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Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Boudko et al. and Pedchenko et al. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Companion Papers II and III. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge, and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Companion Papers II and III. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge, and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Mandibular implant placement (MIP) has been accepted and widely used for decades all over the world, and has reached a very high level of therapeutic reliability. MIP is used mostly in elderly edentulous patients who lost their teeth when dentistry was not oriented to fixed or removable prosthetic. Notwithstanding this, every year cases of severe complications during MIP due to haemorrhage causing life-threatening airway’s obstruction are reported. These severe complications of MIP need immediate therapy, usually with hospitalization, and may be potentially fatal. A 56-year-old man presented to the private practice requesting the placement of two dental implants at 41 and 31 previously lost for periodontal disease. Two implants of 3.3 mm of diameter, and 10 mm of length were inserted replacing teeth 31 and 41. Two hours after surgery and home delivery, the patient came to the emergency room complaining of dyspnoea and edema at the floor of the mouth. The maxillo-facial surgeon decided to perform tracheostomy and haemostasis under general anaesthesia. Two weeks after demission a complete healing was performed. This is important for dental practitioners to avoid severe bleeding complications during the MIP in the interforaminal region, especially on the midline. Moreover, when mandibles are severely atrophic, practitioners should be aware of this fact and the possible implications. The evaluation of these data is essential in the correct preoperative planning of implant procedures in the mandible, and with the increasing demand for MIP, the variations of the lingual foramen of the mandible should receive more attention.

BACKGROUND Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (Lu-177)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. METHODS We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either Lu-177-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (Lu-177-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. RESULTS At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the Lu-177-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the Lu-177-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the Lu-177-Dotatate group and 26 in the control group (P = 0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the Lu-177-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. CONCLUSI

The endoplasmic reticulum (ER) responds to changes in intracellular homeostasis through activation of the unfolded protein response (UPR). Yet, it is not known how UPR-signaling coordinates adaptation versus cell death. Previous studies suggested that signaling through PERK/ATF4 is required for cell death. We show that high levels of ER stress (i.e., ischemia-like conditions) induce transcription of the ubiquitin ligases Siah1/2 through the UPR transducers PERK/ATF4 and IRE1/sXBP1. In turn, Siah1/2 attenuates proline hydroxylation of ATF4, resulting in its stabilization, thereby augmenting ER stress output. Conversely, ATF4 activation is reduced upon Siah1/2 KD in cultured cells, which attenuates ER stress-induced cell death. Notably, Siah1a(+/-)::Siah2(-/-) mice subjected to neuronal ischemia exhibited smaller infarct volume and were protected from ischemia-induced death, compared with the wild type (WT) mice. In all, Siah1/2 constitutes an obligatory fine-tuning mechanism that predisposes cells to death under severe ER stress conditions.

We develop an analytic theory based on an earlier model of the admittance of a ballistic transit time diode terahertz oscillator with tunnel emission of electrons into a transit space. The focus of this work is on the actual case when electrons are injected with high enough energy to move from the start with maximal (saturated) ballistic velocity (∼1×108(∼1×108 to 2×108 cm/s).2×108 cm/s). On the one hand, such diodes have maximal oscillation frequencies and, on the other hand, a simple analytic theory describes them and allows us to avoid a cumbersome numerical procedure, which characterizes the general case. Such a description is analogous to the description of oscillatory diodes with diffusive transport and saturated drift velocity. We have also considered a special case when a small part of the ballistic electrons crossing the transit space scatter into a diffusive subsystem with a small drift velocity. The appearance of such slow-drifting electrons substantially increases space charge in the transit space and influences the static JV-characteristic but the high-frequency admittance is almost invariable. © 2004 American Institute of Physics.

Numerical solution of the time‐dependent Schrödinger equation for resonant‐tunneling diodes has been impeded by the difficulty in handling open‐system boundary conditions. This paper presents a boundary condition method to simulate the interaction with ideal particle reservoirs at the device boundaries. A switching transient is calculated where the device is switched from the peak current state to the valley current state. In addition, this method was used to develop a small‐signal analysis of resonant‐tunneling diodes. Results for the small‐signal equivalent circuit of a particular device versus frequency are presented.

