Volume 41; Issue 7-9

Vacuum

Volume 41; Issue 7-9
1

Concept and realization of a photon-induced scanning Auger microscope

Year:
1990
Language:
english
File:
PDF, 394 KB
english, 1990
4

ESCA and SEXAFS investigations of insulating materials for ULSI microelectronics

Year:
1990
Language:
english
File:
PDF, 330 KB
english, 1990
5

Ellipsometric response to hydrogen adsorption on thin iron films

Year:
1990
Language:
english
File:
PDF, 220 KB
english, 1990
6

Positron beam studies of doped Cz-grown silicon

Year:
1990
Language:
english
File:
PDF, 190 KB
english, 1990
7

Auger electron spectroscopy of adsorbed layers—quantitative analysis

Year:
1990
Language:
english
File:
PDF, 313 KB
english, 1990
8

Recent applications of high resolution secondary-ion-mass-spectrometry imaging microanalysis

Year:
1990
Language:
english
File:
PDF, 364 KB
english, 1990
10

Effect of instrumental resolution on quantification in Auger electron spectroscopy measurements

Year:
1990
Language:
english
File:
PDF, 273 KB
english, 1990
11

A new consideration for matrix effects correction in quantitative AES analysis

Year:
1990
Language:
english
File:
PDF, 217 KB
english, 1990
13

The role of the fiber-matrix interphase on composite properties

Year:
1990
Language:
english
File:
PDF, 397 KB
english, 1990
15

Chemical sensors based on LB films

Year:
1990
Language:
english
File:
PDF, 458 KB
english, 1990
16

Surface spectroscopic studies on Pd-doped SnO2

Year:
1990
Language:
english
File:
PDF, 324 KB
english, 1990
19

Solid surfaces as the scene of catalytic act

Year:
1990
Language:
english
File:
PDF, 141 KB
english, 1990
20

The oxidation of Gd0.95Si0.05 layers

Year:
1990
Language:
english
File:
PDF, 261 KB
english, 1990
22

Electronic and chemical structure of conjugated polymer ‘surfaces’

Year:
1990
Language:
english
File:
PDF, 299 KB
english, 1990
23

A combined TOF SIMS and FTIR MSR study on the analysis of several polyimide surfaces

Year:
1990
Language:
english
File:
PDF, 224 KB
english, 1990
24

Progress in solids analysis by sputtered neutral mass spectrometry

Year:
1990
Language:
english
File:
PDF, 645 KB
english, 1990
25

A time-of-flight secondary ion microscope

Year:
1990
Language:
english
File:
PDF, 565 KB
english, 1990
27

Aspects of quantification of off-resonance laser ionization for SNMS

Year:
1990
Language:
english
File:
PDF, 144 KB
english, 1990
28

Low energy ion beam mixing of aluminium impurity multilayers

Year:
1990
Language:
english
File:
PDF, 247 KB
english, 1990
29

Depth resolution for sputter sectioning of Ni

Year:
1990
Language:
english
File:
PDF, 193 KB
english, 1990
30

Analysis of multi-layered structures by a non-conventional Auger depth profiling method

Year:
1990
Language:
english
File:
PDF, 300 KB
english, 1990
31

Analysis of Ta2O5Ta interface

Year:
1990
Language:
english
File:
PDF, 285 KB
english, 1990
32

Photoelectron spectroscopic study of copper surfaces changed by oxygen ion bombardment

Year:
1990
Language:
english
File:
PDF, 291 KB
english, 1990
34

Low energy ion bombardment on c-Ge surfaces

Year:
1990
Language:
english
File:
PDF, 151 KB
english, 1990
36

Escascope—a new imaging photoelectron spectrometer

Year:
1990
Language:
english
File:
PDF, 642 KB
english, 1990
37

Deconvolution of UPS and XPS spectra

Year:
1990
Language:
english
File:
PDF, 295 KB
english, 1990
38

Quantitative Auger spectroscopy of titanium nitrides by means of factor analysis

Year:
1990
Language:
english
File:
PDF, 283 KB
english, 1990
39

Auger quantitative analysis and preferential sputtering in brass alloys

Year:
1990
Language:
english
File:
PDF, 295 KB
english, 1990
40

Quantitative analysis of the AuNi(111) system by XPS: separation of peaks and background subtraction

