USSR Space Life Sciences Digest, volume 2, no. 3

Soviet scientists are making significant contributions to the field of space medicine and biology through their active manned space program, frequent biosatellites, and extensive ground-based research. An overview of the developments and direction of the USSR Space Life Sciences Program is provided

Discretionary policy in a monetary union with sovereign debt

This paper examines the interactions between multiple national fiscal policymakers and a single monetary policy maker in response to shocks to government debt in some or all of the countries of a monetary union. We assume that national governments respond to excess debt in an optimal manner, but that they do not have access to a commitment technology. This implies that national fiscal policy gradually reduces debt: the lack of a commitment technology precludes a random walk in steady-state debt, but the need to maintain national competitiveness avoids excessively rapid debt reduction. If the central bank can commit, it adjusts its policies only slightly in response to higher debt, allowing national fiscal policy to undertake most of the adjustment. However, if it cannot commit, then optimal monetary policy involves using interest rates to rapidly reduce debt, with significant welfare costs. We show that in these circumstances the central bank would do better to ignore national fiscal policies in formulating its policy

Fiscal sustainability in a new Keynesian model - additional appendix

Additional appendix relating to the article 'Fiscal sustainability in a new Keynesian model', forthcoming in the Journal of Money, Credit and Banking

Preformed stiffeners used to fabricate structural components for pressurized tanks

Process of fabricating stiffened section components of pressurized tanks for aerospace use was developed. A potential use of the fabrication process is the production of gore and quarter-panel sections of hydrogen and oxygen tanks for space vehicle boosters

USSR Space Life Sciences Digest

Research in exobiology, life sciences technology, space biology, and space medicine and physiology, primarily using data gathered on the Salyut 6 orbital space station, is reported. Methods for predicting, diagnosing, and preventing the effects of weightlessness are discussed. Psychological factors are discussed. The effects of space flight on plants and animals are reported. Bioinstrumentation advances are noted

Enzymatic functionalization of carbon-hydrogen bonds

The development of new catalytic methods to functionalize carbon–hydrogen (C–H) bonds continues to progress at a rapid pace due to the significant economic and environmental benefits of these transformations over traditional synthetic methods. In nature, enzymes catalyze regio- and stereoselective C–H bond functionalization using transformations ranging from hydroxylation to hydroalkylation under ambient reaction conditions. The efficiency of these enzymes relative to analogous chemical processes has led to their increased use as biocatalysts in preparative and industrial applications. Furthermore, unlike small molecule catalysts, enzymes can be systematically optimized via directed evolution for a particular application and can be expressed in vivo to augment the biosynthetic capability of living organisms. While a variety of technical challenges must still be overcome for practical application of many enzymes for C–H bond functionalization, continued research on natural enzymes and on novel artificial metalloenzymes will lead to improved synthetic processes for efficient synthesis of complex molecules. In this critical review, we discuss the most prevalent mechanistic strategies used by enzymes to functionalize non-acidic C–H bonds, the application and evolution of these enzymes for chemical synthesis, and a number of potential biosynthetic capabilities uniquely enabled by these powerful catalysts (110 references)

Macroscale and Nanoscale Photoelectrochemical Behavior of p-Type Si(111) Covered by a Single Layer of Graphene or Hexagonal Boron Nitride

Two-dimensional (2D) materials may enable a general approach to the introduction of a dipole at a semiconductor surface as well as control over other properties of the double layer at a semiconductor/liquid interface. Vastly different properties can be found in the 2D materials currently studied due in part to the range of the distribution of density-of-states. In this work, the open-circuit voltage (V_(oc)) of p-Si–H, p-Si/Gr (graphene), and p-Si/h-BN (hexagonal boron nitride) in contact with a series of one-electron outer-sphere redox couples was investigated by macroscale measurements as well as by scanning electrochemical cell microscopy (SECCM). The band gaps of Gr and h-BN (0–5.97 eV) encompass the wide range of band gaps for 2D materials, so these interfaces (p-Si/Gr and p-Si/h-BN) serve as useful references to understand the behavior of 2D materials more generally. The value of V_(oc) shifted with respect to the effective potential of the contacting solution, with slopes (ΔV_(oc)/ΔE_(Eff)) of −0.27 and −0.38 for p-Si/Gr and p-Si/h-BN, respectively, indicating that band bending at the p-Si/h-BN and p-Si/Gr interfaces responds at least partially to changes in the electrochemical potential of the contacting liquid electrolyte. Additionally, SECCM is shown to be an effective method to interrogate the nanoscale photoelectrochemical behavior of an interface, showing little spatial variance over scales exceeding the grain size of the CVD-grown 2D materials in this work. The measurements demonstrated that the polycrystalline nature of the 2D materials had little effect on the results and confirmed that the macroscale measurements reflected the junction behavior at the nanoscale