Emission payback periods for increased residential insulation using marginal electricity modeling: a life cycle approach

Purpose

Increases in residential insulation can reduce energy consumption and corresponding life cycle emissions, but with increased manufacturing and transportation of insulation and the associated impacts. In this study, we conducted life cycle analyses of residential insulation and estimated payback periods for carbon dioxide (CO₂), nitrogen oxides (NOx), and sulfur dioxide (SO₂) emissions, using modeling techniques that account for regional variability in climate, fuel utilization, and marginal power plant emissions.

Methods

We simulated the increased production of insulation and energy savings if all single-family homes in the USA increased insulation levels to the 2012 International Energy Conservation Code, using an energy simulation model (EnergyPlus) applied to a representative set of home templates. We estimated hourly marginal changes in electricity production and emissions using the Avoided Emissions and Generation Tool (AVERT), and we estimated emissions related to direct residential combustion. We determined changes in upstream emissions for both insulation and energy using openLCA and ecoinvent. Payback periods were estimated by pollutant and region. In sensitivity analyses, we considered the importance of marginal versus average power plant emissions, transportation emissions, emission factors for fiberglass insulation, and sensitivity of emission factors to the magnitude of electricity reduction.

Results and discussion

Combining the life cycle emissions associated with both increased insulation manufacturing and decreased energy consumption, the payback period for increased residential insulation is 1.9 years for CO₂ (regional range 1.4–2.9), 2.5 years for NOx (regional range 1.8–3.9), and 2.7 years for SO₂ (regional range 1.9–4.8). For insulation, transportation emissions are limited in comparison with manufacturing emissions. Emission benefits displayed strong regional patterns consistent with relative demands for heating versus cooling and the dominant fuels used. Payback periods were generally longer using average instead of marginal emissions and were insensitive to the magnitude of electricity savings, which reflects the structure of the intermediate complexity electricity dispatch model.

Conclusions

The life cycle benefits of increased residential insulation greatly exceed the adverse impacts related to increased production across all regions, given insulation lifetimes of multiple decades. The strong regionality in benefits and the influence of a marginal modeling approach reinforce the importance of site-specific attributes and time-dynamic modeling within LCA.

     

Life-cycle assessment and cost analysis of residential buildings in South East of Turkey: part 2—a case study

Purpose

Residential buildings play an important role in consumption of energy resources. About 40 % of all primary energy is used in buildings all over the world. This paper is the second part of the study on the life-cycle energy (LCEA), emissions (LCCO₂A) and cost (LCCA) assessment of two residential buildings constructed in urban and rural areas.

Methods

In the first part, the methodology, formulations and procedure for such a comprehensive analysis are provided, while this paper provides an application of the methodology that considers two actual buildings located in Gaziantep, Turkey. The proposed model focused on building construction, operation and demolition phases to estimate energy use, carbon emissions and costs per square meter over a 50-year lifespan. The optimum thickness of insulation used to reduce energy consumption and emissions per square meter is determined.

Results and discussion

It is found that the operating phase is dominant in both urban and rural residential buildings and contributes 87–85 % of the primary energy requirements and 88–82 % of CO₂ emissions, respectively. Life-cycle greenhouse gas emissions were 5.8 and 3.9 tons CO₂ eqv. for BT1 and BT2, respectively. It is calculated that the life-cycle energy consumption and CO₂ emissions of the residential buildings can be reduced by up to 22.8 and 23.4 %, respectively, by using a proper insulation material for the external walls. The life-cycle cost, consisting of mortgage, energy, maintenance, service and demolition payments are calculated to be 7.28 and 1.72 million USD for BT1 and BT2, respectively.

Conclusions

Building envelope developments, such as better wall insulation, provide noteworthy potential energy savings and contribute to the reductions from cooling and space heating. Therefore, primary strategies and technologies needed for efficient buildings include optimal insulation of external walls. The economic insulation thickness of the residential buildings in Gaziantep is determined to be 80 mm by using a life-cycle cost analysis. The results show that because of the differences in building structures and living standards, life-cycle energy intensity and CO₂ emissions in urban residential buildings are 29 and 25 % higher than in rural conditions.