Year:
1990
Language:
english
File:
PDF, 323 KB
english, 1990
41

Mechanical stability of a STM junction

Year:
1990
Language:
english
File:
PDF, 178 KB
english, 1990
42

A new type of combined bipole deflector for a rf glow discharge ion source

Year:
1990
Language:
english
File:
PDF, 185 KB
english, 1990
43

Electron backscattering and penetration in the small-angle and transport approximation model

Year:
1990
Language:
english
File:
PDF, 205 KB
english, 1990
44

Inelastic scattering of middle-energy electrons by solid surfaces

Year:
1990
Language:
english
File:
PDF, 294 KB
english, 1990
45

Quantitative depth analysis of impurities in solids based on combination of AES and EPMA

Year:
1990
Language:
english
File:
PDF, 238 KB
english, 1990
46

Soft X-ray photoelectron spectroscopy studies of the initial oxidation of AlxGa1−xAs(100) surfaces

Year:
1990
Language:
english
File:
PDF, 137 KB
english, 1990
47

SNMS—SNART: focusing on insulator analysis

Year:
1990
Language:
english
File:
PDF, 248 KB
english, 1990
48

A study of secondary ion emission from silicon under improved experimental conditions

Year:
1990
Language:
english
File:
PDF, 283 KB
english, 1990
49

Reaction of clean lithium with O2, SO2 and liquid LiAlCl4·3(SO2), an XPS and Auger analysis

Year:
1990
Language:
english
File:
PDF, 171 KB
english, 1990
50

Surface segregation and sodium transport in NaxCoO2

Year:
1990
Language:
english
File:
PDF, 372 KB
english, 1990
51

AES analysis of grain boundary segregation and precipitation in electron beam welded molybdenum and Mo-0.56% Nb alloy

Year:
1990
Language:
english
File:
PDF, 281 KB
english, 1990
52

Oxidation of a Au + 4 at% Ti alloy

Year:
1990
Language:
english
File:
PDF, 360 KB
english, 1990
54

Investigation of electron emission stability of negative electron affinity cathodes

Year:
1990
Language:
english
File:
PDF, 276 KB
english, 1990
55

Investigation of contact surfaces and protective gas atmosphere in reed switches

Year:
1990
Language:
english
File:
PDF, 270 KB
english, 1990
57

Emission characteristics and surface composition of dispenser cathodes in realistic vacuum

Year:
1990
Language:
english
File:
PDF, 245 KB
english, 1990
58

Weakly bound hydrogen state on thin iron films

Year:
1990
Language:
english
File:
PDF, 308 KB
english, 1990
59

High response humidity sensors with plasma polymerized organic film

Year:
1990
Language:
english
File:
PDF, 229 KB
english, 1990
61

Ultra high vacuum depth selective conversion electron Mössbauer spectroscopy

Year:
1990
Language:
english
File:
PDF, 375 KB
english, 1990
74

Gauge calibration in the high and medium vacuum range by a series expansion standard

Year:
1990
Language:
english
File:
PDF, 251 KB
english, 1990
75

Application of metal-insulator-metal thin films as cold cathodes to the Bayard-Alpert gauge

