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The total ionizing dose response of 4th-generation SiGe HBTs is assessed at both low and high dose rates to evaluate enhanced low dose rate sensitivity (ELDRS) in a new SiGe BiCMOS technology. Both device and circuit results are presented. A bandgap reference circuit topology is chosen to monitor for ELDRS in TID-induced collector current shifts, which have previously been reported in low dose rate studies of SiGe HBTs. The results in this paper also cover previous technology generations from this foundry in order to incorporate a broader view of dose rate effects in SiGe HBTs. No indication of ELDRS was found in any technology generation.

Electronics in space-based systems are in the process of a paradigm shift moving from centralized, heavily shielded, temperature-controlled warm boxes to distributed, minimally shielded sensing and control nodes. SiGe BiCMOS technology is one of the enablers of this move with its ability to withstand extremely wide variations in temperature and high radiation doses. This article has presented two SiGe BiCMOS wireline transceivers designed to be a part of the new system perspective by creating a means of control and communication across vehicle-wide buses. Both the RS-485 and ISO 11898 transceivers have been shown to work robustly from 90 K to 390 K, with consistent rise/fall times, propagation delays, and output amplitudes. Additionally, the ISO 11898 transceiver is TID tolerant to 2 Mrad, and the transmitter is hardened to single-event effects.

The single-event effect sensitivity of fourth-generation, 90 nm SiGe HBTs is investigated. Inverse-mode, ≥1.0 Gbps SiGe digital logic using standard, unoptimized, fourth-generation SiGe HBTs is demonstrated and the inverse-mode shift register exhibited a reduction in bit-error cross section across all ion-strike LETs. Ion-strike simulations on dc calibrated, 3-D TCAD SiGe HBT models show a reduction in peak current transient magnitude and a reduction in overall transient duration for bulk SiGe HBTs operating in inverse mode. These improvements in device-level SETs are attributed to the electrical isolation of the physical emitter from the subcollector-substrate junction and the high doping in the SiGe HBT base and emitter, suggesting that SiGe BiCMOS technology scaling will drive further improvements in inverse-mode device and circuit-level SEE. Two-photon absorption experiments at NRL support the transient mechanisms described in the device-level TCAD simulations. Fully-coupled mixed-mode simulations predict large improvements in circuit-level SEU for inverse-mode SiGe HBTs in multi-Gbps, inverse-mode digital logic.

The single-event effect sensitivity of inverse-mode biased SiGe HBTs in both bulk and SOI technology platforms are investigated, for the first time, using digital circuits and stand-alone device test structures. Comparisons of heavy-ion broad beam data of shift register circuits constructed with forward-mode and inverse-mode biased SiGe HBTs from a first-generation, complementary SOI SiGe BiCMOS process, reveal an improvement in SEU mitigation for the inverse-mode shift register architecture. Full 3D TCAD simulations highlight the differences in transient current origination between forward and inverse-mode biased devices, illustrating the impact of doping profiles on ion-induced shunt duration. To extend the analysis to a bulk platform, new fourth-generation npn , SiGe HBTs were biased in both the forward and inverse-mode and irradiated at NRL using the two photon absorption measurement system. These measurements support the analysis of transient origination using 3D TCAD simulations. Furthermore, the isolation of the output terminal from the sensitive subcollector-substrate junction is experimentally demonstrated for the inverse-mode bias. Fully coupled mixed-mode simulations predict a significant reduction in sensitive area for inverse-mode shift registers built in a bulk SiGe platform.

Single-event transient (SET) simulations of a Gb/s SiGe BiCMOS master/slave D flip-flop circuit are performed, employing both a decoupled current-injection SET modeling technique and a fully-coupled mixed-mode TCAD technique to model heavy-ion strikes to the storage and input cells. New insights are provided into the physical mechanisms underlying the single-event upset (SEU) sensitivity of high-speed SiGe digital latches and shift registers. A close analysis of the transient circuit behavior identifies the limitations of the current-injection approach in predicting SEU in fast SiGe digital logic. Furthermore, the physical ion track linear energy transfer (LET) is varied to establish the threshold LET for SEU using each simulation technique, further highlighting the SEU prediction error inherent to conventional decoupled modeling approaches. Finally, clocked mixed-mode circuit simulations are used to explain the fundamental SEU mechanisms and relate them to corresponding regions of the device-level SET.