     

Comprehensive optimization of LC–MS metabolomics methods using design of experiments (COLMeD)

Introduction

Both reverse-phase and HILIC chemistries are deployed for liquid-chromatography mass spectrometry (LC–MS) metabolomics analyses, however HILIC methods lag behind reverse-phase methods in reproducibility and versatility. Comprehensive metabolomics analysis is additionally complicated by the physiochemical diversity of metabolites and array of tunable analytical parameters.

Objective

Our aim was to rationally and efficiently design complementary HILIC-based polar metabolomics methods on multiple instruments using design of experiments (DoE).

Methods

We iteratively tuned LC and MS conditions on ion-switching triple quadrupole (QqQ) and quadrupole-time-of-flight (qTOF) mass spectrometers through multiple rounds of a workflow we term Comprehensive optimization of LC–MS metabolomics methods using design of experiments (COLMeD). Multivariate statistical analysis guided our decision process in the method optimizations.

Results

LC–MS/MS tuning for the QqQ method on serum metabolites yielded a median response increase of 161.5 % (p < 0.0001) over initial conditions with a 13.3 % increase in metabolite coverage. The COLMeD output was benchmarked against two widely used polar metabolomics methods, demonstrating total ion current increases of 105.8 and 57.3 %, with median metabolite response increases of 106.1 and 10.3 % (p < 0.0001 and p < 0.05 respectively). For our optimized qTOF method, 22 solvent systems were compared on a standard mix of physiochemically diverse metabolites, followed by COLMeD optimization, yielding a median 29.8 % response increase (p < 0.0001) over initial conditions.

Conclusions

The COLMeD process elucidated response tradeoffs, facilitating improved chromatography and MS response without compromising separation of isobars. COLMeD is efficient, requiring no more than 20 injections in a given DoE round, and flexible, capable of class-specific optimization as demonstrated through acylcarnitine optimization within the QqQ method.

     

Recent advances in human sweat metabolomics for lung cancer screening

Introduction

Lung cancer is the leading cause of cancer related mortality owing to the advanced stage it is usually detected because the available diagnostic tests are expensive and invasive; therefore, they cannot be used for general screening.

Objectives

To increase robustness of previous biomarker panels—based on metabolites in sweat samples—proposed by the authors, new samples were collected within different intervals (4 months and 2 years), analyzed at different times (2012 and 2014, respectively) by different analysts to discriminate between LC patients and smokers at risk factor.

Methods

Sweat analysis was carried out by LC–MS/MS with minimum sample preparation and the generated analytical data were then integrated to minimize variability in statistical analysis.

Results

Panels with capability to discriminate LC patients from smokers at risk factor were obtained taken into account the variability between both cohorts as a consequence of the different intervals for samples collection, the times at which the analyses were carried out and the influence of the analyst. Two panels of metabolites using the PanelomiX tool allow reducing false negatives (95 % specificity) and false positives (95 % sensitivity). The first panel (96.9 % specificity and 83.8 % sensitivity) is composed by monoglyceride MG(22:2), muconic, suberic and urocanic acids, and a tetrahexose; the second panel (81.2 % specificity and 97.3 % sensitivity) is composed by the monoglyceride MG(22:2), muconic, nonanedioic and urocanic acids, and a tetrahexose.

Conclusion

The study has allowed obtaining a prediction model more robust than that obtained in the previous study from the authors.

     

Random and independent sampling of endogenous tryptic peptides from normal human EDTA plasma by liquid chromatography micro electrospray ionization and tandem mass spectrometry

Background

Normal human EDTA plasma samples were collected on ice, processed ice cold, and stored in a freezer at – 80 °C prior to experiments. Plasma test samples from the – 80 °C freezer were thawed on ice or intentionally warmed to room temperature.

