Evaluating the Laboratory Performance of Pellet-Fueled Semigasifier Cookstoves.

This study examines three representative semigasifier cookstove models each burning four types of pelletized-biomass fuel (hardwood, peanut hull, rice husk, and wheat straw) using the International Organization for Standardization (ISO) 19867-1:2018 protocol. ISO tier ratings for fine particulate matter (PM) and carbon monoxide (CO) emissions ranged 1-4 and 2-5 (where 5 = cleanest), respectively, suggesting that pellet-fueled cookstoves may provide substantial emissions reductions, dependent upon stove/fuel matching and operation, over other biomass-fueled cooking alternatives. PM emission factors based on useful energy delivered (EF) varied by up to 25-fold, and organic and elemental carbon (OC and EC) EF values respectively varied by >200- and ∼100-fold, reflecting complex variability in PM composition.

Quantifying functional group compositions of household fuel-burning emissions.

Globally, billions of people burn fuels indoors for cooking and heating, which contributes to millions of chronic illnesses and premature deaths annually. Additionally, residential burning contributes significantly to black carbon emissions, which have the highest global warming impacts after carbon dioxide and methane. In this study, we use Fourier transform infrared spectroscopy (FTIR) to analyze fine-particulate emissions collected on Teflon membrane filters from 15 cookstove types and 5 fuel types.

A global review of the state of the evidence of household air pollution's contribution to ambient fine particulate matter and their related health impacts.

Direct exposure to household fine particulate air pollution (HAP) associated with inefficient combustion of fuels (wood, charcoal, coal, crop residues, kerosene, etc.) for cooking, space-heating, and lighting is estimated to result in 2.3 (1.

Cookstove Emissions and Performance Evaluation Using a New ISO Protocol and Comparison of Results with Previous Test Protocols.

In 2018, the International Organization for Standardization (ISO) 19867-1 "Harmonized laboratory test protocols" were released for establishing improved quality and comparability for data on cookstove air pollutant emissions, efficiency, safety, and durability. This is the first study that compares emissions [carbon dioxide, carbon monoxide, total hydrocarbons, methane, nitrogen oxides, fine particulate matter (PM), organic carbon, elemental carbon, and ultrafine particles] and efficiency data between the ISO protocol and the Water Boiling Test (WBT). The study examines six stove/fuel combinations [liquefied petroleum gas (LPG), pellet, wood fan, wood rocket, three stone fire, and charcoal] tested in the same US EPA laboratory.

Chemical composition, structures, and light absorption of N-containing aromatic compounds emitted from burning wood and charcoal in household cookstoves.

N-containing aromatic compounds (NACs) are an important group of light-absorbing molecules in the atmosphere. They are often observed in combustion emissions, but their chemical formulas and structural characteristics remain uncertain. In this study, red oak wood and charcoal fuels were burned in cookstoves using the standard water boiling test (WBT) procedure.

Evaluation of performance of household solar cookers.

Household solar cookers were evaluated according to ASAE (American Society of Agricultural Engineers) Standard S580.1 - Testing and Reporting Solar Cooker Performance. Per ASAE S580.

Mutagenicity- and pollutant-emission factors of pellet-fueled gasifier cookstoves: Comparison with other combustion sources.

Emissions from solid-fuel burning cookstoves are associated with 3 to 4 million premature deaths annually and contribute significantly to impacts on climate. Pellet-fueled gasifier stoves have some emission factors (EFs) approaching those of gas-fuel (liquid petroleum gas) stoves; however, their emissions have not been evaluated for biological effects. Here we used a new International Organization for Standardization (ISO) testing protocol to determine pollutant- and mutagenicity-EFs for a stove designed for pellet fuel, the Mimi Moto, and for two other forced-draft stoves, Xunda and Philips HD4012, burning pellets of hardwood or peanut hulls.

Field-based emission measurements of biomass burning in typical Chinese built-in-place stoves.

Residential combustion emission contributes significantly to ambient and indoor air pollution in China; however, this pollution source is poorly characterized and often overlooked in national pollution control policies. Few studies, and even fewer field-based investigations, have evaluated pollutant emissions from indoor biomass burning. One significant feature of Chinese household biofuel stoves is that many are built on site.

Light absorption of organic carbon emitted from burning wood, charcoal, and kerosene in household cookstoves.