An analysis of charge pump design for improved radiation tolerance of phase locked loops is presented. Two radiation-hardened-by-design approaches are considered to mitigate the total ionizing dose damage of the circuit, and a thick-film SOI SiGe process technology has been used to reduce charge collection of single event strikes. The results show that a modified design approach to implement the charge pump using SiGe HBTs can provide advantages in radiation tolerance to improve tri-state leakage performance, particularly for missions expecting large accumulated doses.

We report new results from both broad-beam, heavy-ion and proton experiments for circuit-level RHBD techniques in SiGe digital logic. Redundant circuit elements within the latches are used to significantly reduce single-event upset rates in shift registers and clock paths, without resorting to TMR techniques.

SiGe HBTs are very attractive devices to be used in space communication applications. This technology combines the high speed of the III–V semiconductors with the well-established and easy manufacturing processes of silicon, which allows the manufacturing of RF, analog, and digital devices on the same wafer. In addition, SiGe HBTs were found to be extremely radiation hard in the context of total ionizing dose and displacement damage. However, it was shown through experiments and simulations that these devices are vulnerable to single event effects (SEEs). SEEs are changes in the normal operation of the device (its logical state, currents, transients, etc.) due to the induced currents in the electrodes by the movement of carriers created by the incident ions. We used four electrode (base, emitter, collector, and substrate) IBIC measurements at the Sandia Heavy Ion Nuclear Microprobe Facility. SiGe HBTs are usually designed using deep trench isolation (DTI) to minimize parasitic capacitances from the subcollector to the substrate (faster speed), as well as allow devices to be fabricated much closer together. It is an added bonus that the DTI does not let carriers from outside hits to diffuse into the junction and induce current. Our experiments and TCAD simulations showed that while the above goal was accomplished by this design, it increased the amount of induced charge for ion hits in the active area. Single event transients (SETs) were investigated in both standard and radiation hardened by design (RHBD) bandgap voltage reference (BGR) circuits.

We investigate, for the first time, the potential for SEE mitigation of a newly-developed device architecture in a 3rd generation high-speed SiGe platform. This new device architecture is termed the ?inverse-mode cascode SiGe HBT? and is comprised of two standard devices sharing a buried subcollector and operated in a cascode configuration. Verification of the TID immunity is demonstrated using 10 keV X-rays, while an investigation of the SEE susceptibility is performed using a 36 MeV 16O ion. IBICC results show strong sensitivities to device bias with only marginal improvement when compared to a standard device; however, by providing a conductive path from the buried subcollector (C-Tap) to a voltage potential, almost all collected charge is induced on the C-Tap terminal instead of the collector terminal. These results are confirmed using full 3-D TCAD simulations which also provides insight into the physics of this new RHBD device architecture. The implications of biasing the C-Tap terminal in a circuit context are also addressed.

We investigate a novel implementation of junction isolation to harden a 200 GHz SiGe:C HBT technology without deep trench isolation against single event effects. The inclusion of isolation is shown to have no effect on the dc or ac performance of the nominal device, and likewise does not reduce the HBTs inherent tolerance to TID radiation exposure on the order of a Mrad. A 69% reduction in total integrated charge collection across a slice through the center of the device was achieved. In addition, a 26% reduction in collected charge is reported for strikes to the center of the emitter. 3-D NanoTCAD simulations are performed on RHBD and control device models yielding a good match to measured results for strikes from the emitter center to 8 ?m away. This result represents one of the most effective transistor layout-level RHBD approaches demonstrated to date in SiGe.

Silicon-germanium heterojunction bipolar transistor (SiGe HBT) heavy ion-induced current transients are measured using Sandia National Laboratories' microbeam and high- and low-energy broadbeam sources at the Grand Acce?le?rateur National d'Ions Lourds, Caen, France, and the University of Jyva?skyla?, Finland. The data were captured using a custom broadband IC package and real-time digital phosphor oscilloscopes with at least 16 GHz of analog bandwidth. These data provide detailed insight into the effects of ion strike location, range, and LET.