Year:
1990
Language:
english
File:
PDF, 229 KB
english, 1990
76

An axial-emission bent beam gauge

Year:
1990
Language:
english
File:
PDF, 157 KB
english, 1990
77

The influence of the external circuit on the ionization gauge stability

Year:
1990
Language:
english
File:
PDF, 214 KB
english, 1990
79

Design and performance of oil-free pumps

Year:
1990
Language:
english
File:
PDF, 446 KB
english, 1990
80

Operational experience with totally oil-free rough vacuum pumps

Year:
1990
Language:
english
File:
PDF, 262 KB
english, 1990
81

Multistage dry pumps

Year:
1990
Language:
english
File:
PDF, 373 KB
english, 1990
82

Evaluation of dry pumps vs rotary vane pumps in aluminum etching

Year:
1990
Language:
english
File:
PDF, 336 KB
english, 1990
83

Handling of particles in forevacuum pumps

Year:
1990
Language:
english
File:
PDF, 385 KB
english, 1990
84

Spiral grooved visco-vacuum pumps with various groove shapes

Year:
1990
Language:
english
File:
PDF, 263 KB
english, 1990
85

Development of a bakeable cryopump for extreme high vacuum

Year:
1990
Language:
english
File:
PDF, 354 KB
english, 1990
86

New methods and investigations for regenerating refrigerator cryopumps

Year:
1990
Language:
english
File:
PDF, 291 KB
english, 1990
88

Contamination control in vacuum systems: venting and pumping

Year:
1990
Language:
english
File:
PDF, 209 KB
english, 1990
91

An ion pump based leak detector

Year:
1990
Language:
english
File:
PDF, 261 KB
english, 1990
92

Theoretical and experimental studies of a platinum wire-glass standard leak

Year:
1990
Language:
english
File:
PDF, 290 KB
english, 1990
93

Temperature dependence and long term behaviour of capillary-type helium reference leaks with gas reservoir

Year:
1990
Language:
english
File:
PDF, 281 KB
english, 1990
94

Overview on new materials for vacuum techniques

Year:
1990
Language:
english
File:
PDF, 358 KB
english, 1990
95

A new magnetic material with low outgassing rate for the electron storage ring of HESYRL

Year:
1990
Language:
english
File:
PDF, 204 KB
english, 1990
96

Surface precipitation of boron nitride on the surface of stainless steel/boron nitride film

Year:
1990
Language:
english
File:
PDF, 471 KB
english, 1990
97

New self-lubricating aluminum alloy base composites for vacuum technology

Year:
1990
Language:
english
File:
PDF, 412 KB
english, 1990
98

Low-load metal seals to replace elastomer O-rings: the Helicoflex-delta (Δ) seals

Year:
1990
Language:
english
File:
PDF, 269 KB
english, 1990
99

LEP vacuum system: present status

Year:
1990
Language:
english
File:
PDF, 511 KB
english, 1990
100

The vacuum system of the HERA electron storage ring

Year:
1990
Language:
english
File:
PDF, 479 KB
english, 1990
101

The vacuum system of the Amsterdam pulse stretcher ring, AmPS

Year:
1990
Language:
english
File:
PDF, 262 KB
english, 1990
102

Vacuum system of the VUV source of the Brazilian synchrotron light laboratory

Year:
1990
Language:
english
File:
PDF, 204 KB
english, 1990
103

Vacuum system of TARN II

Year:
1990
Language:
english
File:
PDF, 230 KB
english, 1990
104

Vacuum system design for a superconducting X-ray lithography light source

Year:
1990
Language:
english
File:
PDF, 250 KB
english, 1990
105

The AGS Booster vacuum systems

Year:
1990
Language:
english
File:
PDF, 346 KB
english, 1990
106

Non-evaporable getter performance in the Photon Factory electron storage ring

Year:
1990
Language:
english
File:
PDF, 285 KB
english, 1990
108

Corrosion of accelerator vacuum systems: risks and prevention

Year:
1990
Language:
english
File:
PDF, 357 KB
english, 1990
109

Industrial fabrication of uhv quadrupole chambers for LEP

Year:
1990
Language:
english
File:
PDF, 236 KB
english, 1990
110

Non-standard vacuum hardware for an accelerator vacuum system

Year:
1990
Language:
english
File:
PDF, 344 KB
english, 1990
111

Metal and elastomer seal tests for accelerator applications

Year:
1990
Language:
english
File:
PDF, 389 KB
english, 1990
113

UHV pumping equipment and the expanding field of UHV activity

Year:
1990
Language:
english
File:
PDF, 284 KB
english, 1990
114

A new Ti-based non-evaporable getter

Year:
1990
Language:
english
File:
PDF, 267 KB
english, 1990
115

XPS analysis of the getter mechanism and getter activation process

Year:
1990
Language:
english
File:
PDF, 266 KB
english, 1990
116

Capability of obtaining extreme high vacuum by commercial G-M refrigerator-cooled cryopump

