U.S. consumers are the largest contributors to food waste generation (FWG), but few models have e... more U.S. consumers are the largest contributors to food waste generation (FWG), but few models have explained how households waste food. This study examines how discrete-event simulation (DES) can identify areas for reducing FWG through packaging and consumer milk consumption behavioral changes. Household model parameters included: amount and type of consumption, type and number of containers bought, buying behavior, and shelf life of milk. Simulations comparing the purchase of quart, half gallon, and gallon milk containers were run for 10,000 days to identify which package type reduced waste for 50 1, 2 and 4-person households. Based on consumption averages from the U.S. National Dairy Council, results suggest that if 1 and 4-person households change their purchasing behavior from 1 half-gallon to 1 quart and 2 gallons to 3 half-gallons, they can reduce their greenhouse gas (GHG) emissions from milk consumption by 33% and 12%, respectively, without reducing their total milk consumption...
The research on a self-decontaminating surface has received significant attention because of the ... more The research on a self-decontaminating surface has received significant attention because of the growth of pathogenic microorganisms on surfaces. In this study, a novel and simple technique for producing an active surface with antimicrobial functionality is demonstrated. A tethering platform was developed by grafting the biocide ampicillin (Amp) to a nanoclay and dispersing the nanoclay in a UV-curable acrylate coating applied on polypropylene films as the substrate. A coupling agent, [3-(glycidyloxy)propyl]trimethoxysilane, was used as a linker between the nanoclay and Amp. The Amp-functionalized clay was further modified with an organic surfactant to improve the compatibility with the coating. Several characterization assays, such as Fourier infrared transform analysis, thermogravimetric analysis, and X-ray diffraction, were conducted to confirm the presence of Amp in the nanoclay. Transmission electron microscopy images revealed that the clay particles were well dispersed in the coating and had a partial exfoliated morphology. The active coating surface was effective in inhibiting the growth of Gram-positive Listeria monocytogenes and Gram-negative Salmonella Typhimurium via contact. These findings suggest the potential for the development of active surfaces with the implementation of nanotechnology to achieve diverse functionalities.
Poly(L-lactic acid) (PLLA) -20% (w/w) and Cu 3 (BTC) 2 metal organic framework (MOF) based mixed ... more Poly(L-lactic acid) (PLLA) -20% (w/w) and Cu 3 (BTC) 2 metal organic framework (MOF) based mixed matrix membranes (MMMs) were fabricated by a vertical corotating twin screw microcompounder followed by an injection molding process. Water vapor, CO 2, O 2 , and selected aroma mass transfer properties of PLLA and PLLA MMMs were evaluated. The CO 2 /O 2 perm-selectivity of PLLA (a CO2/O2 ) MMMs increased from 7.6 to 10.3 with the incorporation of 20% Cu 3 (BTC) 2 MOF. Gravimetric permeability studies of trans-2-hexenal performed at 238C and 50% RH indicated that permeability coefficient of PLLA MMMs increased by around 60% as compared to regular PLLA film. However, no changes in mass transfer rates were observed for acetaldehyde. Furthermore, the thermal processing parameters as well as the presence of MOF did not show any significant effect on the molecular weight of the PLLA matrix nor on the crystalline structure of the Cu 3 (BTC) 2 MOF, which was confirmed by both gel permeation chromatography and X-ray diffraction studies.
Container-grown woody ornamentals were irrigated with 4 treatments based on daily water use (DWU)... more Container-grown woody ornamentals were irrigated with 4 treatments based on daily water use (DWU) to study the impact of irrigation regime on plant growth, leachate electrical conductivity and pH, and runoff water volume and nutrient content. Hibiscus syriacus ‘Bricotts’, Euonymus alatus ‘Select’, Weigela florida ‘Alexandra’, and Spiraea japonica ‘Yan’ were grown in 10.2-L (#3) containers and subject to four overhead irrigation treatments: 1) irrigation scheduled to replace 100% DWU per application (100DWU); 2) irrigation alternating every other application with 100% replacement of DWU and 75% DWU the following application (100-75); 3) irrigation scheduled on a three-application cycle replacing 100% DWU followed by two applications replacing 75% DWU (100-75-75); and 4) irrigation scheduled on a four-application cycle replacing 100% DWU followed by three application replacing 75% DWU (100-75-75-75). Container substrate consisted of 85% pine bark: 15% peatmoss (vol: vol). Plants were ...
Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes f... more Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes for traditional plastic containers in the nursery industry. However, growers' acceptance of alternative containers is limited by the lack of information on how alternative containers impact plant growth and water use (WU). We conducted experiments in Michigan, Kentucky, Tennessee, Mississippi, and Texas to test plant growth and WU in five different alternative containers under nursery condition. In 2011, 'Roemertwo' wintercreeper (Euonymus fortunei) were planted in three types of #1 (%1 gal) containers 1) black plastic (plastic), 2) wood pulp (WP), and 3) recycled paper (KF). In 2012, 'Green Velvet' boxwood (Buxus sempervirens · B. microphylla siebold var. koreana) was evaluated in 1) plastic, 2) WP, 3) fabric (FB), and 4) keratin (KT). In 2013, 'Dark Knight' bluebeard (Caryopteris ·clandonensis) was evaluated in 1) plastic, 2) WP, and 3) coir fiber (Coir). Pla...
Ultraviolet-visible (UV-Vis) spectroscopy methodology was developed and utilized for the in situ ... more Ultraviolet-visible (UV-Vis) spectroscopy methodology was developed and utilized for the in situ nanoscale measurement of the size of mineral clay agglomerates in various liquid suspensions. The clays studied were organomodified and unmodified montmorillonite clays (I.44p, Cloisite 93a, and PGN). The methodology was compared and validated against dynamic light scattering (DLS) analysis. The method was able to measure clay agglomerates in solvents in situations where DLS analysis was unsuccessful due to the shapes, polydispersity, and high aspect ratios of the clay particles and the complexity of the aggregates, or dispersion medium. The measured clay agglomerates in suspension were found to be in the nanometer range in the more compatible solvents, and their sizes correlated with the Hansen solubility parameter space distance between the clay modifiers and the solvents. Mass detection limits for size determination were in the range from 1 to 9 mg/L. The methodology thus provides simple, rapid, and inexpensive characterization of clays or particles in the nano- or microsize range in low concentrations in various liquid media, including complex mixtures or highly viscous fluids that are difficult to analyze with DLS. In addition, by combining UV-VIS spectroscopy with DLS it was possible to discern flocculation behavior in liquids, which otherwise could result in false size measurements by DLS alone.
Container grown woody ornamentals were irrigated with four different treatments based on daily wa... more Container grown woody ornamentals were irrigated with four different treatments based on daily water use (DWU) to study the impact on plant growth, leachate electrical conductivity and pH, and runoff water volume and nutrient content. A completely randomized design was used with 4 overhead irrigation treatments: 1) irrigation scheduled to replace 100% DWU per application (100DWU); 2) irrigation alternating every other application with 100% replacement of DWU and 75% DWU the following application (100-75); 3) irrigation scheduled on a three-application cycle replacing 100% DWU followed by two applications replacing 75% DWU (100-75-75); 4) irrigation scheduled on a four-application cycle replacing 100% DWU followed by three applications replacing 75% DWU (100-75-75-75). The substrate volumetric moisture content (SVMC) was determined by soil moisture sensors (Model 10 HS, Decagon Devices, Inc., Pullman, WA 99163) placed in a subset of containers. Plant DWU was calculated as the differe...
a Dto. Materiales, CAC-CNEA, Avda. del Libertador 8250, (1429) Ciudad de Bs. As. b Laboratorio de... more a Dto. Materiales, CAC-CNEA, Avda. del Libertador 8250, (1429) Ciudad de Bs. As. b Laboratorio de Tribología, FRBA-UTN, Medrano 951, 3er. P, (1179) Ciudad de Bs. As. c Facultad de Ingeniería Química, Universidad Nacional de Misiones. Pcia de Misiones.