Methods

Protein content was measured by CBBR binding and the release of alcohol soluble amines by the Cd ninhydrin assay. Plasma peptides released over time were collected over C18 for random and independent sampling by liquid chromatography micro electrospray ionization and tandem mass spectrometry (LC–ESI–MS/MS) and correlated with X!TANDEM.

Results

Fully tryptic peptides by X!TANDEM returned a similar set of proteins, but was more computationally efficient, than “no enzyme” correlations. Plasma samples maintained on ice, or ice with a cocktail of protease inhibitors, showed lower background amounts of plasma peptides compared to samples incubated at room temperature. Regression analysis indicated that warming plasma to room temperature, versus ice cold, resulted in a ~ twofold increase in the frequency of peptide identification over hours–days of incubation at room temperature. The type I error rate of the protein identification from the X!TANDEM algorithm combined was estimated to be low compared to a null model of computer generated random MS/MS spectra.

Conclusion

The peptides of human plasma were identified and quantified with low error rates by random and independent sampling that revealed 1000s of peptides from hundreds of human plasma proteins from endogenous tryptic peptides.

     

Removal of sulfur-containing organic molecules adsorbed on inorganic supports by <Emphasis Type="Italic">Rhodococcus Rhodochrous</Emphasis> spp.

Objective

To remove dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) adsorbed on alumina, silica and sepiolite through biodesulfurization (BDS) using Rhodococcus Rhodochrous spp., that selectively reduce sulfur molecules without generating of gaseous pollutants.

Results

The adsorption of DBT and 4,6-DMDBT was affected by the properties of the supports, including particle size and the presence of surface acidic groups. The highest adsorption of both sulfur-containing organic molecules used particle sizes of 0.43–0.063 mm. The highest percentage removal was with sepiolite (80 % for DBT and 56 % for 4,6-DMDBT) and silica (71 % for DBT and 37 % for 4,6-DMDBT). This is attributed to the close interaction between these supports and the bacteria.

Conclusions

Biodesulfurization is effective for removing the sulfur-containing organic molecules adsorbed on inorganic materials and avoids the generation of gaseous pollutants.

     

Comparative life cycle assessment and life cycle costing of lodging in the Himalaya

Purpose

The main aim of the study is to assess the environmental and economic impacts of the lodging sector located in the Himalayan region of Nepal, from a life cycle perspective. The assessment should support decision making in technology and material selection for minimal environmental and economic burden in future construction projects.

Methods

The study consists of the life cycle assessment and life cycle costing of lodging in three building types: traditional, semi-modern and modern. The life cycle stages under analysis include raw material acquisition, manufacturing, construction, use, maintenance and material replacement. The study includes a sensitivity analysis focusing on the lifespan of buildings, occupancy rate and discount and inflation rates. The functional unit was formulated as the ‘Lodging of one additional guest per night’, and the time horizon is 50 years of building lifespan. Both primary and secondary data were used in the life cycle inventory.

Results and discussion

The modern building has the highest global warming potential (kg CO_2-eq) as well as higher costs over 50 years of building lifespan. The results show that the use stage is responsible for the largest share of environmental impacts and costs, which are related to energy use for different household activities. The use of commercial materials in the modern building, which have to be transported mostly from the capital in the buildings, makes the higher GWP in the construction and replacement stages. Furthermore, a breakdown of the building components shows that the roof and wall of the building are the largest contributors to the production-related environmental impact.

Conclusions

The findings suggest that the main improvement opportunities in the lodging sector lie in the reduction of impacts on the use stage and in the choice of materials for wall and roof.

     

Conidiation of <Emphasis Type="Italic">Penicillium camemberti</Emphasis> in submerged liquid cultures is dependent on the nitrogen source

Objective

To study the ability of a commercial Penicillium camemberti strain, used for Camembert type cheese ripening, to produce conidia during growth in liquid culture (LC), in media containing different sources of nitrogen as, industrially, conidia are produced by growth at the surface of a solid state culture because conidiation in stirred submerged aerobic LC is not known.