Army communication systems have several major limitations, including limited bandwidth, low throughput, dependence upon terrestrial line-of-sight, lack of full mobility and limited support for intelligence and imagery requirements. Additional requirements include low probability of intercept, jam resistant, multi-frequency systems and low power, weight and cost and small size. The purpose of this program was to address the fundamental limitations of these issues from an overall systems objective and develop appropriate modulation techniques, analog and digital devices and circuits in order to optimize the performance and significantly lower power consumption.

This research project was aimed at an investigation of far-infrared (FIR) and terahertz (THz) sources using intersubband transitions in step quantum well structures. Theoretical studies were carried out in order to determine the optical gain spectra. The intersubband gain was formulated as a function of the dipole matrix elements, the lineshape function, and the electron distribution functions in the lasing subbands. The dependence of the spectral gain on optical phonon scattering was investigated. Non-Lorentzian lineshape functions were obtained and it was found that the magnitude and overall shape of the spectral gain are significantly modified by the intra- and inter-subband phonon scattering rates. Effects of the confined phonon modes were evaluated and it was found that they have a significant effect on the devices considered.

The purpose of this program was to demonstrate the capabilities of NDR device for the design and fabrication of high-functionality for the design and fabrication of high-functionality digital circuits. Several basic circuit functions have been demonstrated using RTD-HBT devices and extensive software for CAD of various types of circuits including adders a correlators and multivalued logic circuits was developed and employed to estimate power/speed tradeoffs in various logic circuits. Several Resonant Tunneling devices were fabricated including RTD's, RHET's, Esaki diodes and others. These diodes were then employed to demonstrate various logic functions such as AND, XNOR, Flip Flops and others. A Monolithic RTBT circuit to demonstrate a minority gate was also fabricated and demonstrated.

The objective of this program was the realization of optically controlled millimeter wave and microwave GaAs and InP based circuits. The primary goal was the development of heterojunction bipolar transistors (HBTs) with the ability to be controlled optically. Of particular interest is the ability to convert a microwave signal modulated onto an optical carrier into an electrical signal which in turn will be used to injection lock a microwave oscillator. This optically injection locked oscillator has application to optically implemented control of phased array antenna systems. This report documents significant device developments such as a high frequency, discrete device for injection locking (lnP based MODFET with fmax approx. 300 GHz; GaAs based HBTs with fmax approx. 90GHz; lnP based HBTs with fmax approx. 110 GHz), an Indium-Tin-Oxide (ITO) transparent ohmic contact technology, a high speed Barrier Reservoir and Quantum Well Electron Transport (BRAQWET) modulator (17 GHz bandwidth in GaAs based devices), and monolithically integrated oscillator circuits with guided wave optical injection with tuning range of 100 MHz injection locked at 14 GHz

Several different IMPATT diode structures operating in the precollection mode at X-band (9 to 11 GHz) are examined, both using a complete finite-difference program and a simplified analysis which is developed in the report. The details of the precollection mode are examined, and large-signal solutions are presented for each different structure. Both single- and double- drift diodes are considered. Dynamic temperature effects are included and the differences between simulations at constant temperature and those with variable temperature are noted.

The objective of this study is to investigate the performance of heterojunction MITATT (mixed tunnel-avalanche transit time) diodes at millimeter-wave frequencies. Along with the heterojunction MITATT diodes, GaAs double-drift IMPATT (impact ionization avalanche transit-time) diodes were also fabricated and their RF performance were evaluated. Keywords: Mixed tunnel-avalanche transit-time (MITATT); Heterojunction; Millimeter-wave frequencies; Impact ionization avalanche transit time (IMPATT); Tunnel transit time (TUNNETT).

This final report is a brief description of the work carried out under this program. In addition to the work described here, several technical reports and journal articles were issued which describe the work performed in much greater detail. These reports and articles are available. The work carried out in this program included the following: IMPATT device modeling and prediction of Si, GaAs and InP IMPATT performance at millimeter wavelengths and their optimum design; modeling and characterization of GaAs MESFETs and measurement of small- and large-signal equivalent circuit parameters; design and fabrication of a monolithic GaAs integrated circuit FET-varactor doubler; and analysis and design of a YIG loaded waveguide for magnetostatic device applications, such as tunable delay lines. Keywords include: IMPATT devices, Millimeter waves, Power combining, FET modeling, FET characterization, GaAs Integrated circuits, and Magnetostatic waves.