We investigate the single-event transient (SET) response of bandgap voltage references (BGRs) implemented in SiGe BiCMOS technology through heavy ion microbeam experiments. The SiGe BGR circuit is used to provide the input reference voltage to a voltage regulator. SiGe HBTs in the BGR circuit are struck with 36-MeV oxygen ions, and the subsequent transient responses are captured at the output of the regulator. Sensitive devices responsible for generating transients with large peak magnitudes (more than 5% of the dc output voltage) are identified. To determine the effectiveness of a transistor-layout-based radiation hardened by design (RHBD) technique with respect to immunity to SETs at the circuit level, the BGR circuit implemented with HBTs surrounded by an alternate reverse-biased pn junction (n-ring RHBD) is also bombarded with oxygen ions, and subsequent SETs are captured. Experimental results indicate that the number of events causing transients with peak magnitude more than 5% above the dc level have been reduced in the RHBD version; however, with the inclusion of the n-ring RHBD, new locations for the occurrence of transients (albeit with smaller peak magnitude) are created. Transients at the transistor-level are also independently captured and are presented. It is demonstrated that while the transients are short at the transistor level (ns duration), relatively long transients are obtained at the circuit level (hundreds of nanoseconds). In addition, the impact of the SET response of the BGR on the performance of an ultra-high-speed 3-bit SiGe analog-to-digital converter (ADC) is investigated through simulation. It is shown that ion-induced transients in the reference voltage could eventually lead to data corruption at the output of the ADC.

We investigate the applicability of current total ionizing dose (TID) test protocols in the context of advanced transistor technologies such as Silicon-Germanium heterojunction bipolar transistors(SiGe HBTs). In SiGe HBTs, an unexpected shift in collector current is observed during total dose irradiation. Using both device and circuit measurements, we investigate this phenomenon and assess its potential importance in hardness assurance of SiGe components. TCAD simulations were performed to explain the observed current shifts.

The effects of 63 MeV proton irradiation on 65nm Silicon-On-Insulator (SOI) CMOS technology are presented for the first time. The radiation response of the CMOS devices was investigated up to an equivalent total gamma dose of 4.1 Mrad (SiO2). We analyze the implications of proton irradiation on RF performance of these devices. The cut-off frequency is degraded due to post-irradiation degradation of device transconductance. High-frequency measurements show that the input and output matching conditions are not affected, up to a cumulative dose of 4.1 Mrad. The implications of proton irradiation on device design constraints, particularly device width and number of gate fingers, are discussed in the context of high performance RF CMOS technology. These results suggest that the higher finger width devices, of sufficient gate width, are well-suited for the development of total-dose radiation tolerant analog and RF circuits without additional radiation hardening.

Silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies promise several advantages over CMOS for the front-end readout electronics for the ATLAS upgrade. We have evaluated the relative merits of the latest generations of IBM SiGe HBT BiCMOS technologies, the 8WL and 8HP platforms. These 130 nm SiGe technologies show promise to operate at lower power than do CMOS technologies and would provide a viable alternative for the silicon strip detector and liquid argon calorimeter upgrades, provided that the radiation tolerance studies at multiple gamma and neutron irradiation levels, included in this investigation, show them to be sufficiently radiation tolerant.

This paper presents the first comprehensive investigation of the impact of proton irradiation on the performance of high-voltage (HV) nMOS transistors implemented in a low-voltage (LV) SiGe BiCMOS technology. The effects of irradiation gate bias, irradiation substrate bias, and operating substrate bias on the radiation response of these transistors are examined. Experimental results show that the radiation-induced subthreshold leakage current under different irradiation biasing conditions remains negligible after exposure to a total dose of 600 krad(Si). We find that there are differences in the radiation response of LV and HV MOSFETs, suggesting that the mechanisms involved in causing degradation in LV and HV transistors could be of fundamentally different origins.

We report the first irradiation results on high-frequency SiGe HBT and CMOS phase shifters for space-based, phased-array antennas used in radar or wireless communication systems. Both phase shifter circuits remain functional with acceptable dc and RF performance up to multi-Mrad proton exposure, and are thus suitable for many orbital applications. In addition, simulation results probing the limits of phase shifter performance in a radiation environment are presented. These results show that both CMOS and SiGe HBT based phase shifters can be used for space-based applications without any specific radiation hardening techniques.