Results

In complex media containing peptic digest of meat, hyphae ends did not differentiate into phialides and conidia. Contrarily, in a synthetic media containing KNO₃ as sole nitrogen source, hyphae ends differentiated into phialides producing 0.5 × 10⁷ conidia/ml. Conidia produced in LC were 25 % less hydrophobic than conidia produced in solid culture, and this correlates with a seven-times-lower expression of the gene rodA encoding hydrophobin RodA in the mycelium grown in LC.

Conclusion

Conidiation of P. camembertii is stimulated in iquid medium containing KNO₃ as sole source of nitrogen and therefore opens up opportunities for using liquid medium in commercial productions.

     

Eicosapentaenoic acid protects cardiomyoblasts from lipotoxicity in an autophagy-dependent manner

Background and aims

The cardiovascular health benefits of eicosapentaenoic acid (EPA) have been demonstrated previously; however, the exact mechanism underlying them remains unclear. Our previous study found that lipotoxicity induced cardiomyocyte apoptosis via the inhibition of autophagy. Accordingly, in this study, we investigated whether EPA attenuated lipotoxicity-induced cardiomyocyte apoptosis through autophagy regulation. The role of EPA in mitochondrial dynamics was analyzed as well.

Methods

To explore how EPA protected against lipotoxicity-induced myocardial injury, cardiomyoblast (H9C2) cells were left untreated or were treated with 400 μM palmitic acid (PAM) and/or 80 μM EPA for 24 h.

Results

Excessive PAM treatment induced apoptosis. EPA reduced this PAM-induced apoptosis; however, EPA was unable to ameliorate the effects of PAM when autophagy was blocked by 3-methyladenine and bafilomycin A1. PAM blocked the autophagic flux, thus causing the accumulation of autophagosomes and acid vacuoles, whereas EPA restored the autophagic flux. PAM caused a decrease in polyunsaturated fatty acid (PUFA) content and an increase in saturated fatty acid content in the mitochondrial membrane, while EPA was incorporated in the mitochondrial membrane and caused a significant increase in the PUFA content. PAM also decreased the mitochondrial membrane potential, whereas EPA enhanced it. Finally, PAM elevated the expressions of autophagy-related proteins (LC3I, LC3II, p62) and mitochondrial fission protein (Drp1), whereas EPA inhibited their elevation under PAM treatment.

Conclusions

EPA reduces lipotoxicity-induced cardiomyoblast apoptosis through its effects on autophagy.

     

Redo renal denervation using a multi-electrode radiofrequency system in patients with persistent therapy-resistant hypertension

Objectives

Renal sympathetic denervation has been studied as a potential therapeutic option for patients with therapy-resistant hypertension; however, a significant proportion of patients do not show a significant reduction in blood pressure and are classified as non-responders. The objective of the present study was to assess whether a redo renal denervation procedure increases response rates.

Methods

We present a case series of three consecutive renal denervation non-responders treated with the multi-electrode radiofrequency St. Jude EnligHTN catheter after an average of 22 months. Patients were followed for 6 months.

Results

Mean age was 66 years and two patients were male. Patients were previously treated using either ReCor’s Paradise system, the Vessix V2 system or the Covidien OneShot system. Mean office blood pressure one year after the initial procedure was 187/102?mm?Hg with a mean 24?h ambulatory blood pressure of 166/102?mm?Hg. All patients underwent a successful redo procedure using the EnligHTN system because of persistent therapy-resistant hypertension. At 6 months a significant drop in both office and ambulatory blood pressure of ?27/?6?mm?Hg and ?15/?13?mm?Hg, respectively, was observed. No significant renal artery stenosis was observed at 6 months.

Conclusions

In patients with therapy-resistant hypertension who do not respond to an initial renal denervation procedure, a redo procedure using the St. Jude EnligHTN system may help to significantly improve blood pressure control.

     

Strategies to assess and optimize stability of endogenous amines during cerebrospinal fluid sampling

Introduction

Metabolic profiling of cerebrospinal fluid (CSF) is a promising technique for studying brain diseases. Measurements should reflect the in vivo situation, so ex vivo metabolism should be avoided.