Theoretical investigations of IMPATT diodes are carried out at 30, 40, 60 and 94 GHz. GaAs, Si and InP diodes are simulated. Several single- and double-drift doping profiles are considered. Extensive results as a function of RF voltage amplitude and dc current density are presented. Taking thermal resistance into account, the expected CW performance of each structure is presented, such that the maximum allowable diode temperature is 525 deg K. Matching each device to 1-ohm circuit resistance gives an estimate of maximum obtainable pulsed power. Finally, CW and pulsed performance for all structures and materials are compared over the entire frequency range simulated. (Author)

A method for simulating the dynamic behavior of pulsed IMPATT oscillators using a quasi-static approximation is presented. The method used to characterize the IMPATT diode is explained. A particular circuit model is used which models the cylindrical cavity power combining circuit. The overall device-circuit interaction technique is outlined. Simulation results for a high-low, single-drift X-band GaAs IMPATT are presented. The method presented here can be employed for any type of IMPATT device. The pulsed oscillator properties of double-drift IMPATT diode structures are presently being investigated. (Author)

This technical report contains a description of a quasi-two-dimensional model for GaAs FET operation. The model is based on modified expressions for the carrier continuity and Poisson equations in the conducting channel of an FET. The model is compared to full two-dimensional results to determine its accuracy. It is then used to study a variety of operating conditions. The effect of various material and device parameters are also discussed. (Author)

Circuit design and stability criteria are developed for a new class of IMPATT diode power combiners. These combiners make use of radial-symmetric circuits and provide an optimal integration of device and circuit properties to perform the power adding function. Both lossless N-way combiners and resistively stabilized N-way combiners are considered. Examples of this combining technique are given at frequencies of 10 GHz and 90 GHz which make use of realistic IMPATT diode parameters. The 30-W, ten-diode lossless X-band combiner indicates a 1-dB locking bandwidth of 300 MHz and 10 dB gain, while the millimeter-wave combiner provides a 1-dB bandwidth of 9 GHz at 87 GHz and 10 dB locking gain. A 100-W, resistively stabilized 10 GHz, ten-diode combiner shows a 150 MHz locking bandwidth, also at 10 dB locking gain. (Author)

The properties of BARITT devices and their application as mixers and detectors particularly at millimeter wavelengths have been considered and their characteristics have been determined. It is shown that the BARITT device will have several advantages over existing devices such as Schottky-barrier diodes in these applications and thus warrant further development. Several modes of operation have been identified and include: self-oscillating mixers where the device due to its negative resistance generates power and is utilized as a mixer simultaneously; a video detector and mixer element which exhibits a negative resistance over a band of frequencies determined by the width of the depletion layer; and a conventional video detector and mixer element which does not exhibit a negative resistance but has a negligible series resistance due to the basic nature of the device. This leads to a detector and mixer element with an extremely high cut-off frequency and can lead to better performance than existing Schottky-barrier diodes. (Author)

A description has been given of the device simulation computer program which is the basis of the theoretical results obtained. Different methods for obtaining solutions using this program with current drive and voltage drive have been discussed, and a particular current drive yielding negative resistance at least up to the third harmonic has been presented. It was demonstrated that a one cycle simulation is sufficient to characterize the diode impedance, thus avoiding the time and expense of obtaining converged solutions. From a series of diode simulations at different frequencies, the required impedance vs. frequency characteristics for a broadband amplifier was presented. An optimization procedure was discussed whereby the parameters of a stepped coaxial line are adjusted so that the input impedance approximates the required theoretical impedance as closely as possible. The fabrication of the resulting circuit was outlined. Impedance vs. frequency measurements of the fabricated circuit were presented and reasons given for discrepancies between the measured circuit impedances and the expected impedance based on the original circuit model. Finally, experimental results for an amplifier circuit were given as well as suggestions for future measurements and circuit fabrication modifications. (Author)

This is the fifth and sixth quarterly report under subject contract whose objectives are to investigate theoretically and experimentally new solid state devices and circuits for microwave duplication generation and control. Tasks under this program are: avalanche diodes (IMPATT and TRAPATT), field-effect transistors, self mixing BARITT diodes and applications of BARITT type structures. (Author)

