Implications of Charcoal Briquette Produced by Local Communities on Livelihoods and Environment in Nairobi Kenya

The residents of Nairobi, Kenya, use 700 tonnes of charcoal per day, producing about 88 tonnes of charcoal dust that is found in most of the charcoal retailing stalls that is disposed of in water drainage systems or in black garbage heaps. The high costs of cooking fuel results in poor households using unhealthy materials such as plastic waste. Further, poor households are opting to cook foods that take a short time to prepare irrespective of their nutritional value. This article presents experiences with community self-help groups producing charcoal fuel briquettes from charcoal dust in poorer nieghbourhoods of Nairobi for home use and sale. Households that produced charcoal fuel briquettes for own use and those that bought them saved 70% and 30% of money spent on cooking energy respectively. The charcoal fuel briquettes have been found to be environmentally beneficial since they produce less smoke and increase total cooking energy by more than 15%, thereby saving an equivalent volume of trees that would be cut down for charcoal. Charcoal briquette production is a viable opportunity for good quality and affordable cooking fuel. Bioenergy and waste management initiatives should promote recovery of organic by-products for charcoal briquette production

Optimizing silicon avalanche photodiode fabricated by standard CMOS process for 8 GHz operation

Silicon avalanche photodiode (APD) was fabricated by standard 0.18 μm CMOS process. The current-voltage characteristic and frequency response was measured for the APD with and without guard ring. With the guard ring around the perimeter of the diode junction, it shows a better performance for the maximum bandwidth but in contrast lower in responsivity. To enhance the bandwidth, the detection area and the PAD size for RF probing are optimized to 10 × 10 μm2 and 30 × 30 μm2, respectively, to decrease the device capacitance, the spacing of interdigital electrode is narrowed to 0.84 μm to decrease carrier transit time, and by cancelling the carriers photo-generated in the deep layer and the substrate because the carriers are slow diffusion carriers. As a result, the maximum bandwidth of 8 GHz was achieved along with a gain-bandwidth product of 280 GHz. © 2015 IEEE

Innovative biomass cooking approaches for sub-Saharan Africa.

Eradicating poverty and achieving food and nutrition security in a sustainable environment is difficult to achieve without adequate access to affordable cooking fuel. It is therefore important to understand the common sources of cooking energy used by people in rural areas and the challenges faced in making fuel sources economically viable, socially acceptable and ecologically sustainable. In the sub-Saharan Africa (SSA) region, more than 90% of the population relies on firewood and charcoal (wood fuel, collectively) as a primary source of domestic energy. Wood fuel sustainability is challenged by unsustainable harvesting and inefficient methods of converting wood into energy. The use of inefficient cook stoves contributes to wood wastage and smoke exposure associated with severe illnesses. Households often abandon traditional nutritious diets that take a long time to cook, reduce the number of meals, and spend income on fuel at the expense of food costs. Innovations exist that have the potential to provide affordable and cleaner tree-based cooking fuel. Pruning trees on the farm as a fuel source brings firewood closer to women, lightens their workload, saves time and reduces income spent on cooking fuel. Using briquettes or gas cook stoves can reduce health risks associated with food preparation and reduce income spent on cooking fuel due to increased fuel efficiency. The development of these innovations indicates the need for a multi-disciplinary approach to increase awareness of the benefits of cooking fuel innovations, encourage further research on product quality enhancement and standardization, to understand cultural and behavioral issues influencing adoption, and integrate innovations into bioenergy policy frameworks

Inflammation and Progressive Nephropathy in Type 1 Diabetes in the Diabetes Control and Complications Trial

OBJECTIVE—Progressive nephropathy represents a substantial source of morbidity and mortality in type 1 diabetes. Increasing albuminuria is a strong predictor of progressive renal dysfunction and heightened cardiovascular risk. Early albuminuria probably reflects vascular endothelial dysfunction, which may be mediated in part by chronic inflammation

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

Compressed representation of a partially defined integer function over multiple arguments

In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one