Inverse-mode (collector-up) operation is proposed as a solution to the single-event-upset susceptibility observed in commercially available bulk silicon-germanium heterojunction bipolar transistors. Inverse-mode performance optimization techniques, which require no process changes or added lithographic masks, are demonstrated, yielding inverse-mode transistor performance capable of supporting gigabit-per-second digital logic needed in space-based communication systems.

We present the first measurement results for silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) and SiGe BiCMOS circuits operating in the sub-1-K regime. Robust transistor operation of a first-generation 0.5 times 2.5 times 4-mum2 SiGe transistor is demonstrated at package temperatures as low as 300 mK. In addition, a SiGe BiCMOS bandgap voltage reference is verified to be fully functional at operating temperatures below 700 mK. The SiGe voltage reference exhibits a temperature coefficient of 160 ppm/degC over the temperature range of 700 mK-300 K.

We report results on the cryogenic operation of two different monolithic X-band silicon-germanium (SiGe) heterojunction bipolar transistor low noise amplifiers (LNAs) implemented in a commercially-available 130 nm SiGe BiCMOS platform. These SiGe LNAs exhibit a dramatic reduction in noise temperature with cooling, yielding Teff of less than 21 K (0.3 dB noise figure) across X-band at a 15 K operating temperature. To the authors’ knowledge, these SiGe LNAs exhibit the lowest broadband noise of any Si-based LNA reported to date.

The total ionizing dose and laser-induced transient response of a new 4th generation 90 nm IBM SiGe 9HP technology are investigated. Total dose testing was performed with 63.3 MeV protons at the Crocker Nuclear Laboratory at the University of California, Davis. Transient testing was performed on the two-photon absorption system at Naval Research Laboratory. Results show that the SiGe HBTs are dose-tolerant up to 3 Mrad(SiO2) and exhibit reduced single event transients compared to earlier SiGe generations.

A theory of the circuit-based response to SET phenomena in resonant tank oscillators is presented. Transients are shown to be caused by a change in the voltage state of the circuit's characteristic differential equation. The SET amplitude and phase response is derived for arbitrary strike waveforms and shown to be time-variant based on the strike time relative to the period of oscillation. Measurements in the time-domain are used to support the theory, while the frequency-domain is used to gauge potential impact on system performance. A design-oriented analysis of the relevant trade-offs is also presented.

We investigate the efficacy of mitigating radiation-based single event effects (SEE) within circuits incorporating SiGe heterojunction bipolar transistors (HBTs) built with an N-Ring, a transistor-level layout-based radiation hardened by design (RHBD) technique. Previous work of single-device ion-beam induced charge collection (IBICC) studies has demonstrated significant reductions in peak collector charge collection and sensitive area for charge collection; however, few circuit studies using this technique have been performed. Transient studies performed with Sandia National Laboratory's (SNL) 36 MeV 16O microbeam on voltage references built with N-Ring SiGe HBTs have shown mixed results, with reductions in the number of large voltage disruptions in addition to new sensitive areas of low-level output voltage disturbances. Similar discrepancies between device-level IBICC results and circuit measurements are found for the case of digital shift registers implemented with N-Ring SiGe HBTs irradiated in a broadbeam environment at Texas A&M's Cyclotron Institute. The error cross-section curve of the N-Ring based register is found to be larger at larger ion LETs than the standard SiGe register, which is clearly counter-intuitive. We have worked to resolve the discrepancy between the measured circuit results and the device-level IBICC measurements, by re-measuring single-device N-Ring SiGe HBTs using a time-resolved ion beam induced charge (TRIBIC) set-up that allows direct capture of nodal transients. Coupling these measurements with full 3-D TCAD simulations provides complete insight into the origin of transient currents in an N-Ring SiGe HBT. The detailed structure of these transients and their bias dependencies are discussed, together with the ramifications for the design of space-borne analog and digital circuits using SiGe HBTs.

We report on the design and measured results of a new SiGe HBT radiation hardening by design technique called the “inverse-mode cascode” (IMC). A third-generation SiGe HBT IMC device was tested in a time resolved ion beam induced charge collection (TRIBICC) system, and was found to have over a 75% reduction in peak current transients with the use of an n-Tiedown on the IMC sub-collector node. Digital shift registers in a 1st-generation SiGe HBT technology were designed and measured under a heavy-ion beam, and shown to increase the LET threshold over standard npn only shift registers. Using the CREME96 tool, the expected orbital bit-errors/day were simulated to be approximately 70% lower with the IMC shift register. These measured results help demonstrate the efficacy of using the IMC device as a low-cost means for improving the SEE radiation hardness of SiGe HBT technology without increasing area or power.