The objectives of this program were to study the fundamental properties of semiconductor materials and devices and their utilization in microwave power generation, amplification, detection, and control and thus ultimately to improve the state of the art in microwave devices. Work was conducted in the following areas: IMPATT Devices, Properties of BARITT Devices, BARITT Device Fabrication and Results, Tunnel Transit-Time Devices, Baritt Varactors, and Video Detectors and Mixers Using BARITT Devices. (Author)

This is the third and fourth quarterly progress report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Tasks under this program are: Properties of IMPATT Diodes, Properties of TRAPATT Diodes, Field-Effect Transistors, Field-Effect Transistor Fabrication, IMPATT Diode Amplifiers and Experiments on TRAPATT Diodes., See also report dated Jun 74, AD-783 900.

A method of simulating the dynamic behavior of pulsed IMPATT oscillators is presented. It is assumed that the simulation variables change slowly with respect to the RF period so that the quasi-static approximation may be used. A comparison of simulation results with experimental results for an X-band circuit is given. (Author)

The theorectical and experimental characteristics of BARITT and TUNNETT devices for use as millimeter-wave mixers and detectors were investigated. Theoretical calculations of BARITT conversion loss, noise figure, and RF and IF impedence levels were carried out. BARITT device fabrication was studied. Three BARITT structures, useful for frequencies between 35 and 95 GHz were fabricated and tested. BARITT devices were tested as mixers and detectors at 35 and 95 GHz. BARITTs were found to be useful millimeter-wave mixers or detectors. BARITT detector performance is comparable to more conventional detectors with TSS levels of - 48 dB per 1 MHz bandwidth and a dynamic range to 1-dB compression of 40 dB. The BARITT pulse burnout performance is superior to any conventional detector with a pulsed burnout level greater than 45 W. BARITT mixer performance is also comparable to Schottky-barrier mixers with conversion losses of 5 dB and 30 MHz noise figures of 6.8 dB. This performance, coupled with the high burnout level and ease of fabrication, makes the BARITT a useful millimeter-wave device. (Author), Prepared in cooperation with Microwave Associates, Inc., Burlington, MA.

This final report is a brief description of the work carried out under this program. In addition to the work reported here, several technical reports have been issued which describe in detail the work performed under this program. These reports are available and are considered as a part of this final report. The work carried out under this program included the following: properties of controlled avalanche transit-time (CATT) triode amplifiers, properties of high-efficiency X-band GaAs IMPATTs including single- and double-drift devices as well as CW and pulsed operation, power combining studies including fundamental and harmonic power combining, GaAs FET modeling, characterization and circuit studies, and development of a model to study the effects of energy and momentum relaxation effects on IMPATT device performance particularly at millimeter wavelengths. (Author)

The limitations and control of pulsed IMPATT diode millimeter-wavelength oscillators are described. A quasi-static oscillator model is established for characterizing amplitude and frequency behavior during pulsed operation in response to external influences such as bias current, temperature, optical injection, locking signal injection and RF circuit. The effect of these external parameters in oscillator turn-on, turn-off, frequency chirp during the pulse, and start-up jitter are given for a millimeter-wavelength oscillator using a Si double-drift diode.

The research is concerned with the investigation and utilization of various phenomena and techniques for the generation, amplification, detection and control of electromagnetic energy at microwave frequencies. The work is mainly oriented toward an investigation of the basic properties, capabilities and potential of: Avalanche transit-time devices including IMPATTs and TRAPATTs; Transferred-electron devices; Microwave field-effect transistors; Microwave integrated circuits.

This is the final report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Tasks under this program were: Modulation properties of Gunn-Effect Devices; Properties of IMPATT Diodes; High Efficiency Avalanche Diodes; Properties of TRAPATT Diodes; Field-Effect Transistors; Solid State Device Fabrication. (Author), See also AD-774 456.