The wear behaviors of five different zinc-aluminum (ZA)-based alloys containing silicon, copper, ... more The wear behaviors of five different zinc-aluminum (ZA)-based alloys containing silicon, copper, and 8 and 16 pct on volume of reinforcing silicon carbide (SiC) particles were analyzed. Hardness, dimensional stability, and wear tests were performed on these five alloy samples. Microstructural investigation and semiquantitative chemical analysis of the different alloying characteristics of the cast samples, the wear surface, and the
International Journal of Biological Macromolecules, 2013
The characterization and antimicrobial properties of water chestnut starch-chitosan (WSC) films c... more The characterization and antimicrobial properties of water chestnut starch-chitosan (WSC) films containing Cornus officinalis fruit extract (COE 1% w/w), glycerol monolaurate (GML 1% w/w), nisin (10,000 IU/g), pine needle essential oil (PNEO 0.35% v/v), and their combinations were evaluated. Incorporation of COE decreased pH value of the film-forming solution, the moisture content and the water absorption expansion ability (WAEA). GML-incorporated film had lower WAEA, tensile strength, elongation and puncture strength. However, films with nisin displayed good mechanical properties. All the treated films were less transparent and higher in water vapour permeability values. For film microstructure, the presence of PNEO caused discontinuities with lipid droplets or holes embedded in a continuous network and the incorporation of GML led to abaisse-like structures. The COE, GML, nisin, PNEO and their combinations incorporated in the WSC films are effective in inhibiting the growth of Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes at different levels. The results showed that WSC films containing COE and GML, GML and nisin, COE and nisin were able to reduce the number of E. coli O157:H7, S. aureus and L. monocytogenes. This research has potential applications to the extension of the shelf life of food products.
Abstract The properties of sheet containing mechanically recycled postconsumer poly (L-lactic aci... more Abstract The properties of sheet containing mechanically recycled postconsumer poly (L-lactic acid) bottle flakes blended with virgin poly (L-lactic acid) resin were assessed. Poly (L-lactic acid) bottles were flaked, cleaned, blended with virgin resin and then extruded and ...
reported that the SRS enhanced their classroom experience; and 56% of the student respondents ind... more reported that the SRS enhanced their classroom experience; and 56% of the student respondents indicated that the system helped them to comprehend the material better. These numbers are supported by the vast majority of research studies, which indicate improved attendance, participation and comprehension when using SRSs for large classrooms.
Poly(e-caprolactone)/nanoclay composite (PCLNC) films were prepared by solvent casting method usi... more Poly(e-caprolactone)/nanoclay composite (PCLNC) films were prepared by solvent casting method using a wide range of layered silicate (2.5-10%) and were characterized by different techniques. Nanofiller dispersions in PCL matrix were studied by wide-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM), and results indicated the formation of some intercalated nanostructure of PCLNC. Rheological and thermal properties of PCLNC were measured by parallel-plate oscillatory rheometry and differential scanning calorimetry (DSC), respectively. Rheological study indicated that the predominating liquid-like properties (viscous modulus, G 00 > elastic modulus, G 0 ) of neat PCL gradually transformed to solid-like (G 0 > G 00 ) behavior after incorporation of clay in the temperature range of 90-120°C. A plot of G 0 vs. G 00 provide information on intercalation and microstructure of nanocomposite. Applicability of time-temperature superposition (TTS) principle and van Gurp-Palmen plot (phase angle vs. absolute complex modulus) on rheological data of clay incorporated PCL were employed and found that the results failed to follow the rules. Incorporation of the nanoclay into PCL matrix increased the crystallization temperature (T c ) and melting temperature (T m ) of neat PCL from 28.7 to 32.3°C and 56.3 to 59.2°C, respectively due to the nucleating effect, but the glass transition temperature (T g ) (%À65°C) was remained unaffected. The decrease in crystallinity with increase in clay concentration was confirmed by both XRD and DSC data.
