Total Carbon Dioxide Research Articles

Reuse of shipping materials in the intravitreal bevacizumab supply chain: feasibility, cost, and environmental impact

BackgroundIntravitreal injections are the most common ophthalmic procedure worldwide and are also a prime opportunity for waste reduction. This study analyzes the feasibility, environmental impact, and cost of reusing shipping materials for intravitreal injection medications, as compared to wasting coolers and cold packs after single-use.MethodsIn this prospective pilot study, shipping materials (cardboard boxes, polystyrene foam coolers, and cold packs) from repackaged bevacizumab delivered to our clinic (500 doses per week) were saved and reused over a 10-week study period. The shipping supplies were photographed and inspected for defects at point of care (Twin Cities, MN), and returned via standard ground shipping to the outsourcing facility (Tonawanda, NY).ResultsPolystyrene foam coolers (n = 3) survived 10 roundtrips between the outsourcing facility and retina clinic (600 mi each way), although wear-and-tear was visible in the form of marks and dents. Cold packs (n = 35) were less durable, lasting 3.1 ± 2.0 roundtrips. Total carbon dioxide equivalent (CO2e) emissions were reduced 43%, by reusing shipping materials (12.88 kgCO2e per 1000 bevacizumab doses), as compared to the standard practice of disposing containers after single-use (22.70 kgCO2e per 1000 bevacizumab doses), and landfill volume was reduced by 89%. Cost savings from reusing containers offset expenses incurred with return shipping and extra handling in the reuse cohort (net savings: $0.52 per 1000 bevacizumab doses).ConclusionsReusing shipping supplies can be cost neutral, with less CO2e emissions and reduced landfill. Robust environmental benefit is possible if retina clinics partner with manufacturers to reuse shipping containers.

Proposal and analysis for effective implementation of new measures to reduce the operational carbon intensity of ships

The Carbon Intensity Indicator (CII) requirements for international shipping regulate total annual carbon dioxide emissions (by transport work proxy using the ship's Deadweight Tonnage (DWT) instead of the actual cargo carried). It limits the accurate calculation of operational efficiency and causes an overestimation of the operational energy efficiency of international shipping. Due to lack of research on the International Maritime Organization's (IMO) CII requirements (energy efficiency based on actual cargo), the effects of CII requirements were investigated by contrasting the CII values based on DWT and actual cargo carried from data provided by the European Union Monitoring, Reporting and Verification. Results demonstrated that the CII calculated using actual cargo carried differed from that calculated using DWT by an average of 30%. Thus, future data collection must be based on actual cargo volume to apply IMO CII criteria more precisely, intuitively, and consistently.

Sacred groves: a model of Zagros forests for carbon sequestration and climate change mitigation

SummaryForests are the most important carbon pools among terrestrial ecosystems, and ensuring less disturbance of sacred groves might constitute a form of forest management for carbon sequestration and climate change reduction. The carbon contents in Zagros oak sacred groves and silvopastoral lands were compared to determine the carbon sequestration potential of these forests. Using a nested sampling design, we measured total carbon content (tC ha–1; aboveground tree biomass, aboveground sapling biomass, belowground biomass, soil organic carbon, leaf litter, herbs and grasses and dead wood and fallen stumps) in both forest groves and silvopastoral lands. The mean total biomass and mean total carbon content varied between sacred groves (453.8 t ha–1 and 338.79 tC ha–1, respectively) and silvopastoral lands (89.4 t ha–1 and 113.46 tC ha–1, respectively). Mean soil organic carbon was significantly lower (71.44 tC ha–1) in silvopastoral lands than in sacred groves (125.49 tC ha–1). The mean total sequestered carbon dioxide (CO2) was 1243.36 tCO2 ha–1 in the sacred groves and 416.40 tCO2 ha–1 in silvopastoral lands. We conclude that human activities have reduced the CO2 absorption capacity of the forests. The substantial disparities between the landscapes emphasize the need to restore damaged forests, and sacred groves might be a useful model for increasing carbon storage in these forests.

