Inmos

Although Python has the statsmodels library that can be used to perform different statistical analyses, including multiple regression, it has not yet implemented multivariate regression (MVR) as one of its methods. An investigator interested in conducting a multivariate regression is thus limited to running a series of univariate regression models, which do not take into account the collinearity among variables in the models. Thus, the purpose of this tutorial is to demonstrate how to perform multivariate regression in Python using custom user-defined classes, and linear hypothesis testing using statsmodels.

Transitioning to clean cooking fuels is not only part of achieving SDG7, but also makes a significant contribution to mitigating climate change by reducing carbon emissions. The paper contradicts the conventional wisdom that electricity is too expensive to cook with. The paper explores the energy required to cook dishes using different technologies and fuels by analysing data from Cooking Diaries and Controlled Cooking tests conducted under the MECS programme. Electric pressure cookers (EPCs) use least energy when compared with electric hotplates, and a detailed description of how the EPC works explains why this should be. The paper draws out distinctions between African and Asian dishes, notably the impact of energy intensive dishes prepared mostly in Africa. Standard efficiency based approaches to comparing the performance of stoves are not appropriate to modern electric cooking devices so an alternative approach based on specific energy consumptions is proposed e.g. charcoal stoves use 15 times as much energy as EPCs to cook African dishes. Energy ratios provide a basis for estimating carbon emission reductions associated with transitioning to modern cooking fuels. Historical costs show that the cost of cooking with an EPC can be only 20% of the cost of cooking with charcoal, which highlights the potential for modern, energy efficient electric cooking devices to defy the conventional wisdom of the energy ladder.

ABSTRACT Introduction Biantheridion undulifolium (Nees) Konstant. & Vilnet [Jamesoniella undulifolia (Nees) Müll.Frib.] is a globally rare liverwort threatened with extinction. This study was carried out to investigate its population status and ecology in England and Wales, UK. Methods Surveys were undertaken at all previously known sites where the species may currently occur in England and Wales. Geographical coordinates of colonies were recorded with a GPS unit, and counts made of occupied 1 m grid cells. Habitat and community composition were recorded by relevés. Key results Biantheridion undulifolium has been reported from 16 sites in England and Wales. It has become extinct at six (38%), and its continued existence at two others is uncertain. Following 52 h of search effort, 88 occupied 1 m grid cells were found across eight sites. The estimated true total is 196–433 occupied 1 m grid cells. Only three sites support sizeable populations; most sites support < 10 occupied 1 m grid cells. The species is confined to mesotrophic flushes and bogs, mostly occurring on hummocks of Sphagnum capillifolium s.l. that are moderately to heavily compacted by grazing livestock. Occupied hummocks tend to be composed of Sphagnum in good health, with few signs of necrosis. Fertile plants of this dioicous liverwort are rare, and no sporophytes were found. Conclusions Biantheridion undulifolium is a ‘competitive perennial stayer’ with limited dispersal ability, and has undergone a significant decline in England, and probably also in Wales. Adequate grazing pressure appears to be especially important for its survival. Most sites occur outside protected areas.

Abstract This paper describes an approach for framing a problem where the potential operational scope is large and diverse, and for quickly evaluating potential points in the solution‐space in a manner which is easy for non‐technical stakeholders to digest and interact with. The two aspects of scenario framing and concept assessment work well together but can easily be decoupled depending on the needs of the task at hand. It has been used so far on series of tasks exploring concept and pre‐concept phase options in the UK Defence environment, but has wider applicability to any situation that shares similar characteristics.The scenario framing approach addresses the familiar problem of getting past stakeholder responses of “it depends” when they are asked to validate processes or behavioural models. The concept assessment approach, based upon the acronym BRAIN, is intended to be quick and easy to apply, supporting rapid iteration. Two case studies are used to illustrate the combined approach.

Whilst the rapid spread of solar photovoltaics (PV) across Africa has already transformed millions of lives, it has yet to have an impact on the main energy need of poor households: cooking. In the context of falling global PV prices, recent advancements in battery technology and rising charcoal/fuelwood prices in severely deforested regions, the door is opening for a potentially transformative alternative – solar electric cooking (PV-eCook). While initial investigations focused on solar home systems sized for cooking (cooking device, battery storage, charge controller and PV array), it has since been shown that battery-supported electric cooking (eCook) can also strengthen national, mini, micro and nano grids. This paper presents a multi-criteria decision analysis (MCDA) based methodology, accounting for a wide variety of socio-cultural, political, technical and economic factors which are expected to affect the uptake and potential impact of eCook across a variety of African contexts. It shows the concept has considerable viability in many African countries, that there are significant sizeable markets (millions of potential users), and that within the next five years the anticipated costs of eCook are highly competitive against existing ‘commercialised polluting fuels’.

A series of sample stability tests has been undertaken to support a large UK-based survey of trace substances in wastewater. This program aims to quantify the input of priority chemicals to the aquatic environment via sewage effluent. The stability tests have demonstrated that, in most cases, the proposed approach of chilling samples meets the target that sample concentrations should not change by more than 25%, provided samples are analyzed or otherwise stabilized within 3–5 d. Substances tested fall into three main classes: Instability in effluents greater than the project-based threshold of 25% over 3–5 d can be ruled out provided samples are chilled for: DEHP (DEHA), glyphosate, AMPA, bentazone, mecoprop, ofloxacin, erythromycin, and ibuprofen; Some indication of possible instability up to 25% provided chilled storage periods do not extend beyond 3–5 d for: mercury (note requires acid dichromate preservation on site or as soon as possible), tributyltin, bisphenol A, reactive aluminum (in effluents, note requires filtration on sampling), oxytetracycline, and propranolol; and Clear stability problems are demonstrated for salicylic acid (effluents and influents), with indications of important instability (>25%) for bisphenol (effluents) AMPA and glyphosate (influents).

Some of the issues arising in the design of the T9000 transputer, which integrates a complete computer in a single VLSI chip of over two million transistors, are discussed. High performance has been achieved by extensive use of caching and a novel processor implementation. The processor uses a fat pipeline and dispatches several dependent instructions into the pipeline each cycle. The resulting processor is able to saturate a 25-MFLOP floating-point unit. The processor is supported by a communications system that supports communications at high speed and low latency. >

Photoresist defectivity is a major source of yield loss in the manufacture of integrated circuits. Contamination may result from the resist, the resist process or coating track components. Much work has been carried out to reduce the causes of defects whilst maintaining the properties of the resist fi1m. Exposure of the resist to air is thought to result in solvent loss and moisture absorption which causes the information of gel slugs and dried resist flakes. These gel slugs and dried resist flakes form defects in the resist film. Traditional containment systems for resist such as glass bottles allow for high exposure to air. The irregular physical properties of resultant contaminants from air exposure may allow random passage through filtration systems and can then be incorporated within the film causing pattern defects to occur. Sealed "Bag-in-Bottle" (BIB) systems considerably reduce the exposure of the enclosed chemical to the environment, and have been demonstrated to have an effect in controlling pattern defectivity as part of a total system improvement3. Potential advantages of such sealed systems include improved package cleanliness, reduced exposure of the resist to air during use and improved resist utilization. This investigation involves a comparison between standard glass bottle and BIB containment for undyed and dyed resists. The analysis techniques used were short loop defectivity monitors, laser scanning of resist-coated wafers and defectivity analysis on actual device at wafer probe yield check. Chemical analysis of ionic contaminants and total resist utilization were also measured for both containment systems.