Objective

To investigate the effects of temperature (room temperature vs. 4 °C), centrifugation and ethanol, as anti-enzymatic additive during CSF sampling on concentrations of glutamic acid, glutamine and other endogenous amines.

Methods

CSF samples from 21 individuals were processed using five different protocols. Isotopically-labeled alanine, isoleucine, glutamine, glutamic acid and dopamine were added prior to sampling to trace any degradation. Metabolomics analysis of endogenous amines, isotopically-labeled compounds and degradation products was performed with a validated LC–MS method.

Results

Thirty-six endogenous amines were quantified. There were no statistically significant differences between sampling protocols for 31 out of 36 amines. For GABA there was primarily an effect of temperature (higher concentrations at room temperature than at 4 °C) and a small effect of ethanol (lower concentrations if added) due to possible degradation. O-phosphoethanolamine concentrations were also lower when ethanol was added. Degradation of isotopically-labeled compounds (e.g. glutamine to glutamic acid) was minor with no differences between protocols.

Conclusion

Most amines can be considered stable during sampling, provided that samples are cooled immediately to 4 °C, centrifuged, and stored at ??80 °C within 2 h. The effect of ethanol addition for more unstable metabolites needs further investigation. This was the first time that labeled compounds were used to monitor ex vivo metabolism during sampling. This is a useful strategy to study the stability of other metabolites of interest.

     

Life cycle environmental impacts and costs of beer production and consumption in the UK

Purpose

Global beer consumption is growing steadily and has recently reached 187.37 billion litres per year. The UK ranked 8th in the world, with 4.5 billion litres of beer produced annually. This paper considers life cycle environmental impacts and costs of beer production and consumption in the UK which are currently unknown. The analysis is carried out for two functional units: (i) production and consumption of 1 l of beer at home and (ii) annual production and consumption of beer in the UK. The system boundary is from cradle to grave.

Methods

Life cycle impacts have been estimated following the guidelines in ISO 14040/44; the methodology for life cycle costing is congruent with the LCA approach. Primary data have been obtained from a beer manufacturer; secondary data are sourced from the CCaLC, Ecoinvent and GaBi databases. GaBi 4.3 has been used for LCA modelling and the environmental impacts have been estimated according to the CML 2001 method.

Results and discussion

Depending on the type of packaging (glass bottles, aluminium and steel cans), 1 l of beer requires for example 10.3–17.5 MJ of primary energy and 41.2–41.8 l of water, emits 510–842 g of CO₂ eq. and has the life cycle costs of 12.72–14.37 pence. Extrapolating the results to the annual consumption of beer in the UK translates to a primary energy demand of over 49,600 TJ (0.56 % of UK primary energy consumption), water consumption of 1.85 bn hl (5.3 % of UK demand), emissions of 2.16 mt CO₂ eq. (0.85 % of UK emissions) and the life cycle costs of £553 million (3.2 % of UK beer market value). Production of raw materials is the main hotspot, contributing from 47 to 63 % to the impacts and 67 % to the life cycle costs. The packaging adds 19 to 46 % to the impacts and 13 % to the costs.

Conclusions

Beer in steel cans has the lowest impacts for five out of 12 impact categories considered: primary energy demand, depletion of abiotic resources, acidification, marine and freshwater toxicity. Bottled beer is the worst option for nine impact categories, including global warming and primary energy demand, but it has the lowest human toxicity potential. Beer in aluminium cans is the best option for ozone layer depletion and photochemical smog but has the highest human and marine toxicity potentials.

     

Stability of targeted metabolite profiles of urine samples under different storage conditions

Introduction

Few studies have investigated the influence of storage conditions on urine samples and none of them used targeted mass spectrometry (MS).

Objectives

We investigated the stability of metabolite profiles in urine samples under different storage conditions using targeted metabolomics.

