41530 research outputs found
Sort by
California Off-Road Engines and Components Life Span Assessment
Get PDFThe useful life and warranty periods for off-road equipment in California for engines rated at 37 kilowatts (kW) and greater have not been updated since the Tier 1 rule phased in from 1996 to 2000; for engines rated below 37 kW, not since the Tier 2 and Tier 3 rules phased in from 2000 to 2008. The California Air Resources Board (CARB) staff is seeking information regarding useful life and warranty to evaluate whether amendments to those requirements are necessary after two decades of technology advancement.
Cal Poly researchers called 55 service providers across the state of California to collect information regarding useful life of engines, repair of emission-related components, and warranty information associated with various off-road agricultural & construction equipment. The responses below reflect 40 completed interviews. The data was collected via telephone interview with the service manager of each company. The interviews took place during the post-harvest, pre-plant season of November 2022 through early May 2023. Most interviews took from 20 – 40 minutes to complete.
Participants were asked about the types of equipment and most common range of horsepower (HP) engines they saw in their shop. The equipment each service provider dealt with mostly depended on the type of agriculture surrounding their area. Tree and vineyard crops typically use smaller HP tractors (less than 100), while large row crop operations in the southern San Joaquin Valley more commonly use 200 – 500 HP equipment. Construction equipment providers reported the largest horsepower, in the 400 – 600 HP range, though that varied depending on whether they were dealing with bulldozers, graders, or smaller equipment such as skid steers. Of the 40 service managers interviewed, 32 represented agricultural shops, six were exclusively construction and two shops worked on both agricultural and construction equipment, but tilted more heavily toward agriculture. The following data was collected for each participating service provider. Types of equipment and horsepower range Percentage of rebuild vs. replacement engine work Issues with replacement engines Customer decision factors for rebuilding vs. replacement Rebuild information for off-road engines Hourly Rate in Shop/Field Useful life & repair costs for various engine and emissions components: o Selective Catalytic Reduction Turbochargers Diesel Oxidation Catalysts (DOC) Exhaust Gas Recirculation (EGR) Valve and EGR Coolers Oxides of nitrogen (NOx) Sensors Diesel Particulate Filters (DPF) Fuel Injectors Diesel Exhaust Fluid (DEF) Doser/Header DEF Quality Sensors Engine Control Unit (ECU) Exhaust Manifold
The power range of equipment most commonly serviced by each provider is noted in Table 1. Though most providers reported working on a wide variety of machinery, most had an engine size range that was more common, as noted below. The construction dealers were the most variable, while the agriculture equipment dealers typically had more common ranges of sizes based on the type of agriculture in the area
A Review of Brenda Cossman\u27s The New Sex Wars
Get PDFIn The New Sex Wars: Sexual Harm in the #MeToo Era, Brenda Cossman unpacks the contemporary debates of the #MeToo movement through the lens of the 1970s and 1980s feminist sex wars. Cossman seeks to deconstruct the binary conversation of the feminist sex wars, both in the past and present. She offers an alternative read of these debates, rooted in anti-carceral feminism and reparative justice. This book is a must read for scholars, activists, and educators alike, as she provides innovative analytical approaches that transform feminist praxis inside and outside the classroom, the academic journal, the courtroom, and the online forum
LGBTQ People of Color and Digital Spaces of Empowerment
Get PDFIn recent history, the internet has been considered a place where disembodied users can escape the limitations of their corporeal bodies. But in the contemporary moment, the digital and the physical worlds have become mutually constitutive. What happens when a politics of race, sexuality, and gender is centered in an analysis of digital activity? LGBTQ people of color use strategies to navigate marginalizing social dynamics of power both offline and online. This negotiation is important because of how integral the internet has become to everyday life. In the age of social media, cultural production has become the business of the masses. Digital democracy decentralizes the production of media that helps us to define ourselves. By participating in this process, LGBTQ people of color self-empower by promoting visibility among both themselves and other communities
Revolutionizing Space: A Case Study on Accessibility and Comfort