We report heavy-ion microbeam and total dose data for a new complementary (npn + pnp) SiGe on thick-film SOI technology. Measured transient waveforms from heavy-ion strikes indicate a significantly shortened single-event-induced transient current, while maintaining the total dose robustness associated with SiGe devices. Heavy-ion broad-beam data confirm a reduced single event upset (SEU) cross-section in a high-speed shift register circuit.

We investigate the single-event transient (SET) response of T-body and notched-body contacted MOSFETs from a commercial 45 nm SOI RF-CMOS technology. Although body-contacted devices suffer from reduced RF performance compared to floating body devices, previous work on 65 nm and 90 nm MOSFETs has shown that the presence of a body-contact significantly mitigates the total ionizing dose (TID) sensitivity that is exhibited in floating-body SOI MOSFETs. The influence of body-contacting schemes on the single-event effect (SEE) sensitivity is examined here through time-resolved measurements of laser and microbeam-induced transients from T-body and notched-body MOSFETs. Laser-induced transients demonstrate the reduced SEE sensitivity of the notched-body MOSFETs as compared to the T-body MOSFETs; this is evidenced by a uniform reduction in the peak transient magnitudes and collected charge for transients captured at the worst-case bias of VDS = 1.0 V, as well as with all terminals grounded. Microbeam-induced transient data are also presented to support the validity of the laser-induced transient data. Together, these data provide new insight into the RF versus TID versus SEE tradeoffs associated with body contacting schemes in nm-scale MOSFETs, an important concern for emerging space-based electronics applications.

Low-frequency noise in complementary SiGe HBTs on SOI is investigated. S ib is extracted using a custom measurement setup, and the corresponding K factors are compared across multiple SiGe technology platforms for better understanding of SiGe evolutionary trends. We find that low-frequency noise has generally decreased with scaling for both npn and pnp SiGe HBTs, despite the low thermal cycles that aggressive scaling techniques utilized. In general, pnp SiGe HBTs have higher noise than npn's, and this is true for Si BJTs as well as SiGe HBTs. The SiGe HBTs on SOI from an early C-SiGe platform presented here fit these trends, demonstrating their maturity and competitiveness. Low input-impedance noise measurement were also measured and analyzed in these SiGe HBTs, using a common-collector and a common-base configuration. We find that noise term S ic can be significant at high injection levels.

We present a novel device structure using an inverse-mode, cascoded (IMC) SiGe HBT for improved tolerance of heavy ion irradiation. The cascoded SiGe device consists of a forward-mode, common-emitter SiGe HBT cascoded with a common-base inverse-mode SiGe HBT, with the subcollector region of the two devices shared. The device was fabricated in both first and third-generation, commercially-available SiGe HBT technologies. The third-generation IMC device was measured to have over 20 dB of current gain and over 30 dB of power gain at 10 GHz. In addition, the measured total dose radiation response and simulated current transients are presented. These results demonstrate the potential use of these devices in high-speed circuits intended for operation in space or other extreme environments.

The radiation response of strained SiGe p-MODFETs to 63 MeV protons is investigated for the first time. It is observed that both the drain current and the transconductance of the devices improve (increase) marginally following proton exposure. Low-frequency noise measurements were made both before and after irradiation to better understand the role of traps, and also improves following exposure. Localized strain in high Ge content SiGe layers of the device may affect the trap density after irradiation.

We investigate, for the first time, the impact of deep trench isolation on the total ionizing dose (TID) and single event upset (SEU) tolerance of advanced SiGe HBTs. We employ a combination of 63MeV protons, 10keV X-rays, and 36MeV oxygen ion microbeam irradiation and compare a 3rd generation, high-performance (HP), deep-trench isolated, SiGe BiCMOS platform with its cost-performance (CP) variant without deeptrenches. Although the CP SiGe HBTs are shown to be more susceptible to TID damage, the elevated damage is not attributed to variations in deep trench isolation (DTI), but to spacer oxide differences. CP SiGe HBTs are surprisingly found to offer a potential built-in self-mitigation mechanism for SEU, which is a direct result of the influence of the deep trench isolation on the charge collection dynamics associated with ion strikes. Calibrated, full 3D ion strike TCAD simulations are employed to explain the results, revealing substantial enhancement of radial charge diffusion for structures implemented with little to no deep trench. Mitigation of charge collection events are found to occur for emitter-center strikes for devices with limited/eliminated DTI with the caveat of larger collection for outside-DTI ion strikes.