Methods

Pooled, fasting urine samples were collected and stored at ?80 °C (biobank standard), ?20 °C (freezer), 4 °C (fridge), ~9 °C (cool pack), and ~20 °C (room temperature) for 0, 2, 8 and 24 h. Metabolite concentrations were quantified with MS using the AbsoluteIDQ? p150 assay. We used the Welch-Satterthwaite-test to compare the concentrations of each metabolite. Mixed effects linear regression was used to assess the influence of the interaction of storage time and temperature.

Results

The concentrations of 63 investigated metabolites were stable at ?20 and 4 °C for up to 24 h when compared to samples immediately stored at ?80 °C. When stored at ~9 °C for 24 h, few amino acids (Arg, Val and Leu/Ile) significantly decreased by 40% in concentration (P < 7.9E?04); for an additional three metabolites (Ser, Met, Hexose H1) when stored at ~20 °C reduced up to 60% in concentrations. The concentrations of four more metabolites (Glu, Phe, Pro, and Thr) were found to be significantly influenced when considering the interaction between exposure time and temperature.

Conclusion

Our findings indicate that 78% of quantified metabolites were stable for all examined storage conditions. Particularly, some amino acid concentrations were sensitive to changes after prolonged storage at room temperature. Shipping or storing urine samples on cool packs or at room temperature for more than 8 h and multiple numbers of freeze and thaw cycles should be avoided.

     

Miniaturized <Superscript>1</Superscript>H-NMR method for analyzing limited-quantity samples applied to a mouse model of Leigh disease

Introduction

The analysis of limited-quantity samples remains a challenge associated with mouse models, especially for multi-platform metabolomics studies. Although inherently insensitive, the highly specific characteristics of nuclear magnetic resonance (NMR) spectroscopy make it an advantageous platform for global metabolite profiling, particularly in mitochondrial disease research.

Objectives

Show method equivalency between a well-established standard operating protocol (SOP) and our novel miniaturized ¹H-NMR method.

Method

The miniaturized method was performed in a 2 mm NMR tube on a standard 500 MHz NMR spectrometer with a 5 mm triple-resonance inverse TXI probe at room temperature.

Results

Firstly, using synthetic urine spiked with low (50 µM), medium (250 µM) and high (500 µM) levels (n?=?10) of nine standards, both the SOP and miniaturized method were shown to have acceptable precision (CV?<?15%), relative accuracy (80–120%), and linearity (R²?>?0.95), except for taurine. Furthermore, statistical equivalence was shown using the two one-sided test. Secondly, pooled mouse quadriceps muscle extract was used to further confirm method equivalence (n?=?3), as well as explore the analytical dynamics of this novel approach by analyzing more-concentrated versions of samples (up to 10× concentration) to expand identification of metabolites qualitatively, with quantitative linearity. Lastly, we demonstrate the new technique’s application in a pilot metabolomics study using minute soleus muscle tissue from a mouse model of Leigh syndrome using Ndufs4 KO mice.

Conclusion

We demonstrate method equivalency, supporting our novel miniaturized ¹H-NMR method as a financially feasible alternative to cryoprobe technology—for limited-quantity biological samples in metabolomics studies that requires a volume one-tenth of the SOP.

     

Mechanical stimuli modulate intracellular calcium oscillations: a pathological model without chemical cues

Objective

To control the oscillatory behavior of the intracellular calcium ([Ca²⁺]_i) concentration in endothelial cells via mechanical factors (i.e., various hydrostatic pressures) because [Ca²⁺]_i in these cells is affected by blood pressure.

Results

Quantitative analyses based on real-time imaging showed that [Ca²⁺]_i oscillation frequency and relative concentration increased significantly when 200 mm Hg pressure, mimicking hypertension, was applied for >10 min. Peak height and peak width decreased significantly at 200 mm Hg. These trends were more marked as the duration of the 200 mm Hg pressure was increased. However, no change was observed under normal blood pressure conditions 100 mm Hg.