This report summarizes the work done to date on the general program of applied research in microwave and quantum electronics. All the investigations carried out are directed toward ex tending the state of the art in microwave and quantum electronics. The research is theoretical as well as experimental in nature. The theoretical work is largely devoted to an investigation of low-noise phenomena and beam-plasma interactions. The experimental work is concerned with electromagnetic generation, particularly in the short wavelength regions. This includes several plasma devices, masers, and a Cerenkov radiation device. In addition crossed field electron guns and high- thermal-conductivity dielectric materials for high-average-power microwave tubes are studied from a theoretical as well as experimental point of view.

This is the fourth quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are the following: High-power Gunn-effect devices; gunn-effect amplifiers; modulation properties of gunn-effect devices; avalanche-diode amplifiers; high-efficiency avalanche diodes; nonlinear operating characteristics of IMPATT diodes; solid-state device fabrication; and, instabilities in germanium., See also AD730636.

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: Microwave noise emission from indium antimonide; Instabilities in Germanium; Transverse and magnetic field effects on instabilities in bulk semiconductors; Gunn effect amplifiers; High power gunn effect devices; Large signal analysis of avalanche diodes; Multifrequency operation of avalanche diodes; Multifrequency operation of avalanche diodes; Solid state device construction and evaluation. (Author), See also Quarterly progress rept. no. 10, AD-871 171.

The objectives were to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. (Author), See also Quarterly progress rept. no. 8, AD-863 199.

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: Microwave radiation from indium antimonide; Instabilities in germanium; Transverse and magnetic field effects on instabilities in bulk semiconductor plasmas; Gunn effect amplifiers; High power Gunn effect devices; Avalanche diode devices; Large signal analysis of high efficiency avalanche diodes; Multifrequency operation of avalanche diodes; Solid state device construction. (Author), See also Quarterly progress rept. no. 9, AD-867 777.

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: Microwave radiation from indium antimonide; Instabilities in germanium; Transverse and magnetic field effects on instabilities in bulk semiconductor plasmas; Gunn-effect oscillators and frequency converters; Gunn-effect amplifiers; High-power Gunn-effect devices; Avalanche-diode devices; High-power avalanche diodes; High-efficiency avalanche diodes; Solid-state device construction. (Author), See also Quarterly progress rept. no. 6, AD-855 150.

The objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: (a) Microwave noise emission from indium antimonide (A method of estimating mobility from the transverse magnetoresistance characteristics is included in report); (b) Instabilities in germanium; (c) Transverse and magnetic field effects on instabilities in bulk semiconductors; (d) Gunn-effect oscillators and frequency converters (Includes a large-signal analysis of quenched-domain mode of Gunn-effect devices); (e) Gunn-effect devices; (f) High-power Gunn-effect devices; (g) Avalanche-diode devices; (h) High-power avalanche diodes; (i) High-efficiency avalanche diodes; (j) Solid-state device construction. (Author), See also Quarterly progress rept. no. 7, AD-860 714.

This is the 3rd quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are: (a) Microwave noise emission from indium antimonide; (b) Instabilities in germanium; (c) Transverse and magnetic field effects on instabilities in bulk semiconductors; (d) Gunn Effect oscillators and frequency converters; (e) Gun Effect amplifiers; (f) Avalanche-diode devices; (g) High-power avalanche diodes; and (h) Solid-state device construction.

ATE Device and Circuit Studies.Quarterly progress rept. no. 10, 1 Dec 72-1 Mar 73,10Haddad,G. I. ;Lomax,R. J. ;Tang,D. ;F30602-71-C-0099AF-5573557303RADCTR-73-157See also Quarterly progress rept. 8/9, AD-759 833.(*semiconductor devices, *microwave equipment), (*integrated circuits, microwave equipment), avalanche diodes, microwave amplifiers, microwave oscillators, field effect transistors, silicon, gallium arsenides, manufacturinggunn diodes, impatt diodes, avalanche diodesThe tenth quarterly report investigates theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are: Modulation properties of Gunn-effect devices, nonlinear operating characteristics of IMPATT diodes, high-efficiency avalanche diodes, properties of TRAPATT diodes, field-effect transistors, CW power capability of IMPATT devices, solid-state device fabrication., See also Quarterly progress rept. 8/9, AD-759 833.

