Supply chain network optimization : low volume industrial chemical product

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 60-62).The chemical industry is a highly competitive and low margin industry. Chemical transportation faces stringent safety regulations meaning that Cost-To-Serve (C2S), costs associated with products net flow from manufacturers to customers, consists of a big percentage of the delivered product cost. Supply chain practitioners in this industry need to make key logistics decisions to minimize C2S for profitability and business sustainability. In this thesis, we present a network optimization model to minimize the total C2S for SKU-1, a low volume and low margin industrial chemical with a customer base spread across North and South America. We use a mathematical linear program to investigate the effects on total C2S when available production capacities and sources are shifted. We develop the model as a minimum cost flow problem, and more specifically, as a production and transportation problem (PTP). We analyze the total C2S under three scenarios. In the baseline scenario there are three manufacturing facilities in the Midwest, South East, and Europe. In the second scenario, where the Midwest supplier is excluded from the network, the C2S increases by 3%. In the third scenario, where both the Midwest and South East facilities are excluded, the C2S increases by 13%. Under each scenario we calculate the C2S for each individual customer and identify the customers most impacted by the change in supply. Our results provide insight regarding the changes expected to the supply network under capacity constraints and how those changes may affect the profitability of individual customers.by Fred Dacha and Li Jin.M.Eng.in Logistic

Pemanfaatan Material Baja X-Ses Di Kota Cilegon Sebagai Material Bilah Golok Banten

Sulangkar machetes is one of the typical Banten machetes that have strong cultural values. Sulangkar means “sulang” and “sekar” which means stacked with two different materials. The lack of raw materials is a problem in the process of making sulangkar machetes. In this study, the combination of SS400 Steel and Leaf Spring Steel was observed for its mechanical properties as the raw material for Sulangkar machetes. In this study, Sulangkar machetes material consists of three layers of material, two layers of SS400 steel and leaf-spring steel inserted in the middle. The three-layers material are forged after being heated to a temperature of 750°C in a furnace. The material that has been forged then tested for tensile strength, toughness and hardness. The results of the tensile test showed that the leaf spring steel has the highest strength value of 1324.52 Mpa. The results of the Impact test show that the SS400 material has the highest Impact value of 163 J. The hardness test results show that the combination material has the highest hard value of 716.89 HBW

Spatiotemporal Nonlinear Optical Effects in Multimode Fibers

The advent of the optical fiber in the second half of the 20th century has had numerous consequences not only for the advancement of telecommunication and information transfer technologies, but also for humanity as a whole. At the time of writing of this thesis, we live in a world that is defined by unprecedented and unparalleled access to information made possible by fiber optic cables that line the ocean beds. As the world becomes increasingly reliant upon the internet, the demand for access is outgrowing the pace at which the capacity of our fiber optic networks can be scaled up. In the past decade, a consensus has emerged among researchers in academia and the industry that we are now approaching the fundamental classical capacity limit of a conventional single mode fiber, namely the Shannon limit. This has spurred interest in multimode fibers that allow for hundreds of spatial modes to co-propagate, potentially allowing for at least an order of magnitude increase in capacity per fiber. While multiplexing in the spatial domain has the potential to offer significantly higher capacities, linear and nonlinear mixing between the spatial modes of a fiber are expected to play an important role in determining the capacity and performance of spatially multiplexed telecommunication systems. So far, multimode fibers have mostly been relegated to low-power short- distance links, as a result of which nonlinear propagation effects in the presence of multiple spatial modes has received relatively little attention. This thesis adds to a growing body of literature that is increasingly interested in uncovering the physics of multimodal propagation in the nonlinear regime. Although the need for spatial multiplexing is important factor driving research interest in this topic, experiments in recent years have revealed a plethora of complex spatiotemporal non- linear phenomena occurring in multimode fibers, including Kerr-induced beam self-cleaning, parametric instability processes and the existence of multimode solitons. This has sparked great interest in understanding multimodal nonlinearity from a fundamental and applied physics per- spective. Nonlinear multimode fiber optics is also of central importance for the development of high power fiber-coupled lasers as the larger core size of multimode fibers allow for far higher power throughput than current state-of-the-art lasers based on single mode fibers. Most literature reported thus far in multimodal nonlinear optics focuses on complex phe- nomena occurring when hundreds of spatial modes co-propagate in the nonlinear regime. While that has proven to be a fascinating field of study, there have not been many studies on experimental investigation of intermodal nonlinear effects in the presence of a small number of spatial modes. Furthermore, nonlinear phenomena in multimode fibers are ‘spatiotemporal’ in nature, meaning that the spatial and time-domain waveforms are intertwined, and the two degrees of freedom cannot be separated. Conventional measurement techniques are not capable of resolving such a multimodal beam in space and time simultaneously. Finally, most research involving nonlinear optical effects has thus far focused on linearly polarized modes in conventional fibers, and nonlinear effects involving vector orbital angular momentum modes remains relatively understudied. In this thesis, we seek to study nonlinear optical effects involving a small number of selectively excited scalar as well as vector spatial modes, and to develop experimental techniques capable of resolving the output in both space, frequency and time. To this end, we design, prototype and fabricate devices and methods aimed at exciting a small number of spatial modes of a fiber. In particular, we adopt methods from integrated photonics such as focused ion beam milling and metasurface devices to selectively excite modes of a fiber in an efficient manner. Spatial and temporal resolution of the output beam is achieved by the development of a new technique that involves raster-scanning of a near-field scanning optical microscopy probe, coupled with a high speed detector, along the output end-face of the fiber. Using these methods, we uncover and report our observations of spatiotemporal nonlinear phenomena that are unique to multimodal systems. We first demonstrate nonlinear intermodal interference of radially symmetric modes in step-index and parabolic index fibers. We then apply the same spatiotemporal measurement technique to observe the Kerr-induced beam self-cleaning phenomenon in a parabolic index fiber. And finally, we discuss our discovery of a spin-orbit coupled generalization of the well-known nonlinear polarization rotation phenomenon

