Compilation of rocket spin data. Volume 2 - Literature survey Final report, Nov. 1966 - Aug. 1968

Literature survey of acceleration spin effects on solid propellant rocket engine

Compilation of rocket spin data. Volume 3 - Data evaluation and recommendations Final report, Nov. 1964 - Aug. 1968

Qualitative analysis of spin acceleration effects on solid propellant rocket engine performanc

Compilation of rocket spin data. Volume 1 - Acceleration test facilities Final report

Spin and centrifuge test facilities for testing solid rocket propellant engines - annotated bibliograph

Power Coupling Alternatives for the NEP Thermionic Power System

Three output power coupling methods which can eliminate the high temperature insulator from the Nuclear Electric Propulsion (NEP) power system are described and estimates of their effects on the NEP system masses and cooling requirements are presented. Nominal 400 kWe power systems using push-pull and flux reset inductive output coupling are shown to have specific masses of 22.2 kg/kWe and 18.8 kg/kWe, respectively. Series connected heat pipe systems, which use the heat pipe-to-heat pipe resistance to isolate converters on adjacent heat pipes, are shown to have specific masses 0.5 to 1.4 kg/kWe lower than the NEP baseline system. Increasing the number and temperature of the heat pipes in the system without changing the electric output reduces the calculated system specific mass only slightly, whereas increasing the output power significantly reduces the specific mass. Estimates of cooling requirements indicate that 11-45 sq m of power conditioning radiator are needed. A possible location for the power conditioning radiator may be in the present location of the kapton sputter shield

The patient-provider relationship and antenatal care uptake at two referral hospitals in Malawi: A qualitative study

Background In post-stroke patients, impairment of quality of life (QOL) has been associated with functional impairment, age, anxiety, depression, and fatigue. Good social support, higher education, and better socioeconomic status are associated with better QOL among stroke survivors. In Africa, studies from Nigeria and Tanzania have reported on post-stroke QOL.Background Approximately 90% of Malawian women attend antenatal care at least once during their pregnancies; however, most mothers first present during months five and six and do not adhere to the World Health Organization’s recommended four visits. The objective of this study was to explore the role the patient-provider relationship has on antenatal care uptake.Methods A qualitative study, consisting of interviews with 20 urban pregnant mothers and eight health workers, was conducted from September to December 2014. Two large tertiary care hospitals in the Central and Southern regions of Malawi were selected as study sites.Results Several factors influenced antenatal care attendance. Significant barriers reported included the patient-provider relationship, clinic wait times, family and friend support, distance from home to the clinic, transportation, cost, and number of visits. The patient-provider relationship appears to have a large impact on antenatal clinic participation. Mothers indicated that health workers often mistreat or demean them during visits. Additionally, health workers revealed that, due to staff shortages, patients often do notreceive the care they deserve.Conclusions The results of this study suggest that, in addition to other factors, healthcare provider attitudes influence antenatal clinic attendance. Improving the patient-provider relationship may increase antenatal clinic attendance and decrease pregnancy complications during pregnancy. Professional development opportunities and quality improvement programmes are would help improve patient care and health outcomes while the continued staff shortages in the country are addressed

Adoption of improved soybean and gender differential productivity and revenue impacts: evidence from Nigeria

Open Access Journal; Published online: 06 May 2022Despite the considerable soybean varietal improvement and dissemination efforts in Nigeria and other parts of Sub-Saharan Africa, empirical evidence on farm-level yield and revenue impacts of improved soybean varieties (ISVs) from a gender perspective are limited. In this paper, we analyze the impact of the adoption of ISVs on soybean yield and net revenue, and the associated gender differential effects in northern Nigeria. We use the endogenous and exogenous switching treatment effects regression frameworks to estimate the impacts. We find that the adoption of ISVs significantly increased soybean yield and net revenue of the soybean-producing households by 26% and 32%, respectively. In addition, we find that the gender gap in yield between male and female-headed soybean-producing households was small, with a yield gap of about 1%. However, we find a substantial gender gap in soybean net revenue, as the net revenue of female-headed households was lower by about 20%, as compared to male-headed households. Overall, our findings show that policymakers and their development partners can leverage varietal improvement to boost the yields of both male- and female-headed households. However, closing the gender gap in crop income necessitates reducing the disparity in market linkages so that the female farmers can equally have better market access

Two 'transitions': the political economy of Joyce Banda's rise to power and the related role of civil society organisations in Malawi

This is an Accepted Manuscript of an article published by Taylor & Francis in Review of African Political Economy on 21/07/2014, available online: http://www.tandfonline.com/doi/abs/10.1080/03056244.2014.90194

Welfare impacts of smallholder farmers’ participation in multiple output markets: empirical evidence from Tanzania

Open Access Journal; Published online: 06 May 2021A relatively large body of literature has documented the welfare effects of smallholder farmers’ participation in single-commodity output markets. However, limited empirical evidence is available when smallholder farmers participate in multiple-commodities output markets. We tried to fill this gap in the literature by estimating the impacts of smallholder farmers’ contemporaneous participation in both maize and legume markets vis-à-vis in only maize or legume markets using household-level data from Tanzania. Applying a multinomial endogenous switching regression model that allows controlling for observed and unobserved heterogeneity associated with market participation in single-commodity and multiple-commodity markets, results showed that smallholder farmers’ participation in both single–and multiple–commodity markets was positively and significantly associated with household income and food security. Moreover, the greatest benefits were obtained when farmers participated in multiple-commodity markets, suggesting the importance of policies promoting diversification in crop income sources to increase welfare and food security. Our findings also signal the complementary–rather than substitute–nature of accessing multiple-commodity markets for enhancing household livelihoods under a specialization strategy. Finally, important policy implications are suggested, from promoting and supporting public infrastructure investments to expanding road networks to reduce transportation costs, especially in remote communities, to enhance smallholder farmer access to profitable maize and legume markets in Tanzania

Microgravity diode laser spectroscopy measurements in a reacting vortex ring

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76896/1/AIAA-2001-187-556.pd

High-redshift Extremely Red Quasars in X-Rays

Quasars may have played a key role in limiting the stellar mass of massive galaxies. Identifying those quasars in the process of removing star formation fuel from their hosts is an exciting ongoing challenge in extragalactic astronomy. In this paper, we present X-ray observations of 11 extremely red quasars (ERQs) with L bol ~ 1047 erg s−1 at z = 1.5–3.2 with evidence for high-velocity (v $\geqslant$ 1000 km s−1) [O iii] λ5007 outflows. X-rays allow us to directly probe circumnuclear obscuration and to measure the instantaneous accretion luminosity. We detect 10 out of 11 ERQs available in targeted and archival data. Using a combination of X-ray spectral fitting and hardness ratios, we find that all of the ERQs show signs of absorption in the X-rays with inferred column densities of N H ≈ 1023 cm−2, including four Compton-thick candidates (N H $\geqslant$ 1024 cm−2). We stack the X-ray emission of the seven weakly detected sources, measuring an average column density of N H ~ 8 × 1023 cm−2. The absorption-corrected (intrinsic) 2–10 keV X-ray luminosity of the stack is 2.7 × 1045 erg s−1, consistent with X-ray luminosities of type 1 quasars of the same infrared luminosity. Thus, we find that ERQs are a highly obscured, borderline Compton-thick population, and based on optical and infrared data we suggest that these objects are partially hidden by their own equatorial outflows. However, unlike some quasars with known outflows, ERQs do not appear to be intrinsically underluminous in X-rays for their bolometric luminosity. Our observations indicate that low X-rays are not necessary to enable some types of radiatively driven winds