Tin cans : : a manufacturing opportunity in Georgia

Projects A-380 and E-127-15, Engineering Experiment Station, Georgia Institute of Technolog

Development of an ex vivo model for the study of cerebrovascular function utilizing isolated mouse olfactory artery

OBJECTIVE: Cerebral vessels, such as intracerebral perforating arterioles isolated from rat brain, have been widely used as an ex vivo model to study the cerebrovascular function associated with cerebrovascular disorders and the therapeutic effects of various pharmacological agents. These perforating arterioles, however, have demonstrated differences in the vascular architecture and reactivity compared with a larger leptomeningeal artery which has been commonly implicated in cerebrovascular disease. In this study, therefore, we developed the method for studying cerebrovascular function utilizing the olfactory artery isolated from the mouse brain. METHODS: The olfactory artery (OA) was isolated from the C57/BL6 wild-type mouse brain. After removing connective tissues, one side of the isolated vessel segment (approximately -500 µm in length) was cannulated and the opposite end of the vessel was completely sealed while being viewed with an inverted microscope. After verifying the absence of pressure leakage, we examined the vascular reactivity to various vasoactive agents under the fixed intravascular pressure (60 mm Hg). RESULTS: We found that the isolated mouse OAs were able to constrict in response to vasoconstrictors, including KCl, phenylephrine, endothelin-1, and prostaglandin PGH(2). Moreover, this isolated vessel demonstrated vasodilation in a dose-dependent manner when vasodilatory agents, acetylcholine and bradykinin, were applied. CONCLUSION: Our findings suggest that the isolated olfactory artery would provide as a useful ex vivo model to study the molecular and cellular mechanisms of vascular function underlying cerebrovascular disorders and the direct effects of such disease-modifying pathways on cerebrovascular function utilizing pharmacological agents and genetically modified mouse models

A Development of Multi-Site Rainfall Simulation Model Using Piecewise Generalize Pareto Distribution

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Assessment of highway construction schedule review problems of Departments of Transportation : case study of Texas

Schedule review is an important aspect of schedule management for the owners like the state Department of Transportation (DOTs) to successfully deliver projects on time. However, the quality of schedules submitted by the contractors varies greatly, without having the required formats and information. Therefore, the competency of schedule reviewers to accurately detect problems in the submitted schedule and make sure that the schedule fulfills all the contractual requirements is essential. Past studies in schedule review focused on developing review criteria and thresholds focusing on the schedule itself. There has not been a comprehensive study to collect problems arising from the entire DOT’s schedule review process. To assist schedule reviewers in detecting the problems and making decisions based on the problems, three objectives were defined: 1) assembling and categorizing common contractor schedule problems faced by DOT’s schedule reviewers, 2) defining the criticality of identified problems, and 3) identifying high and low critical problems that are perceived by the practitioners. To achieve these objectives, this study developed a list of construction schedule problems that are found during the schedule review process. Three main categories are covered in this problem list: 1) schedule planning problems, 2) Critical Path Method (CPM) scheduling problems, and 3) contractual compliance problems. Furthermore, a survey was deployed to DOT practitioners to assess the level of impact and the likelihood of occurrence of each identified problem and to determine the criticality of the identified problems. By ranking the most critical problems perceived by the DOT practitioners, this study analyzed the discrepancies between the survey results and industry standards. Also, areas for improvement in DOT’s standard specifications were identified. This paper contributes to the body of knowledge in schedule management by expanding the research on schedule review by investigating actual problems faced by DOT practitioners. Furthermore, the study makes an impact on DOTs’ schedule management by diagnosing and exploring their current status and procedure.Civil, Architectural, and Environmental Engineerin

Titanium oxide Films Prepared by Sputtering, Sol Gel and Dip Coating Methods for Photovoltaic Application

AbstractDye-sensitized solar cells (DSCs) without using transparent conducting oxides (TCO) electrode can be produced at much lower cost with a flexible structure. A new type of DSCs using flexible stainless steel mesh sheets based electrode is reported in this research. The working electrode of DSCs is processed with conductive and flexible stainless mesh coated with metal oxides (TiO2) layer either by sputtering, sol gel or dip coating methods. Structures of the TCO-less DSCs sample is a stainless mesh for working electrode/dye sensitized TiO2 layer/liquid type electrolyte with polymer film/Pt doped Ti plate for counter electrode. The metal oxide coated stainless mesh sample showed higher photo-current conversion efficiency in general. The best cell performance in this experiment showed the efficiency of 3.11% (Voc = 0.58V, Jsc = 11.98mA/cm2, ff = 0.45)

Comparison Of Interpolation Technique For Rain Gauge Data Through The Distributed Rainfall-Runoff Model

Precipitation estimated from different measuring techniques such as rain gauge, radar and satellite have some similarities, but there are also differences among them. For example, techniques based on radar and satellite data underestimate rainfall than those using rain gauge data. In addition, many different interpolation techniques have been used to measure spatial pattern of precipitation but it is still difficult to have an accurate pattern by any one of them. The differences between the rainfall estimates from different techniques vary seasonally as well as regionally so that the radar or satellites are not directly applied into hydrologic analysis. In this regard, a main objective of this study is to develop a systematic way to interpolate ground rain gauge using discharge data from distributed rainfall-runoff model The spatial rainfall patterns estimated from the interpolation methods will be evaluated with the object function to minimize the difference between observed and estimated discharge. In other words, this study seeks to identify the optimal spatial pattern in rain field that can generate a similar pattern of observed discharge through the distributed rainfall-runoff model. This study will compare the spatial pattern from different types of climate systems and different seasons derived from different interpolation methods may help to validate the proposed algorithms