Comparison of on-wafer calibrations using the concept of reference impedance

A novel method that allows to compare different calibration techniques has been developed. It is based on determining the reference impedance of a given Network Analyzer calibration from the reflection coefficient measurement of a physical open circuit. The method has been applied to several on-wafer calibrations.Peer ReviewedPostprint (published version

Dense granular flows: two-particle argument accounts for friction-like constitutive law with threshold

A scalar constitutive law is obtained for dense granular flows, both in the inertial regime where the grain inertia dominates, and in the viscous regime. Considering a pair of grains rather than a single grain, the classical arguments yield a constitutive law that exhibits a flow threshold expressed as a finite effective friction at flow onset. The value of the threshold is not predicted. The resulting law seems to be compatible with existing data, provided the saturation at high velocity (collisional regime) is added empirically. The law is not exactly the same in both regimes, which seems to indicate that there is no "universal" law.Comment: 4 page

Is Vivaldi smooth and takete? Non-verbal sensory scales for describing music qualities

Studies on the perception of music qualities (such as induced or perceived emotions, performance styles, or timbre nuances) make a large use of verbal descriptors. Although many authors noted that particular music qualities can hardly be described by means of verbal labels, few studies have tried alternatives. This paper aims at exploring the use of non-verbal sensory scales, in order to represent different perceived qualities in Western classical music. Musically trained and untrained listeners were required to listen to six musical excerpts in major key and to evaluate them from a sensorial and semantic point of view (Experiment 1). The same design (Experiment 2) was conducted using musically trained and untrained listeners who were required to listen to six musical excerpts in minor key. The overall findings indicate that subjects\u2019 ratings on non-verbal sensory scales are consistent throughout and the results support the hypothesis that sensory scales can convey some specific sensations that cannot be described verbally, offering interesting insights to deepen our knowledge on the relationship between music and other sensorial experiences. Such research can foster interesting applications in the field of music information retrieval and timbre spaces explorations together with experiments applied to different musical cultures and contexts

Thermal Conductivity Measurements of Wet Paper

The thermal conductivity of wet paper mats was studied as a function of moisture content and porosity. The conductivity measurements were conducted with a steady-state hot plate apparatus. Results show the relationship of conductivity and moisture content to be non-linear in an increasing fashion. Large variability in results obtained is largely attributed to experimental apparatus design and engineering. Solid cellulose conductivities were calculated using experimental results and the average value was found to be 0.317 ± 0.188 BTU/hr-ft-°F. Close correlation of data using different pulp furnishes indicate type of furnish is not a major variable in conductivity determinations

Microscopic and qPCR comparison of fungal growth in residential carpets with different carpet fiber materials, at varying relative humidity levels, and presence of household dust

People spend 90% of their time indoors exposed to the microbiome of the built environment. Fungal species are part of this indoor microbiome that have been found to grow on various components of residential homes including house dust, wallpaper, gypsum, insulations, and carpet. Fungal fragments resuspended from carpets are a significant source of human exposure and emissions from metabolic processes can have adverse health effects, such as allergies and exacerbation of asthmatic symptoms. Understanding the process and resulting morphology of fungal growth on residential carpet can provide valuable insights for creating indoor environmental conditions that can improve quality of life for sensitive groups. The goal of this study was to compare fungal growth morphology in residential carpet in varying environmental conditions including relative humidity (RH), carpet fiber material, and the presence/absence of house dust. RH conditions were simulated using three carpet and dust samples extracted from homes in Ohio. Wool, olefin, and nylon carpet fibers were also tested using no dust, sterilized dust, and non-sterile house dust spiked with Aspergillus versicolor and Alternaria alternata spores obtained from ATCC. Morphology was observed using scanning electron microscopy and confocal microscopy. Fungi were resolved utilizing Uvitex 2B fluorescent stain. qPCR was used to quantify fungal growth in the conditions tested. The presence of house dust was determined to be the most important variable that increased fungal growth. Elevated RH (>90%) and natural carpet fibers compared to synthetic were also factors that increased fungal growth in carpets. The results of this study can provide valuable insights for care providers to look for in patient’s homes, motivating improved cleaning practices to remove dust, and guide future building designs to mitigate human exposure to fungi in the built environment. In addition, these results show that synthetic carpet fibers can minimize the growth and proliferation of fungi.Undergraduate Research Scholarship, The College of Engineering Research Office, The Ohio State UniversityAdvanced Undergraduate Research Award, The Office of Undergraduate Research and Creative Inquiry, The Ohio State UniversityStartup Grant, The Institute for Materials Research, The Ohio State UniversityAlfred P. Sloan Foundation Grant #G-2016-7262A one-year embargo was granted for this item.Academic Major: Environmental Engineerin

Carbonisation of biomass-derived chars and the thermal reduction of a graphene oxide sample studied using Raman spectroscopy

