Use of Explosives on The Moon

The utilization of explosives for excavation on the lunar surface is under serious consideration as a part of the design for construction of temporary and permanent bases. An excavation research program has shown that small‐scale explosives blasting in a lunar‐soil simulant will greatly reduce the digging forces required for scoop and dragline excavators. Some crater‐blasting parameters were determined for the lunar soil simulant at one Earth gravity and at 10 Earth gravities using a centrifuge. The size of the craters produced at 10 Earth gs matched those formed at one earth g by scaling according to the weight of the explosive. These data can be applied to explosive‐excavation problems such as habitat construction, burial of nuclear power sources, and the rapid construction of shelters remote from the main base to shield against solar‐flare activity.     

Properties of titanium-containing sol-gel films modified with copper and vanadium oxides

Translated from Steklo i Keramika, No. 1, pp. 4–6, January, 1994.     

Tracheobronchial ruptures in closed thoracic trauma

Authors refer about their experience on five cases of thoracic trauma. Following a review of international literature, they analyze the clinical, diagnostic and therapeutic aspects of this kind of injuries.     

Effect of energy shortage and oxidative stress on amyloid precursor protein metabolism in COS cells

The standard method for assessing the carcinogenicity of lubricating oil base stocks is the mouse skin-painting bioassay. This assay has the advantage of directly measuring the endpoint of interest, dermal carcinogenicity, but has the drawback of being time-consuming and expensive. For this reason, a variety of biological and chemical assays have been developed as predictive alternatives to the in vivo assay. This publication describes the application of three such methods to the assessment of carcinogenic potential of hydrotreated, re-refined oils: the modified Ames test, the analytical determination of 3-7-ring polycyclic aromatic compound content and the 32P-postlabeling assay for DNA adduct induction.     

9-Benzyladenines: potent and selective cAMP phosphodiesterase inhibitors

A 6-year-old Quarter Horse gelding with acute onset of a grade-4/5 lameness of the left forelimb 21 days after an encounter with a porcupine was examined. Quills had been removed by the referring veterinarian, and the horse had been treated with antibiotics and hydrotherapy for 14 days. The horse was pyretic and had effusion in the digital synovial sheath. Signs of pain were elicited on palpation of the area. A tentative diagnosis of septic tenosynovitis caused by a porcupine quill was made. Exploratory tenoscopy revealed large amounts of fibrin in the sheath and a 1.2-cm quill. Bacteriologic culture of synovial fluid yielded a pure growth of Staphylococcus aureus. The horse improved dramatically after tenoscopic removal of the quill, debridement of fibrin, and lavage to dilute inflammatory mediators and bacteria, debridement of fibrin, discovery and removal of a quill, and complete evaluation of the sheath for prognostic purposes. Tenoscopy can provide a means for direct observation and enhance the ability of clinicians to debride a septic synovial sheath in a minimally invasive manner.     

Two-level optimal output feedback stabilizer design

The paper addresses the design of two-level power system stabilizers using an optimal reduced order model whose state variables are torque angles and speeds. The reduced order model retains their physical meaning and is used to design a two-level linear feedback controller that takes into account the realities and constraints of electrical power systems. The two-level control strategy is used, and a global control signal is generated from the output variables to minimize the effect of interactions. The effectiveness of this controller is evaluated and a multimachine system is given as an example to illustrate the advantages of the proposed method. Responses of the system with a two-level scheme and an optimal reduced order scheme are included for comparative analysis.     

Pressure indicators for measurements in wind tunnels

The results of an investigation of new materials sensitive to air pressure in a given pressure range are reported. Examples of their application to wind tunnels are given.Central Aero-Hydrodynamics Institute, Moscow. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 63, No. 2, pp. 183–187, August, 1992.     

All-optical photonic switches using integrated inverted asymmetricFabry-Perot modulators and heterojunction phototransistors

InGaAs/GaAs(100) multiple-quantum-well-based inverted cavity asymmetric Fabry-Perot modulators are vertically integrated with GaAs/AlGaAs heterojunction phototransistors to yield all-optical photonic switches. The photonic switches using `normally on' modulator pixels exhibit an output on-off ratio of 12:1 with internal optical gain of 4 dB. The photonic switches using `normally off' modulator pixels yield similar contrast and gain, but exhibit intrinsic bistable behavior. The inverted cavity modulators employed permit utilizing the transparency of the GaAs substrate at the operating wavelength and offer advantages for fabricating large arrays for optical signal processing