Single CNC machine scheduling with controllable processing times to minimize total weighted tardiness

Cataloged from PDF version of article.Advanced manufacturing technologies, such as CNC machines, require significant investments, but also offer new capabilities to the manufacturers. One of the important capabilities of a CNC machine is the controllable processing times. By using this capability, the due date requirements of customers can be satisfied much more effectively. Processing times of the jobs on a CNC machine can be easily controlled via machining conditions such that they can be increased or decreased at the expense of tooling cost. Since scheduling decisions are very sensitive to the processing times, we solve the process planning and scheduling problems simultaneously. In this study, we consider the problem of scheduling a set of jobs on a single CNC machine to minimize the sum of total weighted tardiness, tooling and machining costs. We formulated the joint problem, which is NP-hard since the total weighted tardiness problem (with fixed processing times) is strongly NP-hard alone, as a nonlinear mixed integer program. We proposed a DP-based heuristic to solve the problem for a given sequence and designed a local search algorithm that uses it as a base heuristic

Effects of hourly, daily and seasonal variation of hazardous gases and climatic factors on the welfare of sheep housed in solid-floor confinement barns

Ambient air quality in livestock buildings is one of the most important factors affecting environmental pollution and global warming. Carbon dioxide (CO2), methane (CH4), ammonia (NH3) and hydrogen sulphide (H2S) are among the most hazardous gases in terms of human and animal health. The aim of this study was to determine the effect of hourly, daily and seasonal variations in the levels of hazardous gases, such as CO2, CH4, NH3 and H2S in a solid-floor confinement sheep barn; as well as the effect of climatic parameters, temperature (T), relative humidity (RH) and air flow (AF) on animal welfare. The correlation between hazardous gases and climatic factors in the barn was also determined. The study was carried out on a sheep farm between July 2012 and June 2013 in Konya (Turkey) where few data are currently available on this subject. Climatic data were measured at intervals of five minutes at different points during this study, while hazardous gases were measured at the same intervals during the experimental periods (10 days for each season). All data were analysed by one-way analysis of variance (ANOVA) and Tukey’s method was used to reveal intergroup differences. Cross-bilateral correlation between all data and different time periods was examined. There were significant differences between hourly and daily mean values of CO2, NH3, T, RH and AF. CO2 and NH3 levels showed a significant correlation with T and RH. Unfortunately, H2S and CH4 were below the level of detection in the study. Reducing the formation of these harmful gases, which have negative effects on animal production and cause environmental pollution, will be carried out with new sheep barn designs that take into account ambient air quality appropriate for animal welfare.Keywords: Ambient air quality, animal production, CH4, CO2, environmental pollution, H2S, NH3, sheep bar

Macroanatomical and histological study of the structure of intercornual gland in Abaza (Capra Aegagrus) and Gurcu (Capra Falconeri) goats breeds

Background: The anatomical localisation of the odour glands, which increase activity during the reproduction period and help goat species to find each other, varies. Materials and methods: In our study, the anatomical and histological structures of the glands around the horn were examined in the Gurcu and Abaza goats, which are native breeds. In this study a total of 12 Abaza and Gurcu goat heads were used. Results: The area between the two horns and area at the back of the horns were shaved to remove all hair. The distance between the horns of both goat breeds was measured using an electronic calliper. The mean distance between the horns of the Abaza goats was determined as 36.80 ± 8.62 mm while this distance was 39.63 ± 4.10 mm for the Gurcu goats. Gland tissue that could not be seen anatomically under the skin was examined histologically. For the histological examination, skin samples were taken from the anterior, middle, right posterior and left posterior of the area between the two horns of both breeds. Crossman triple staining and haematoxylin and eosin staining were applied to the samples. Conclusions: Glandula intercornualis was found to be slightly caudal between the horns in both breeds and normal sebaceous glands were almost absent in the areas where these glands were found. Lobes and branched alveolar glands were located around the hair follicles

Controlling Josephson transport by manipulation of Andreev levels in ballistic mesoscopic junctions

We discuss how to control dc Josephson current by influencing the structure and nonequilibrium population of Andreev levels via external electrostatic gates, external current injection and electromagnetic radiation. In particular we will consider the "giant" Josephson current in "long" SIS tunnel junctions and the regular and anomalous nonequilibrium Josephson currents in three terminal SNS junctions. We will briefly discuss applications to the Josephson field effect transistor (JOFET) and to the newly invented Josephson interference transistor (JOINT).Comment: 10 pages, 3 figures; contribution to a special volume of Superlattices and Microstructures journal (ed. P.F. Bagwell

Coatings Containing Functionalized Graphene Sheets and Articles Coated Therewith

Coatings are provided containing functionalized graphene sheets and at least one binder. In one embodiment, the coatings are electrically conductive

Impaired fasting glucose is associated with increased perioperative cardiovascular event rates in patients undergoing major non-cardiothoracic surgery

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus (DM) is a well-established risk factor for perioperative cardiovascular morbidity and mortality in patients undergoing noncardiac surgery. However, the impact of preoperative glucose levels on perioperative cardiovascular outcomes in patients undergoing nonemergent, major noncardiothoracic surgery is unclear.</p> <p>Methods and Results</p> <p>A total of 680 patients undergoing noncardiothoracic surgery were prospectively evaluated. Patients older than 18 years who underwent an elective, nonday case, open surgical procedure were enrolled. Electrocardiography and cardiac biomarkers were obtained 1 day before surgery, and on days 1, 3 and 7 after surgery. Preoperative risk factors and laboratory test results were measured and evaluated for their association with the occurrence of in-hospital perioperative cardiovascular events. Impaired fasting glucose (IFG) defined as fasting plasma glucose values of 100 to 125 mg/dl; DM was defined as fasting plasma glucose ≥ 126 mg/dl and/or plasma glucose ≥ 200 mg/dl or the current use of blood glucose-lowering medication, and glucose values below 100 mg/dl were considered normal. Plasma glucose levels were significantly higher in patients with perioperative cardiovascular events (n = 80, 11.8%) in comparison to those without cardiovascular events (131 ± 42.5 <it>vs </it>106.5 ± 37.5, p < 0.0001). Multivariate analysis revealed that patients with IFG and DM were at 2.1- and 6.4-fold increased risk of perioperative cardiovascular events, respectively. Every 10 mg/dl increase in preoperative plasma glucose levels was related to a 11% increase for adverse perioperative cardiovascular events.</p> <p>Conclusions</p> <p>Not only DM but also IFG is associated with increased perioperative cardiovascular event rates in patients undergoing noncardiothoracic surgery.</p