Bentuk Tanggung Jawab Pemerintah Dalam Permasalahan Kreditur Pemegang Hak Tanggungan Jika Pengajuan Pailit Ditolak Oleh Pengadilan Niaga

Di Indonesia terdapat beberapa kasus sengketa tentang suatu perusahaan dalam  mengajukan sebuah pailit. Pailit diajukan oleh kreditur karena utang piutang yang dilakukan pihak debitur tidak ditunaikan dengan baik. Kreditur dalam hal ini merupakan pemegang hak tanggungan yang merupakan pihak yang memberikan pinjaman dan memegang hak jaminan atas properti yang dijaminkan oleh debitur sebagai jaminan pelunasan atas utang. Akan tetapi, Permasalahan kreditur pemegang hak tanggungan yang mengajukan permohonan pailit dan kemudian ditolak oleh pengadilan niaga merupakan situasi yang memerlukan perhatian serius. Kegagalan pengajuan pailit ini dapat memberikan dampak negatif pada kreditur. Karena kreditur hak tanggungan memiliki kedudukan yang penting dalam pengajuan permohonan pailit oleh kreditur terhadap debitur. Hal ini dikarenakan kreditur hak tanggungan memiliki hak jaminan atas properti yang dijaminkan oleh debitur sebagai jaminan atas kewajiban pembayaran hutang. Sehingga bentuk tanggung jawab pemerintah dalam konteks ini sangat penting untuk memastikan adanya keadilan dan perlindungan hukum bagi kreditur pemegang hak tanggungan. Pemerintah memiliki peran utama dalam menyediakan kerangka hukum yang jelas dan efektif dalam menangani situasi ini.Kata Kunci: Kreditur, Hak Tanggungan, Pailit, Bentuk Tanggung Jawab Pemerinta

Perceived Adequacy of Training and Identification of Barriers to Choosing Academic Faculty Positions Among Psychiatry Postgraduate Students in India

The increasing burden of psychiatric morbidity will proportionately increase the need for teachers of psychiatry in medical colleges. There are no studies on the current postgraduates’ perception about taking up faculty positions. We conducted an online cross-sectional study among 101 postgraduates using self-reporting questionnaires from October 2021 to November 2021. Majority were female, in 25-30 years age group, studying final year in private medical college. They willing to consider teaching positions and expressed interest in training programs. Significant facilitators and barriers to taking up faculty posts included interest in private practice, politics and vacancies available in place of interest

Harm Reduction Approach to Increasing Self-reported Safe Medication Storage Among Pregnant and Parenting People Receiving Opioid Use Disorder Treatment

ObjectivesThe expansion of access to buprenorphine-naloxone (BUP-NAL) for the treatment of opioid use disorder (OUD) is critical to combat the overdose crisis. Evidence is lacking to guide providers on how to best promote BUP-NAL medication safety for their patients. This study assessed (1) the current medication storage practices among a sample of pregnant and parenting people receiving BUP-NAL for OUD; (2) the feasibility and acceptability of providing a lockbox for safe medication storage.MethodsPregnant and/or parenting patients receiving sublingual BUP-NAL in an outpatient OUD clinic were recruited between June and November 2021. Participants completed a baseline survey, received a lockbox, and a follow-up survey 3 to 8 weeks later. The primary outcome of current self-reported safe medication storage practice was defined by storing BUP-NAL in a locked/latched place "almost always" or "always" on the baseline survey. Outcomes were analyzed using simple proportions.ResultsSixty-three participants completed the baseline survey, and 50 completed the follow-up survey. Baseline survey results indicated that only a quarter of patients (26.6%) were practicing safe BUP-NAL medication storage practices. At follow up, 93.6% of patients were using the lockbox provided by the study, 93.4% reported being satisfied with the lockbox, and most participants (89.3%) reported safe BUP-NAL medication storage practices.ConclusionsMany pregnant and parenting patients with OUD receiving BUP-NAL do not store their medications safely. The provision of a lockbox as part of OUD treatment is a feasible, acceptable, and potentially effective harm reduction intervention

Influence of chemical interactions on the electronic properties of BiOI/organic semiconductor heterojunctions for application in solution-processed electronics

Bismuth oxide iodide (BiOI) has been viewed as a suitable environmentally-friendly alternative to lead-halide perovskites for low-cost (opto-)electronic applications such as photodetectors, phototransistors and sensors. To enable its incorporation in these devices in a convenient, scalable, and economical way, BiOI thin films were investigated as part of heterojunctions with various p-type organic semiconductors (OSCs) and tested in a field-effect transistor (FET) configuration. The hybrid heterojunctions, which combine the respective functionalities of BiOI and the OSCs were processed from solution under ambient atmosphere. The characteristics of each of these hybrid systems were correlated with the physical and chemical properties of the respective materials using a concept based on heteropolar chemical interactions at the interface. Systems suitable for application in lateral transport devices were identified and it was demonstrated how materials in the hybrids interact to provide improved and synergistic properties. These indentified heterojunction FETs are a first instance of successful incorporation of solution-processed BiOI thin films in a three-terminal device. They show a significant threshold voltage shift and retained carrier mobility compared to pristine OSC devices and open up possibilities for future optoelectronic applications