Pay-as-you-go LPG: A mixed-methods pilot study in urban Rwanda

2.8 billion people still cook with biomass fuels, resulting in devastating impacts on health, gender equity and the environment. Pay-as-you-go (PAYG) liquid petroleum gas (LPG) is a new technology designed to make LPG affordable for urban biomass users by allowing customers to pay for fuel in small amounts. This mixed-methods study (N = 64) combined stove usage data, cooking diaries, household interviews and telephone surveys to examine a commercial PAYG LPG pilot in Kigali. It aimed to understand how households used PAYG LPG and its potential in accelerating access to clean cooking in urban Rwanda. PAYG LPG rapidly displaced charcoal as the primary cooking fuel for the majority of participants, resulting in a mean monthly reduction in household fuel expenditure of 3240 RWF (3.50 USD) and a mean consumption of 1.2 kg/capita/month. Participants spanning all income brackets in Kigali made use of PAYG LPG. The ability to pay in smaller amounts seemed to be critical to initial adoption and sustained use during the pilot. Follow-up activities with a small subsample of participants (N = 10) found that 70% continued to use full cylinder LPG (typically 12 kg) as their primary cooking fuel in the two months after the PAYG service was withdrawn. Throughout the pilot almost all participants continued to use charcoal, which accounted for 21% of cooking events. We identified a range of drivers of fuel stacking that encompassed both cultural and practical factors such as cylinder delivery delays and taste preferences for certain foods. We conclude that PAYG LPG could contribute to the clean cooking transition in urban Rwanda, but that larger scale pilots are needed to better understand both the supply- and demand-side viability

Towards measurable resilience: A novel framework tool for the assessment of resilience levels in slums

This paper investigates the need for a generic technique to be applied in the assessment of resilience-related projects in slums – particularly for localised infrastructure at a community level – and proposes a novel framework tool for this purpose. The paper outlines the development of the framework tool, as well as its pilot testing on the Kenya Slum Upgrading Programme in Kibera, Nairobi. The evaluation demonstrates an improvement in asset base, capacities and external resources for the community post intervention. The lack of land tenure was identified to be a key weakness and factor which impacted resilience of the local residents

Cleaning up the stack: Evaluating a clean cooking fuel stacking intervention in urban Kenya

There are a growing number of market-based providers of clean cooking solutions in sub-Saharan Africa that rely on use customer fuel sales to subsidise upfront cost of equipment. These business models can widen access to clean cooking but are undermined by the continued use of polluting fuels, known as “fuel stacking”, which limits provider revenues whilst perpetuating the negative impacts of cooking with traditional fuels. This study aimed to design and test a fuel stacking intervention with commercial pay-as-you-go LPG customers in Kisumu, Kenya. It consisted of three main phases: developing and testing a survey tool for diagnosing drivers of stacking (n = 99); using an intervention design framework (the Behaviour Change Wheel) to design an intervention consisting of the bundled provision of a pressure cooker, chapati pan and training; and testing the intervention in a small (n = 19) pre-post study. There was high uptake of the intervention, with the pans being used by all participants on roughly two-fifths of days. Target foods were cooked more frequently on LPG in the intervention phase, resulting in a significant increase in PAYG LPG use and an insignificant decrease in charcoal use. A third of participants stopped cooking with charcoal altogether, but some residual charcoal usage continued amongst the remainder. The results show that targeted stacking interventions can simultaneously promote sustained use of clean fuels and dis-adoption of polluting ones, resulting in commercial gains for clean cooking fuel providers. This could address the wicked problem of fuel stacking and accelerate progress towards Sustainable Development Goal 7

Double Charge Exchange And Configuration Mixing

The energy dependence of forward pion double charge exchange reactions on light nuclei is studied for both the Ground State transition and the Double-Isobaric-Analog-State transitions. A common characteristic of these double reactions is a resonance-like peak around 50 MeV pion lab energy. This peak arises naturally in a two-step process in the conventional pion-nucleon system with proper handling of nuclear structure and pion distortion. A comparison among the results of different nuclear structure models demonstrates the effects of configuration mixing. The angular distribution is used to fix the single particle wave function.Comment: Added 1 figure (now 8) corrected references and various other change

Effective temperature for black holes

The physical interpretation of black hole's quasinormal modes is fundamental for realizing unitary quantum gravity theory as black holes are considered theoretical laboratories for testing models of such an ultimate theory and their quasinormal modes are natural candidates for an interpretation in terms of quantum levels. The spectrum of black hole's quasinormal modes can be re-analysed by introducing a black hole's effective temperature which takes into account the fact that, as shown by Parikh and Wilczek, the radiation spectrum cannot be strictly thermal. This issue changes in a fundamental way the physical understanding of such a spectrum and enables a re-examination of various results in the literature which realizes important modifies on quantum physics of black holes. In particular, the formula of the horizon's area quantization and the number of quanta of area result modified becoming functions of the quantum "overtone" number n. Consequently, the famous formula of Bekenstein-Hawking entropy, its sub-leading corrections and the number of microstates are also modified. Black hole's entropy results a function of the quantum overtone number too. We emphasize that this is the first time that black hole's entropy is directly connected with a quantum number. Previous results in the literature are re-obtained in the limit n \to \infty.Comment: 10 pages,accepted for publication in Journal of High Energy Physics. Comments are welcom

