Characterization of Polymer Hermetic Sealed Tantalum Capacitors Using Thin-film Devices

Polymer Hermetic Sealed (PHS) capacitors are advanced polymer capacitors with a hermetic seal enclosing the materials inside a metal enclosure. Their primary features include leakage current stability, high volumetric efficiency, and low weight compared to both wet and solid-state polymer tantalum capacitors. However, Life Tests performed on these capacitors have revealed a failure to withstand their rated voltage in a working temperature range over the long-term. There are also other interesting properties which have been observed such as Breakdown voltage (BDV) exceeding the Formation Voltage (Vf), anomalous transient currents, and a larger than expected capacitance dependence on temperature, C(T). A primary goal in this research is to understand whether the observed characteristics of PHS capacitors are a result of their complex structure or due more to the nature of interactions between the organic and inorganic material layers present. C(T) and BDV measurements were performed on thin-film MIS capacitors representing the material layers of PHS capacitors. Measurements were performed in the voltage range (0V-100V), a temperature range (-550C to 1250C), with varying frequency (20-10kHz), under both humid and dry conditions. Furthermore, one sample went through a curing process referred to as Heat Treatment , which is thought to improve device stability. Results from these measurements show that thin-film devices can be reasonable representatives of discrete PHS capacitors, and the properties observed in PHS capacitors are significantly dependent on the material layers in the capacitors. Thus, the thin-film MIS capacitor is shown to be a useful test structures for investigating physical phenomena observed in the more complex polymer Ta capacitor structure

Assortment Planning of Automotive Products: Considerations for Economic and Environmental Impacts of Technology Selection

A manufacturer’s assortment is the set of products that the company offers to its customers. Assortment planning considerably affects both the sales revenue and product offering costs for the company and it had experienced growing attention across different industries over recent decades. In this study, we propose a modeling framework that seeks to identify the optimal assortment for a manufacturer of configurable products (in particular, automobiles). Our model accounts for environmental considerations (Corporate Average Fuel Economy requirements, tail-pipe emissions, and greenhouse gas emissions related to the production of the fuel used to power the vehicle) during assortment planning. We formulate the economic and environmental requirements in the model through a mixed-integer programming framework and present a hypothetical product case study motivated by an American automaker that involves 120 potential configurations employing different engine technologies (gasoline, diesel, and hybrid technologies). Notwithstanding consideration for consumer perceptions and acceptance, the results of this research work show that diesel technologies are a better choice to satisfy average fuel economy requirements compared to hybrid and conventional powertrains with current technology maturity

15-08 Community-Aware Charging Station Network Design for Electrified Vehicles in Urban Areas: \u3c/i\u3e Reducing Congestion, Emissions, Improving Accessibility, and Promoting Walking, Bicycling, and use of Public Transportation\u3c/i\u3e

A major challenge for achieving large-scale adoption of EVs is an accessible infrastructure for the communities. The societal benefits of large-scale adoption of EVs cannot be realized without adequate deployment of publicly accessible charging stations due to mutual dependence of EV sales and public infrastructure deployment. Such infrastructure deployment also presents a number of unique opportunities for promoting livability while helping to reduce the negative side-effects of transportation (e.g., congestion, emissions, and noise pollution). In this phase, we develop a modeling framework (MF) to consider various factors and their associated uncertainties for an optimal network design for electrified vehicles. The factors considered in the study include: state of charge, dwell time, Origin-Destination (OD) pair

Aluminium oxide prepared by UV/ozone exposure for low-voltage organic thin-film transistors

We have developed a gate dielectric for low-voltage organic thin-film transistors based on an inorganic/organic bi-layer with a total thickness of up to ~ 20 nm. The inorganic layer is aluminium oxide formed by UV/ozone treatment of aluminium layers. The organic layer is 1-octylphosphonic acid. The preparation of aluminium oxide was studied with respect to the threshold voltage of p-channel thin-film transistors based on thermally evaporated pentacene. The results demonstrate that the threshold voltage decreases with increasing UV/ozone exposure time. The threshold voltage varies by 0.7 V and the gate-source leakage current by a factor of 10 as a function of aluminium oxide preparation. The electrical breakdown field of the bi-layer gate dielectric is at least 5 MV/cm for all AlOx preparation conditions

Outbreaks of aflatoxicoses in India

Mycotoxins particularly aflatoxins are gaining increasing importance due to their deleterious effects on human and animal health and also due to ubiquitous  presence  of aflatoxigenic fungi in all the agricultural commodities under field and storage conditions. In general, aflatoxins occur more frequently in tropical  countries  because of high temperature, moisture, unseasonal rains and flash  floods.  Poor harvesting practices, improper storage and less than optimal  conditions during transport and marketing can also contribute to mycotoxin production. Chronic health risks are particularly prevalent in India where the diets of people are highly prone to aflatoxigenic fungi and aflatoxins. The present paper reviews the disease outbreaks of aflatoxicoses in India due to the ingestion of contaminated food and feed with aflatoxins. One of the first outbreaks of  aflatoxicosis was reported from western India during 1974 with 106 deaths of indigenous people whose staple food was maize. This is perhaps the first report directly incriminating aflatoxin in food as a human health hazard at the indigenous community level. An independent study of the same outbreak was carried out  subsequently also indicated that the aflatoxins were the major cause of the  outbreak. Indian childhood cirrhosis, a clinical condition mainly confined to the Indian subcontinent has been attributed to aflatoxin   contamination. They also found a correlation between aflatoxin contamination and fungal load on the one hand and hepatomegaly in children on the other in south Canara district of Karnataka. Another outbreak of toxic hepatitis affecting both humans and dogs was reported in India during 1974. Heavy mortality in chicks in Chittoor district of Andhra Pradesh was reported in 1982 due to aflatoxicosis. Another outbreak of aflatoxicosis in commercial poultry farms was also reported in the same district with hundred percent mortality. A case of aflatoxicosis in Murrah buffaloes from Andhra Pradesh was also reported. Occurrence of aflatoxicosis in poultry in Mysore state was first recognized in 1966 where 2219 chicks died in one week. Subsequently, several sporadic incidences were found in various poultry farms in Karnataka. Most of the outbreaks of aflatoxicoses described here are a  consequence of ingestion of food that is contaminated with aflatoxins. Disease outbreaks due to aflatoxins continue to be problems of significant public health concern in India as long as people will consume contaminated food. The strict control of food quality is therefore  necessary to avoid such incidences.Keywords:  Aflatoxicoses, Aflatoxins, Fungi, Food qualit