Year:
1990
Language:
english
File:
PDF, 221 KB
english, 1990
117

The study of an aluminum-alloy distributed ion pump

Year:
1990
Language:
english
File:
PDF, 146 KB
english, 1990
118

Stepping motor for use in uhv

Year:
1990
Language:
english
File:
PDF, 207 KB
english, 1990
119

Development of the harmonic drive rotary feedthrough

Year:
1990
Language:
english
File:
PDF, 323 KB
english, 1990
120

Automation of all-metal uhv valves by compact actuator

Year:
1990
Language:
english
File:
PDF, 471 KB
english, 1990
121

Autovacuum and its application for product cladding

Year:
1990
Language:
english
File:
PDF, 537 KB
english, 1990
122

Plasma processes under vacuum conditions

Year:
1990
Language:
english
File:
PDF, 487 KB
english, 1990
123

Electron behaviour in cylindrical magnetron sputtering source

Year:
1990
Language:
english
File:
PDF, 251 KB
english, 1990
124

Plasma activated physical vapour deposition (PAPVD) by hollow cathode arc (HCA)

Year:
1990
Language:
english
File:
PDF, 279 KB
english, 1990
125

A highest rate self-sputtering magnetron source

Year:
1990
Language:
english
File:
PDF, 218 KB
english, 1990
126

Fabrication of AIN thin films by reactive ionized cluster beam deposition technique

Year:
1990
Language:
english
File:
PDF, 227 KB
english, 1990
127

Dynamic modeling of the process control of reactive sputtering

Year:
1990
Language:
english
File:
PDF, 256 KB
english, 1990
128

Discharge cleaning and gas trapping by use of a glow-mode plasma source

Year:
1990
Language:
english
File:
PDF, 231 KB
english, 1990
129

Experimental study of I–V characteristics of dc magnetron sputtering sources

Year:
1990
Language:
english
File:
PDF, 184 KB
english, 1990
130

Tritium handling experience in vacuum systems at TSTA

Year:
1990
Language:
english
File:
PDF, 400 KB
english, 1990
131

Leak evaluation in JET and its consequences for future fusion machines

Year:
1990
Language:
english
File:
PDF, 355 KB
english, 1990
132

Development of ceramic turbomolecular pumps for fusion devices

Year:
1990
Language:
english
File:
PDF, 291 KB
english, 1990
133

Reduction of outgassing from stainless surfaces by surface oxidation

Year:
1990
Language:
english
File:
PDF, 292 KB
english, 1990
134

Surface modification of vacuum wall by carbon and its outgassing

Year:
1990
Language:
english
File:
PDF, 280 KB
english, 1990
135

Optimization of the operation of the small quadrupole mass spectrometer to give minimum long-term instability

Year:
1990
Language:
english
File:
PDF, 273 KB
english, 1990
136

Accuracy of the conductance modulation method for the measurement of pumping speed and outgassing rate

Year:
1990
Language:
english
File:
PDF, 146 KB
english, 1990
137

The measurement of high pressures in the vacuum range with the help of hot filament ionization gauges

Year:
1990
Language:
english
File:
PDF, 291 KB
english, 1990
138

Apparatus and testing method of desorbed gases for qualification of solid materials

Year:
1990
Language:
english
File:
PDF, 261 KB
english, 1990
139

Pumping of condensable vapours and exhaust vapour condensation

Year:
1990
Language:
english
File:
PDF, 229 KB
english, 1990
140

Microscopic theory of drag molecular dynamics in the range of free molecular flow

Year:
1990
Language:
english
File:
PDF, 181 KB
english, 1990
141

High vacuum pumps according to Holweck principle for semiconductor production

Year:
1990
Language:
english
File:
PDF, 322 KB
english, 1990
142

Influence of clearances on turbomolecular pump performance

Year:
1990
Language:
english
File:
PDF, 312 KB
english, 1990
143

Resistance of turbo-molecular pump to gallium

Year:
1990
Language:
english
File:
PDF, 326 KB
english, 1990
144

Demands for turbo-molecular pumps in the aluminium etching process

Year:
1990
Language:
english
File:
PDF, 569 KB
english, 1990
145

Experimental study of forced oscillations in the Orbitron

Year:
1990
Language:
english
File:
PDF, 221 KB
english, 1990
146

Reactor-characteristics parameters for low pressure CVD processes

Year:
1990
Language:
english
File:
PDF, 251 KB
english, 1990
147

Estimation of sublimation rate from ice disk on heating plate at low pressures

Year:
1990
Language:
english
File:
PDF, 207 KB
english, 1990
148

On the significance of mean free path to vacuum physics and technology

Year:
1990
Language:
english
File:
PDF, 320 KB
english, 1990
149

Vacuum in space—an isotropic regime?