F30602-71-C-0099AF-5573557303RADCTR-73-60See also Quarterly progress rept. no. 7, AD-749 500.(*semiconductor devices, *microwave equipment), (*integrated circuits, microwave equipment), avalanche diodes, microwave amplifiers, microwave oscillators, field effect transistors, silicon, gallium arsenides, manufacturinggunn diodes, impatt diodes, avalanche diodesThis is the eighth and ninth quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are: Power combining schemes for solid-state devices, Modulation properties of Gunn-effect devices, Avalanche-diode amplifiers, Operating characteristics of IMPATT diodes, High-efficiency avalanche diodes, Properties of TRAPATT diodes, Field-effect transistors, and Solid-state device fabrication. (Author), See also Quarterly progress rept. no. 7, AD-749 500.

Objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are the following: High-power Gunn-effect devices; Gunn-effect amplifiers; Modulation properties of Gunn-effect devices; Avalanche-diode amplifiers; High-efficiency avalanche diodes; Nonlinear operating characteristics of IMPATT diodes; Solid-state device fabrication; Instabilities in germanium. (Author), See also AD-744 015.

The ultraviolet absorption cross-section for molecular hydrogen at room temperature was measured absolutely at a resolution of 0.3A, between 1060 and 1130A. This range of wavelengths covers the (0-0) through (3-0) vibrational bands of the B(1)Sigma(+)u - X(1)Sigma(+)g Lyman system. The nature of the curve of growth of an individual line was investigated in detail, and shown to agree closely with the expected behavior of a Doppler broadened Lorentz line for hydrogen at room temperature. A curve of growth analysis has been used to determine absolute line strengths for all observed transitions within each band. For each band the distribution of line strengths is in accordance with the expected weighted Boltzmann distribution of initial states at room temperature, with most of the observed absorption concentrated in the Ro, R1 and P1 transitions. Oscillator strengths for these bands were derived from the integrated band intensities, and confirm, within the limits of the experimental errors, the theoretical Franck-Condon factors. (Author)

Objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: High-power Gunn-effect devices; Gunn-effect amplifiers; Modulation properties of Gunn-effect devices; Avalanche-diode amplifiers; High-efficiency avalanche diodes; Nonlinear operating characteristics of IMPATT diodes; Solid-state device fabrication; Instabilities in germanium. (Author)

High-Conductivity Materials for Microwave Tubes. Extensive cold test results are reported for a tungsten wire helix mounted in a fluted BeO cylinder. Low-Noise Investigations. The analysis of multivelocity low-noise streams is described. Plasmas and Quantum Electronics. The results of space-charge calculations made to evaluate the influence of various operating parameters on the nonlinear interaction process in a beam-plasma system are described. Crossed-Field Electron Gun Studies. The Kino gun is analyzed theoretically by means of the Poisson cell and experimentally in the beam analyzer. (Author)

This is the Fourth Quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. (Author)

This is the sixth Quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification, and control. Current tasks under this program are: Microwave noise emission from Indium Antimonide. (A special mount is described), Instabilities in Germanium, Transverse and magnetic field effects on instabilities in bulk semiconductor plasmas, Gunn effect oscillators and frequency converters. (Frequency limitations are presented), Gunn effect amplifiers (considers the effects of diffusion and thermal currents, and finite transverse dimensions on admittance calculations), High power Gunn effect devices, Avalanche-diode devices, High power avalanche diodes, High efficiency avalanche diodes, and Solid-state device construction. (Author), See also Quarterly progress rept. no. 5, AD-849 141.

Objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under the program are: High-power Gunn-effect devices; Gunn-effect amplifiers; Modulation properties of Gunn-effect devices; Avalanche-diode amplifiers; High-efficiency avalanche diodes; Nonlinear operating characteristics of IMPATT diodes; Solid-state device fabrication; Instabilities in germanium., See also AD-739 549.

This is the fifth quarterly report on subject contract whose objectives are to investigate theoretically and experimentally new solid-state phenomena and techniques having application to microwave generation, amplification and control. Current tasks under this program are the following: High-power Gunn-effect devices; Gunn-effect amplifiers; Modulation properties of Gunn-effect devices; Avalanche-diode amplifiers; High-efficiency avalanche diodes; Nonlinear operating characteristics of IMPATT diodes; Solid-state device fabrication; and Instabilities in germanium., See also report dated Aug 71, AD-730 636.