Study on Effects of Land Use Change on Carbon Emissions in Beijing Tianjin Hebei region from 1990 to 2020

In order to deeply understand the impact of land use types on carbon effect, we choose the Beijing Tianjin Hebei region as the study area. By using the IPCC calculation method and the modified carbon emission calculation model, our paper estimates the carbon source and carbon sink effects of change in land use type in Hebei, Beijing and Tianjin from 1990 to 2020, and analyzes their temporal and spatial changes. The results show that: (1) Development of some factories has gradually shifted to Hebei, so its land area for industrial development has increased. The corresponding total energy consumption has also increased. (2) Construction land is the primary carbon source. The region is in the golden stage of urban construction and industrial development, and the regional infrastructure land will increase accordingly. The construction land will maintain a high growth trend over a long period. (3) Total carbon dioxide in this study area is increasing, and the massive carbon dioxide emissions of change in land use type is far greater than the amount of carbon dioxide absorbed.

Methane anomaly in soil gas above an abandoned oil & gas exploration borehole in NE Czechia

In the 1950s–1960s, 71 coal and gas exploration wells were drilled in the area of interest in the Western Carpathian Flysch Belt (WCFB) in the NE Czech Republic. Some wells were abandoned while others were used for gas production and storage in the Třanovice underground gas storage (UGS). A monitoring campaign was carried out in place of an earlier abandoned exploration well Žu-108 aiming at proving or ruling out a geochemical relationship of the soil gas and the stored gas in the UGS. The measurements were carried out each month from June 2018 to October 2019 and included amount of methane (CH4), total petroleum gases (CH4 to C4H10), carbon dioxide (CO2) and oxygen (O2) in soil gas in a grid of up to 41 probes. The results show a methane gas peak occurrence with 10 m diameter around the well-top with maximum methane content of 57%vol, while the natural background value of methane content outside the plume is < 500 ppm. The position of the methane peak is associated with significant O2 drop down to 0.25%vol and is surrounded by up to 8.34%vol CO2 halo produced most probably by methanotrophic archea-bacteria. The natural background CO2 values are ca. 0.80%vol. CH4 flux to the atmosphere from the topsoil directly above the well-top of Žu-108 well was measured using the accumulation chamber and range from 2126 to 26 197 g d−1 m−2. The flux increased during drops in atmospheric pressure and ground water level in situ. In contrast, low methane flux was registered after strong rainfalls and when the soil was covered by ice and snow which acted as seal. Based on chemical composition and isotopic signature of methane, the gas is of oil-associated type and methane is thermogenic, similar to that of the original (i.e. pre-UGS) Žukov gas field as well as other small accumulations in the WCFB on the territory of the Czech Republic. It statistically differs from imported mixture of Siberian and Norwegian gas stored in the Třanovice UGS. Based on it, the possible natural gas leakage from the UGS to the Žu-108 is in this case ruled out.

Optimal configuration of integrated energy station using adaptive operation mode of combined heat and power units

Operation modes of combined heat and power (CHP) units are closely related to the economic benefits of energy application in integrated energy station. In this paper, a novel bi-level optimal configuration method is proposed considering different operation modes of CHP, and a life-cycle assessment system on economic and environmental benefits is constructed using system dynamics (SD) method. Firstly, the basic structure and operation issues of a typical integrated energy station employing CHP are addressed. Secondly, the bi-level collaborative optimization model of the integrated energy station is constructed to minimize the annualized cost considering three operating modes, namely following the thermal load (FEL), following the electric load (FTL) and switching adaptively between FEL and FTL. Then, the model is solved by the column-and-constraint generation and particle swarm optimization coordination with mixed-linear integer programming respectively. Subsequently, the sensitivity of CHP units heat-to-electric ratio and electric storage to the planning results are analyzed in detail. Finally, case studies are carried out based on an actual integrated energy station. The optimization results show that, compared with FEL and FTL operating modes of the CHP units, the annualized cost of the system under adaptive operation mode is reduced by 26.5% and 42.8%, respectively. Besides, the assessment of the optimized system indicates that the total profit and carbon dioxide emission reduction of the station during its life-cycle are expected to reach 28.53 million CNY and 25.33 ten thousand tons respectively, which provides a reference for decision-making and a basis for flexible operation.

Indoor air quality in a training centre used for sports practice.