Year:
1990
Language:
english
File:
PDF, 202 KB
english, 1990
150

How to characterize the vacuum environment

Year:
1990
Language:
english
File:
PDF, 172 KB
english, 1990
151

Measurement of conductances of models in the molecular and viscous flow regime

Year:
1990
Language:
english
File:
PDF, 217 KB
english, 1990
152

Determination of the (pl) value based on the measurement of viscosity and thermal conductivity in the transition region

Year:
1990
Language:
english
File:
PDF, 168 KB
english, 1990
153

Vacuum micro-chambers in electron microscopes

Year:
1990
Language:
english
File:
PDF, 283 KB
english, 1990
154

Status of vacuum industry in India

Year:
1990
Language:
english
File:
PDF, 308 KB
english, 1990
155

Investigation of diffusion pumps

Year:
1990
Language:
english
File:
PDF, 214 KB
english, 1990
156

Diaphragm pumps down to 2 mbar and their application in nuclear physics

Year:
1990
Language:
english
File:
PDF, 277 KB
english, 1990
157

The helical channel pumping mechanism of compound molecular pumps

Year:
1990
Language:
english
File:
PDF, 217 KB
english, 1990
158

The optimization design for turbo blades of a hybrid-type molecular pump

Year:
1990
Language:
english
File:
PDF, 196 KB
english, 1990
159

New research on re-outgassing of SIP

Year:
1990
Language:
english
File:
PDF, 210 KB
english, 1990
160

A Si single crystal photon-absorber for a compact SR ring

Year:
1990
Language:
english
File:
PDF, 221 KB
english, 1990
161

An aluminum vacuum chamber for the bending magnet of the SRRC synchrotron light source