U.S. consumers are the largest contributors to food waste generation (FWG), but few models have e... more U.S. consumers are the largest contributors to food waste generation (FWG), but few models have explained how households waste food. This study examines how discrete-event simulation (DES) can identify areas for reducing FWG through packaging and consumer milk consumption behavioral changes. Household model parameters included: amount and type of consumption, type and number of containers bought, buying behavior, and shelf life of milk. Simulations comparing the purchase of quart, half gallon, and gallon milk containers were run for 10,000 days to identify which package type reduced waste for 50 1, 2 and 4-person households. Based on consumption averages from the U.S. National Dairy Council, results suggest that if 1 and 4-person households change their purchasing behavior from 1 half-gallon to 1 quart and 2 gallons to 3 half-gallons, they can reduce their greenhouse gas (GHG) emissions from milk consumption by 33% and 12%, respectively, without reducing their total milk consumption...
The research on a self-decontaminating surface has received significant attention because of the ... more The research on a self-decontaminating surface has received significant attention because of the growth of pathogenic microorganisms on surfaces. In this study, a novel and simple technique for producing an active surface with antimicrobial functionality is demonstrated. A tethering platform was developed by grafting the biocide ampicillin (Amp) to a nanoclay and dispersing the nanoclay in a UV-curable acrylate coating applied on polypropylene films as the substrate. A coupling agent, [3-(glycidyloxy)propyl]trimethoxysilane, was used as a linker between the nanoclay and Amp. The Amp-functionalized clay was further modified with an organic surfactant to improve the compatibility with the coating. Several characterization assays, such as Fourier infrared transform analysis, thermogravimetric analysis, and X-ray diffraction, were conducted to confirm the presence of Amp in the nanoclay. Transmission electron microscopy images revealed that the clay particles were well dispersed in the coating and had a partial exfoliated morphology. The active coating surface was effective in inhibiting the growth of Gram-positive Listeria monocytogenes and Gram-negative Salmonella Typhimurium via contact. These findings suggest the potential for the development of active surfaces with the implementation of nanotechnology to achieve diverse functionalities.
Poly(L-lactic acid) (PLLA) -20% (w/w) and Cu 3 (BTC) 2 metal organic framework (MOF) based mixed ... more Poly(L-lactic acid) (PLLA) -20% (w/w) and Cu 3 (BTC) 2 metal organic framework (MOF) based mixed matrix membranes (MMMs) were fabricated by a vertical corotating twin screw microcompounder followed by an injection molding process. Water vapor, CO 2, O 2 , and selected aroma mass transfer properties of PLLA and PLLA MMMs were evaluated. The CO 2 /O 2 perm-selectivity of PLLA (a CO2/O2 ) MMMs increased from 7.6 to 10.3 with the incorporation of 20% Cu 3 (BTC) 2 MOF. Gravimetric permeability studies of trans-2-hexenal performed at 238C and 50% RH indicated that permeability coefficient of PLLA MMMs increased by around 60% as compared to regular PLLA film. However, no changes in mass transfer rates were observed for acetaldehyde. Furthermore, the thermal processing parameters as well as the presence of MOF did not show any significant effect on the molecular weight of the PLLA matrix nor on the crystalline structure of the Cu 3 (BTC) 2 MOF, which was confirmed by both gel permeation chromatography and X-ray diffraction studies.
Container-grown woody ornamentals were irrigated with 4 treatments based on daily water use (DWU)... more Container-grown woody ornamentals were irrigated with 4 treatments based on daily water use (DWU) to study the impact of irrigation regime on plant growth, leachate electrical conductivity and pH, and runoff water volume and nutrient content. Hibiscus syriacus ‘Bricotts’, Euonymus alatus ‘Select’, Weigela florida ‘Alexandra’, and Spiraea japonica ‘Yan’ were grown in 10.2-L (#3) containers and subject to four overhead irrigation treatments: 1) irrigation scheduled to replace 100% DWU per application (100DWU); 2) irrigation alternating every other application with 100% replacement of DWU and 75% DWU the following application (100-75); 3) irrigation scheduled on a three-application cycle replacing 100% DWU followed by two applications replacing 75% DWU (100-75-75); and 4) irrigation scheduled on a four-application cycle replacing 100% DWU followed by three application replacing 75% DWU (100-75-75-75). Container substrate consisted of 85% pine bark: 15% peatmoss (vol: vol). Plants were ...
Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes f... more Containers made from natural fiber and recycled plastic are marketed as sustainable substitutes for traditional plastic containers in the nursery industry. However, growers' acceptance of alternative containers is limited by the lack of information on how alternative containers impact plant growth and water use (WU). We conducted experiments in Michigan, Kentucky, Tennessee, Mississippi, and Texas to test plant growth and WU in five different alternative containers under nursery condition. In 2011, 'Roemertwo' wintercreeper (Euonymus fortunei) were planted in three types of #1 (%1 gal) containers 1) black plastic (plastic), 2) wood pulp (WP), and 3) recycled paper (KF). In 2012, 'Green Velvet' boxwood (Buxus sempervirens · B. microphylla siebold var. koreana) was evaluated in 1) plastic, 2) WP, 3) fabric (FB), and 4) keratin (KT). In 2013, 'Dark Knight' bluebeard (Caryopteris ·clandonensis) was evaluated in 1) plastic, 2) WP, and 3) coir fiber (Coir). Pla...
Ultraviolet-visible (UV-Vis) spectroscopy methodology was developed and utilized for the in situ ... more Ultraviolet-visible (UV-Vis) spectroscopy methodology was developed and utilized for the in situ nanoscale measurement of the size of mineral clay agglomerates in various liquid suspensions. The clays studied were organomodified and unmodified montmorillonite clays (I.44p, Cloisite 93a, and PGN). The methodology was compared and validated against dynamic light scattering (DLS) analysis. The method was able to measure clay agglomerates in solvents in situations where DLS analysis was unsuccessful due to the shapes, polydispersity, and high aspect ratios of the clay particles and the complexity of the aggregates, or dispersion medium. The measured clay agglomerates in suspension were found to be in the nanometer range in the more compatible solvents, and their sizes correlated with the Hansen solubility parameter space distance between the clay modifiers and the solvents. Mass detection limits for size determination were in the range from 1 to 9 mg/L. The methodology thus provides simple, rapid, and inexpensive characterization of clays or particles in the nano- or microsize range in low concentrations in various liquid media, including complex mixtures or highly viscous fluids that are difficult to analyze with DLS. In addition, by combining UV-VIS spectroscopy with DLS it was possible to discern flocculation behavior in liquids, which otherwise could result in false size measurements by DLS alone.
Container grown woody ornamentals were irrigated with four different treatments based on daily wa... more Container grown woody ornamentals were irrigated with four different treatments based on daily water use (DWU) to study the impact on plant growth, leachate electrical conductivity and pH, and runoff water volume and nutrient content. A completely randomized design was used with 4 overhead irrigation treatments: 1) irrigation scheduled to replace 100% DWU per application (100DWU); 2) irrigation alternating every other application with 100% replacement of DWU and 75% DWU the following application (100-75); 3) irrigation scheduled on a three-application cycle replacing 100% DWU followed by two applications replacing 75% DWU (100-75-75); 4) irrigation scheduled on a four-application cycle replacing 100% DWU followed by three applications replacing 75% DWU (100-75-75-75). The substrate volumetric moisture content (SVMC) was determined by soil moisture sensors (Model 10 HS, Decagon Devices, Inc., Pullman, WA 99163) placed in a subset of containers. Plant DWU was calculated as the differe...
a Dto. Materiales, CAC-CNEA, Avda. del Libertador 8250, (1429) Ciudad de Bs. As. b Laboratorio de... more a Dto. Materiales, CAC-CNEA, Avda. del Libertador 8250, (1429) Ciudad de Bs. As. b Laboratorio de Tribología, FRBA-UTN, Medrano 951, 3er. P, (1179) Ciudad de Bs. As. c Facultad de Ingeniería Química, Universidad Nacional de Misiones. Pcia de Misiones.