Household cookstove emissions are an important source of carbonaceous aerosols globally. The light-absorbing organic carbon (OC), also termed brown carbon (BrC), from cookstove emissions can impact the Earth's radiative balance, but is rarely investigated. In this work, PM filter samples were collected during combustion experiments with red oak wood, charcoal, and kerosene in a variety of cookstoves mainly at two water boiling test phases (cold start CS, hot start HS).

Evaluating the Performance of Household Liquefied Petroleum Gas Cookstoves.

Liquefied petroleum gas (LPG) cookstoves are considered to be an important solution for mitigating household air pollution; however, their performance has rarely been evaluated. To fill the data and knowledge gaps in this important area, 89 laboratory tests were conducted to quantify efficiencies and pollutant emissions from five commercially available household LPG stoves under different burning conditions. The mean thermal efficiency (±standard deviation) for the tested LPG cookstoves was 51 ± 6%, meeting guidelines for the highest tier level (Tier 4) under the International Organization for Standardization, International Workshop Agreement 11.

Differential exposure and acute health impacts of inhaled solid-fuel emissions from rudimentary and advanced cookstoves in female CD-1 mice.

Background: There is an urgent need to provide access to cleaner end user energy technologies for the nearly 40% of the world's population who currently depend on rudimentary cooking and heating systems. Advanced cookstoves (CS) are designed to cut emissions and solid-fuel consumption, thus reducing adverse human health and environmental impacts.

Study Premise: We hypothesized that, compared to a traditional (Tier 0) three-stone (3-S) fire, acute inhalation of solid-fuel emissions from advanced natural-draft (ND; Tier 2) or forced-draft (FD; Tier 3) stoves would reduce exposure biomarkers and lessen pulmonary and innate immune system health effects in exposed mice.

A Laboratory Comparison of Emission Factors, Number Size Distributions, and Morphology of Ultrafine Particles from 11 Different Household Cookstove-Fuel Systems.

Ultrafine particle (UFP) emissions and particle number size distributions (PNSD) are critical in the evaluation of air pollution impacts; however, data on UFP number emissions from cookstoves, which are a major source of many pollutants, are limited. In this study, 11 fuel-stove combinations covering a variety of fuels and different stoves are investigated for UFP emissions and PNSD. The combustion of LPG and alcohol (∼10 particles per useful energy delivered, particles/MJ), and kerosene (∼10 particles/MJ), produced emissions that were lower by 2-3 orders of magnitude than solid fuels (10-10 particles/MJ).

Polycyclic Aromatic Hydrocarbons in Fine Particulate Matter Emitted from Burning Kerosene, Liquid Petroleum Gas, and Wood Fuels in Household Cookstoves.

This study measures polycyclic aromatic hydrocarbon (PAH) compositions in particulate matter emissions from residential cookstoves. A variety of fuel and cookstove combinations are investigated, including: (i) liquid petroleum gas (LPG), (ii) kerosene in a wick stove, (iii) wood (10 and 30% moisture content on a wet basis) in a forced-draft fan stove, and (iv) wood in a natural-draft rocket cookstove. The wood burning in the natural-draft stove had the highest PAH emissions followed by the wood combustion in the forced-draft stove and kerosene burning.

Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources.

Background: Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects.

Objective: We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions.

Cleaner cooking solutions to achieve health, climate, and economic cobenefits.

Nearly half the world's population must rely on solid fuels such as biomass (wood, charcoal, agricultural residues, and animal dung) and coal for household energy, burning them in inefficient open fires and stoves with inadequate ventilation. Household solid fuel combustion is associated with four million premature deaths annually; contributes to forest degradation, loss of habitat and biodiversity, and climate change; and hinders social and economic progress as women and children spend hours every day collecting fuel. Several recent studies, as well as key emerging national and international efforts, are making progress toward enabling wide-scale household adoption of cleaner and more efficient stoves and fuels.

Pollutant emissions and energy efficiency under controlled conditions for household biomass cookstoves and implications for metrics useful in setting international test standards.

Realistic metrics and methods for testing household biomass cookstoves are required to develop standards needed by international policy makers, donors, and investors. Application of consistent test practices allows emissions and energy efficiency performance to be benchmarked and enables meaningful comparisons among traditional and advanced stove types. In this study, 22 cookstoves burning six fuel types (wood, charcoal, pellets, corn cobs, rice hulls, and plant oil) at two fuel moisture levels were examined under laboratory-controlled operating conditions as outlined in the Water Boiling Test (WBT) protocol, Version 4.