Year:
1990
Language:
english
File:
PDF, 243 KB
english, 1990
162

FEM calculations of uhv all-metal demountable joints for LEP

Year:
1990
Language:
english
File:
PDF, 355 KB
english, 1990
163

Effects of high energy synchrotron radiation at copper surfaces

Year:
1990
Language:
english
File:
PDF, 315 KB
english, 1990
164

Gas adsorption/desorption and materials stability

Year:
1990
Language:
english
File:
PDF, 282 KB
english, 1990
165

Pressure dependence of the sensitivity of a triode gauge

Year:
1990
Language:
english
File:
PDF, 219 KB
english, 1990
166

Application of spiromolecular pumps in helium leak detection

Year:
1990
Language:
english
File:
PDF, 603 KB
english, 1990
167

Mass spectrometric observation of vacuum treated oxygen free copper

Year:
1990
Language:
english
File:
PDF, 230 KB
english, 1990
168

Total and partial pressure measurement in the low 10−12 mbar range

Year:
1990
Language:
english
File:
PDF, 227 KB
english, 1990
170

Calibration of vacuum systems by gas quantities

Year:
1990
Language:
english
File:
PDF, 326 KB
english, 1990
171

Measurement of diffusion data in small samples

Year:
1990
Language:
english
File:
PDF, 241 KB
english, 1990
172

The effect of housing tubes on the zero stability of spinning rotor gauges

Year:
1990
Language:
english
File:
PDF, 321 KB
english, 1990
173

The quartz tuning fork as a total pressure gauge: a versatile concept

Year:
1990
Language:
english
File:
PDF, 192 KB
english, 1990
174

Procedures for measuring pumping speeds

Year:
1990
Language:
english
File:
PDF, 256 KB
english, 1990
175

Molecular flow in composite systems and the resonance concept

Year:
1990
Language:
english
File:
PDF, 235 KB
english, 1990
176

Calculated and measured flow conductance for butterfly valves

Year:
1990
Language:
english
File:
PDF, 259 KB
english, 1990
177

Gas flux distributions from cylindrical tubes in molecular flow

Year:
1990
Language:
english
File:
PDF, 234 KB
english, 1990
178

An analysis of a complex network of vacuum components and its application

Year:
1990
Language:
english
File:
PDF, 212 KB
english, 1990
179

Vacuum systems for microgravity experiments

Year:
1990
Language:
english
File:
PDF, 257 KB
english, 1990
181

A study of measuring characteristics of vibrating diaphragm gauges

Year:
1990
Language:
english
File:
PDF, 227 KB
english, 1990
182

Scrubbing of Cl-containing plasma waste gases

Year:
1990
Language:
english
File:
PDF, 211 KB
english, 1990
183

Performance studies of partial pressure analysers

Year:
1990
Language:
english
File:
PDF, 228 KB
english, 1990
184

Some information problems in the presentation of vacuum science data

Year:
1990
Language:
english
File:
PDF, 248 KB
english, 1990
185

A preliminary study of the cascade static lens gauge

Year:
1990
Language:
english
File:
PDF, 205 KB
english, 1990
186

A dynamic flow calibration system with four-sphere construction

Year:
1990
Language:
english
File:
PDF, 172 KB
english, 1990
187

Monte Carlo analysis in a refrigerator cryopump

Year:
1990
Language:
english
File:
PDF, 202 KB
english, 1990
188

Trends and specific features of special metallurgical concepts in the German Democratic Republic

Year:
1990
Language:
english
File:
PDF, 396 KB
english, 1990
189

Experience with large scale electron beam cold hearth melting (EBCHM)

Year:
1990
Language:
english
File:
PDF, 217 KB
english, 1990
190

Advanced melting and casting plants with the high power electron and plasma beam

Year:
1990
Language:
english
File:
PDF, 640 KB
english, 1990
191

Refinement of Ti and Mo using electron beam melting

Year:
1990
Language:
english
File:
PDF, 293 KB
english, 1990
192

On the problem of growing tungsten single-crystal tubes from the melt

Year:
1990
Language:
english
File:
PDF, 354 KB
english, 1990
193

Sintering of tantalum powder from aluminothermic reduction product

Year:
1990
Language:
english
File:
PDF, 483 KB
english, 1990
194

Monitoring of vacuum sintering furnace atmosphere with a quadrupole mass spectrometer

Year:
1990
Language:
english
File:
PDF, 186 KB
english, 1990
195

Modern systems for production of high quality metal alloy powder

Year:
1990
Language:
english
File:
PDF, 627 KB
english, 1990
196

Application of glow discharge electron gun to surface modification

Year:
1990
Language:
english
File:
PDF, 424 KB
english, 1990
197

Thermal cycling of cast iron surface by electron beam fusion treatment

Year:
1990
Language:
english
File:
PDF, 411 KB
english, 1990
198

Magnetron-sputtered superhard coatings within the system TiBCN

Year:
1990
Language:
english
File:
PDF, 333 KB
english, 1990
199

Optimization of evaporation and sputtering devices through substrate heating parameter

Year:
1990
Language:
english
File:
PDF, 264 KB
english, 1990
200

Plasma-assisted deposition techniques for hard coatings

Year:
1990
Language:
english
File:
PDF, 567 KB
english, 1990
201

Process effects in ion plating

Year:
1990
Language:
english
File:
PDF, 417 KB
english, 1990
203

TiAlOn black decorative coatings deposited by magnetron sputtering

Year:
1990
Language:
english
File:
PDF, 734 KB
english, 1990
204

Present status of low pressure and atmospheric plasma spraying

Year:
1990
Language:
english
File:
PDF, 493 KB
english, 1990
206

Vacuum arc coatings in low pressure atmosphere cases

Year:
1990
Language:
english
File:
PDF, 263 KB
english, 1990
207

Advanced concepts of PVD hard coatings

Year:
1990
Language:
english
File:
PDF, 326 KB
english, 1990
208

The influence of surface topography on the adhesion of a TiN layer as a hard coating on different materials

Year:
1990
Language:
english
File:
PDF, 449 KB
english, 1990
209

Influencing properties of high-speed cutting steel, ion-nitrided and subsequently coated

Year:
1990
Language:
english
File:
PDF, 265 KB
english, 1990
210

Wear mode of a copper wire during a sliding contact with copper/chrome steel: influence of oxygen

Year:
1990
Language:
english
File:
PDF, 260 KB
english, 1990
212

Evaluation of adhesive energy in the process of material formation by a method of thermo spraying

Year:
1990
Language:
english
File:
PDF, 617 KB
english, 1990
213

Author index

Year:
1990
File:
PDF, 215 KB
1990
214

Volume 41 title page, volume contents and author index

Year:
1990
Language:
english
File:
PDF, 2.60 MB
english, 1990
215

Diffusion of isolated In atoms on Ag and Cu surfaces

Year:
1990
Language:
english
File:
PDF, 224 KB
english, 1990