOR SOLID OXIDE FUEL CELL (SOFC) CATHODE APPLICATIONS. FURTHERMORE, THIN FILMS OF BSCF WERE PREPARED BY PULSED LASER DEPOSITION (PLD) ON SRTIO3 (STO) SUBSTRATES IN DIFFERENT PARTIAL PRESSURE OF OXYGEN. CRYSTAL STRUCTURE STUDIED BY X-RAY DIFFRACTION (XRD). THE SURFACE MORPHOLOGY OF FILMS WAS ANALYZED BY ATOMIC FORCE MICROSCOPE (AFM). THE ELECTRICAL RESISTIVITIES WERE MEASURED BY FOUR-POINT PROBE METHOD. THE ELECTRICAL RESISTIVITY WAS MEASURED FROM ROOM TEMPERATURE UP TO 600OC AND MORE IN AIR ATMOSPHERE THAT SHOWED A SHARP DROP COMPARED TO INITIAL VALUE.

ZNO VERTICALLY ALIGNED NANOSTRUCTURES WITH HEXAGONAL CROSS SECTION HAVE BEEN GROWN BY REACTIVE DC SPUTTERING METHOD. USING THERMAL TREATMENT IN VACUUM TUBE FURNACE AND CONTROLLING THE PROCESS, FAVORABLE STRUCTURES WITH GOOD EMISSION WERE OBTAINED. SEM IMAGES VERIFIED THE HEXAGONAL CROSS SECTION OF NANOSTRUCTURES WITH DIAMETERS IN THE RANGE OF 50-150 NM. XRD PATTERN INDICATED THAT THE SAMPLES ARE CRYSTALLINE. THE OPTICAL PROPERTY OF NANOSTRUCTURES WAS INVESTIGATED USING PHOTOLUMINESCENCE (PL) SPECTRUM. PL SPECTRA INDICATED A SHARP PEAK IN NEAR-UV RANGE OF ELECTROMAGNETIC SPECTRUM. THE OUTSTANDING APPLICATION OF NANOSTRUCTURES WITH THIS PROPERTY IS IN OPTOELECTRONIC DEVICES SUCH AS UV-LEDS AND UV DIODE LASERS.

THE INTEREST IN DUSTY PLASMA RESEARCH, WHICH IS A RELATIVELY NEW FIELD IN PLASMA PHYSICS, HAS INCREASED WITH THE DEVELOPMENT OF MICROELECTRONICS AND SURFACE ENGINEERING. THE DUST PARTICLES APPEAR AS POLLUTANT IN THIS INDUSTRIAL PROCESSING. RECENTLY, HOWEVER, THEY ARE SEEN FROM A DIFFERENT POINT OF VIEWS – THEY CAN BE USEFUL IN COATINGS VARIOUS TECHNOLOGIES. ONE THE TYPE OF DEPOSITION IS PLASMA REACTIVE SPUTTERING. THE TARGET POISONING IN THE PROCESSES DEPOSITION FOR REACTIVE SPUTTERING IS IMPORTANT. THE RESULTANT OF TARGET POISONING IS INSTABILITY IN THE SYSTEM. THERE HAVE VERY INFLUENCE ON THE ELECTRICAL, OPTICAL AND CONSTRUCTION PROPERTIES. THE STOCHIOMETRY IS CHANGING ALONG TARGET POISONING.

DRYING IS AN ANCIENT PROCESS USED TO PRESERVE FOODS. CONVENTIONAL DRYING (HOT AIR) OFFERS DEHYDRATED PRODUCTS THAT CAN HAVE AN EXTENDED LIFE OF A YEAR. UNFORTUNATELY, THE QUALITY OF A CONVENTIONALLY DRIED PRODUCT IS DRASTICALLY REDUCED FROM THAT OF ORIGINAL FOODSTUFF. VACUUM DRYING IS BASED ON THE DEHYDRATION BASED ON REDUCING OF THE PRESSURE AND TEMPERATURE OF THE DRYING. DUE TO EMPLOYING MICROWAVE THE FOOD STUFF WOULD BE HEATED SIMULTANEOUSLY AND EMPLOYING OF VACUUM WOULD REDUCE THE EVAPORATING TEMPERATURE OF WATER SO THAT THE REQUIRING TEMPERATURE WOULD DECREASE. MOST OF THE DETERIORATION AND MICROBIOLOGICAL REACTIONS ARE STOPPED WHICH GIVES THE FINAL PRODUCT EXCELLENT QUALITY.