Chars and carbonised chars were produced from three different oxygen-rich precursors (Pinus radiata wood, Phormium tenax leaf fibres, and sucrose crystals). These non-graphitisable carbons were analysed with Raman spectroscopy in order to study the nanostructural development which occurs with increasingly severe heat treatments up to approximately 1000 °C. The thermal reduction of a graphene oxide sample was similarly studied, as this is considered to involve the development of nanometre-scale graphene-like domains within a different oxygen-rich precursor. Increasing the heat treatment temperatures used in the charring and carbonisation processes, led to significant changes in a number of parameters measured in the Raman spectra. Correlations based on these parameter changes could have future applications in evaluating various char samples and estimating the heat treatment temperatures employed during their manufacture. After production heat treatment temperatures exceeded 700 °C, the Raman spectra of the carbonised chars appeared to be largely precursor independent. The spectra of these carbonised chars were similar to the spectra obtained from thermally-reduced graphene oxides, especially when compared to a wide range of other carbonaceous materials analysed using this particular methodology. Partial reduction of a graphene oxide sample due to reasonably mild laser exposures during Raman analysis was also observed

Spartan Daily, April 27, 1959

Volume 46, Issue 113https://scholarworks.sjsu.edu/spartandaily/3892/thumbnail.jp

Increasing ecological safety during underground mining of iron-ore deposits

Purpose. To create the technology increasing the level of ecological safety of underground mining of iron ores by means of decreasing the number of harmful substances released into the atmosphere. Methodology. Laboratory and industrial research studies of the condition of the atmospheric air around mine arrangement were conducted by means of a physical-and-chemical method and biological testing. The standard method for calculation of their concentration in the atmosphere was used for determination of features of harmful substance dispersion. Findings. Regularities of ground concentration of total influence of harmful substances changing with taking into account a specific consumption of explosives and distance from an emission source are revealed. The dependence of conditional indicator of damageability of bioindicators changing with increase in distance from a source of emission and specific consumption of explosives is established. The method for calculation of ecological assessment of atmospheric air condition around an emission source is developed. Originality. Dependence of influence of ground concentration of harmful substances on damageability of bioindicators at the cellular and organismal levels is established, which allows estimating an ecological state of atmospheric air on industrial territories. Practical value. Regularities of inluence of ground concentration of total impact of harmful substances on a condition of indicator systems are determined that allows estimating the state of the environment and increasing reliability of local environmental monitoring around an iron-ore mine. The technology of drilling-and-blasting operations conducting in which emulsion explosives are used during mining of iron ores by means of the chamber mining methods, which allows decreasing the hazard index of harmful substances influence on the atmosphere, is developed and implemented.Мета. Створити технологію, що підвищує рівень екологічної безпеки підземного видобутку залізних руд шляхом зниження кількості шкідливих речовин, які викидаються до атмосфери. Методика. Лабораторні й промислові дослідження стану атмосферного повітря в районі розташування шахти виконувалися за допомогою фізико-хімічного методу й біологічного тестування. Для визначення особливостей розсіювання шкідливих речовин використовувалася нормативна методика розрахунку їх концентрацій в атмосфері. Результати. Виявлені закономірності зміни приземної концентрації сумарного впливу шкідливих речовин з урахуванням питомої витрати вибухових речовин і відстані від джерела викиду. Встановлена залежність зміни умовного показника пошкоджуваності біоіндикаторів зі збільшенням відстані від джерела викиду й питомої витрати вибухових речо- вин. Розроблена методика розрахунку екологічної оцінки стану атмосферного повітря навколо джерела викиду. Наукова новизна. Встановлення залежності впливу приземних концентрацій шкідливих речовин на пошкоджуваність біоіндикаторів на клітинному та організмовому рівнях дозволяє оцінити екологічний стан атмосферного повітря на промислових територіях. Практична значимість. Встановлені закономірності впливу приземної концентрації сумарного впливу шкідливих речовин на стан індикаторних систем, що дозволяє оцінити стан навколишнього середовища й підвищити достовірність локального екологічного моніторингу в районі роботи залізорудної шахти. Розроблена й впроваджена технологія ведення буропідривних робіт, в якій використовуються емульсійні вибухові речовини при відпрацюванні залізних руд за допомогою камерних систем розробки, що дозволяє знизити індекс небезпеки впливу шкідливих речовин на атмосферу.Цель. Создать технологию, повышающую уровень экологической безопасности подземной добычи железных руд путем снижения количества вредных веществ, выбрасываемых в атмосферу. Методика. Лабораторные и промышленные исследования состояния атмосферного воздуха в районе расположения шахты выполнялись с помощью физико-химического метода и биологического тестирования. Для определения особенностей рассеивания вредных веществ использовалась нормативная методика расчета их концентраций в атмосфере. Результаты. Выявлены закономерности изменения приземной концентрации суммарного воздействия вредных веществ с учетом удельного расхода взрывчатых веществ и расстояния от источника выброса. Установлена зависимость изменения условного показателя повреждаемости биоиндикаторов с увеличением расстояния от источника выброса и удельного расхода взрывчатых веществ. Разработана методика расчета экологической оценки состояния атмосферного воздуха вокруг источника выброса. Научная новизна. Установление зависимости влияния приземных концентраций вредных веществ на повреждаемость биоиндикаторов на клеточном и организменном уровнях, что позволяет оценить экологическое состояние атмосферного воздуха на промышленных территориях. Практическая значимость. Установлены закономерности влияния приземной концентрации суммарного воздействия вредных веществ на состояние индикаторных систем, что позволяет оценить состояние окружающей среды и повысить достоверность локального экологического мониторинга в районе работы железорудной шахты. Разработана и внедрена технология ведения буровзрывных работ, в которой используются эмульсионные взрывчатые вещества при отработке железных руд при помощи камерных систем разработки, что позволяет снизить индекс опасности влияния вредных веществ на атмосферу