An assessment of the radiation tolerance of the latest generation IBM silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies (SiGe 8WL and SiGe 8HP) at extreme dose/fluence is reported. These BiCMOS technologies are of great interest for analog readout circuits in high energy physics detectors, especially the planned upgrade of the ATLAS detector for the upgraded Large Hadron Collider (sLHC) in Geneva, Switzerland. These third-generation, 130 nm SiGe HBTs show promise to operate at lower power than CMOS circuits provided that they can be shown to be sufficiently radiation tolerant. This study presents evidence of the radiation tolerance of these two candidate technologies with parametric measurements after irradiation up to a fluence of 1016 1 MeV equivalent neutrons/cm2 and a gamma dose of 100 Mrad (SiO2).

An 850 mW SiGe power amplifier operating at X-Band (8.5-10.5 GHz) frequencies with over 11 dB of gain and 18% PAE is presented. This SiGe PA was implemented in a commercially-available, third-generation 130 nm 200 GHz SiGe BiCMOS platform using a hybrid high-breakdown / high-speed cascode pair to enhance voltage swing.

Device-level current transients are induced by injecting carriers using two-photon absorption from a subbandgap pulsed laser and recorded using wideband transmission and measurement equipment. These transients exhibit three distinct temporal trends that depend on laser pulse energy as well as the transverse and vertical charge generation location. The nature of the current transient is controlled by both the behavior of the subcollector-substrate junction and isolation biasing. However, substrate potential modulation, due to deformation of the subcollector-substrate depletion region, is the dominant mechanism affecting transient characteristics.

In this paper we compare 10 keV X-ray and 63 MeV proton radiation effects on 4H-SiC vertical trench JFET power transistors. The schematic cross-section of the 4H-SiC depletion-mode vertical trench JFET was investigated. For a direct comparison, total dose levels were held constant between the two radiation sources. The significant differences in device response for the two different radiation sources, and the isochronal annealing effects on proton-irradiated devices, are presented in this paper.

Progress in the production of hot-gas filtered biocrude oils from a dry hybrid poplar feedstock in the NREL vortex ablative pyrolysis reactor is discussed. In particular, adjusting the pyrolysis severity in the vortex reactor and the cracking severity in the char baghouse resulted in increased oil yields of very low-ash and low-alkali biocrude oils. The viscosity of these oils meets the requirements for American Society for Testing and Materials (ASTM) No.4 fuel oils. Increasing the water content to 30% decreased the viscosity by half, but not enough to meet the viscosity requirement for ASTM No.2 fuel oil. Viscosity contours for water and methanol dilution are shown. The addition of water or methanol or both to make a more consistent product may be advantageous. Aging studies of this low-alkali oil showed a slower increase in viscosity with time equal to one-third the rate of a biocrude oil with higher alkali contents. It appears that removal of the char fines results in a more stable oil. In fact, after 24 hours at 90 C, the viscosity of this low-ash biocrude oil was lower than that seen previously for the unaged sample of higher ash oil. It is concluded that the removal of char fines to produce a premium biocrude oil will be even more important than was previously supposed.

The intense luminescence of [Ir(2=phos)2]ClO4[2=phos is cis-1,2-bis(diphenylphosphino)ethylene] in a rigid glass matrix at 9.5 K was monitored while external magnetic field (Bmax = 6.7 T) were applied. Radiative coupling to the ground state from a forbidden component was induced by the field.

Based on previous energy management experience and extensive research ( 1 ), an existing contemporary high-rise office building was examined for potential energy consumption savings. By effecting various system and component revisions, significant operating savings have been achieved, and based on projected utility cost data, the long term savings have been identified. In conjunction with estimated and realized capital costs of implementing the building system revisions, the simple economic payback is established. The approach to identifying and effecting energy consumption savings is generally applicable, and has been successful in numerous other case studies.