Clinical profile of patients presenting with heart failure with preserved ejection fraction

Background: Evaluate the clinical profile of patients presenting with heart failure having normal or preserved ejection fraction and to determine the prevalence of comorbid illnesses in these patients.Methods: The study was carried out on patients that presented with heart failure at the Vadilal Sarabhai hospital, Ahmedabad between September 2014-2016. Heart failure patients with normal ejection fraction (>50%) were selected. Socio-demographic, vital signs, data of 2D Echocardiography and Tissue Doppler study were collected. The patients were classified as per the Echocardiographic study into four categories. Different laboratory parameters were compared in patients with respect to (a) grade of Hypertension (b), grade of anemia (c), HbA1c levels. Statistical analysis was done using the SPSS software v20. Mann-Whitney and Kruskal-Wallis tests were performed to compare the means between different study groups.Results: Out of the 70 patients, a majority (47%) belonged to the Grade 2 (pseudo-normalized) group of diastolic dysfunctions with most of them having only dyspnea and pedal edema (33%). 58.6% patients required intensive care for at least one day. Regarding co-morbidities 27 (38.6%) had hypertension, 34 (48.6%) were diabetic and 49(70%) had anemia. Patients with higher grade of dysfunction had higher HbA1c (p=0.023) and worsening anemia (p=0.003).Conclusions: Authors concluded that it is of prime importance to find, prevent and treat the comorbidities along with targeted therapies for HFpEF. Further evaluation can be done for clinical applicability of different markers including HbA1c and U.ACR for renal dysfunction in HFpEF

Spectral fluctuation characterization of random matrix ensembles through wavelets

A recently developed wavelet based approach is employed to characterize the scaling behavior of spectral fluctuations of random matrix ensembles, as well as complex atomic systems. Our study clearly reveals anti-persistent behavior and supports the Fourier power spectral analysis. It also finds evidence for multi-fractal nature in the atomic spectra. The multi-resolution and localization nature of the discrete wavelets ideally characterizes the fluctuations in these time series, some of which are not stationary.Comment: 7 pages, 2 eps figure

Scattering of positrons and electrons by alkali atoms

Absolute total scattering cross sections (Q sub T's) were measured for positrons and electrons colliding with sodium, potassium, and rubidium in the 1 to 102 eV range, using the same apparatus and experimental approach (a beam transmission technique) for both projectiles. The present results for positron-sodium and -rubidium collisions represent the first Q sub T measurements reported for these collision systems. Features which distinguish the present comparisons between positron- and electron-alkali atom Q sub T's from those for other atoms and molecules (room-temperature gases) which have been used as targets for positrons and electrons are the proximity of the corresponding positron- and electron-alkali atom Q sub T's over the entire energy range of overlap, with an indication of a merging or near-merging of the corresponding positron and electron Q sub T's near (and above) the relatively low energy of about 40 eV, and a general tendency for the positron-alkali atom Q sub T's to be higher than the corresponding electron values as the projectile energy is decreased below about 40 eV

Stellar population properties of individual massive early-type galaxies at 1.4 &lt; <i>z</i> &lt; 2

We analyse publicly available, individual spectra of four massive (⁠M>1011M⊙⁠) early-type galaxies with redshifts in the range 1.4 ≤ z ≤ 2 to determine their stellar content, extending our previous work up to z ∼ 2. The wide wavelength range of the VLT/X-Shooter spectroscopic data in the UV–Optical–NIR arms along with the availability of spectro-photometry allows us to explore different techniques to obtain the stellar population properties, namely through age/metallicity-sensitive spectral indices, full spectral fitting, and broad-band photometric fitting. Moreover, together with the widely used optical Lick indices, we consider further indices in the UV rest frame, and demonstrate that UV indices significantly help the accuracy of the resulting population parameters. We find galaxy ages ranging from 0.2 to 4 Gyr, where the oldest galaxy is found at the lowest redshift, with an excellent agreement between ages determined via indices, full spectral fitting, or broad-band colours. These ages are in perfect agreement with ages of local galaxies at the same velocity dispersion when we assume pure passive evolution. Total metallicities derived from indices show some scatter (between less than half-solar to very high values, [Z/H] ∼ 0.6). We speculate on possible mechanisms explaining these values, but given the sample size and low S/N of the spectra no conclusion can be made. Indices in the UV rest frame generally lead to similar conclusions as optical indices. For the oldest galaxy (4 Gyr), we show that its UV indices can only be explained by stellar population models including a UV contribution from old stellar populations, suggesting that old, UV bright populations start to inhabit mature galaxies of a few Gyr of age. This is the highest redshift (z ∼ 1.4) detection of the UV upturn up to date