Get PDFInfluenced by a dynamic and revolutionary crip theory, this piece seeks to operationalize the combination of crip theory/disability studies and intersectional feminist praxis. Dis/ability is consistently disregarded as a central social identity, as the world has been literally built and maintained by (temporarily) able-bodied people with the intent to accommodate able-bodied people’s needs and comfort. DeafSpace, a revolutionary project prioritizing deaf people’s needs and comfort, serves as a case study for potential revolutionary architectural projects that focus on dis/ability accommodation, accessibility, and comfort. However, in seeking additional solutions to this issue, we must be conscious of tokenizing the experiences of individuals with disabilities, and rather, seek to revolutionize architecture and engineering developments as a whole. Keywords: crip theory, dis/ability, feminism, intersectionality, architectur
Inclusive Safety Understanding the Safety Managers\u27 Views on the Fit and Function of Construction Safety Vests for all Body Types
Get PDFWith the construction industry evolving to embrace a more diverse workforce, it is crucial that personal protective equipment (PPE) adapts alongside this demographic shift to better accommodate women and those with diverse body types in the industry. To provide tangible momentum for the growing need of inclusive PPE, the Cal Poly Construction Management Department developed and hosted a “Verifying Everybody’s Safety Together” (VEST) Hackathon Event. This event provided an all-encompassing look at women’s construction vests and how they can be improved upon. The event had a variety of construction industry personnel in attendance, including five safety managers of different companies. These safety managers offered their insights, perspectives, and experiences regarding ill-fitting construction vests through a series of individually conducted, semi-structured interviews. The perspectives shared by these safety managers proved to be especially significant, because they are often directly responsible for the PPE acquisition and distribution process for all construction personnel at their respective firms. The perspectives shared by the safety managers helped reveal how and why safety vests fail to properly accommodate women and those with diverse body types, and what can be done about it to support them while promoting a more inclusive and accommodating construction industry at large
Evaluating The Field Efficacy Of UV-C On Two California Strawberry Arthropod Pests
Get PDFThe efficacy of two different autonomous Ultraviolet-C (UV-C) units on two spotted spidermite, Tetranychus urticae Koch (Acari: Tetranychidae), and greenhouse whitefly, Trialeurodes vaporariorum. (Hemiptera: Aleyrodidae). was tested in four commercial strawberry fields in California.
In 2020, California strawberry growers used 12 million pounds of active ingredients (AIs) to keep pests under economic thresholds. While pesticides are an important part of an integrated pest management program, their use poses threats to the environment and human health. To protect agricultural workers, the public and the environment, regulators in California have consistently limited or removed the use of certain pesticide AIs. For strawberry growers in the state, this trend signifies that reliance on pesticides may not be a sustainable approach. Resistant pest populations further intensify the need for more sustainable pest control measures. Tetranychus urticae populations in California strawberry production have documented resistance to at least three AIs; abamectin, bifenazate, and hexythiazox. Trialeurodes vaporariorum populations in California strawberry production have documented resistance to five AIs; imidacloprid, thiamethoxam, dinotefuran, acetamiprid, and chlorpyrifos.
To address this issue, stakeholders must invest in research and development of new non-chemical control methods. One of these methods is the use of autonomous UV-C for pest control. These systems emit UV-C radiation, which affects the cellular and genetic structure of organisms, leading to detrimental effects. One unit, by Tric Robotics, emits an avg of 250 J m−2 of UV-C irradiation and was tested in three different strawberry fields. Another unit by Saga Robotics emits an avg of 200 J m−2 was tested on a single field different from the first three. In each field, a plot was treated with UV-C twice weekly at night. Untreated controls were not possible with this study, so UV-C has been tested against each grower’s standard (GS) treatment. Twenty leaflets from the middle and 20 bottom tier of the strawberry plant canopy were collected weekly to assess the presence of T. urticae and T. vaporariorum. Samples were compared using Kruskal-Wallis rank sum tests with Bonferroni adjusted Dunn tests in the R statistical environment. The data showed that UV-C may be an effective tool for the control of certain T. vaporariorum stages in strawberry. Follow-up studies with untreated controls are needed to validate the efficacy of UV-C on T. urticae and further validate the positive results observed on T. vaporariorum