19 research outputs found
Economic and environmental implications of biomass commercialization in agricultural processing
Electric Vehicles with a Battery Switching Station: Adoption and Environmental Impact
The transportation sector's carbon footprint and dependence on oil are of deep concern to policy makers in many countries. Use of all-electric drive trains is arguably the most realistic medium-term solution to address these concerns. However, motorist anxiety induced by an electric vehicle's limited range and high battery cost have constrained consumer adoption. A novel switching-station-based solution is touted as a promising remedy. Vehicles use standardized batteries that, when depleted, can be switched for fully charged batteries at switching stations, and motorists only pay for battery use. We build a model that highlights the key mechanisms driving adoption and use of electric vehicles in this new switching-station-based electric vehicle system and contrast it with conventional electric vehicles. Our model employs results from repairable item inventory theory to capture switching-station operation; we embed this model in a behavioral model of motorist use and adoption. Switching-station systems effectively transfer range risk from motorists to the station operator, who, through statistical economies of scale, can better manage it. We find that this transfer of risk can lead to higher electric vehicle adoption than in a conventional system, but it also encourages more driving than a conventional system does. We calibrate our models with motorist behavior data, electric vehicle technology data, operation costs, and emissions data to estimate the relative effectiveness of the two systems under the status quo and other plausible future scenarios. We find that the system that is more effective at reducing emissions is often less effective at reducing oil dependence, and the misalignment between the two objectives is most severe when the energy mix is coal heavy and has advanced battery technology. Increases in gasoline prices (by imposition of taxes, for instance) are much more effective in reducing carbon emissions, whereas battery-price-reducing policy interventions are more effective for reducing oil dependence. Taken together, our results help a policy maker identify the superior system for achieving the desired objectives. They also highlight that policy makers should not conflate the dual objectives of oil dependence and emissions reductions as the preferred system, and the policy interventions that further that system may be different for the two objectives. This paper was accepted by Yossi Aviv, operations management. </jats:p
Bitkisel ve hayvansal protein kaynaklarının termodinamik analizi: Kinoa ve sığır eti örneği
Termodinamik analizler, proseslerin fizibilitesini test etmek ve enerji veya
ekserji verimliliğini tahmin etmek için yapılır. Termodinamik analiz tıpkı kimyasal
sistemler gibi biyokimyasal sistemlere uygulanır. Biyolojik sistemler için
termodinamik analizler, belirli bir dizi reaksiyonun veya sürecin sistem için faydalı
olup olmadığını, yani enerjiye değip değmediğini değerlendirmek için kullanılır.
Biyolojik enerji kaynakları üzerine yapılan çalışmaların çoğu karbonhidratlar
üzerinde yapılmıştır.
Bu çalışmada, yaygın olarak tüketilen sekiz gıda üzerinde iki yöntemle
termodinamik analizi yapılmıştır. Seçilen gıdalardan dördü bitkisel iken dördü
hayvansal gıdalardır. Seçilen bitkisel gıdalar bezelye, kinoa, mantar ve yulaf iken;
hayvansal gıdalar balık, sığır eti, tavuk ve yumurtadır. Termodinamik analizler için
uygulanan ilk yöntemde gıdaların sadece protein içerikleri ele alınmış, içerdikleri
amino asitlerin tamamının oksidasyona uğradığı ve ATP üretiminin gerçekleştiği
kabul edilmiş, metabolik ekserji kaybı her gıda için ayrı ayrı hesaplanmıştır. Bu
yöntemi uygulamak için öncelikle 20 amino asidin oksidasyon reaksiyonları
sadeleştirilmiş ve reaksiyonların ekserji kayıpları hesaplanmıştır. Her amino asidin
oksidasyon reaksiyonlarının termodinamik analizi ilk kez bu çalışmada yapılmıştır.
Yapılan hesaplama sonucunda bitkisel kaynaklı gıdalardan mantarın metabolik
ekserji kaybının 0.993 MJ/kg ile en düşük iken; kinoanın metabolik ekserji kaybı
ise 2.308 MJ/kg ile en yüksektir. Hayvansal kaynaklılar ise en düşük metabolik
ekserji kaybına uğrayan gıda 11,169 MJ/kg ile yumurta iken, diğer üç gıdanın
ekserji kaybının birbirlerine daha yakın olduğu görülmüştür. Bu grupta en fazla
ekserji kaybına uğrayan gıda 25,239 MJ/kg ile sığır eti olmuştur.
Gıdaların termodinamik analizlerinin yapıldığı ikinci yöntemde ise gıdanın
barındırdığı tüm enerji kaynakları ele alınmıştır. Burada kullanılan termodinamik
değerler glikoz ve yağ asitleri için literatürdeki benzer yöntemle hesaplamalar
yapılan çalışmalardan edinilmiştir. Proteinler için literatürde ayrıntılı bir değer
bulunmadığı için 20 amino asidin eşit miktarda bulunduğu bir peptit zinciri ele
alınmıştır ve çalışma kapsamında hesaplanan değerler kullanılmıştır. Bu
hesaplamalar sonucunda hayvansal ve bitkisel kaynaklı gıdalar için ilk yöntemle
paralel sonuçlar elde edildiği görülmüştür. Her iki gıda grubunda da en yüksek
ekserji kaybına uğrayan gıdalar ile en düşük ekserji kaybına uğrayan gıdaların
değişmediği görülmüştür.
