Rocketdyne's advanced coal slurry pumping program

The Rocketdyne Division of Rockwell International Corporation is conducting a program for the engineering, fabrication, and testing of an experimental/prototype high-capacity, high-pressure centrifugal slurry feed pump for coal liquefaction purposes. The abrasion problems in a centrifugal slurry pump are primarily due to the manner in which the hard, solid particles contained in the slurry are transported through the hydraulic flow passages within the pump. The abrasive particles can create scraping, grinding, cutting, and sandblasting effects on the various exposed parts of the pump. These critical areas involving abrasion and impact erosion wear problems in a centrifugal pump are being addressed by Rocketdyne. The mechanisms of abrasion and erosion are being studied through hydrodynamic analysis, materials evaluation, and advanced design concepts

Further Studies on Fire Retardant Polystyrene by Friedel–Crafts Chemistry

The combination of a copolymer of 4-vinylbenzyl alcohol and styrene with 2-ethylhexyldiphenylphosphate (DPP) and with metal chlorides has been studied by TGA, radiative gasification, Cone Calorimetry, and oxygen index measurements. Evidence is presented in support of a cross-linking reaction with the additives and the copolymer, which proceeds through a Friedel–Crafts mechanism. This approach reduces the peak heat release rate (HRR) by 60% as measured in the Cone Calorimeter. There is a significant reduction in the mass loss rate during the thermal degradation, and evidence of char formation is observed in the radiative gasification experiments

Operational and research aspects of a radio-controlled model flight test program

The operational and research aspects of a subscale, radio-controlled model flight test program are presented. By using low-cost free-flying models, an approach was developed for obtaining research-quality vehicle performance and aerodynamic information. The advantages and limitations learned by applying this approach to a specific flight test program are described. The research quality of the data acquired shows that model flight testing is practical for obtaining consistent and repeatable flight data

G protein beta gamma subunits synthesized in Sf9 cells. Functional characterization and the significance of prenylation of gamma

Heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) consist of a nucleotide-binding alpha subunit and a high- affinity complex of beta and gamma subunits. There is molecular heterogeneity of beta and gamma, but the significance of this diversity is poorly understood. Different G protein beta and gamma subunits have been expressed both singly and in combinations in Sf9 cells. Although expression of individual subunits is achieved in all cases, beta gamma subunit activity (support of pertussis toxin-catalyzed ADP-ribosylation of rGi alpha 1) is detected only when beta and gamma are expressed concurrently. Of the six combinations of beta gamma tested (beta 1 or beta 2 with gamma 1, gamma 2, or gamma 3), only one, beta 2 gamma 1, failed to generate a functional complex. Each of the other five complexes has been purified by subunit exchange chromatography using Go alpha-agarose as the chromatographic matrix. We have detected differences in the abilities of the purified proteins to support ADP- ribosylation of Gi alpha 1; these differences are attributable to the gamma component of the complex. When assayed for their ability to inhibit calmodulin-stimulated type-I adenylylcyclase activity or to potentiate Gs alpha-stimulated type-II adenylylcyclase, recombinant beta 1 gamma 1 and transducin beta gamma are approximately 10 and 20 times less potent, respectively, than the other complexes examined. Prenylation and/or further carboxyl-terminal processing of gamma are not required for assembly of the beta gamma subunit complex but are indispensable for high affinity interactions of beta gamma with either G protein alpha subunits or adenylylcyclases

Observations of Plant Diseases in Iowa from 1924-1926

The diseases of plants especially those diseases due to the invasion of parasites are always markedly influenced by the environment and therefore any discussion of their occurrence in a stated period must also involve a discussion of the weather during that period. According to the reports of Reed,1 the season of 1924 was characterized by a dry, cool spring, a rainy June and a cool summer. August was normal in temperature but with frequent heavy rains and September was unusually and persistently cool

Impact of Financial Inclusion on SME Growth: A Bibliometric Analysis of OIC and Non-OIC Countries

Financial inclusion (FI) is perceived as an imperative tool for reducing poverty and stimulating economic growth. In particular, FI provides access to capital and financial services to small and medium-sized enterprises (SMEs) and enables them to manage their finances, mitigate risks, expand operations, facilitate innovation, and drive job creation. SMEs are considered the backbone of an economy regardless of the level of development of that economy. However, their potential is not fully tapped yet and is hindered due to several constraints. Among its constraints, the unavailability of financial resources is considered a major barrier to SME growth. The International Finance Corporation (IFC) evidenced that 40% of formal SMEs in emerging economies suffer from unmet yearly financial needs of USD 5.2 trillion. Despite all the advantages of FI, it is argued that FI is contingent upon various factors such as structural and policy-related factors and cannot be achieved in isolation. The effectiveness of FI requires collective effort. On the other hand, information and communication technology (ICT) is considered a key enabler of FI. The existing literature has been debated the relationship between FI and SME growth; nonetheless, a lack of consensus exists for the role of FI in SMEs' performance and/or growth. It is also evidenced that the level of FI varies among countries as well as within a country. Therefore, this chapter reviews the academic literature on FI in SMEs by employing bibliometric analysis methods. A total of 62 publications related to FI in SMEs between 2206 and 2024 were identified from a widely recognised Scopus online database. Using VOSviewer software, the analysis established how research has evolved in this area. The authors identified main current themes, emerging trends, and gaps for future research directions

Effect of thermal exposure, forming, and welding on high-temperature, dispersion-strengthened aluminum alloy: Al-8Fe-1V-2Si

The feasibility of applying conventional hot forming and welding methods to high temperature aluminum alloy, Al-8Fe-1V-2Si (FVS812), for structural applications and the effect of thermal exposure on mechanical properties were determined. FVS812 (AA8009) sheet exhibited good hot forming and resistance welding characteristics. It was brake formed to 90 deg bends (0.5T bend radius) at temperatures greater than or equal to 390 C (730 F), indicating the feasibility of fabricating basic shapes, such as angles and zees. Hot forming of simple contoured-flanged parts was demonstrated. Resistance spot welds with good static and fatigue strength at room and elevated temperatures were readily produced. Extended vacuum degassing during billet fabrication reduced porosity in fusion and resistance welds. However, electron beam welding was not possible because of extreme degassing during welding, and gas-tungsten-arc welds were not acceptable because of severely degraded mechanical properties. The FVS812 alloy exhibited excellent high temperature strength stability after thermal exposures up to 315 C (600 F) for 1000 h. Extended billet degassing appeared to generally improve tensile ductility, fatigue strength, and notch toughness. But the effects of billet degassing and thermal exposure on properties need to be further clarified. The manufacture of zee-stiffened, riveted, and resistance-spot-welded compression panels was demonstrated