Synthesis of 4-(3-biaryl)quinoline sulfones as potent liver X receptor agonists.

A series of 4-(3-biaryl)quinolines with sulfone substituents on the terminal aryl ring (8) was prepared as potential LXR agonists. High affinity LXRbeta ligands with generally modest binding selectivity over LXRalpha and excellent agonist potency in LXR functional assays were identified. Many compounds had LXRbeta binding IC(50) values <10 nM while the most potent had EC(50) values <1.

Identification of phenylsulfone-substituted quinoxaline (WYE-672) as a tissue selective liver X-receptor (LXR) agonist.

A series of phenyl sulfone substituted quinoxaline were prepared and the lead compound 13 (WYE-672) was shown to be a tissue selective LXR Agonist. Compound 13 demonstrated partial agonism for LXRbeta in kidney HEK-293 cells but did not activate Gal4 LXRbeta fusion proteins in huh-7 liver cells. Although 13 showed potent binding affinity to LXRbeta (IC(50) = 53 nM), it had little binding affinity for LXRalpha (IC(50) > 1.

A pilot simulation study of arsenic tracked from CCA-treated decks onto carpets.

A controlled simulation experiment was performed to assess whether dislodgeable arsenic can be tracked onto carpets via foot traffic from chromated copper arsenate (CCA) pressure-treated decks. The pilot simulation study demonstrated that it is possible to track arsenic from CCA-decks onto carpets under the test conditions evaluated. A total of nine CCA-decks and two non-CCA-treated control surfaces were tested under wet and dry conditions.

Discovery of 6-({4-[2-(4-tert-butylphenyl)-1H-benzimidazol-4-yl]piperazin-1-yl}methyl)quinoxaline (WAY-207024): an orally active antagonist of the gonadotropin releasing hormone receptor (GnRH-R).

A potent, highly insoluble, GnRH antagonist with a 2-phenyl-4-piperazinylbenzimidazole template and a quinoxaline-2,3-dione pharmacophore was modified to maintain GnRH antagonist activity and improve in vitro pharmaceutical properties. Structural changes to the quinoxaline-2,3-dione portion of the molecule resulted in several structures with improved properties and culminated in the discovery of 6-([4-[2-(4-tert-butylphenyl)-1H-benzimidazol-4-yl]piperazin-1-yl] methyl)quinoxaline (WAY-207024). The compound was shown to have excellent pharmacokinetic parameters and lowered rat plasma LH levels after oral administration.

2-phenyl-4-piperazinylbenzimidazoles: orally active inhibitors of the gonadotropin releasing hormone (GnRH) receptor.

Antagonism of the gonadotropin releasing hormone (GnRH) receptor has shown positive clinical results in numerous reproductive tissue disorders such as endometriosis, prostate cancer and others. Traditional therapy has been limited to peptide agonists and antagonists. Recently, small molecule GnRH antagonists have emerged as potentially new treatments.

Carboxylic acid based quinolines as liver X receptor modulators that have LXRbeta receptor binding selectivity.

A series of potent and binding selective LXRbeta agonists was developed using the previously reported non-selective LXR ligand WAY-254011 as a structural template. With the aid of molecular modeling, it was found that 2,3-diMe-Ph, 2,5-diMe-Ph, and naphthalene substituted quinoline acetic acids (such as quinoline 33, 37, and 38) showed selectivity for LXRbeta over LXRalpha in binding assays.

Further modification on phenyl acetic acid based quinolines as liver X receptor modulators.

A series of phenyl acetic acid based quinolines was prepared as LXR modulators. An SAR study in which the C-3 and C-8 positions of the quinoline core were varied led to the identification of two potent LXR agonists 23 and 27. Both compounds displayed good binding affinity for LXRbeta and LXRalpha, and increased expression of ABCA1 in THP-1 cells.

5-Alkylated thiazolidinones as follicle-stimulating hormone (FSH) receptor agonists.

We prepared analogs of potent thiazolidinone-based follicle-stimulating hormone (FSH) agonists 1, that is, 3 that contained an additional 5-alkyl substituent. This extra substituent was added to reduce synthetic problems that arose during preparation of analogs of 1. These compounds (3) were evaluated in a Chinese hamster ovary (CHO) cell line that expressed recombinant human FSH receptor (FSHR) and a luciferase reporter gene regulated by a cAMP response element (CRE).