Yapılan çalışma sonucunda bitkisel kaynaklı gıdaların ekserji kayıpları
hayvansal kaynaklı gıdaların ekserji kayıplarına göre oldukça düşük çıkmıştır. Bu
durum, kıyaslanan gıdalardan bitkisel kaynaklı olanların metabolik işe
yararlılığının enerji açısından daha verimli olduğunu göstermiştir.Thermodynamic analyses are performed to test the feasibility of processes
and to estimate energy or exergy efficiency. The thermodynamic analysis is
applied to biochemical systems just like chemical systems. Thermodynamic
analyses for biological systems are used to assess whether a particular set of
reactions or processes are beneficial to the system, ie, whether it is worth the
energy. Most of the studies on biological energy sources have been done on
carbohydrates.
In this study, the thermodynamic analysis was performed on eight
commonly consumed foods by two methods. Four of the selected foods are
vegetable and four are animal foods. The selected vegetable foods were peas,
quinoa, mushrooms, and oats; animal foods are fish, meat, chicken, and eggs. In
the first method applied for thermodynamic analysis, only protein contents of
foods were considered, all of the amino acids contained were oxidized and ATP
production was realized and metabolic exergy loss was calculated separately for
each food. To apply this method, oxidation reactions of 20 amino acids were
simplified and exergy losses of the reactions were calculated. The thermodynamic
analysis of the oxidation reactions of each amino acid was made for the first time
in this study. As a result of the calculation, the fungal metabolic exergy loss of
plant-derived foods was the lowest with 0.993 MJ / kg; metabolic exergy loss of
quinoa is highest with 2,308 MJ / kg. On the other hand, while the food with the
lowest metabolic exergy loss was 11,169 MJ / kg, it was seen that the exergy loss
of the other three foods was closer to each other. In this group, the highest exergy
loss was meat with 25,239 MJ / kg.
In the second method in which thermodynamic analysis of food is carried
out, all energy sources of food are discussed. The thermodynamic values used
here are derived from the studies performed by a similar method in the literature
for glucose and fatty acids. Since there is no detailed value in the literature for
proteins, a peptide chain with equal amounts of 20 amino acids is considered and
the values calculated in the study are used. As a result of these calculations, it was
seen that parallel results were obtained with the first method for animal and
vegetable origin foods. It was observed that the foods with the highest exergy loss
and the foods with the lowest exergy loss did not change in both food groups.
As a result of the study, exergy losses of plant-derived foods were
considerably lower than those of animal-derived foods. This showed that the
metabolic usefulness of plant-derived foods compared to foods was more energy
efficient
Electric Vehicles with a Battery Switching Station: Adoption and Environmental Impact Electric Vehicles with a Battery Switching Station: Adoption and Environmental Impact ELECTRIC VEHICLES WITH A BATTERY SWITCHING STATION: ADOPTION AND ENVIRONMENTAL IMPA
Abstract. Widespread adoption of Electric Vehicles can limit the environmental impact of transportation and reduce oil dependence. However, limited range and high upfront battery costs have limited consumer adoption. A novel switching-station-based solution is extensively touted as a promising remedy that resolves range anxiety. Vehicles use standardized batteries that when depleted can be switched for fully charged batteries at switching stations. Further, instead of making an upfront battery purchase, motorists pay for miles driven. We develop a stylized analytical model that captures the key tradeoffs in the adoption of electric vehicles to assess the effectiveness of this remedy. Our model uses a classical repairable item inventory model to capture switching station operation; we combine it with a moral hazard construct from the contracting literature to capture customer adoption and usage. We find that electric vehicles with switching stations can indeed incent adoption and reduce oil dependence but, paradoxically, we also show that this increased adoption may not necessarily benefit the environment. A profit-maximizing operator increases adoption by limiting motorist range anxiety and the effective marginal costs of driving, which leads motorists to increase their driving, and hence increase electricity consumption. Depending on the source of electricity, this can be more harmful to the environment than the nonadoption of electric vehicles. Further, we show that switching-station electric-vehicle adoption and driving are strategic complements; thus, any policy intervention that increases adoption will also increase driving. Using real data, we calibrate the model and show numerically that with the current generation mix in the USA, switching-station electric vehicles would lead to reduced oil dependence and net environmental benefits, but in just 10 years electric vehicles with switching stations would be harmful to the environment. Further, well-intended policy interventions such as battery purchase subsidies, and seemingly helpful battery technology advances can actually be harmful to the environment
Economic and environmental implications of biomass commercialization in agricultural processing
The paper has been accepted at Management Science</p
The impact of commodity price uncertainty on the economic value of waste-to-energy conversion in agricultural processing
The effect of liposome on dyeing mohair/wool blends
The aim of this study was to examine the use of liposome in the dyeing of wool and mohair fibres with acid dyestuffs. Soybean lecithin and cholesterol were used to form the liposome membrane utilised in the dyebath. Liposome production was performed according to the thin lipid layer method (Bangham Method) using a rotary evaporator. Two different forms of liposome were used for dyeing wool and mohair fibres. In its first form, liposome was utilised as an auxiliary agent, where it was added to a conventional dyebath at the beginning of the process. In its second form, dyes were encapsulated with liposome and then used in dyeing. The effects of these two different forms of liposome were compared with conventional dyeing. Dyeing was carried out at depths of shade of 0.5%, 1.0% and 2.0% using three different concentrations of liposome (0.33%, 0.66% and 1.33%). An analysis of K/S values, fastness to washing, and the alkali solubility of fibres was conducted. The fibre samples dyed in the presence of liposome exhibited very good fastness to light (grade 8). The wash fastness test results of the liposomal-dyed samples were significantly better (grade 4-5) than for those samples which were conventionally dyed. In the presence of liposome, the tensile strength of fibres was 20 gf, whereas it was 11 gf without liposomes