One of the measures for controlling the coronavirus disease 2019 (COVID-19) pandemic was the mass closure of gyms. This measure leads us to determine the differences between indoor and outdoor air quality. That is why the objective of this study was to analyse the indoor air quality of a sports centre catering to small groups and rehabilitation. The study was conducted in a single training centre, where 26 measurements were taken in two spaces (indoors and outdoors). The air quality index, temperature, relative humidity, total volatile compounds, carbon monoxide, ozone, formaldehyde, carbon dioxide, and particulate matter were measured indoors and outdoors using the same protocol and equipment. These measurements were taken twice, once in the morning and once in the afternoon, with all measurements made at the same time, 10 am and 6 pm, respectively. Additionally, four determinations of each variable were collected during each shift, and the number of people who had trained in the room and the number of trainers were counted. In the different variables analysed, the results show that CO2 and RH levels are higher indoors than outdoors in both measurement shifts. Temperatures are higher outside than inside and, in the evening, than in the morning. TVOC, AQI and PM show less variation, although they are higher outdoors in the morning. CO is highest indoors. HCHO levels are almost negligible and do not vary significantly, except for a slight increase in the afternoon outside. Ozone levels are not significant. All the variables showed practically perfect reliability in all the measurements, except for ozone measured outside in the morning. On the other hand, the variables exhibit variations between indoors and outdoors during the morning and afternoon, except for the three types of PM. Also, the data show that all the main variables measured inside the sports training centre are similar between morning and afternoon. However, outside, temperature, relative humidity and HCHO levels show significant differences between morning and afternoon while no differences are observed for the other variables. The indoor air quality of the training centre assessed was good and met current regulations; some of its components even exhibited better levels than fresh air. This article is the first to measure indoor air quality in a sports training centre catering to rehabilitation and small groups.

Effects of body size and countermeasure exercise on estimates of life support resources during all-female crewed exploration missions

Employing a methodology reported in a recent theoretical study on male astronauts, this study estimated the effects of body size and aerobic countermeasure (CM) exercise in a four-person, all-female crew composed of individuals drawn from a stature range (1.50- to 1.90-m) representative of current space agency requirements (which exist for stature, but not for body mass) upon total energy expenditure (TEE), oxygen (O2) consumption, carbon dioxide (CO2) and metabolic heat (Hprod) production, and water requirements for hydration, during space exploration missions. Assuming geometric similarity across the stature range, estimates were derived using available female astronaut data (mean age: 40-years; BMI: 22.7-kg·m−2; resting VO2 and VO2max: 3.3- and 40.5-mL·kg−1·min−1) on 30- and 1080-day missions, without and with, ISS-like countermeasure exercise (modelled as 2 × 30-min aerobic exercise at 75% VO2max, 6-day·week−1). Where spaceflight-specific data/equations were not available, terrestrial equivalents were used. Body size alone increased 24-h TEE (+ 30%), O2 consumption (+ 60%), CO2 (+ 60%) and Hprod (+ 60%) production, and water requirements (+ 17%). With CM exercise, the increases were + 25–31%, + 29%, + 32%, + 38% and + 17–25% across the stature range. Compared to the previous study of theoretical male astronauts, the effect of body size on TEE was markedly less in females, and, at equivalent statures, all parameter estimates were lower for females, with relative differences ranging from -5% to -29%. When compared at the 50th percentile for stature for US females and males, these differences increased to − 11% to − 41% and translated to larger reductions in TEE, O2 and water requirements, and less CO2 and Hprod during 1080-day missions using CM exercise. Differences between female and male theoretical astronauts result from lower resting and exercising O2 requirements (based on available astronaut data) of female astronauts, who are lighter than male astronauts at equivalent statures and have lower relative VO2max values. These data, combined with the current move towards smaller diameter space habitat modules, point to a number of potential advantages of all-female crews during future human space exploration missions.

