Carbon regulated supply chain management

Cansız, Selcan
In this study, carbon dioxide emissions resulting from transportation are assessed, carbon emission reduction opportunities in the current service supply chain design of Cisco Systems, Inc. are explored. Among these opportunities, changing transport mode from a high-carbon transport mode to a low-carbon transport mode is found to be the most promising option and is scrutinized. The effect of transportation mode change on carbon emission and expected total cost are scrutinized by developing a mathematical model that minimizes expected total cost subject to aggregate fill rate constraint. Furthermore, a second model that minimizes the expected total cost under aggregate expected fill rate and carbon emission constraints is developed. In this model transportation mode choice decisions are integrated into inventory decisions. Since it is difficult to make transportation mode selection for each individual item, the items are clustered and transportation mode selection is made for each cluster. Therefore we propose two clustering methods that are k-means clustering and an adopted ABC analysis. In addition, a greedy algorithm based on second model is developed. Since currently there are no regulations on carbon emissions, in order to examine possible regulation scenarios computational studies are carried out. In these studies, efficient solutions are generated and the most preferred solutions that have less carbon emission and lower total cost among all efficient solutions are examined.


Self-consistent treatment of gas heating in modeling of a coaxial DBD in atmospheric pressure CO2
Zhou, Chen; Yuan, Chengxun; Kudryavtsev, Anatoly; Yasar Katircioglu, T.; Rafatov, İsmail; Yao, Jingfeng (2023-01-01)
This work is devoted to the numerical study of characteristics of dielectric barrier discharge maintained in a coaxial reactor in atmospheric pressure CO2. The numerical model is based on the drift-diffusion theory of gas discharges, and takes into account the gas heating in a self-consistent manner. The effect of incorporating gas heating into the discharge properties, specifically, on CO2 decomposition, is investigated for wide range of amplitude and frequency of the applied voltage. Calculations revealed...
Carbon content influence on the optical constants of hydrogenated amorphous silicon carbon alloys
Akaoglu, B.; Sel, K.; Atilgan, I.; Katircioglu, B. (Elsevier BV, 2008-04-01)
Hydrogenated amorphous silicon carbon alloys (a-Si1-xCx:H) with different carbon contents are deposited by a plasma enhanced chemical vapor deposition (PECVD) system with different hydrogen diluted ethylene (C2H4) concentrations at two power densities of 30 and 90 mW/cm(2). First, the carbon and hydrogen configurations and their relative concentrations in these films are investigated in details by IR spectroscopy. Then, the ultraviolet/visible transmittance spectroscopy and a relevant characterization softw...
Carbon dioxide reforming of methane on Ni-based bimetallic catalyts
Ay, Hale; Üner, Deniz; Department of Chemical Engineering (2014)
Carbon dioxide reforming of methane is a promising process for the utilization of two important greenhouse gases and the production of synthesis gas with a lower H2/CO ratio which is preferred in Fischer–Tropsch synthesis. Ni catalysts have taken great interest in dry reforming of methane due to their high catalytic activity, easy availability and low cost. However, the main restriction of Ni-based catalysts is the formation of carbon which causes catalyst deactivation. The objective of this thesis was to r...
Adsorption of aromatic molecules on rutile TiO2(110) surfaces
Mesta, Murat; Ellialtıoğlu, Süleyman Şinasi; Department of Physics (2009)
Transition metal oxides having high dielectric constants and wide band gaps find very important and interesting technological applications in surface physics. In particular, titania is the most commonly used material in heterogeneous catalysis because of its stable and flat surfaces. Having Ti cations at different charge states within the system brings about various novel electronic properties which are mainly surface related. Adsorption of catalytically important or chemically useful molecules on titania s...
Carbon Encapsulated Silicon Nanoparticles as Anodes for Lithium Ion Batteries
Livan, P.; Miser, B.; Altinok, S.; Eyovge, C.; Aydınol, Mehmet Kadri; Öztürk, Tayfur (2017-06-01)
An investigation is carried out on the encapsulation of silicon with carbon nanomaterial via gas phase synthesis. Two methods were used; a spark discharge synthesis and RF induction thermal plasma. In the former, the use of silicon and graphite electrodes resulted in the formation of encapsulated nanoparticles 3-5 up to 70 nm in size. The particles were typically agglomerates of sub particles, encapsulated with 3-5 graphitic layers. Synthesis with RF thermal plasma yielded carbonaceous powders comprising Si...
Citation Formats
S. Cansız, “Carbon regulated supply chain management,” M.S. - Master of Science, Middle East Technical University, 2010.