The wear behaviors of five different zinc-aluminum (ZA)-based alloys containing silicon, copper, ... more The wear behaviors of five different zinc-aluminum (ZA)-based alloys containing silicon, copper, and 8 and 16 pct on volume of reinforcing silicon carbide (SiC) particles were analyzed. Hardness, dimensional stability, and wear tests were performed on these five alloy samples. Microstructural investigation and semiquantitative chemical analysis of the different alloying characteristics of the cast samples, the wear surface, and the
International Journal of Biological Macromolecules, 2013
The characterization and antimicrobial properties of water chestnut starch-chitosan (WSC) films c... more The characterization and antimicrobial properties of water chestnut starch-chitosan (WSC) films containing Cornus officinalis fruit extract (COE 1% w/w), glycerol monolaurate (GML 1% w/w), nisin (10,000 IU/g), pine needle essential oil (PNEO 0.35% v/v), and their combinations were evaluated. Incorporation of COE decreased pH value of the film-forming solution, the moisture content and the water absorption expansion ability (WAEA). GML-incorporated film had lower WAEA, tensile strength, elongation and puncture strength. However, films with nisin displayed good mechanical properties. All the treated films were less transparent and higher in water vapour permeability values. For film microstructure, the presence of PNEO caused discontinuities with lipid droplets or holes embedded in a continuous network and the incorporation of GML led to abaisse-like structures. The COE, GML, nisin, PNEO and their combinations incorporated in the WSC films are effective in inhibiting the growth of Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes at different levels. The results showed that WSC films containing COE and GML, GML and nisin, COE and nisin were able to reduce the number of E. coli O157:H7, S. aureus and L. monocytogenes. This research has potential applications to the extension of the shelf life of food products.
Abstract The properties of sheet containing mechanically recycled postconsumer poly (L-lactic aci... more Abstract The properties of sheet containing mechanically recycled postconsumer poly (L-lactic acid) bottle flakes blended with virgin poly (L-lactic acid) resin were assessed. Poly (L-lactic acid) bottles were flaked, cleaned, blended with virgin resin and then extruded and ...
reported that the SRS enhanced their classroom experience; and 56% of the student respondents ind... more reported that the SRS enhanced their classroom experience; and 56% of the student respondents indicated that the system helped them to comprehend the material better. These numbers are supported by the vast majority of research studies, which indicate improved attendance, participation and comprehension when using SRSs for large classrooms.
Poly(e-caprolactone)/nanoclay composite (PCLNC) films were prepared by solvent casting method usi... more Poly(e-caprolactone)/nanoclay composite (PCLNC) films were prepared by solvent casting method using a wide range of layered silicate (2.5-10%) and were characterized by different techniques. Nanofiller dispersions in PCL matrix were studied by wide-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM), and results indicated the formation of some intercalated nanostructure of PCLNC. Rheological and thermal properties of PCLNC were measured by parallel-plate oscillatory rheometry and differential scanning calorimetry (DSC), respectively. Rheological study indicated that the predominating liquid-like properties (viscous modulus, G 00 > elastic modulus, G 0 ) of neat PCL gradually transformed to solid-like (G 0 > G 00 ) behavior after incorporation of clay in the temperature range of 90-120°C. A plot of G 0 vs. G 00 provide information on intercalation and microstructure of nanocomposite. Applicability of time-temperature superposition (TTS) principle and van Gurp-Palmen plot (phase angle vs. absolute complex modulus) on rheological data of clay incorporated PCL were employed and found that the results failed to follow the rules. Incorporation of the nanoclay into PCL matrix increased the crystallization temperature (T c ) and melting temperature (T m ) of neat PCL from 28.7 to 32.3°C and 56.3 to 59.2°C, respectively due to the nucleating effect, but the glass transition temperature (T g ) (%À65°C) was remained unaffected. The decrease in crystallinity with increase in clay concentration was confirmed by both XRD and DSC data.
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Papers by Rafael Auras