Conclusion

We generated a simple in vitro model to study [Ca²⁺]_i behavior in relation to various pathologies and diseases by eliminating possible complicating effects induced by chemical cues.

     

Life cycle assessment of construction and renovation of sewer systems using a detailed inventory tool

Purpose

The objective was to provide comprehensive life cycle inventories for the construction and renovation of sewers. A detailed inventory was provided with multiple options of pipe materials, diameters and site-specific characteristics, and was embedded into the Excel^®-based tool SewerLCA. The tool allows for life cycle evaluation of different sewers. It was applied to determine the most important phases, processes, and related parameters involved in the construction and renovation of sewers from an environmental and economical perspective.

Methods

Comprehensive life cycle inventories (LCIs) for sewers construction and renovation were obtained by first identifying all processes involved after interviewing construction experts and reviewing sewer construction budgets from a Catalan company; and second transforming the processes into masses of materials and energy usage using construction databases. In order to run the life cycle impact assessment (LCIA) the materials and energy typologies from the inventories were matched to their corresponding equivalents into available LCI databases. Afterwards the potential impacts were calculated through the use of LCIA characterization factors from ReCiPe. Life cycle assessment (LCA) was run several times to assess the construction of a 1-km-long sewer with varying pipe materials, life spans for each material, diameters, transport distances, site-specific characteristics, and pipe deposition options.

Results and discussion

The environmental impacts generated by construction and renovation of a 1 km Polyvinylchloride (PVC) pipe with a diameter of 40 cm are mainly associated with pipe laying and backfilling of the trench. The evaluation of several pipe materials and diameters shows that the exclusion of renovation would underestimate the impacts by 38 to 82 % depending on the pipe materials and diameters. Including end-of-life phase for plastic pipe materials increases climate change (up to an extra 71 %) and human toxicity (up to an extra 147 %) impacts (among all diameters). The preferred pipe materials from an environmental point of view are precast concrete and High-Density Polyethylene (HDPE). Site-specific characteristics (specially the presence of rocky soil and asphalt placement) and material life span have a high influence on the overall environmental profile, whereas changes in transport distances have only a minor impact (<4 %).

Conclusions

Environmental impacts during the construction and renovation of sewers are subject to differences in material type, site-specific characteristics and material life span. Renovation of sewers has a large influence on all potential environmental impacts and costs and, hence, should not be omitted in LCA studies. The treatment and disposal processes of plastic pipes at the end of their life has to be accounted in LCA studies.

     

Comparative life-cycle impact assessment of concrete manufacturing in Singapore

Purpose

For countries like Singapore that is highly dependent on imported goods, it is essential to consider the consequences of consumption of imported cement and other concrete constituents for a fair carbon trading at global and regional levels. Recently, as a result of reduction in trade barriers and costs of materials and fuels, Singapore does not have much incentive in reducing environmental impacts of these imported goods. However, Singapore has set high environmental targets nationally to reduce impacts from building and construction. In addition to its national efforts, Singapore also needs to take action in trade-related consequences of importing energy-intensive products like cement and aggregates to Singapore. The purpose of this study is to quantify and suggest alternatives for reducing the embodied energy and life-cycle impacts of concrete consumption in Singapore on the basis of current trading volumes of these materials from Singapore’s importers.

Methods

A detailed life-cycle assessment of concrete manufacturing in Singapore is performed to suggest possible ways to reduce the environmental impacts from importing cement and aggregates from Singapore’s trade partners based on an earlier life-cycle inventory developed for Singapore and its neighboring countries. Life-cycle impact assessment (LCIA) impact characterization factors are based on a midpoint-oriented and hierarchist approach as defined by ReCiPe method. Following the LCIA, a scenario analysis is conducted to select the best combination of cement and aggregate importers of Singapore based on their environmental performance.

Results and discussion

Results from the scenario analysis show that overall impacts can be reduced by importing the materials from a nearer source with efficient production technologies and greener fuel mixes. About 10–34 % reduction is estimated in embodied energy, acidification, eutrophication, global warming potential, smog, and health impacts by importing from a closer and technologically greener source.