The impacts of globalization, renewable energy, and agriculture on CO2 emissions in India: Contextual evidence using a novel composite carbon emission-related atmospheric quality index

At the 26th Conference of Parties in Glasgow, India declared the environmental agendas of turning carbon neutral by 2070 and substantially lowering its carbon intensity level. Thus, it can be assumed that India is committed to improving its atmospheric health over the next couple of decades. Thus, strategizing plans for limiting carbon emission-related environmental pollution has gone on to become a critically important objective of the Indian government. Against this backdrop, this current study aims to examine the factors influencing atmospheric quality in India. As opposed to the previously adopted approaches in the existing studies, a composite atmospheric quality index is estimated using data concerning different carbon dioxide emission-related atmospheric quality indicators (total carbon dioxide emissions, carbon footprints, and carbon intensity levels). Furthermore, the analysis of the possible non-linear association between renewable energy use and atmospheric pollution makes an additional contribution to the environmental literature. Using quarterly frequency data from 1990q1 to 2018q4 and employing advanced econometric techniques suitable for handling structural break issues, the empirical results reveal that globalization through economic and social channels, agricultural output expansion, and greater population density trigger atmospheric pollution in the long run. Besides, the relationship between renewable energy consumption and atmospheric quality is found to exhibit an inverted U-shape. In this regard, the threshold share of renewable energy in the total final energy consumption level of India is predicted at around 45.75% which is comparatively higher than India’s current renewable energy consumption share. Furthermore, urbanization is evidenced to stimulate the deterioration of India's atmospheric quality, both in the short- and long-run. In line with these major findings, some policy-oriented recommendations are made.

Effect on mechanical properties of geopolymer concrete by addition of polypropylene fibers

Geopolymer Concrete (GPC) is an innovative solution in construction industry which is manufactured to replace ordinary concrete. Ordinary concrete is considered as a major construction material around the globe, but cement involved in its production contributes about 5% of world’s total carbon dioxide emissions. GPC uses alternative materials such as Fly Ash (FLA), GGBS as a replacement for cement. These materials are waste by-products of thermal and coal industries and using those materials results in reduction of overall carbon footprint. However, research shows that overall embodied energy generated by GPC is greater than traditional concrete due to extensive use of elevated curing methodology. Alkaline Binder Solutions are used as a major binder material in the process. The research incorporated addition of Polypropylene Fibers (PF) into GPC because of its high tensile capacity and crack resistance ability. Further, the research investigated mechanical properties of GPC such as Compressive Strength (CS) and Flexural Strength (FS) through varying proportions of PF from 0 to 5%, by weight respectively. Simultaneously, the research also focused on physical properties of GPC like density. CS and FS were tested conforming to the requirements of IS: 516. Moreover, a Compression Testing Machine and an Automatic Flexural Testing Machine having respective capacities of 3000kN and 300kN were used for testing CS and FS. The research findings show the addition of fibers increases FS by 49% in M6 mix which contained 5% of polypropylene fibers. However, the CS of GPC was affected negatively by the addition of PF for M6 mix, it reduced to 46% in comparison to Mix M1 with 0% fibers. Physical properties of concrete such as density also got negatively affected by the inclusion of PF. At the end of the research, Mix M3 which contained 2% PF was found more reliable than other mix proportions.

Comparison of Venous Blood Gas and Biochemical Parameters in Sunda Pangolin (Manis javanica) and Chinese Pangolin (Manis pentadactyla) before and after Isoflurane Anesthesia

Venous blood gas analytes are commonly examined in animals, and the results may be important when evaluating the overall health status of an animal. Pangolins are critically endangered mammals, and there is limited information on their physiological reference values in the literature. The aim of this study was to analyze venous blood gas and biochemical parameters before and during isoflurane anesthesia in wild healthy Sunda and Chinese pangolins. The results obtained showed that the blood gas index trends of the two pangolin species before and after isoflurane anesthesia were the same. After anesthesia, the partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (CO2), mean blood bicarbonate (HCO3-), extracellular fluid compartment (BEecf) base excess and the mean blood glucose (Glu) levels of both pangolin species showed a significant increase compared to the pre-anesthesia period. In contrast, the mean blood potassium (K+), lactate (Lac) and mean blood pH levels were significantly lower. No significant differences in the mean blood sodium (Na+) or blood ionized calcium (iCa) levels were observed during anesthesia. This study is important for future comparisons and understanding the health status of this endangered species.