Conclusions

Despite the limitations due to data and modeling uncertainties, this study constitutes a baseline/benchmark for addressing the current cement and aggregate markets and associated environmental impacts of concrete consumption in Singapore based on historical import quantities of cement and aggregates from neighboring countries of Singapore. In the near future, policy-related action would be influential in achieving Singapore’s national and global environmental targets in buildings and construction sector. Incorporation of an LCA approach into Green Mark Scheme (GMS) by the Building and Construction Authority (BCA) is recommended for Singapore to comply both with its national goals and with its new climate action plan to the UN Framework Convention on Climate Change.

     

Effect of geographical location and stochastic weather variation on life cycle assessment of biodiesel production from camelina in the northwestern USA

Purpose

The effect of regional factors on life cycle assessment (LCA) of camelina seed production and camelina methyl ester production was assessed in this study. While general conclusions from LCA studies point to lower environmental impacts of biofuels, it has been shown in many studies that the environmental impacts are dependent on location, production practices, and even local weather variations.

Methods

A cradle-to-farm gate and well-to-pump approaches were used to conduct the LCA. To demonstrate the impact of agro-climatic and management factors (weather condition, soil characteristics, and management practices) on the overall emissions for four different regions including Corvallis, OR, Pendleton, OR, Pullman, WA, and Sheridan, WY, field emissions were simulated using the DeNitrification-DeComposition (DNDC) model. openLCA v.1.4.2 software was used to quantify the environmental impacts of camelina seed and camelina methyl ester production.

Results and discussion

The results showed that greenhouse gas (GHG) emissions during camelina production in different regions vary between 49.39 and 472.51 kg CO₂-eq./ha due to differences in agro-climatic and weather variations. The GHG emissions for 1 kg of camelina produced in Corvallis, Pendleton, Pullman, and Sheridan were 0.76 ± 11, 0.55 ± 10, 0.47 ± 18, and 1.26 ± 6 % kg CO₂-eq., respectively. The GHG emissions for 1000 MJ of camelina biodiesel using camelina produced in Corvallis, Pendleton, Pullman, and Sheridan were 53.60 ± 5, 48.87 ± 5, 44.33 ± 7, and 78.88 ± 4 % kg CO₂-eq., respectively. Other impact categories such as acidification and ecotoxicity for 1000 MJ of camelina biodiesel varied across the regions by 43 and 103 %, respectively.

Conclusions

It can be concluded that process-based crop models such as DNDC in conjunction with Monte Carlo analysis are helpful tools to quantitatively estimate the influence of regional factors on field emissions which consequently can provide information about the expected variability in LCA results.

     

Highly efficient transglycosylation of sialo-complex-type oligosaccharide using <Emphasis Type="Italic">Coprinopsis cinerea</Emphasis> endoglycosidase and sugar oxazoline

Objectives

To establish an efficient method of chemoenzymatic modification for making N-linked oligosaccharide chains of glycoproteins structurally homogeneous, which crucially affects their bioactivities.

Results

Deglycosylated-RNase B (GlcNAc-RNase B; acceptor), sialylglyco (SG)-oxazoline (donor) and an N180H mutant of Coprinopsis cinerea endo-β-N-acetylglucosaminidase (Endo-CC^N180H) were employed. pH 7.5 was ideal for both SG-oxazoline’s stability and Endo-CC’s transglycosylation reaction. The most efficient reaction conditions for producing glycosylated-RNase B, virtually modified completely with sialo-biantennary-type complex oligosaccharide, were: 80 μg GlcNAc-RNase B, 200 μg SG-oxazoline and 3 μg Endo-CC^N180H in 20 μl 20 mM Tris/HCl pH 7.5 at 30 °C for 30–60 min.

Conclusions

This transglycosylation method using SG-oxazoline and Endo-CC^N180H is beneficial for producing pharmaceutical glycoproteins modified with homogenous biantennary-complex-type oligosaccharides.