Do Economic Depressions Contribute to CO2 Emissions? An ARDL Bound Approach

Total carbon dioxide (CO2) emissions are undoubtedly emitted to the environment, humans, ecosystems, and global economic growth. However, less research has examined the effect of economic depression on carbon dioxide emission (CO2), especially in Malaysia. Thus, this study intents to examine the impact of the macroeconomic problems, namely unemployment (UNEMP) and the growing number of people: population (POP), on the CO2 emissions in Malaysia. The study analyzes the data for 28 years, covering the period of 1991–2019, employing a bound ARDL model as an estimation method. The time series data were sourced from the World Bank Development Indicators database. The finding from the study shows that CO2 emissions, POP, and UNEMP have a long-term cointegration. Under this situation, all variables indicated; UNEMP and POP lead to environmental degradation in Malaysia in the long run. The impact of both UNEMP and POP on CO2 emissions is positive. Moreover, it is also found that the damage of economic depression will take only around one year and a month on CO2 emissions. Thus, based on this novel finding, a comprehensive set of economic policies is required to ensure our economy is in good condition and hence suggested for maintaining the environmental quality.

Blood Gas, Acid-Base and Electrolyte Analysis in Healthy Dromedary Camel Calves up to 21 Days of Life.

The importance of prompt evaluation and care of the newborn is essential for reducing neonatal mortality, which represents a major cause of loss in camelids. This study investigated the blood gases, acid-base and electrolyte profiles in healthy dromedary calves during the first 3 weeks of life, assessing possible associations with age. Twenty-one dromedary camel calves aged 1 to 21 days were sampled, and venous whole blood analyzed through a VETSTAT® analyzer. The following parameters were measured: sodium (Na+), potassium (K+), chloride (Cl-), hydrogen ion concentration (pH), partial pressure carbon dioxide (pCO2), partial pressure oxygen (pO2), total hemoglobin concentration (tHb), hemoglobin oxygen saturation (sO2), total carbon dioxide (tCO2), bicarbonate (HCO3-), base excess (BE) and anion gap (AG). Calves were divided in two groups; younger calves (1-10 d), and older calves (11-21 d). Statistical analysis showed an effect of age, with lower K+ (p < 0.001) and higher Na+ and Cl- (p < 0.05) mean concentrations in the younger calves compared to the older ones, and higher pCO2 and lower sO2 mean concentrations in the older group. These preliminary results firstly described the blood gas, acid-base and electrolyte profiles in the healthy dromedary calf during the first 3 weeks of age, suggesting an effect of age on some parameters.

Can Carbon Emission Trading Policy Improve the Emission Performance? Evidence From China

The carbon emission trading system (ETS) has become one of the most crucial environmental regulations for emission mitigation and energy conservation in China. This thesis uses the difference-in-difference (DID) model to analyze the causal influence of China's ETS on carbon emission performance. The results show that the implementation of the ETS is an effective way to mitigate carbon intensity and total carbon dioxide emissions (12%), thus promoting carbon emission reductions. In contrast, economic development, energy intensity and population size hindered the carbon reduction process, while industrial structure had no significant impact on carbon reduction. Further PSM-DID models confirmed the reliability of the above conclusions. Based on these conclusions, this study provides inspiration and suggestions for the implementation of the nationwide ETS in the new stage of environmental governance.

Effect of recycled coarse aggregate quality on the interfacial property and sulfuric acid resistance of geopolymer concrete at different acidity levels

Geopolymer recycled concrete (GRC) is a green and low-carbon building material which can promote the early achievement of the goals of carbon peak and carbon neutral globalization. This study aims to clarify the effect of recycled coarse aggregate (RA) quality on the interfacial property and sulfuric acid resistance of geopolymer concrete (GPC) at different acidity levels. Specimens with three qualities of coarse aggregates were prepared, which were immersed in sulfuric acid solution of three acidities (pH = 0.5, 1.0, 1.5) for 98 d to evaluate their acid resistance. The results showed that the adhered mortar attached on the surface of RA affected the inhomogeneous distribution of interfacial transition zones (ITZs) and weakened the bond strength between aggregate and paste, threatening the development of concrete strength. Low-quality coarse aggregate accelerated the deterioration of sulfuric acid resistance of GPC. But at the exposure time of 28 d, GRC showed a lower mass loss rate than that of GPC prepared with natural aggregate (GPCNA) regardless of acid environment levels, indicating the presence of RA resulted in the loose ITZ structure in GRC which could provide more space for gypsum generation to some extent. As exposure time goes on, the adhered mortars of RA provided extra calcium source for GPC to generate gypsum. More adhered mortar content caused overmuch gypsum crystals, generating internal stress, thus resulting in spalling of mortar and worsen acid resistance of concrete. In addition, the fracture of Si-O-Al bonds and disappearance of amorphous N-A-S-H gels caused by the dealuminization was another key reason for failure of the GRC in high acid environment (pH = 0.5 and 1.0). At last, based on the carbon emission calculations of raw materials, transportation and production of concrete, more than 20% of total carbon dioxide (CO2) emissions can be reduced using GRC to replace ordinary Portland cement concrete (OPCC).

Satellite observation of atmospheric CO2 and water storage change over Iran

Like many other Middle East countries, Iran has been suffering from severe water shortages over the last two decades, as evidenced by significant decline in surface water and groundwater levels. The observed changes in water storage can be attributed to the mutually reinforcing effects of human activities, climatic variability, and of course the climate change. The objective of this study is to analyze the dependency of atmospheric CO2 increase on the water shortage of Iran, for which we investigate the spatial relationship between water storage change and CO2 concentration using large scale satellite data. We conduct our analysis using water storage change data from GRACE satellite and atmospheric CO2 concentration from GOSAT and SCIAMACHY satellites during 2002–2015. To analyze the long-term behavior of time series we benefit from Mann-Kendal test and for the investigation of the relationship between atmospheric CO2 concentration and total water storage we use Canonical Correlation Analysis (CCA) and Regression model. Our Results show that the water storage change anomaly and CO2 concentration are negatively correlated especially in northern, western, southwest (Khuzestan province), and also southeast (Kerman, Hormozgan, Sistan, and Baluchestan provinces) of Iran. CCA results reveal that in the most of northern regions, the decrease in water storage is significantly influenced by the increase of CO2 concentration. The results further show that precipitation in the highland and peaks does not seem to be influenced by the long and short-term variation in CO2 concentration. Besides, our results show that the CO2 concentration is slightly correlated with a weak positive trend in evapotranspiration over agricultural areas. Thus, the indirect effect of CO2 on increasing evapotranspiration is observed spatially in the whole of Iran. The results of the regression model between total water storage change and carbon dioxide (R2 = 0.91)/water discharge/water consumption show that carbon dioxide has the highest effect on total water storage change at large scale. The results of this study will contribute to both water resource management and mitigation plans to achieve the goal of CO2 emission reduction.

Effects of pre-analytical sample care and analysis methodology on measures of metabolic acidosis in hemodialysis patients.

We evaluated the effects of pre-analytical care on total carbon dioxide (tCO2 ) in hemodialysis patients, as calculated by blood gas analysis (ctCO2 ) or measured by an enzymatic assay (mtCO2 ). Blood samples were collected via vascular access before dialysis sessions. For blood gas analysis, eight aliquots were collected, refrigerated or non-refrigerated, and analyzed at 0, 4, 8, and 24 h after collection. A blood sample was then collected for the enzymatic method and distributed into 14 aliquots. Half of the aliquots were refrigerated. The samples analyzed at time point 0 were centrifuged immediately. The remaining aliquots of both the refrigerated and non-refrigerated clusters were centrifuged before storage. Samples were analyzed at 4, 8, and 24 h post-collection. By blood gas analysis, no significant change was found in bicarbonate values over time, either in the non-refrigerated or refrigerated samples. ctCO2 values during the experiment showed a minor but statistically significant increase of questionable clinical relevance in both non-refrigerated and refrigerated aliquots. In the enzymatic assay, the reduction in mtCO2 levels during the experiment was negligible. The median absolute reductions at the end of the experiment were 1.77, 1.21, 1.04, and 1.12 mmol/L for the non-centrifuged/non-refrigerated, centrifuged/non-refrigerated, non-centrifuged/refrigerated, and centrifuged/refrigerated aliquots, respectively. Our results suggest that measured or calculated tCO2 levels of capped and cooled samples are adequate for analyzing the acid-base status of hemodialysis patients, even when such determination is not performed immediately after collection.

Assessment of Whole Milk Powder Production by a Cumulative Exergy Consumption Approach

The production of food is a sector that consumes a significant amount of energy and encompasses both agricultural and industrial processes. In this study, the energy consumption of whole milk powder production, which is known to be particularly energy-intensive, was examined. The study used a cumulative exergy consumption approach to evaluate the overall production process of whole milk powder, including the dairy farm (raw milk production) and dairy factory (powder production) stages. The results showed that raw milk production dominated energy and exergy consumption and carbon dioxide emissions. An amount of 68.3% of the total net cumulative exergy consumption in the system was calculated for raw milk production. In the dairy factory process, the highest energy/exergy consumption occurred during spray drying, followed by evaporation and pasteurization. In these three processes, 98.3% of the total energy consumption, 94.6% of the total exergy consumption, and 95.7% of the total carbon dioxide emissions in powder production were realized. To investigate the improvement potentials in the system, replacing fossil fuels with renewable energy sources and using pasture feeding in animal husbandry were evaluated. While using alternative energy sources highly influenced powder production, pasture feeding had a high impact on consumption in raw milk production. By using renewable energy and pasture feeding, the exergy efficiency, cumulative degree of perfection, renewability index, and exergetic sustainability index values for the overall process increased from 40.5%, 0.282, −0.22, and 0.68 to 68.9%, 0.433, 0.65, and 2.21, respectively.

Predictors for surgical site infection after fasciotomy in patients with acute leg compartment syndrome

BackgroundSurgical site infection (SSI) is one of the most common complications of orthopedic surgery, which can result in fever, pain, and even life-threatening sepsis. This study aimed to determine the predictors of SSI after fasciotomy in patients with acute leg compartment syndrome (ALCS).MethodsWe collected information on 125 ALCS patients who underwent fasciotomy in two hospitals between November 2013 and January 2021. Patients with SSI were considered as the SSI group and those without SSI as the non-SSI group. Univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analyses were used to evaluate patient demographics, comorbidities, and admission laboratory examinations.ResultsIn our research, the rate of SSI (26 of 125) was 20.8%. Several predictors of SSI were found using univariate analysis, including body mass index (BMI) (p = 0.001), patients with open fractures (p = 0.003), and patients with a history of smoking (p = 0.004). Besides, the levels of neutrophil (p = 0.022), glucose (p = 0.041), globulin (p = 0.010), and total carbon dioxide were higher in the SSI group than in the non-SSI group. According to the results of the logistic regression analysis, patients with open fractures (p = 0.023, OR 3.714), patients with a history of smoking (p = 0.010, OR 4.185), and patients with a higher BMI (p = 0.014, OR 1.209) were related predictors of SSI. Furthermore, ROC curve analysis indicated 24.69 kg/m2 as the cut-off value of BMI to predict SSI.ConclusionsOur results revealed open fractures, BMI, and smoking history as independent risk factors for SSI following fasciotomy in patients with ALCS and determined the cut-off value of BMI, enabling us to individualize the evaluation of the risk for SSI to implement early targeted treatments.

Assessment of indoor air quality in air-conditioned small business units with no mechanical ventilation

Shophouses, a common building type in Singapore, host small business units typically cooled by non-mechanically ventilated strategies. Activities in these spaces include cooking food and handling nail and hair products, which emit volatile organic compounds (VOCs), carbon monoxide (CO), and other airborne contaminants that could compromise indoor air quality (IAQ). This study assessed potential IAQ risk by quantifying total VOCs (TVOC), formaldehyde, carbon dioxide (CO2), and CO levels in 100 air-conditioned small business units in Singapore's shophouses. The median (maximum) concentrations across all units were TVOC:179 (54,880 ppb), formaldehyde:0 (1.0 ppm), CO2:586 (2750 ppm) and CO:0 (0.5 ppm). The majority (90%) of the units did not have mechanical ventilation provision, and TVOC and formaldehyde levels correlated significantly with corresponding CO2 levels (p ≤ 0.05). The highest levels of TVOC and formaldehyde were measured at nail salons (TVOC: 54,880 ppb, formaldehyde: 1.0 ppm). Improving ventilation combined with use of alternative low-emission products could improve IAQ in small business units.